Total knee arthroplasty (TKA) has been shown to improve knee joint function during gait post-operatively. However, there is considerable patient to patient variability, with most gait mechanics metrics not reaching asymptomatic levels. To understand how to target functional improvements with TKA, it is important to identify an optimal set of functional metrics that remain deficient post-TKA. The purpose of this study was to identify which combination of knee joint kinematics and kinetics during gait best discriminate pre-operative gait from postoperative gait, as well as post-operative from asymptomatic.

Seventy-three patients scheduled to receive a TKA for severe knee osteoarthritis underwent 3D gait analysis 1 week before and 1 year after surgery. Sixty asymptomatic individuals also underwent analysis. Eleven discrete gait parameters were extracted from the gait kinematic and kinetic waveforms, as previously defined (Astephen et al., J Orthop Res., 2008). Stepwise linear discriminant analyses were used to determine the sets of parameters that optimally separated pre-operative from post-operative gait, and post-operative from asymptomatic gait. Cross-validation was used to quantify group classification error.

Knee flexion angle range, knee adduction moment first peak, and gait velocity were included in the optimal discriminant function between the pre- and post-operative groups (P<0.05), with relatively equal standardised canonical coefficients (0.567, −0.501, 0.565 respectively), and a total classification rate of 74%. A number of metrics were included in the discriminant function to optimally separate post-operative and asymptomatic gait function, including the knee flexion angle range, peak stance knee flexion angle, minimum late stance knee extension moment, minimum mid-stance knee adduction moment, and peak knee internal rotation moment (P<0.05). The mid-stance knee adduction moment had the largest standardised canonical coefficients in the function, and 89.5% of cases were correctly classified.

Separation of pre and post-operative gait patterns included only three parameters, suggesting that current standard of care TKA significantly improves only walking velocity, knee flexion angle range, and the peak value of the knee adduction moment. A number of gait metrics, which were included in the discriminant function between post-operative and asymptomatic gait, could benefit from further improvement either through rehabilitation or design. With almost 90% classification, separation of post-operative gait function from asymptomatic levels is significant. The consolidation of knee joint function during gait into single, discrete discriminant scores allows for an efficient summary representation of patient-specific (or implant-specific) improvement in gait function from TKA surgery.

The purpose of this study was to compare lower limb muscle activity in patients who underwent a total knee arthroplasty (TKA) with a medial pivot (MP) implant to healthy controls (CTRL) during a stair ascent task.

Seven MP (age: 61.4±6.5 years, BMI: 30.0±4.7 kg/m2, 12.4±3.8 months post-surgery) patients who underwent a TKA performed using either a subvastus or medial parapatellar approach were age- and BMI-matched to seven healthy CTRL participants (age: 62.4±4.2 years, BMI: 26.3±2.7 kg/m2) for comparison in this study. Participants underwent electromyography (EMG) analysis while completing a three-step stairs ascent task. Portable wireless surface EMG probes were placed on the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM), biceps femoris (BF) and semimembranous (SM) muscles of both lower limbs. Peak linear envelope (peakLE) and total muscle activity (iEMG) were extrapolated and normalised to a maximal voluntary contraction. Nonparametric Kruskal Wallace ANOVA tests were used and Wilcoxon rank sum tests were used to identify where significant (p < 0.05) differences occurred.

The operated limb had significantly lower iEMG in the VAL, RF and BF muscles, and significantly lower peakLE in the SM muscle compared to the non-operated limb. The operated-limb of the MP group had significantly lower iEMG in the VAL and BF muscles, and significantly lower peakLE in the VAL, RF and SM muscles compared to the CTRL group. The non-operated limb in the MP group had significantly larger peakLE and iEMG in the RF muscle compared to the CTRL group.

Differences in muscle activity between the operated and non-operated limbs in TKA patients with a MP implant demonstrates a compensatory strategy to reduce loading on the operated limb by relying on the non-operated limb. This same strategy has been reported in other studies investigating other functional tasks. This reliance on the non-operated limb resulted by having greater peakLE and iEMG in the RF muscle compared to the healthy CTRLs. These differences between limbs could also result from many years of muscle adaptation waiting to receive a knee replacement. In conclusion, TKA patients exhibit discrepancies in muscle activity compared to healthy knees and differences between operated and non-operated limbs. Post-surgery rehabilitation should rely on unilateral strength exercises of the quadriceps and hamstrings muscles to reduce discrepancies to allow for a more balanced muscle activity between limbs.

The purpose of this study was to compare lower limb joint mechanics in patients who underwent a total knee arthroplasty (TKA) with either a posterior stabilised (PS) or with a medial pivot (MP) implant to healthy controls (CTRL) during stair ascent and descent tasks.

Six PS (age: 67.2±1.5 years, BMI: 31.0±3.2 kg/m2) and 11 MP (age: 62.3±6.0 years, BMI: 29.7±3.9 kg/m2) TKA patients matched to 10 healthy CTRL participants (age: 65.6±5.5 years, BMI: 27.2±5.0 kg/m2) were included in the study. TKA patients went through 3D motion analysis after unilateral TKA with either a MP (11.7±3.4 months post-surgery) or PS (10.1±3.4 months post-surgery) implant performed using either a subvastus or medial parapatellar approach. Kinematic and kinetic data was collected using a 10-camera Vicon and two portable Kistler force plates placed on the first and second stair of a three-step staircase. Nonparametric Kruskal Wallace ANOVA tests were used and Wilcoxon rank sum tests were used to identify where significant (p < 0.05) differences occurred.

When comparing both stair tasks, stair ascent showed a larger number of significant differences in kinematic and kinetic variables than stair descent. Peak knee extension was significantly (p < 0.05) greater in both TKA groups compared to the CTRL during stair descent, whereas only the PS group had significantly (p = 0.02) greater knee extension angle than the CTRL during stair ascent. The PS group had a significantly (p = 0.01) lower peak knee extension moment than the CTRL group during both tasks and compared to the MP group during stairs ascent. During stair ascent, the MP group had significantly (p = 0.02) larger peak hip extension moments than both PS and CTRL group.

Greater knee extension angles in TKA groups at foot strike during stair tasks support the notion that TKA groups exhibit stiff knee during stance to reduce or avoid shear displacement on the operated knee. This could also result from many years of muscle adaptation waiting to receive a knee replacement. Reduced peak knee extension moment in the PS group during stairs tasks showed a quadriceps deficiency that could increase the risk of revision or of other joint replacement on the contralateral side or ipsilateral hip. MP group reproduced similar joint loading patterns as the CTRLs which may reduce their risk of revision. In conclusion, TKA patients continue to exhibit discrepancies from healthy knee mechanics during stair ascent and descent. Further research examining muscle function especially during stair ascent is warranted.

There is currently no cure for osteoarthritis (OA), although there are ways to manage it, but most require quite invasive surgeries. There is a resident mesenchymal progenitor cell (MPC) population within the synovial membrane of the joint that have the ability to differentiate into bone, fat, and cartilage. We hypothesise that in vivo and in vitro cell surface marker expression comparisons of the MPCs can determine which population has the highest chondrogenic capacity and is best suited for future clinical trials.

Method optimisation protocol: Synovial biopsies (2 or 5mm) were obtained from patients undergoing surgery. The biopsies were digested in either collagenase type I, IA, IV or II at a concentration of 0.5 or 1.0 mg/mL. Digestion was conducted at 37°C for 30, 60, 90 or 120min. To assay for the number of MPCs obtained, the cell suspension was stained with CD90 (a synovial MPC marker) and magnetically purified. The purified cells were then assayed by flow cytometry (Co-stained with a live/dead cell marker, BV510) or bright-field microscopy. Study protocol: Synovial tissues were digested in type IV collagenase for two hours to obtain a single cell suspension. The cells were subsequently stained with mesenchymal stem cell markers, including CD 90, CD 271, CD 44, CD73, and CD105, a macrophage marker, CD68. The macrophages were excluded and the remaining cells were index sorted into 96-well plates. The cells were expanded, and underwent 21-day chondrogenic, adipogenic, and osteogenic differentiation. Differentiation was assayed using RT-qPCR and histological methods. Additionally, the cells were re-analysed for marker expression after culturing.

Optimisation: Synovial biopsies of 5mm produced a greater number of live CD90+ cells than 2mm biopsies. It was observed that type IV collagenase at 1mg/ML treatment for 120 min (hip) and 90 min (knee) obtained the greatest number of CD90+ MPCs from the synovium. Results: A single cell was isolated from an OA hip biopsy and was positive for the markers CD90, CD44, CD73, and negative for the markers CD68, CD271, CD105. Following differentiation, PCR analysis suggested that the cell line was able to differentiate into chondrocytes and adipocytes, but not osteoblasts. Histology data agreed with the PCR data with the adipocytes and chondrocytes having positive staining, whereas the osteoblasts were negative. FACS analysis following proliferation showed that the expression in vivo versus in vitro was the same except CD105 that became positive after proliferation in vitro.

MPCs express cell surface markers that provide information as to populations have the best cartilage regeneration abilities. By determining the properties of the MPCs in OA hips that allow for better chondrogenic differentiation abilities in vitro, selecting the optimal cells for regenerating cartilage can be done more efficiently for novel cell therapies for OA.

Radiostereometric analysis (RSA) has become the gold standard technique for measuring implant migration and wear following joint replacement due to its high measurement precision and accuracy. However, RSA is conventionally performed using two oblique radiographic views with the presence of a calibration cage. Thus, a second set of radiographs must be acquired for clinical interpretation, for example anterior-posterior and cross-table lateral views following total hip arthroplasty (THA). We propose a modification to the RSA setup for examining THA, in which RSA measurements are performed from anterior-posterior and lateral views, with the calibration cage images acquired separately from the patient images. The objective of the current study was to compare the accuracy and precision of the novel technique to the conventional technique using a phantom.

X-ray cassette holders were developed to enable simultaneous acquisition of anterior-posterior and cross-table lateral radiographs with the patient in a supine position in the RSA suite. A Sawbones phantom with total hip implant components was attached to a micrometer-driven stage. The femoral component was translated known distances relative to the acetabular cup in all planes, mimicking head penetration due to wear. Double RSA examinations were acquired for each increment using the traditional and novel radiograph orientations. Translations were measured from the radiographic images using RSA software. For both techniques, accuracy was calculated by comparing the measured translations to the known translation from the micrometer, and reported as the 95% confidence interval. Precision was measured by comparing the measured translations between the double exams, and reported as the standard deviation.

Accuracy was greater for the conventional technique in the inferior-superior axis (p = 0.03), greater for the novel technique in the anterior-posterior axis (p = 0.01), and equivalent in the medial-lateral axis (p = 0.06). Overall accuracy for both the conventional and novel techniques was identical at ±0.022 mm. Precision was equivalent between both techniques for the medial-lateral (p = 0.68), inferior-superior (p = 0.14), and anterior-posterior axes (p = 0.86). Overall precision for the conventional technique was ±0.127 mm and for the novel technique was ±0.095 mm.

Utilising standard clinical radiograph view angles within an RSA exam had no detrimental effect on wear measurement accuracy or precision. This reduces the barriers to implementing RSA imaging in routine follow-up of arthroplasty patients, potentially greatly increasing the numbers of patients that can have quantitative data on implant performance. Future applications can involve applying more clinically relevant radiograph view angles to RSA exams of the knee and shoulder.

Failure of reverse total shoulder arthroplasty (rTSA) due to loosening of the metaglene remains a concern. The metaglene is typically affixed to the glenoid via four peripheral bone screws, and the orientations of these screws can affect the stability of the metaglene. The purpose of this finite element analysis (FEA) study was to investigate whether screw orientations should be considered on a patient-specific basis to maximise early fixation.

Three-dimensional geometries of four scapula specimens were obtained by segmenting from CT data in 3D Slicer. A metaglene and four rigidly attached 4.5 mm diameter, 18 mm long cylinders representing screws, were placed on each reamed glenoid. Each screw was placed at one of four orientations, 15° or 7.5° toward or away from the central axis of the metaglene face, while all others were held in the baseline (BL) configuration, where all screws were perpendicular to the metaglene face. Finite element models were created by meshing with linear tetrahedral elements. Material properties of titanium (E=113.8 GPa, v=0.34) were applied to the metaglene and screws. Cortical bone material properties were considered uniform (E=17.5 GPa, ν=0.3) while cancellous bone material properties were non-uniform and mapped on an element-by-element basis using CT attenuation data. The scapula was fully constrained, and a 252 N superiorly oriented shear force was applied to the inferior portion of the metaglene. Contact was modelled at bone-implant and bone-screw interfaces. Displacements of the metaglene with respect to the glenoid were measured. The orientations of each screw that minimised in-plane displacement were used for specimen-specific (SS) configurations. A global (GL) configuration was also defined based on the averages of SS orientations. FE model-predicted metaglene displacements of the SS, GL, and BL screw configurations were compared using paired t-tests.

The average in-plane metaglene displacements for the SS, GL, and BL configurations were 4.8 ± 1.2, 6.5 ± 3.7, and 5.3 ± 1.5 um, respectively. SS configurations significantly decreased displacements by −0.4 ± 0.3 um (−8.5%, p = 0.024) when compared to BL, but the difference of −1.6 ± 3.1 um (25.3%, p = 0.187) was not significant when compared to the GL configuration.

In general, the SS configurations resulted in smaller metaglene displacements than the GL configurations, however the difference was not statistically significant. In one specimen, the GL configuration resulted in abnormally large displacements. These results indicate that, while on average, patient-specific orientations won't yield significantly greater fixation than global configurations; non-patient-specific configurations can, in some cases, yield poor results. Therefore, to ensure optimal fixation for all patients, screw orientations should be considered on a patient-specific basis.

There are a variety of sizes currently available for reverse total shoulder arthroplasty (RTSA) implant systems. Common sizing options include a smaller 36 to 38 mm or a larger 40 to 42 mm glenosphere, and are typically selected based on surgeon preference or patient size. Previous studies have only evaluated the abduction and adduction range of motion within a single plane of elevation, providing a limited view of the joint's possible range of motion. The purpose of this study was to use computer modeling to evaluate the abduction and adduction range of motion across multiple planes of elevation for a range of glenosphere sizes.

Computed tomography images of four cadaveric specimens (age: 54 ± 24 years) were used to obtain the osseous anatomy to be utilised in the model. Solid-body motion studies of the RTSA models were constructed with varying glenosphere diameters of 33, 36, 39, 42, and 45 mm in Solidworks (Dassault Systems, US). The implant components were scaled, while maintaining a consistent centre of rotation. Simulations encompassing the full range of abduction and adduction were conducted for the planes of elevation between −15˚ and 135˚ at 15˚ intervals, with the motion of the humerus being constrained in neutral internal-external rotation throughout all planes. Angles of elevation were obtained utilising the humeral long axis and the RTSA centre of rotation. Statistical analysis was performed using repeated measures ANOVA.

Glenosphere diameter was found to significantly affect the adduction range of motion (p=0.043), in which the largest size provided approximately 17˚ more adduction range of motion than the smallest. However, abduction range of motion was not found to be significantly affected through the alteration of glenosphere size (p=0.449). The plane of elevation was not found to significantly affect abduction or abduction (p=0.585 & p=0.225, respectively).

Increasing glenosphere diameter resulted in an increased adduction range of motion when averaged across the tested planes of elevation; however the observed influence on abduction was not significant. These are similar to the trends observed in the previous single plane of elevation studies. These findings illustrate the importance of implant sizing related to range of motion. Further studies are required to determine the influence of glenosphere size on internal and external range of motion.

Shoulder arthroplasty, both primary (TSA) and reverse (RTSA), are common interventions for arthritis and cuff tear arthropathy. The effect of shoulder arthroplasty on shoulder motion is of particular interest in assessing the effectiveness of the procedure and the development and biomechanical testing of implants. A comparison of the arthroplasty shoulder to that of the non-operated contralateral shoulder provides insight into how well the reconstruction has restored natural shoulder motion. The purpose of this study was to ascertain the shoulder motion of patients who have undergone shoulder arthroplasty and to compare the motion of the reconstructed and contralateral natural sides.

Eleven human subjects (70±9yrs) who had undergone total shoulder arthroplasty wore a custom instrumented shirt for the waking hours of one day. The 3D orientation of each humeral sensor was transformed with respect to the torso to allow for the calculation of humeral elevation and plane of elevation angles. Joint angles for each subject were then discretised, and the operative and contralateral normal (control) shoulders were then compared.

The majority of both the arthroplasty and control shoulder elevation motions took place below 80° of elevation, totaling on average 1910±373 and 1887±312 motions per hour, respectively. Conversely, elevations greater than 80° were significantly less with occurrences totaling only 55±31 and 78±41 motions per hour for the arthroplasty and control shoulders, respectively (p<0.01). Both the arthroplasty and control shoulder were at elevations below 80° for 88±7% and 87±7% of the day, respectively. When the total motion of the arthroplasty and non-operative control shoulders were compared, no statistically significant difference was detected (p=0.8), although the non-operated side exhibited marginally more motion than the operated side, an effect which was larger at higher elevation angles (p=0.3).

This study provides insight into the effects of shoulder arthroplasty on thoraco-humeral motion and compares it to the non-operative side. Interestingly, there were no significant differences measured between the arthroplasty and the control side, which may demonstrate the effectiveness of reconstruction on restoring natural shoulder motion. It is interesting to note that on average, each shoulder arthroplasty elevated above 80° approximately 55 times per hour, corresponding to just under 330,000 motions per year. Similarly, when elevations greater than 60° are extrapolated, the resulting yearly motions total approximately 1.5 million cycles (Mc), which suggests that the ‘duty cycle’ of the shoulder is similar to the hip, approximated to be between 1–2 Mc per year. Arthroplasty wear simulators should be calibrated to simulate these patterns of motion, and component design may be improved by understanding the kinematics of actual shoulder motion.

Bone fracture healing is regulated by a series of complex physicochemical and biochemical processes. One of these processes is bone mineralisation, which is vital for normal bone development, its biomechanical competence and fracture healing. Phosphatase, orphan 1 (PHOSPHO1), a bone-specific phosphatase, has been shown to be involved in the mineralisation of the extracellular matrix in bone. It can hydrolyse phosphoethanolamine and phosphocholine to generate inorganic phosphate, which is crucial for bone mineralisation. Phospho1−/− mice show hypomineralised bone and spontaneous fractures. All these data led to the hypothesis that PHOSPHO1 is essential for bone mineralisation and its structural integrity. However, no study to our knowledge has shown the effects of PHOSPHO1 on bone fracture healing. In this study, we examined how PHOSPHO1-deficiency might affect the healing and quality of the fractured bones in Phospho1−/− mice.

We performed rodded immobilised fracture surgery on the right tibia of control wild type (WT) and Phospho1−/− mice (n=16 for each group) at eight weeks of age. Bone was left to heal for four weeks and then the mice were euthanised and their tibias were analysed using Faxitron X-ray analyses, microCT, histology and histomorphometry and three-point bending test.

Our microCT and X-ray analyses revealed that the appearance of the callus and several static parameters of bone remodeling at the fracture sites were markedly different in WT and Phospho1−/− mice. We observed a significant increase of BS/BV, BS/TV and trabecular number and decrease in trabecular thickness and separation in Phospho1−/− callus in comparison to the WT callus. These observations were further confirmed by histomorphometry. The increased bone mass at the fracture sites of Phospho1−/− mice appears to be caused by increased bone formation as there is a significant increase of osteoblast number, while osteoclast numbers remained unchanged. There was a marked increase of osteoid volume over bone volume (OV/BV) in the Phospho−/− callus. Interestingly, the amount of osteoid was markedly higher at the fracture sites than that of normal trabecular bones. The three-point bending test showed that Phospho 1 −/− fractured bone had more of an elastic characteristics than the WT bone as they underwent more of a plastic deformity before the breakage point compare to the WT.

Our work suggests that PHOSPHO1 plays an integral role during bone fracture repair. PHOSPHO1 can be an interesting target to improve the fracture healing process.

Predictable fracture healing fails to occur in 5–10% of cases. This is particularly concerning among individuals with osteoporosis. With an increasing aging population, one in three women and one in five men above the age of 50 experience fragility fractures. As such, there is a critical need for an effective treatment option that could enhance fracture healing in osteoporotic bone. Lithium, the standard treatment for bipolar disorder, has been previously shown to improve fracture healing through modulation of the Wnt/beta-catenin pathway. We optimised the precise oral lithium administration parameters to improve mechanical strength and enhance healing of femoral fractures in healthy rats. A low dose of Lithium (20 mg/kg) administered seven days post fracture for a two week duration improved torsional strength by 46% at four weeks post fracture compared to non-treated animals. Application of lithium to enhance fracture healing in osteoporotic bone would have a significant healthcare impact and requires further study. Aim: To evaluate the efficacy of optimal lithium administration post fracture on quality of fracture healing in a rat osteoporotic model. Hypothesis: Lithium treatment in osteoporotic rats will improve the structural and mechanical properties of the healing bone despite the impaired nature of bone tissue.

Sprague Dawley female rats (∼350 g, age ∼3 months) were bilaterally ovariectomised and maintained for 3 months to establish the osteoporotic phenotype. A unilateral, closed mid-shaft femoral fracture was created using a weight-drop apparatus. At seven days post fracture, the treatment group received 20 mg/kg-wt lithium chloride via oral gavage daily for 14 days. The control group received an equivalent dose of saline. All animals were sacrificed at day 28 and the femurs harvested bilaterally. Treatment efficacy was evaluated based on torsional loading and stereologic analysis.

Lithium treatment positively impacted the healing femurs, with an average yield torque ∼1.25-fold higher than in the saline group (200±36 vs. 163±31 N-mm, p=0.15). Radiographically, the lithium-treated rats had a high level of restored periosteal continuity, larger bridging and intercortical callus at the fracture site. These hallmarks of healing were generally absent in the saline group. The Lithium group had significantly higher total volume (624±32 vs. 568±95 mm3), lower bone volume fraction (41±4 vs. 50±5%) and higher theoretical torsional rigidity (477±50 vs. 357±93 kN-mm2) compared to the saline group. Torsional strength and stereology values were similar for the contralateral femurs of the two groups.

Lithium was found to enhance fracture healing in osteoporotic bone under the dosing regimen optimised in healthy femora. This is promising data as treatment represents an easily translatable pharmacological intervention for fracture healing that may ultimately reduce the healthcare burden of osteoporotic fractures.

Structural bone allografts are a viable option in reconstructing massive bone defects in patients following musculoskeletal (MSK) tumour resection and revision hip/knee replacements. To decrease infection risk, bone allografts are often sterilised with gamma-irradiation, which consequently degrades the bone collagen connectivity and makes the bone brittle. Clinically, irradiated bone allografts fracture at rates twice that of fresh non-irradiated allografts. Our lab has developed a method that protects the bone collagen connectivity through ribose pre-treatment while still undergoing gamma-irradiation. Biomechanical testing of bone pretreated with our method provided 60–70% protection of toughness and 100% protection of strength otherwise lost with conventional irradiation. This study aimed to determine if the ribose-treated bone allografts are biocompatible with host bone.

The New Zealand White rabbit (NZWr) radius segmental defect model was used, in which 15-mm critically-sized defects were created. Bone allografts were first harvested from the radial diaphysis of donor female NZWr, and treated to create 3 graft types: C=untreated controls, I=conventionally-irradiated (33 kGy), R=our ribose pretreated + irradiation method. Recipient female NZWr (n=24) were then evenly randomised into the 3 graft groups. Allografts were surgically fixed with a 0.8-mm Kirschner wire. Post-operative X-rays were taken at 2, 6, and 12 weeks, with bony healing assessed by a blinded MSK radiologist using an established radiographic scoring system. The reconstructed radii were retrieved at 12 weeks and analysed using bone histomorphometry and microCT. Kruskal-Wallis and Mann-Whitney tests were utilised to compare groups, with statistical significance when p<0.05.

Radiographic analysis revealed no differences in periosteal reaction and degree of osteotomy site union between the groups at any time point. Less cortical remodeling was observed in R and I grafts compared to untreated controls at 6 weeks (p=0.004), but was no longer evident by 12 weeks. Radiographic union was achieved in all groups by 12 weeks. Histologic and microCT analysis further confirmed union at the graft-host bone interface, with the presence of mineralising callus and osteoid. Histomorphometry also showed the bridging external callus originated from host bone periosteum and a distinct cement line between allograft and host bone was present at the union site.

Previous studies have shown that the presence of non-enzymatic glycation end products in bone can impair fracture healing. However, these studies investigated bony healing in the setting of diabetic states. Our findings showed that under normal conditions, ribose pretreated grafts healed at rates similar to controls via mechanisms also seen in retrieved human allografts clinically in use. These findings that grafts pretreated with our method are biocompatible with host bone in the rabbit help to further advance this technology for clinical trials.

The T-lymphocyte secreted pro-inflammatory cytokine, interleukin-17F (IL-17F), was found to be a key mediator in the cellular response of the immune system in the early phase of fracture repair but its intracellular signaling processes are currently not known in osteoblasts. The objective of this study was to identify the signaling proteins and crucial gene targets involved in osteoblast activation via IL-17F. It was hypothesised that IL-17F stimulated osteoblast maturation through a novel GSK3beta / beta-catenin independent pathway.

Mouse pre-osteoblast cell line (MC3T3-E1) was used for IL-17F or Wnt3a treatment. Desired proteins were detected using western blot analysis (antibodies: Phospho-GSK-3beta (Tyr 216), Phospho-GSK-3beta (Ser9), Runx2/cbfa1, TRAF6, Act1, p-ERK2, p-JNK and p-MAPK, C/EBP-beta and & delta). Gene-specific siRNAs of mouse IL-17Ra, IL-17Rc and a non-targeting siRNA (control) were utilised. MC3T3-E1 were transfected with IL-17Ra, IL-17Rc or Negative Control and treated with IL-17F. Chromatin Immunoprecipitation (ChIP-qPCR) was used to evaluate the mouse Runx2 P1 promoter region.

IL-17F increased expression of Col1, BSP, Runx2/cbfa1 and osteocalcin in MC3T3-E1 cells. Western blot analysis confirmed expression of known Wnt signaling proteins TRAF6, Act1, p-ERK2, p-JNK and p-MAPK in both IL-17F and Wnt3a treated cultures, including up-regulation of Runx2/cbfa1, a key transcription factor associated with osteoblast differentiation. IL-17F up-regulation of Runx2/cbfa1 appears independent of the Wnt/beta-catenin pathway as phosphorylated GSK-3beta at the Ser9 site was not detected with IL-17F treatment. Despite this, IL-17F treatment still increased expression of Runx2/cbfa1 downstream, lending evidence for a GSK3beta/beta-catenin independent manner of IL-17F stimulated osteogenesis. While IL-17F and Wnt3a both induced expression of C/EBP-delta, only IL-17F treatment induced expression of C/EBP-beta, an upstream transcription factor of Runx2/cbfa1. Further, siRNA knock down of the IL-17 receptors directly decreased Act1, C/EBP-beta and Runx2/cfba1 expression. By ChIP analysis, IL-17F was shown to upregulate C/EBP-beta expression and stimulated its binding to the P1 Promoter of the Runx2/cbfa1 gene.

The C/EBP-beta transcription factor was shown to be a key regulator of early osteogenesis. C/EBP-beta up-regulates Runx2/cbfa1 expression by directly binding to the Runx2/cbfa1 P1 promoter in osteoblasts. C/EBP-beta was activated in the osteoblast by IL-17F but not by Wnt3a adding further support to a novel GSK3beta/beta-catenin independent pathway. Our data shows that IL-17F, a cytokine secreted by T-lymphocytes, stimulates osteoblast maturation through a novel GSK3beta/beta-catenin independent pathway and reveals a crucial interaction between C/EBP-beta and the Runx2/cbfa1 P1 promoter not previously been shown in osteogenesis signaling further.

Bone metastases are common and severe complications of cancers. It is estimated to occur in 65–75% of breast and prostate cancer patients and cause 80% of breast cancer-related deaths. Metastasised cancer cells have devastating impacts on bone due to their ability to alter bone remodeling by interacting with osteoblasts and osteoclasts. Exercise, often used as an intervention for cancer patients, regulates bone remodeling via osteocytes. Therefore, we hypothesise that bone mechanical loading may regulate bone metastases via osteocytes. This provides novel insights into the impact of exercises on bone metastases. It will assist in designing cancer intervention programs that lowers the risk for bone metastases. Investigating the mechanisms for the observed effects may also identify potential drug targets.

MLO-Y4 osteocyte-like cells (gift of Dr. Bonewald, University of Missouri-Kansas City) on glass slides were placed in flow chambers and subjected to oscillatory fluid flow (1Pa; 1Hz; 2 hours). Media were extracted (conditioned media; CM) post-flow. RAW264.7 osteoclast precursors were conditioned in MLO-Y4 CM for 7 days. Migration of MDA-MB-231 breast cancer cells and PC3 prostate cancer cells towards CM was assayed using Transwell. Viability, apoptosis, and proliferation of the cancer cells in the CM were measured with Fixable Viability Dye eFluor 450, APOPercentage, and BrDu, respectively. P-values were calculated using Student's t-test.

Significantly more MDA-MB-231 and PC3 cells migrated towards the CM from MLO-Y4 cells with exposure to flow in comparison to CM from MLO-Y4 cells not exposed to flow. The preferential migration is abolished with anti-VEGF antibodies. MDA-MB-231 cells apoptosis rate was slightly lower in CM from MLO-Y4 cells exposed to flow, while proliferation rate was slightly higher. The current data showed no difference in cancer cells viability and adhesion to collagen between any two groups. On the other hand, it was observed that less MDA-MB-231 cells migrated towards CM from RAW264.7 cells conditioned in CM from MLO-Y4 cells stimulated with flow in comparison to those conditioned in CM from MLO-Y4 cells not stimulated with flow. TRAP staining results confirmed that there were less differentiated osteoclasts when RAW264.7 cells were cultured in CM from MLO-Y4 cells exposed to flow.

Overall, this study suggests that when only osteocytes and cancer cells are involved, osteocytes subjected to mechanical loading can promote metastases due to the increased secretion of VEGF. However, with the incorporation of osteoclasts, mechanical loading on osteocytes seems to reduce MDA-MB-231 cell migration. This is likely because osteocytes reduce osteoclastogenesis in response to mechanical stimulation, and osteoclasts have been shown to support cancer cells. Animal studies will also be conducted to verify the pro- or anti-metastatic effect of mechanical loading that is observed in the in vitro part of this study.

Lubricin is a proteoglycan that is a boundary lubricant in synovial joints and both a surface and collagen inter-fascicular lubricant in ligaments. The purpose of this study was to characterise the mRNA levels for lubricin in the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL) in aging and surgically-induced menopausal rabbits. We hypothesised that lubricin mRNA levels would be increased in ligaments from aging and menopausal rabbits compared with ligaments from normal rabbits.

All four knee ligaments (ACL, PCL, MCL, LCL) were isolated from normal (1-year-old rabbits, n=8), aging (3-year-old rabbits, n=6), and menopausal (1-year-old rabbits fourteen weeks after surgical ovariohysterectomy, n=8) female New Zealand White rabbits. RT-qPCR was used to evaluate the mRNA levels for lubricin normalised to the housekeeping gene 18S. After removing outliers, data for normal, aging, and menopausal rabbits for each knee ligament (ACL, PCL, MCL, LCL) were compared using ANOVA with linear contrasts or Kruskal-Wallis test with Conover post-hoc analysis.

For ACLs, the mRNA levels for lubricin were increased in menopausal and aging rabbits compared with normal rabbits (p<0.056). For PCLs, trends for increased lubricin mRNA levels were found when comparing menopausal and aging rabbits with normal rabbits (p<0.092). For MCLs, the mRNA levels for lubricin were increased in menopausal and aging rabbits compared with normal rabbits (p<0.050). For LCLs, no differences in lubricin mRNA levels were detected comparing the three groups. For all four knee ligaments (ACL, PCL, MCL, LCL), no differences in lubricin mRNA levels were detected comparing the ligaments from menopausal rabbits with those from aging rabbits.

Lubricin plays a role in collagen fascicle lubrication in ligaments (1,2). Increased lubricin gene expression was associated with mechanical changes (including decreased modulus and increased failure strain) in the aging rabbit MCL (3). Detection of similar molecular changes in the ACL, and possibly the PCL, may indicate that their mechanical properties may also change as a result of increased lubricin gene expression, thereby potentially pre-disposing these ligaments to damage accumulation. Compared to aging ligaments, aging tendons exhibited decreased lubricin gene and protein expression, and increased stiffness (4). Although opposite changes than aging ligaments, these findings support the relationship between lubricin and modulus/stiffness. The similarities between ligaments in the aging and menopausal groups may suggest that surgically-induced menopause results in a form of accelerated aging in the rabbit ACL, MCL and possibly PCL.

Bone marrow concentrates are being used to augment soft tissue healing. However, only 0.01% of these cells meet the criteria of a mesenchymal stem cell (MSC), which likely accounts for the variability in reported results. Previous studies using an established rat rotator cuff repair model have demonstrated that bone marrow-derived MSCs had no effect on healing. In this study we evaluated the effect of purified human MSCs on rotator cuff healing in an athymic rat model. Hypothesis: Purified human MSCs added to the repair site will improve biomechanical strength and fibrocartilage formation of the healing tendon.

Fifty-two athymic rats underwent unilateral detachment and repair of the supraspinatus tendon with either fibrin glue (control) or fibrin glue with 106 hMSCs (experimental) applied at the repair site. Flow cytometry verified the stem cell phenotype of the cells as CD73+, CD90+, CD105+, CD14-, CD34- and CD45-. Rats were sacrificed at 2 and 4 weeks, with 10 used for biomechanical testing and 3 for histologic analysis from each group.

Biomechanical testing revealed a significant increase in failure load (11.5±2.4N vs. 8.5±2.4N, p=0.002) and stiffness (7.1±1.2 N/mm vs. 5.7±2.1 N/mm, p0.17).

These data demonstrate the potential for stem cells to augment tendon healing. This is the first study to use purified stem cells, rather than simple bone marrow concentrate. In the future, cell sorting techniques and culture expansion could be used to select and expand the small population of true stem cells in bone marrow. Furthermore, healing could potentially be improved with repeat cell injection at an additional post-operative time point.

To evaluate the efficacy of using a novel button-suture construct in place of traditional screws to provide bone block fixation for the Latarjet procedure.

Four paired cadaveric shoulders (n=8) were denuded, with the exception of the conjoint tendon on the coracoid, and were potted. A 15% anterior glenoid bone defect was simulated. Right and left specimens were randomised into two groups: double-screw versus quadruple-button Latarjet reconstruction techniques. A uniaxial mechanical actuator loaded the Latarjet reconstructed glenoid articular surface via a 47mm diameter metallic hemisphere. Cyclic loading between 50–200N was applied to the glenoid at a rate of 1Hz for 1000 cycles. Testing was repeated three times for conjoint tendon loads of 0N, 10N and 20N. The relative positions of three points on the inferior, central and superior edges of the coracoid bone fragment were optically tracked with respect to a glenoid coordinate system throughout testing. Screw and button constructs were compared on the basis of maximum relative displacement at these points (RINF, RCENT, RSUP). Statistical significance was assessed using a paired-samples t-test in SPSS.

When conjoint tendon loading was not present the double screw and quadruple button constructs were not significantly (P>0.779) different (0N: RINF: 0.11 (0.05)mm vs. 0.12 (0.03)mm, RCENT: 0.12 (0.04)mm vs. 0.12 (0.03)mm, RSUP: 0.13 (0.04)mm vs. 0.12 (0.03)mm). Additionally, the double screw construct was not found to differ (P>0.062) from the quadruple button in terms of resultant coracoid displacement for all central and superior points, regardless of conjoint loading (10N: RCENT: 0.11 (0.03)mm vs. 0.19 (0.05)mm, RSUP: 0.11 (0.01)mm vs. 0.18 (0.04)mm; 20N: RCENT: 0.13 (0.01)mm vs. 0.30 (0.13)mm, RSUP: 0.13 (0.03)mm vs. 0.26 (0.14)mm). It was only for the inferior point with conjoint loading of 10N and 20N that the double screw construct began to produce significantly lower displacements than the quadruple button (10N: RINF: 0.11 (0.03)mm vs. 0.23 (0.05)mm, P=0.047; 20N: RINF: 0.12 (0.02)mm vs. 0.39 (0.15)mm, P=0.026).

The results of the screw and button constructs when conjoint tendon loading was absent suggest that the button may be a suitable substitute to the screw when the coracoid is used as a bone block. Due to the small resultant displacements (max: screw = 0.19mm, button = 0.52mm), it is suggested that buttons may also act as a substitute to screws for Latarjet procedures, provided conjoint tendon overloading is minimised during the post-operative graft healing period. These in-vitro results support the in-vivo results of Boileau et al (2015) that demonstrated the suture-button technique to be an excellent alternative to screw fixation Latarjet, with graft healing in 91% of their subjects.

The relationship between pain catastrophising and emotional disorders including anxiety and depression in patients with osteoarthritis (OA) undergoing total joint replacement (TJR) is an emerging area of study. The purpose of this study was to examine the association between pain catastrophising, anxiety, depression and preoperative patient characteristics.

A prospective cohort study of preoperative TJR patients at one centre over 12-months was conducted. We examined association between catastrophising, anxiety, depression and preoperative patient characteristics including demographics, pain and function. Pain catastrophising was assessed using the Pain Catastrophising Scale (PCS), and anxiety/depression using the Hospital Anxiety and Depression Scale (HADS-A, HADS-D). Patient perceived level of hip/knee pain was measured using a visual analogue (VAS) pain scale. Patient perception of function was measured using the Oxford Score. Preoperative radiographic grading of OA was determined using the Kellgren and Lawrence (K-L) scale. Logistic regression was used to assess pattern of relationship between preoperative characteristics and PCS or HADS. Adjusted odds ratio (OR) and 95% confidence interval (CI) were reported. A secondary quantile regression analysis examined whether a model not restricted to pre-defined PCS and HADS categories would yield comparable results to the logistic regression model described in the primary analysis. P-values less than 0.05 were considered statistically significant.

The sample included 463 TJR patients (178 hips, 285 knees). VAS pain (OR 1.23,95%CI 1.04–1.45) and Oxford score (OR 1.13,95%CI 1.07–1.20) were identified as significant predictors for PCS. The same two variables were the strong predictors for all sub-domains of PCS excluding rumination. Oxford Score was the only significant predictor for abnormal HADS-A (OR 1.10,95%CI 1.04–1.17) while VAS pain (OR 1.27,95%CI 1.02–1.52) and Oxford (OR 1.09,95%CI 1.01–1.17) were significant predictors for abnormal HADS-D. Similar pattern of association for PCS and HADS was observed in the quantile regression model, where larger VAS pain and Oxford scores significantly increased median PCS across all domains. Female gender, younger age or having a higher ASA grade were associated with higher median HADS-A, but unlike in the logistic regression, this association was statistically significant.

Pain catastrophising and emotional disorders generally result in poor functional outcomes in TJR patients. The most important predictor of catastrophising, anxiety/depression is pain and subjective function. At risk patients include those with high preoperative pain with generally good preoperative function, as well as younger females with significant comorbidities. Such patients should be identified, and targeted psychological therapy implemented preoperatively to optimise coping strategies and adaptive behaviour to mitigate inferior TJR outcomes including pain and patient dissatisfaction.

The purpose of this study was to validate a dry model for the assessment of performance of arthroscopic rotator cuff repair (RCR) and labral repair (LR). We hypothesised that the combination of a checklist and a previously validated global rating scale (GRS) would be a valid and reliable means of assessing RCR and LR when performed by residents in a dry model.

An arthroscopic RCR and LR was performed on a dry model by residents, fellows, and sports medicine staff. Any prior RCR and LR exposure was noted. Participants were given a detailed surgical manuscript and technique video before the study began. Evaluation of residents was performed by staff surgeons with task-specific checklists created using a modified Delphi procedure, and the Arthroscopic Surgical Skill Evaluation Tool (ASSET). The hand movements and arthroscopic view of the procedures were recorded. Both videos were scored by a fellow blinded to the year of training of each participant.

A total of 35 residents, six fellows and five staff surgeons performed both arthroscopic RCR and LR on a dry model model (48 total). The internal reliability (Cronbach's Alpha) of the test using the total ASSET score was high (>0.8)). One-way analysis of variance for the total ASSET score and the total checklist score demonstrated a difference between participants based upon year of training (p<0.05). Post hoc analysis also demonstrated a significant difference in global ratings and checklist scores between junior residents (PGY1–3) and senior residents (PGY4&5), senior residents and fellows, and fellows and staff. A good correlation was seen between the total ASSET score and prior exposure to RCR and LR. The inter-rater reliability (ICC) between the examiner ratings and the blinded assessor ratings for the total ASSET score was good (0.8).

The results of this study provide evidence that the performance of a RCR and LR in a dry model is a valid and reliable method of assessing a resident's ability to perform these procedures, prior to performance in the operating room.

The World Health Organisation (WHO) has recently identified musculoskeletal care as a major global health issue in the developing world. However, little is known about the quality and trends of orthopaedic research in resource-poor settings. The purpose of this study was to perform a systematic review of orthopaedic research in low-income countries (LIC). The primary objective was to determine the quality and publication parameters of studies performed in LIC. Secondary objectives sought to provide recommendations for successful strategies to implement research endeavors in LIC.

A systematic review of the literature was performed by searching MEDLINE (1966-November 2014), EMBASE and the Cochrane Library to identify peer-reviewed orthopaedic research conducted in LICs. The PRISMA guidelines for performing a systematic review were followed. LIC were defined by the WHO and by the World Bank as countries with gross national income per capita equal or less than 1045US$. Inclusion criteria were (1) studies performed in a LIC, (2) conducted on patients afflicted by an orthopaedic condition, and (3) evaluated either an orthopaedic intervention or outcome. The Oxford Centre for Evidence-Based Medicine Levels of Evidence, and Grading of Recommendations Assessment, Development and Evaluation (GRADE) were used to objectively rate the overall methodological quality of each study. Additional data collected from these studies included the publication year, journal demographics, orthopaedic subspecialty and authors' country of origin.

A total of 1,809 articles were screened and 277 studies met our inclusion criteria. Eighty-eight percent of studies conducted in LIC were of lower quality evidence according to the GRADE score and consisted mostly of small case series or case reports. Bangladesh and Nepal were the only two LIC with national journals and produced the highest level of research evidence. Foreign researchers produced over 70% of the studies with no collaboration with local LIC researchers. The most common subspecialties were trauma (42%) and paediatrics (14%). The 3 most frequent countries where the research originated were the United States (42%), United Kingdom (11%), and Canada (8%). The 3 most common locations where research was conducted were Haiti (18%), Afghanistan (14%), and Malawi (7%).

The majority of orthopaedic studies conducted in LIC were of lower quality and performed by foreign researchers with little local collaboration. In order to promote the development of global orthopaedic surgery and research in LIC, we recommend (1) improving the collaboration between researchers in developed and LIC, (2) promoting the teaching of higher-quality and more rigorous research methodology through shared partnerships, (3) improving the capacity of orthopaedic research in developing nations through national peer-reviewed journals, and (4) dedicated subsections in international orthopaedic journals to global healthcare research.

The Spine Adverse Events Severity System (SAVES) and Orthopaedic Surgical Adverse Events Severity System (OrthoSAVES) are standardised assessment tools designed to record adverse events (AEs) in orthopaedic patients. The primary objective was to compare AEs recorded prospectively by orthopaedic surgeons compared to trained independent clinical reviewers. The secondary objective was to compare AEs following spine, hip, knee, and shoulder orthopaedic procedures.

Over a 10-week period, three orthopaedic spine surgeons recorded AEs following all elective procedures to the point of patient discharge. Three orthopaedic surgeons (hip, knee, and shoulder) also recorded AEs for their elective procedures. Two independent reviewers used SAVES and OrthoSAVES to record AEs after reviewing clinical notes by surgeons and other healthcare professionals (e.g. nurses, physiotherapists). At discharge, AEs recorded by the surgeons and independent reviewers were recorded in a database.

AE data for 164 patients were collected (48 spine, 52 hip, 33 knee, and 31 shoulder). Overall, 98 AEs were captured by the independent reviewers, compared to 14 captured by the surgeons. Independent reviewers recorded significantly more AEs than surgeons overall, as well as for each individual group (i.e. spine, hip, knee, shoulder) (p2), but surgeons failed to record minor events that were captured by the independent reviewers (e.g. urinary retention and cutaneous injuries; AEs Grade 0.05). AEs were reported in 21 (43.8%), 19 (36.5%), 12 (36.4%), and five (16.1%) spine, hip, knee, and shoulder patients, respectively. Nearly all reported AEs required only simple or minor treatment (e.g. antibiotic, foley catheter) and had no effect on outcome. Two patients experienced AEs that required invasive or complex treatment (e.g. surgery, monitored bed) that had a temporary effect on outcome.

Similar complication rates were reported in spine, hip, knee, and shoulder patients. Independent reviewers reported more AEs compared to surgeons. These findings suggest that independent reviewers are more effective at capturing AEs following orthopaedic surgery, and thus, could be recruited in order to capture more AEs, enhance patient safety and care, and maximise different complication diagnoses in alignment with proposed diagnosis-based funding models.

There has been a widespread adoption of training programs or “boot-camps” targeting new surgical residents prior to entrance to the hospital environment. A plethora of studies have shown positive reactions to implementations of “boot camps”. Reaction surveys, however, lack the ability to provide a deeper level of understanding into how and why “boot camps” are seen as effective. The purpose of this study was to develop a rich perspective on the role “boot camps” are perceived to play in resident education.

A constructivist approach to qualitative grounded theory methodology, employing iterative semi-structured, in-person, interviews was used to explore the construct of a “boot camp” through the eyes of key stakeholders, including junior surgical residents (n=10), senior surgical residents (n=5), and faculty members (n=5) at a major academic centre. Interviews were coded and analysed thematically using NVIVO software. Three members of the research team coded data independently and compared themes until consensus was reached. A method of constant comparative analysis was utilised throughout the iterative process. Emerging themes were revisited with stakeholders as a measure of rigor. Axial coding of themes was used to discover the overlying purposes embedded in the “boot camp” construct.

The overarching themes resonating from participants were ‘anxiety reduction’, ‘cognitive unloading’ and ‘practical logistics’. Resident anxiety was ameliorated through subthemes of ‘social inclusion’, ‘group formation’, ‘confidence building’ and ‘formalisation of expectations’. A resident commented “the nuances of how things work is more stressful than the actual job.” Residents bonded together to create personal and group identities, “forming the identity of who we are as a group”, that shaped ongoing learning throughout training, “right from the beginning we would be able to call on each other.” Junior residents found themselves cognitively unloaded for higher level learning through ‘expectation setting’ and ‘formalised basic skills’; “I knew how the equipment was going to fit together, it allowed me to focus more on what was happening from the operative perspective.” Stakeholders highlighted the importance of positioning “boot camp” at the beginning of residency training, as it directly influenced the point of transition. This highlights the strength of the “boot camp” construct at targeting the challenges associated with discrete moments of transition in the advancement in practice.

While surgical preparatory “boot camps” were initially born out of a competency-based framework focused on technical skill development, our findings demonstrate that the benefits outweigh simple improvement in technical ability. The formation of a learner group identity has downstream effects on resident perceptions of anxiety and confidence, while priming for higher-level learning. “Boot camp” then, is re-imagined as an experience of social professional enculturation.

The inmate population is a unique cohort with several healthcare-related challenges. International studies have demonstrated higher rates of infectious diseases, chronic diseases and psychiatric disorders in inmates when compared to general population. However, little is known about the outcomes following total joint arthroplasty in this population. This retrospective chart review aims to outline the differences in clinical outcomes after hip and knee total joint arthroplasty in the Kingston inmate population compared to the national population standard.

A list of all inmate inpatient hospital visits with diagnostic/procedure codes pertaining to total joint arthroplasty within the last ten years was obtained through a computer-based search of the Kingston General Hospital Discharge Abstract Database(DAD). The patient charts were reviewed and demographic and outcome data pertinent to our study was collected. Data was compiled using Excel and imported into IBM SPSS for descriptive analysis.

Twenty male inmate patients underwent 24 primary Total Hip Arthroplasties(THA) or Total Knee Arthroplasties(TKA) and one medial unicompartmental knee arthroplasty from May 2003 to January 2013. The average age was 58 with mean Body Mass Index(BMI) of 34. Median American Society of Anesthesiologist(ASA) score was 3 and mean Charlston Comorbidity Index was 3.92. The rates of HCV and HIV were 35%(n=5) and 0%, respectively. Average length of stay from time of initial procedure was 4.2 days. The overall revision rate was 24% (n=6). Reasons for revision included deep prosthetic infection (50%, n=3), aseptic loosening (17%, n=1), arthrofibrosis (17%, n=1) and late periprosthetic fracture (17%, n=1). Infection rates were reported at 16% (n=4); 75% of which were deep prosthetic infections requiring revision surgery. Other complications included ST-elevation myocardial infarction(STEMI) (n=1), and postoperative knee stiffness requiring manipulation under anesthesia(MUA) (n=1).

Compared to Correctional Services Canada(CSC) data on male inmate health in 2012, our study population demonstrated a higher rate of HCV (35% vs. 9.4%), diabetes (30% vs. 4.2%) and overall cardiovascular and respiratory comorbidities. This may reflect the higher rate of comorbidities associated with osteoarthritis, such as BMI>25, which was evident in 95% of our study population vs. 64.5% in Canadian inmates. Total joint revision rates in our inmate study population was 24%, which is higher than the 2014 Canadian Joint Replacement Registry's yearly revision rate of 8.7% in THA and 5.2% in TKA. Our study population also demonstrated infection as the leading cause for revision at 50%, compared to 14.5% for THA and 19.6% for TKA in the general Canadian population. Further study of the complex biopsychosocial risk factors in the inmate population is warranted to better define pre-surgical risk assessment criteria.

With the rapid evolution of surgical techniques every practicing surgeon will need to introduce new skills into their practice. Despite evidence that introducing a new surgical technique is associated with a learning curve during which there are reduced surgical and patient outcomes, there are no suggested protocols in place to support a surgeon in safely introducing a procedure into established practice. The purpose of this pilot study was to compare the effects of a mentored approach to learning new technical skills in practice to an unmentored approach.

A mentorship partnership and learning protocol was developed between a learning surgeon and an expert in the Direct Anterior Approach (DAA) total hip arthroplasty. After training in the technique the learning surgeon was directly supported in the first 3 cases and mentored for the first 15 cases.

Outcomes (surgical times, estimated blood loss, canal fit and fill, acetabular inclination and version, and complications) for the learning surgeons first 30 cases were assessed and compared to another learned cohort (first 30 cases of a percutaneously assisted total hip arthroplasty) integrated into practice without the support of a mentor. This data allow for the comparison of learning curves between the 2 techniques

Use of a mentored approach to the introduction of a new surgical skill was demonstrated to be a safe and more efficient than with an independent introduction of skills. The surgical times and learning curve were reduced and anectodatly the surgeons stress level was markedly reduced with a mentored approach. These findings support further work into surgical mentorship for the safe introduction of surgical skills in practice.

Milestone-based outcome oriented training is now an important framework for residency education and program accreditation. Analysing 18 months of Orthopaedic Surgery Patient Care Milestone real-time evaluations via a web platform in a single residency program demonstrated significant variability in the rate of assessment and competency level among Milestones. In 614 evaluations, there was a strong, positive linear relationship between postgraduate year and competency level. Chief residents achieved an average competency level of 4.0, the graduation target, as assessed by faculty in real-time. These data may inform ongoing discussions about potential revisions to the Orthopaedic Surgery Milestones, and highlight one potential model for improving resident feedback.

The Accreditation Council for Graduate Medical Education (ACGME) now requires the biannual submission of a variety of Milestones by United States residency programs, as part of a move towards competency-based medical training. Our program developed a web-based platform to collect Milestone-based evaluations in real-time, in an effort to improve feedback and facilitate ACGME compliance. After 18 months of use, we assessed how frequently each Milestone is evaluated in real-time, as well as the distribution of competency levels by each Patient Care Milestone and postgraduate year (PGY). These results may inform on relative strengths and weaknesses of a program, or of particular Milestones.

At a single academic orthopaedic residency program with 40 residents in total, the use of a web-based trainee-driven evaluation tool (eMTRCS – electronic Milestone Tracking and Competency System) was initiated in 2014. Residents initiate evaluation in real-time, triggering a digital Milestone-based evaluation by a particular faculty member. De-identified data from January 2014 to December 2015 was abstracted. Descriptive statistics on the distribution of evaluations submissions, type of Milestone, faculty evaluation levels, and resident PGY were calculated. As the data was ordinal with evidence of non-normality, nonparametric tests were utilised to analyse differences in the distribution, and assess correlation between planned outcome variables.

A total of 614 evaluations were included in the analysis, for an average of 38.4 evaluations per Patient Care Milestone. There was a wide variability in the number of evaluations per Milestone, ranging from only four “Diabetic Foot” submissions to 75 submissions on “Hip and Knee Arthritis” (Figure 1). Faculty-scored competency also varied significantly among the Milestones (Figure 2, p = 0.009 by Kruskal-Wallis rank sum test). Higher levels of competency were seen as resident PGY progressed (mean = 2.1, 2.4, 3.1, 3.7, 4.0 for PGY1–5 respectively, p<0.001).

Through 18 months of use and 614 real-time evaluations, a web-based system for assessing Milestone levels showed significant variability in the number of assessments and competency level among the Orthopaedic Surgery Patient Care Milestones. There are multiple possible explanations, ranging from resident and faculty confusion about the Milestones to a lack of clinical volume in specific areas. In contrast to the inter-Milestone variability in assessments and competency levels, the strong stepwise relationship between advancing PGY and increasing levels of competency does provide evidence of validity for Milestone-based evaluations. Graduating residents in this program achieved, on average, the graduation target competency level as assessed by faculty in real-time.

A commonly misunderstood principle in medical literature is statistical significance. Often, statistically non-significant or negative results are thought to be evidence for equivalence; mistakenly validating treatment modalities and putting patients at risk. This study examines the prevalence of misinterpretation of negative results of superiority trials in orthopaedic literature and outlines the need for a non-inferiority or equivalence research design.

Four orthopaedic journals – Journal of Paediatric Orthopaedics A, Journal of Bone and Joint Surgery American Volume, Journal of Arthroplasty and Journal of Shoulder and Elbow Surgery – were hand searched to identify all randomised control trials (RCTs) published within the time periods 2002–2003, 2007–2008 and 2012–2013. The identified RCTs were read and classified by study methodology, results obtained, and interpretation of results.

A total of 237 RCTs were identified. When analysing the primary outcomes, 117 (49.4%) studies yielded negative results and 120 (50.8%) yielded positive results. Out of the 237 articles, 231 (97.5%) used superiority methodology and 6 (2.5%) used non-inferiority or equivalence methodology. Of the 231 studies that used superiority methodology, 115 (49.8%) obtained negative results; and 45 (39.1%) of those misinterpreted the negative results for equivalence. While no statistical differences were seen, there was an upward trend in utilising non-inferiority and equivalence methodologies over time.

Given the frequency of misinterpreted negative results, there is an evident need for a more appropriate research methodology that shows equivalence of treatment methods. A non-inferiority or equivalence study design can address orthopaedic clinical dilemmas more suitably when trying to show one treatment is no worse or is equal to another treatment. Regarding orthopaedic treatment modalities as equivalent when studies show negative statistical results can be detrimental to patients and their clinical outcomes. A non-inferiority methodology can be used to accurately depict no difference between treatment methods rather than attempting to show one treatment method as superior.

Simulated learning is increasingly prevalent in many surgical training programs as medical education moves towards competency based curricula. In orthopaedic surgery, developmental dysplasia of the hip is a commonly treated diagnosis where the standard of care in patients less than six months of age is an orthotic device such as the Pavlik Harness. However, despite widespread use of the Pavlik Harness and the potential complications that may arise from inappropriate application, no formal educational methods exist.

A video and model based simulated learning module for Pavlik Harness application was developed. Two novice groups (residents and allied health professionals) were exposed to the module and at pre-intervention, post-intervention and retention testing were evaluated on their ability to apply a Pavlik Harness to the model. Evaluations were completed using a previously validated Objective Structured Assessment of Technical Skill (OSATS) and a Global Rating Scale (GRS) specific to Pavlik Harness application. A control group who did not undergo the module was also evaluated at two time points to determine if exposure to the Pavlik Harness alone would affect ability. All groups were compared to a group of clinical experts who were used as a competency benchmark. Statistical analysis of skill acquisition and retention was conducted using t-tests and ANOVA.

Exposure to the learning module improved resident and allied health professionals' competency in applying a Pavlik Harness (p<0.05) to the level of expert clinicians and this level of competency was retained one month after exposure to the module. Control subjects who were not exposed to the module did not improve nor did they achieve competency.

The simulated learning module has been shown to be an effective tool for teaching the application of a Pavlik Harness and learners demonstrated retainable skills post intervention. This learning module will form the cornerstone of formal teaching for Pavlik Harness application in developmental dysplasia of the hip.

Electrical stimulators are commonly used to accelerate fracture healing, resolve nonunions or delayed unions, and to promote spinal fusion. The efficacy of electrical stimulator treatment, however, remains uncertain. We conducted a meta-analysis of randomised sham-controlled trials to establish the effectiveness of electrical stimulation for bone healing.

We searched MEDLINE, EMBASE, CINAHL and Cochrane Central to identify all randomised sham-controlled trials evaluating electrical stimulators in patients with acute fractures, non-union, delayed union, osteotomy healing or spinal fusion, published up to February 2015. Our outcomes were radiographic nonunion, patient-reported pain and self-reported function. Two reviewers independently assessed eligibility and risk of bias, performed data extraction, and rated overall confidence in the effect estimates according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Fifteen randomised trials met our inclusion criteria. Electrical stimulation reduced the relative risk of radiographic nonunion or persistent nonunion by 35% (95%CI 19% to 47%; 15 trials; 1247 patients; number needed to treat = 7; p < 0.01; moderate certainty). Electrical stimulation also showed a significant reduction in patient-reported pain (Mean Difference (MD) on the 100-millimeter visual analogue scale = −7.67; 95% CI −13.92 to −1.43; 4 trials; 195 patients; p = 0.02; moderate certainty). Limited functional outcome data showed no difference with electrical stimulation (MD −0.88; 95% CI −6.63 to 4.87; 2 trials; 316 patients; p = 0.76; low certainty).

Patients treated with electrical stimulation as an adjunct for bone healing have a reduced risk of radiographic nonunion or persistent nonunion and less pain; functional outcome data are limited and requires increased focus in future trials.

There is no clear consensus regarding the indications for surgical treatment of middle third clavicle fractures. An initial shortening of 2 cm or more of the clavicle was associated with poor clinical outcomes and higher rate of non-union. The number needed to treat (NNT) clavicle fractures in order to prevent non-union ranges in the recent literature from 4.5 to 9.2. A direct relationship between shortening of the clavicle and a poor clinical outcome has not yet been demonstrated.

Prospective cohort study performed in a Level one trauma centre including 148 clavicle fractures treated conservatively. Eighty-five patients met the inclusion criteria (healed fracture in the middle third, no other upper limb lesions) and 63 were enrolled. A single assessment was realised at a minimum one year follow-up by an independent examiner and consisted in Constant and DASH scores, range of motion, strength in abduction (Isobex) and a specific radiographic evaluation using a calibrated AP radiographs of both clavicles. Two groups were constituted and analysed according to a radiologic shortening > 2 cm (patients and assessor blinded). Sub-analyses were performed to find any relevant clinical threshold.

The rate of shortening > 2cm in this cohort is 16.1% (10 patients). No clinical differences between the two groups for Constant scores (shortened > 2 cm = 96.0 ± 6.0 vs 95.2 ± 6.6, p=0,73) and DASH scores (8.4 ± 11.9 vs 5.4 ± 8.1, p=0,32). A slight loss in flexion was observed with a shortening > 2cm (175 deg ± 8.5 vs 179.3 ± 3.4, p=0,007). No clinical threshold (in absolute or relative length) was associated with lower functional scores. No relationship between clinical results and patient characteristics. Interestingly, cosmesis was not an issue for patients.

This study could not demonstrate any clinical impact of the shortening of the clavicle in patients treated conservatively for a fracture in the middle third. Functional scores are excellent and the slight difference in flexion is not clinically significant. We were not able to found patients unsatisfied with their treatment. The poor functional outcomes described in previous studies are mainly related to non-unions. Just after the trauma, protraction of the scapula and single AP views centered on the clavicle can overestimate the real shortening. An initial shortening of the clavicle > 2 cm is not a surgical indication for fractures in the middle third; patient selection for surgery should focus on risk factors for non-unions.

Tibial plateau fractures are common injuries. Displaced fractures are treated with open reduction and internal fixation (ORIF). Goals of treatment include restoration of extremity axial alignment, joint stability and congruity, allowing for early motion and prevention of osteoarthritis. Short term results of surgical fixation of tibial plateau fractures are good, however, longer term outcomes have demonstrated a higher risk of end-stage arthritis and total knee arthroplasty. Despite the vast literature around tibial plateau fractures, to our knowledge there are no series examining post-operative reductions using axial imaging. It is our goal to define the incidence of articular malreductions following surgical fixation of tibial plateau fractures, to identify patient or surgeon factors associated with malreductions, and to define any regional patterns of malreduction location.

De-identified post operative computed tomography (CT) scans were reviewed to identify tibial plateau malreductions with a step or gap greater than 2 mm, or condylar width greater than 5 mm. Three independent assessors reviewed the scans meeting criteria using Osirix DICOM software. Steps and gaps were mapped onto the axial sequence at the level of the joint line. Images were then matched to side and overlaid as best fit in Photoshop software to create a map of malreductions. A grid was created to divide the medial and lateral plateaus into quadrants to identify the density of malreductions by location. A multi-variate regression model was used to assess risk factors for malreduction.

Sixty five post-operative CT scans were reviewed. Twenty one reductions had a step or gap more than 2 mm for a malreduction incidence of 32.3%. The incidence in patients undergoing submeniscal arthrotomy or fluoroscopic assisted reduction was 16.6% and 41.4%, respectively (p <0.001). Side of injury, age, BMI, AO fracture type, and use of locking plates were not predictive of malreduction. Malreductions were heavily weighted to the posterior lateral tibial plateau.

The incidence of articular malreductions was high at 32.3%. Fluoroscopic reduction alone was a predictor for articular malreduction with most malreductions located in the posterior lateral quadrants of the plateau.

Traditional screw fixation of the syndesmosis can be prone to malreduction. Suture button fixation however, has recently shown potential in securing the fibula back into the incisura even with intentional malreduction. Yet, if there is sufficient motion to aid reduction, the question arises of whether or not this construct is stable enough to maintain reduction under loaded conditions. To date, there have been no studies assessing the optimal biomechanical tension of these constructs. The purpose of this study was to assess optimal tensioning of suture button fixation and its ability to maintain reduction under loaded conditions using a novel stress CT model.

Ten cadaveric lower limbs disarticulated at the knee were used. The limbs were placed in a modified external fixator frame that allows for the application of sustained torsional (5 Nm), axial (500 N) and combined torsional/axial (5Nm/500N) loads. Baseline CT scans of the intact ankle under unloaded and loaded conditions were obtaining. The syndesmosis and the deltoid ligament complex were then sectioned. The limbs were then randomised to receive a suture button construct tightened at 4 kg force (loose), 8 kg (standard), or 12 kg (maximal) of tension and CT scans under loaded and unloaded conditions were again obtained. Eight previously described measurements were taken from axial slices 10 mm above the tibiotalar joint to assess the joint morphology under the intact and repair states, and the three loading conditions: a measure of posterolateral translation (a, b), medial/lateral translation (c, g), a measure of anterior-posterior translation (f), a ratio of anterior-posterior translation (d/e), an angle (Angle 1) created by a line parallel to the incisura and the axis of the fibula, and an angle (Angle 2) created between the medial surfaces of two malleoli. These measurements have all been previously described. Each measurement was taken at baseline and compared with the three loading scenarios. A repeated measures ANOVA with a Bonferroni correction for multiple comparisons was used to test for significance.

Significant lateral (g, maximum 5.26 mm), posterior (f, maximum 6.42 mm), and external rotation (angle 2, maximum 11.71°) was noted with the 4 kg repair when compared to the intact, loaded state. Significant posterior translation was also seen with the both the 8 kg and 12 kg repairs, however the incidence and magnitude was less than with the 4 kg repair. Significant overcompression (g, 1.69 mm) was noted with the 12 kg repair.

Suture button constructs must be appropriately tensioned to maintain reduction and re-approximate the degree of physiological motion at the distal tibiofibular joint. If inserted too loosely, these constructs allow for supraphysiologic motion which may have negative implications on ligament healing. These constructs also demonstrate overcompression of the syndesmosis when inserted at maximal tension however the clinical effect of this remains to be determined.

Orthopaedic surgeons frequently assess fragility fractures (FF), however osteoporosis (OP) is often managed by primary care physicians (PCP). Up to 48% of FF patients have had a previous fracture (Kanis et al., 2004). Discontinuity between fracture care and OP management is a missed opportunity to reduce repeat fractures. This studied aimed to evaluate current OP management in FF patients presenting to cast clinic.

A single centre, prospective observational study where seven traumatologists screened for FF in cast clinic. FF was defined as a hip, distal radius (DR), proximal humerus (PH), or ankle fracture due to a ground level fall. Patients completed a self-administered questionnaire for demographics, fracture type and treatment, medical and fracture history, and previous OP care. The primary outcome was number of FF patients who received OP investigation and/or treatment. Secondary outcomes included Fracture Risk Assessment Tool (FRAX), repeat fracture rate, and anti-resorptive related fractures. Descriptive statistics were used for analysis.

Between November 17, 2014 and October 13, 2015, a total of 1,677 patients attended cast clinic for an initial assessment. FF were identified in 120 patients (7.2%). The FF cohort had a mean age of 65.3 (± 14.3) years, mean BMI of 26.1 (± 5.3), and was comprised of 83.3% females. Fracture distribution was 69 (57.5%) DR, 23 (19%) ankle, 20 (16.5%) PH, and seven (5.8%) hip fractures, with 24 of the FF (19.8%) treated operatively. Thirteen (10.8%) were current smokers and 40 (33.3%) formerly smoked. A history of steroid use was present in 13 patients (10.8%). Ninety (n = 117; 76.9%) of patients ambulated independently. Twenty-two patients (18.3%) reported prior diagnosis of OP, most often by a PCP (n = 19; 73.7%) over 5 years previously. Calcium (n = 59; 49.2%) and Vitamin D (n = 70; 58.3%) were common and 26 patients (21.5%) had a prior anti-resorptive therapy, with Alendronate (n = 9) being most common. One patient had an anti-resorptive-related fracture. Raloxifene was used in ten patients. Forty-seven patients (39.2%) had a prior fracture at a mean age of 61.3 (± 11.9) years, with DR and PH fractures being most common. Eleven patients had two or more prior fractures. A family history of OP was found in 34 patients (28.1%). Mean FRAX score was 20.8% (± 10.8%) 10-year major fracture risk and 5.9% (± 6.6%) 10-year hip fracture risk (n = 30 bone densiometry within one-year). Of the 26 patients with a Moderate (10–20%) or High (> 20%) 10-year major fracture risk, only eight (30.8%) reported a diagnosis of OP and only three (11.5%) had seen an OP specialist.

Cast clinics provide an opportunity for OP screening, initiation of treatment, and patient education. This cohort demonstrated a high rate of repeat fractures and poor patient reporting of prior OP diagnosis. This study likely underestimated FF and calls for resource allocation for quantifying true burden of disease and outpatient fracture liaison service.

Fractures of the anteromedial facet (AO/OTA 21-B1.1, O'Driscoll Type 2, subtype 3) are associated with varus posteromedial rotational instability of the ulnohumeral joint and early post-traumatic arthritis. The purpose of this study was to examine the stability of plate (locking and non-locking) vs screw constructs in the fixation of anteromedial coronoid facet fractures in a sawbone model.

An anteromedial coronoid facet fracture (AO/OTA 21-B1.1) was simulated in 24 synthetic ulna bones. They were then assigned into 3 fracture fixation groups: non-locking plate fixation, locking plate fixation, and dual cortical screw fixation. An AO 2.0 mm screw and plate system was used for the plate fixation groups and 2.0 mm cortical screws were used for the screw-only group. Following fixation, each construct was potted in bismuth alloy and secured to a servohydraulic load frame. Each construct was cycled in tension and then in compression at 0.5Hz. For both cycling modalities, an incremental loading pattern was used starting at 40 N and increased by 20 N every 200 cycles up to 200N. Fracture fragment displacement was recorded with an optical tracking system. Following cyclic loading each construct was loaded to failure (displacement >2 mm) at 10mm/min.

Tension cycling – All constructs in the plated groups (locking and non-locking constructs) survived the cyclic tension loading protocol (to 200N) with maximum fragment displacement of 12.60um and 14.50um respectively. There was no statistical difference between the plated constructs at any load level. No screw-only fixed construct survived the tension protocol with mean force at failure of 110N (range 60–180N).

Compression Testing – All constructs in the plated groups (locking and non-locking constructs) survived the cyclic compression loading protocol (to 200N), while all but one of the screw-only fixation constructs survived. Fracture fragment displacement was significantly greater in the screw-only repair group across all loading levels when compared to the plated constructs. There was no statistically significant difference in fragment motion between the locking and non-locking groups.

Failure Testing – The maximum load at failure in the screw-only group (281.9 N) was significantly lower than locking and non-locking constructs (587.0 N and 515.5N respectively, p <0.05). There was no difference between the locking and non-locking group in mean load to failure or mean stiffness. Screw construct stiffness (337.2 N/mm) was lower than the locking and non-locking constructs (682.9 N/mm and 479.1 N/mm respectively) however this did not reach statistical significance (p=0.051).

Fixation of anteromedial coronoid fractures is best achieved with a plating technique. Locking plates did not offer any advantage over conventional plates. Isolated screw fixation might not provide adequate stability for these fractures which could result in loss of reduction leading to post-traumatic arthrosis or instabilility.

Pilon fractures are associated to significant soft tissue injury, as well as soft tissue complications. The soft tissue on the medial side of the distal tibia is often involved, likely due to a lack of muscle investment. Medial approaches and medial plate application may well add to the soft tissue trauma. The objective of this study was to examine the relationship between medial plating and soft tissue complications in our center.

This is a retrospective study based on a prospective database. Pilon cases treated with plate and screw fixation were identified between 2011 and 2014. Injury characteristics, patient demographics, and soft tissue complications were collected from chart review. Soft tissue complications recorded included any wound or skin problem, as well as patient complaints of hardware irritation leading to hardware removal. Logistic regression was employed. Independent variables for the model included medial plating, the presence of open fracture, smoking status and diagnosis of diabetes. Two models were created, one with the dependent variable as presence of any soft tissue complication, and the second model with the dependent variable as presence of a wound complication, which required surgical intervention.

The study included 91 patients, 89 of whom had full data with an average follow up of 11.6 months (1–33 months). The incidence of soft tissue complications, including hardware irritation, was 26% (n=23), and 13% (n=12) required surgical treatment. Smoking status was the only predictor of soft tissue complications with an odds ratio of 3.6 (95%CI 1.2, 10.4; p=0.02), while controlling for other independent variables. The model explained 12% of the variation in soft tissue complications (Cox and Snell 0.119, p=0.028). In the second model, presence of a medial plate predicted soft tissue complications requiring surgical intervention with an odds ratio of 8.8 (95%CI 1.1, 73.7; p=0.045), while controlling for the other independent variables. The model explained 10% of the variation in soft tissue complications requiring surgical intervention (Cox and Snell 0.095, p=0.035).

The use of a medial plate does not appear to correlate to general soft tissue complications in pilon fractures. Smoking status increased the odds of a soft tissue complication more than three fold. The use of medial plating did increase the odds of soft tissue complications that required surgical treatment almost nine fold. It appears medial plating is not related to soft tissue complications, however treating soft tissue compilations in the presence of a medial plate may require more invasive methods.

Bone metastases are the most common cause of cancer-related pain and often lead to other complications such as pathological fractures and spinal cord compression. Bisphosphonates (BP) are a class of potent anti-resorptive agents commonly prescribed to retard osteoporosis progression. Interestingly, BP may have indirect anti-tumour properties through negative effects on macrophages, osteoclasts, endothelial cells and their ability to suppress matrix metalloproteinase (MMP) activity. Currently, the use of bisphosphonates for cancer therapy is generally restricted to high dose systemic delivery. The purpose of this study was to investigate the effects of direct local delivery of Zoledronate at the metastatic site in a mouse model of breast cancer metastasis to bone.

Seven days following intra-tibial inoculation with MDA-MB-231 (N = 1× 105) breast cancer cells in athymic mice, the experimental group (N = 11) was treated by direct infusion of 2µg of Zoledronate into the tibial lesion (three times/week for three weeks) and compared to vehicle-treated mice (N = 5). The formation of bone metastases and growth of the lesions were followed up by weekly bioluminescence imaging. In a subsequent experiment, a comparison of the effects of local versus systemic delivery of Zoledronate on the formation of osteolytic bone metastases was carried in athymic mice (N = 15). Seven days following intra-tibial inoculation with MDA-MB-231 breast cancer cells, the systemic group (N = 5) was treated with Zoledronate (0.025mg/kg) once per week for four weeks and compared to systemic delivery of vehicle (N = 4). Following treatment, the mice were sacrificed, and micro-CT images of the right tibia were obtained. Bone volume to tissue volume ratio (BV/TV%) was determined using µ-CT biomarkers.

The first experiment showed a statistically significant increase in mean bone volume/tissue volume ratio% (BV/TV%) in the treated group (7.0±1.54%) as compared to the control group (3.8±0.48%) (P <0.001, 95%CI=1.9–4.3). This corresponded to a net increase of 84.21% in response to Zoledronate treatment. Comparison between the local and systemic effects of Zoledronate also revealed a significant increase in the BV/TV% in the locally treated group (6.69±0.62%) when compared to the cohort administered systemic bisphosphonate treatment (4.03±0.44%) (P<0.001, 95%CI=1.24–3.20), corresponding to a net increase of 66.0%.

These preliminary results suggest that high dose sustained release of Zoledronate can lead to a significant inhibition of tumor-induced osteolysis. Moreover, comparison between local and systemic delivery revealed that the effect of local bisphosphonate administration exceeds the benefits of systemic delivery in terms of osteolysis inhibition. Lastly, the noted effects of Zoledronate local delivery triggers the need for further assessment of its anti-tumour activity.

This text has been removed at the authors' request.

Biological reconstruction techniques after diaphyseal tumour resection have increased in popularity in recent years. High complication and failure rates have been reported with intercalary allografts, with recent studies questioning their role in limb-salvage surgery. We developed a technique in which large segment allografts are augmented with intramedullary cement and fixed using compression plating. The goal of this study was to evaluate the survivorship, complications and functional outcomes of these intercalary reconstructions.

Forty-two patients who had reconstruction with an intercalary allograft following tumour resection between 1989 and 2010 were identified from our prospectively collected database. Allograft survival, local recurrence-free, disease-free and overall survival were assessed using the Kaplan-Meier method. Patient function was assessed using the Musculoskeletal Tumour Society (MSTS) scoring system and the Toronto Extremity Salvage Score (TESS).

The 23 women and 19 men had a mean age of 33 years (14–77). The most common diagnoses were osteosarcoma (n=16) and chondrosarcoma (n=9). There were 9 humerus, 18 femur and 15 tibia reconstructions. At a mean follow-up of 95 months (5–288), 31 patients were alive without disease, 10 were dead of disease and 1 was deceased of other causes. There were 4 local recurrences and 11 patients developed metastatic disease. 5-year local recurrence free survival was 92%, 5-year disease-free survival was 70% and overall survival was 75%. Fourteen of 42 patients (33%) experienced complications: 5 wound healing complications, 4 infections, 2 non-unions, 2 fractures and 1 nerve palsy. Four allografts (9.5%) were revised for complications and 2 (5%) for local recurrence. Mean allograft survival was 85 months (4–288). Mean time to union was 8.2 (3–36) months for the proximal osteotomy site and 8.1 (3–23) months for the distal osteotomy site. The mean score for MSTS 87 was 29.4 (+/− 4.4), MSTS 93 was 83.7 (+/−14.8) and TESS was 81.6 (+/−16.9).

An intercalary allograft augmented with intramedullary cement and compression plate fixation provides a reliable and durable method of reconstruction after tumour resection. Complication rates are comparable to the literature and are associated with high levels of patient function and satisfaction.

Musculoskeletal tumours are relatively rare and as such, they are not well known by the population and by general practicioners. We observed that an important proportion of our patients has seen major delays at diferent stages of their referral pathway. It is well recognised that such delays can cause avoidable loss of function, local and systemic recurrence and increase in health system costs. The main objective of this study was to prospectively assess the referral paterns of our patients to pinpoint the causes of the delays. This should allow the formation of strategies to minimise delas and their impact. The secondary objective was to assess the performance of our centre in comparaison to other centre with the goal of improving quality of care.

Prospective follow up data is available for 457 patient referred to our musculoskeletal oncology team between july 2011 and november 2014. Every patients filled questionnaires on their initial referral patterns. Site specific function and quality of life are evaluated at baseline and at subsequent follow-up (six months, one year, three years and five years).

The average delay between the first symptoms and the first medical consultation with a general practitioner was 37 weeks (CI: 27–46). The average delay between the first medical consultation and the referral to orthopaedic oncology was 54 weeks (CI: 43–65). The delay between the first consultation with a general practitioner and the first radiologic test was 31 weeks (CI: 22–39). The delay between the first radiologic test and the referral to orthopaedic oncology was 28 weeks (CI 24–32). The delay between the referral to orthopaedic oncology and the first appointment to our centre was three weeks (CI 2–4). Before the referral to our center, 23% of the patients met two general practitioners and 10% met with 3 or more general practitioner. Fifty-two pervent of the patients had a consultation with a specialist and 19% saw two or more specialists.

It is imperative to raise awareness of musculoskeletal tumours and indication for early referral in general practitioners. One of the main problems in our actual referral patern is early access to appropriate imaging. The creation of a referral program with specific guidelines is, in our opinion, the best way to significantly reduce the delays for appropriate management of patients with suspiscion of musculoskeletal tumours.

This is quite an innovative study that should lead to a multicentre validation trial. We have developed an FDG-PET/MRI texture-based model for the prediction of lung metastases (LM) in newly diagnosed patients with soft-tissue sarcomas (STSs) using retrospective analysis. In this work, we assess the model performance using a new prospective STS cohort. We also investigate whether incorporating hypoxia and perfusion biomarkers derived from FMISO-PET and DCE-MRI scans can further enhance the predictive power of the model.

A total of 66 patients with histologically confirmed STSs were used in this study and divided into two groups: a retrospective cohort of 51 patients (19 LM) used for training the model, and a prospective cohort of 15 patients (two patients with LM, one patient with bone metastases and suspicious lung nodules) for testing the model. In the training phase, a model of four texture features characterising tumour sub-region size and intensity heterogeneities was developed for LM prediction from pre-treatment FDG-PET and MRI scans (T1-weighted, T2-weighted with fat saturation) of the retrospective cohort, using imbalance-adjusted bootstrap statistical resampling and logistic regression multivariable modeling. In the testing phase, this multivariable model was applied to predict the distant metastasis status of the prospective cohort. The predictive power of the obtained model response was assessed using the area under the receiver-operating characteristic curve (AUC). In the exploratory phase of the study, we extracted two heterogeneity metrics from the prospective cohort: the area under the intensity-volume histogram of pre-treatment DCE-MRI volume transfer constant parametric maps and FMISO-PET hypoxia maps (AU-IVH-Ktrans, AU-IVH-FMISO). The impact of the addition of these two individual metrics to the texture-based model response obtained in the testing phase was first investigated using Spearman's correlation (rs), and lastly using logistic regression and leave-one-out cross-validation (LOO-CV) to account for overfitting bias.

First, the texture-based model reached an AUC of 0.94, a sensitivity of 1, a specificity of 0.83 and an accuracy of 0.87 when tested in the prospective cohort. In the exploratory phase, the addition of AU-IVH-FMISO did not improve predictive power, yielding a correlation of rs = −0.42 (p = 0.12) with lung metastases, and a relative change in validation AUC of 0% in comparison with the texture-based model response alone in LOO-CV experiments. In contrast, the addition of AU-IVH-Ktrans improved predictive power, yielding a correlation of rs = −0.54 (p = 0.04) with lung metastases, and a change in validation AUC of +10%.

Our results demonstrate that texture-based models extracted from pre-treatment FDG-PET and MRI anatomical scans could be successfully used to predict distant metastases in STS cancer. Our results also suggest that the addition of perfusion heterogeneity metrics may contribute to improving model prediction performance.

High grade sarcoma present a systemic metastatic progression in approximaly 50% of cases. The effectiveness of palliative chemotherapy as a treatment of systemic metastases is still controversed. The main objectif of this study is to assess disease progression and survival of patients diagnosed with metastatic soft tissue sarcomas treated with palliative chemotherapy, analyse chemotherapy treatment patterns and response to different lines of treatment.

Retrospective chart review of 75 patients treated with palliative chemotherapy for metastatic soft tissue sarcomas between 2003 and 2013 at Maisonneuve-Rosemont Hospital. Data for control group of 40 patients with metastatic soft tissue sarcomas not treated with chemotherapy was collected retrospectively. Collected data include demographic data, overall survival, time free survival, type of chemotherapy treatment, surgical treatment and adverse reaction to palliative chemotherapy. Overall survival was analysed with Kaplan-Meier test. Categorial variable were compared with Log-Rank test.

Seventy-five patients (37% female; mean age 50.4 years) received minimally one line of chemotherapy for their metastatic sarcomas. The regimens most commonly used in first-line were doxorubicin (48%) and doxorubicin combined with ifosfamide (21.3%). Favorable response was achieved by 38.7% in first-line and 27.9% in second-line therapy. Median overall survival with chemotherapy treatments was more than two times overall survival without treatments. Median overall survival was 19 months with chemotherapy treatments and 7 months without chemotherapy (p<0.0001). There was no statistically significant difference between survivals for treated and untreated patients with chemotherapy when analysed in term of the histological subtype, age and monotherapy versus combined treatment. Event-free survival was statistically longer during the first year for the group of patients treated with combined chemotherapy (p=0.0125).

Results have shown a significantly improved overall survival in all histological groups, resulting in an OS of 19 vs 7 months for the chemotherpy and non chemotherapy group respectively. Nevertheless, patients with favorable response to chemotherapy have poor outcomes. Additional treatment options are needed.

Hindquarter amputations for bone or soft tissue sarcoma cause a high degree of disability in patients and are associated with high morbidity rates. The goal of this study is to determine prognostic factors for outcome and analyse quality of life after resection, in order to better select patients who are more likely to benefit from a hindquarter amputation.

Our prospectively collected database was searched for all patients treated with a hindquarter amputation between 1989 and 2015. Clinical and histopathological features were analysed for their prognostic value using Kaplan-Meier and Cox proportional hazard analysis. Endpoints were set at recurrent disease and death. Also, functional and social outcome as well as pain was assessed from the hospital charts in the patients that are still alive.

82 patients underwent a hindquarter resection in the given time frame. Of these patients, 63 were treated with a curative intent. The median hospital stay was 25 days, and 49% of the patients had wound complications. The in-hospital mortality was 6%. The 5-year overall survival in the whole group was 31%, while disease free survival was 26%. As expected, patients with metastases at presentation had a significantly worse outcome, while patients with locally recurrent sarcoma had the same outcome as patients with primary sarcoma. For those patients treated with curative intent, younger age was correlated with better survival, while higher histological grade was correlated with worse disease free survival. The functional and social outcome for patients who survived more then one year varied widely, with about 50% of the patients living an acceptable social life with reasonable pain levels and mobility status.

Hindquarter amputations for sarcoma patients are still indicated for a select group of patients. Younger patients and/or patients with low grade sarcomas are more likely to benefit form this resection in terms of survival and long term function. However, for patients with less favourable prognostic factors a hindquarter operation might be an unreasonable palliative option.

Major wound complication risk factors following soft tissue sarcoma resection.

Wound-healing complications represent an important source of morbidity in patients treated surgically for soft tissue sarcomas (STS). The purpose of this study was to determine which factors are predictive of major wound complication rates following STS resection, including tumour site, size, grade, and depth, as well as radiotherapy and chemotherapy.

We reviewed 256 cases of STS treated surgically between 2000 and 2011. The primary outcome was occurrence of major wound complications post STS resection.

Major wound complications were more likely to occur post STS resection with larger tumour diameters (p = 0.001), high grade tumours (p = 0.04), location in the proximal lower extremity (p = 0.01), and use of preoperative radiotherapy (p = 0.01). Tumours located in the adductor compartment were at highest risk of complications. We did not demonstrate a significant difference in complications rates based on method of closure. Diabetes, smoking, obesity, tumour diameter, tumour location in the proximal lower extremity, and preoperative radiotherapy were independent predictors on multivariate analysis.

There are multiple predictors for major wound complications post STS resection. A more aggressive resection of irradiated soft tissues, combined with primary reconstruction, should be considered in cases with multiple risk factors.

Level of evidence (LOE) determination is a reliable tool to assess the strength of research based on study design. Improvements in LOE are necessary for the advancement of evidence-based clinical care. The objectives of this study were to determine if the LOE presented at the Musculoskeletal Tumour Society (MSTS) annual meeting has improved over time and to determine how the LOE presented at MSTS annual meetings compares to that of the Orthopaedic Trauma Association (OTA) annual meetings.

We reviewed abstracts from the MSTS and OTA annual meeting podium presentations from 2005 to 2014. Three independent reviewers evaluated a total of 1222 abstracts for study type and LOE. Changes in the distributions of study type and LOE over time were evaluated by Pearson Chi-Squared test.

There were a total of 577 podium abstracts from the MSTS and 645 from the OTA. Of the MSTS therapeutic studies, 0.5% (2/376) were level I, while 75% (281/376) were level IV. There was a seven-fold higher proportion of level I studies (3.4% [14/409]) and less than half as many level IV studies (32% [130/409]) presented at OTA. There was no improvement in the MSTS LOE for all study types (p=0.13) and therapeutic study types (p=0.36) over the study decade. In contrast, the OTA LOE increased significantly over this time period for all study types (p<0.01). The proportion of controlled therapeutic studies (LOE I through III) versus uncontrolled studies (LOE IV) increased significantly over time at the OTA (p<0.021), but not at the MSTS (p=0.10).

Uncontrolled case series continue to dominate the MSTS scientific program, whereas over the past decade, higher-level studies and more modern study methodology has been employed by members of the OTA.

Wound complications are common in patients with soft tissue sarcomas (STS) treated with surgical excision. Limited data is available on predictive factors for wound complications beyond the relationship to neo-adjuvant or adjuvant radiotherapy. Likewise, the association between blood transfusion, patient comorbidities and post-operative outcomes is not well described. In the present study we identified the predictive factors for blood transfusion and wound complications in patients undergoing surgical resection of soft tissue sarcoma from a national cohort.

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients who underwent surgical resection of a STS from 2005 to 2013. Primary malignant soft tissue neoplasms were identified using the following ICD-9 codes: 171.2, 171.3 and 171.6. Patients treated with both wide excision and amputation were identified using the current procedural terminology (CPT) codes. Prolonged operative time was defined as greater than 90th percentile of time required per procedure. A multivariable logistic regression model was used to identify associations between patient factors and post-operative wound complications (superficial and deep surgical site infections (SSI), and wound dehiscence). A similar regression model sought to identify prognostic factors for blood transfusion and associations with post-operative outcomes.

A total of 788 patients met our inclusion criteria. Of theses, 64.2% had tumours in the lower limb, 23.1% patients had tumours in the upper limb, and 12.7% patients had pelvic tumours. Six hundred and forty patients (81.2%) underwent surgical excision; 148 (18.8%) patients had an amputation. Multivariable logistic regression modeling identified American Society of Anaesthesiologist (ASA) class 3 and 4 (OR=2.3, P=0.03; OR=8.3, P=0.001, respectively), amputation (OR=14.0, P<0.001) and prolonged operative time (OR=4.6, P<0.001) as significant predictors of blood transfusion. Radiotherapy (OR=2.6, P=0.01) and amputation (OR=2.6, P=0.01) were identified as predictors of superficial SSI, whereas ASA class 4 (OR=6.2, P=0.03), prolonged operative time (OR=3.9, P=0.012) and return to the operating room (OR=10.5, P<0.001) were associated with deep SSI. Male gender (OR=1.8, P=0.03), diabetes (OR=2.3, P=0.03), ASA class 3 (OR=2.4, P=0.003), amputation (OR=3.8, P<0.001) and steroids (OR=4.5, P=0.03) were identified as predictors for wound dehiscence and open SSI.

A national cohort demonstrates that male gender, diabetes, chronic steroid use, higher ASA score and radiotherapy are associated with an increased incidence of wound complications. One in twenty-three patients undergoing resection of an STS will require a blood transfusion, and this risk is correlated with amputation, prolonged operative time and increased ASA score. Strategies to decrease the risk of blood transfusion and wound complication should be considered for these patient groups.

Are there any patho-anatomical features that might predispose to primary knee OA? We investigated the 3D geometry of the load bearing zones of both distal femur and proximal tibias, in varus, straight and valgus knees. We then correlated these findings with the location of wear patches measured intra-operatively.

Patients presenting with knee pain were recruited following ethics approval and consent. Hips, knees and ankles were CT-ed. Straight and Rosenburg weight bearing X-Rays were obtained. Excluded were: Ahlbäck grade “>1”, previous fractures, bone surgery, deformities, and any known secondary causes of OA. 72 knees were eligible. 3D models were constructed using Mimics (Materialise Inc, Belgium) and femurs oriented to a standard reference frame. Femoral condyle Extension Facets (EF) were outlined with the aid of gaussian curvature analysis, then best-fit spheres attached to the Extension, as well as Flexion Facets(FF). Resected tibial plateaus from surgery were collected and photographed, and Matlab combined the average tibia plateau wear pattern.

Of the 72 knees (N=72), the mean age was 58, SD=11. 38 were male and 34 female. The average hip-knee-ankle (HKA) angle was 1° varus (SD=4°). Knees were assigned into three groups: valgus, straight or varus based on HKA angle. Root Mean Square (RMS) errors of the medial and lateral extension spheres were 0.4mm and 0.2mm respectively. EF sphere radii measurements were validated with Bland-Altman Plots showing good intra- and interobserver reliability (+/− 1.96 SD). The radii (mm) of the extension spheres were standardised to the medial FF sphere. Radii for the standardised medial EF sphere were as follows; Valgus (M=44.74mm, SD=7.89, n=11), Straight (M=44.63mm, SD=7.23, n=38), Varus (M=50.46mm, SD=8.14, n=23). Ratios of the Medial: Lateral EF Spheres were calculated for the three groups: Valgus (M=1.35, SD=.25, n=11), Straight (M=1.38, SD=.23, n=38), Varus (M=1.6, SD=.38, n=23). Data was analysed with a MANOVA, ANOVA and Fisher's pairwise LSD in SPSS ver 22, reducing the chance of type 1 error. The varus knees extension facets were significantly flatter with a larger radius than the straight or valgus group (p=0.004 and p=0.033) respectively. In the axial view, the medial extension facet centers appear to overlie the tibial wear patch exactly, commonly in the antero-medial aspect of the medial tibial plateau.

For the first time, we have characterised the extension facets of the femoral condyles reliably. Varus knees have a flatter medial EF even before the onset of bony attrition. A flatter EF might lead to menisci extrusion in full extension, and early menisci failure. In addition, the spherical centre of the EF exactly overlies the wear patch on the antero-medial portion of the tibia plateau, suggesting that a flatter medial extension facet may be causally related to the generation of early primary OA in varus knees.

Osteoarthritis (OA) is the most common form of arthritis worldwide. It is a major cause of disability in the adult population with its prevalence expected to increase dramatically over the next 20 years. Although current therapies can alleviate symptoms and improve function in early course of the disease, OA inevitably progresses to end-stage disease requiring total joint arthroplasty. Mesenchymal stromal cells (MSCs) have emerged as a candidate cell type with great potential for intra-articular (IA) repair therapy. However, there is still a considerable lack of knowledge concerning their behaviour, biology and therapeutic effects. To start addressing this, we explored the secretory profile of bone marrow derived MSCs in early and end-stage knee OA synovial fluid (SF).

Subjects were recruited and categorised into early [Kellgren-Lawrence (KL) grade I and II, n=12] and end-stage (KL grade III and IV, n=11) knee OA groups. The SF proteome of early and end-stage OA was tested before and three days after the addition of bone marrow MSCs (16.5×10^3, single donor) using multiplex ELISA (64 cytokines) and mass spectrometry (302 proteins detected). Non parametric Wilcoxon-signed rank test for paired samples was used to compare the levels of proteins before and after addition of MSCs in early and end-stage knee OA SF. Significant differences were determined after multiple comparisons correction (FDR) with a p<0.05.

Gender distribution and BMI were not statistically different between the two cohorts (p>0.05). However, patients in early knee OA cohort were significantly younger (44.7 years, SD=7.1) than patients in the end-stage cohort (58.6 years, SD=4.4; p<0.05). In both early and end-stage knee OA, MSCs increased the levels of VEGF-A (by 320.24 pg/mL), IL-6 (by 826.78 pg/mL) and IL-8 (by 128.85 pg/mL), factors involved in angiogenesis; CXCL1/2/3 (by 103.35 pg/mL), CCL2 (by 1187.27 pg/mL), CCL3 (by 15.82 pg/mL) and CCL7 (by 10.43 pg/mL), growth factors and chemokines. However, CXCL5 (by 48.61 pg/mL) levels increased only in early knee OA, whereas PDGF-AA (by 15.36 pg/mL) and CXCL12 (by 497.19 pg/mL) levels increased only in end-stage knee OA.

This study demonstrates that bone marrow derived MSCs secrete angiogenic and chemotactic factors both in early and end-stage knee OA. More importantly, MSCs show a differential reaction between early and end-stage OA. Functional assays are required to further understand on how the therapeutic effect of MSCs is modulated when exposed to OA SF.

In addition to mechanical stresses, an inflammatory mediated association between obesity and knee osteoarthritis (OA) is increasingly being recognised. Adipokines, such as adiponectin and leptin, have been postulated as likely mediators. Clinical and epidemiological differences in OA by race have been reported. What contributes to these differences is not well understood. In this study, we examined the profile of adipokines in knee synovial fluid (SF) and the gene expression profile of the infra-patellar fat pad (IFP) by race among patients with end-stage knee OA scheduled for knee arthroplasty.

Age, sex, weight and height (used to derive body mass index (BMI)) and race (White, Asian and Black) were elicited through self-report questionnaire prior to surgery. SF and IFP samples were collected at the time of surgery. Adipokines (adiponectin and leptin) were examined in the SF using MAGPIX Multiplex platform. IFP was profiled using Human Adipogenesis PCRArray and genes of interest were further validated via quantitative relative RT-PCR using Student's t-test. Overall differences in adiponectin and leptin concentrations were tested across race. Linear regression modeling was used to investigate the association between adiponectin and leptin concentrations (outcomes) and race (predictor; referent group: White), adjusting for age, sex and BMI.

67 patients (18 White, 33 Asian, 16 Black) were included. Mean SF adiponectin concentration was greatest in Whites (1175.05 ng/mL), followed by Blacks (868.53 ng/mL) and Asians (702.23 ng/mL) (p=0.034). The mean SF leptin concentration was highest in Blacks (44.88 ng/mL), followed by Whites (29.86 ng/mL) and Asians (20.18 ng/mL) (p=0.021). Regression analysis showed Asians had significantly lower adiponectin concentrations compared to Whites (p<0.05). However, leptin concentrations did not differ significantly by race after adjusting for covariates. Testing of the IFP, using the Adipogenesis PCRArray, showed significant higher expression of LEP gene (leptin, p=0.03) in Asians (n=4) compared to Whites (n=4).

There appears to be important racial differences in the SF adiponectin profile among individuals with end-stage knee OA. Differential gene expression in the IFP across racial groups could be a potential contributory source for the noted SF variations. Further work to determine the source and function of adipokines in knee OA pathophysiology across racial groups is warranted.

Osteoarthritis (OA) is a multifactorial disease that affects millions of Canadians. Although, there is not one specific mechanism that causes OA, the biological outcome is cartilage degradation. The articular cartilage in joints is composed primarily of the proteoglycan aggrecan and type II collagen (Col II) which together provide cartilage with functional properties. In OA, the imbalance of the anabolic and catabolic activities of chondrocytes favors cartilage catalysis. The main inflammatory cytokine involved in cartilage degradation is interleukin (IL) 1β. It has previously been demonstrated that Link N, a 16 residue peptide derived from proteolytic cleavage of link protein, can stimulate matrix proteins in normal cartilage and intervertebral discs (IVDs). Recently, we showed that a shorter sequence of Link N (sLink N), consisting of the first 8 residues of the peptide, has the potential to increase synthesis of matrix proteins in IVD cells in vitro and stimulate repair in ex vivo IVD organ culture. There are currently no treatments that actively repair cartilage in OA joints. In the present study, we aimed to evaluate the potential of sLink N as a therapeutic agent in the repair of OA cartilage.

OA cartilage was isolated from four donors undergoing total knee replacement (50–70 y). Cells were recovered from the cartilage of each knee by sequential digestion with Pronase followed by Collagenase, and expanded in PrimeGrowth culture medium (Wisent Bioproducts, Canada; Cat# 319–510-CL, −S1, and −S2). After 7 days in culture, cells were treated for 24h with sLink N (0.5, 5, 50, 500 or 5000 ng/ml) or sLink N in combination with IL-1β (1 ng/ml) to mimic an inflammatory milieu. Conditioned media was collected and measured for proteoglycan (GAG) release using the safranin O and for Col II synthesis by Western blotting. Human articular cartilage explants including cartilage with subchondral bone were prepared from the same donors using the PrimeGrowth Isolation kit (Wisent, Canada) and cultured for 21 days in presence of IL-1β (1ng/ml) and sLink N (0.5, 5, 50, 500 or 5000 ng/ml). Aggrecan and Col II were extracted with guanidine buffer and measured by Western blotting.

Treatment of OA chondrocytes significantly increased the GAG and Col II synthesis. The EC50 dose-response of sLink N on GAG synthesis was 67 ± 41 nM [65 ± 40 ng/ml] and the GAG synthesis reached a maximum of 194 ± 30% with the highest dose above control. When chondrocytes were cultured in the presence of IL-1β, GAG synthesis was also elevated by sLink N above control. Treatment of OA cartilage explants with sLink N increased the content of aggrecan and Col II even in the presence of IL-1β.

Our results suggest that sLink N is a growth factor supplement that can increase cartilage matrix protein synthesis, and a chondroprotective agent, by modulating the catabolic effects of IL-1β. sLink N is the first small-peptide to demonstrate potential in cartilage repair of OA joints.

Osteoarthritis (OA) is a debilitating disease characterised by degradation of articular cartilage and subchondral bone remodeling. Current therapies for early or midstage disease do not regenerate articular cartilage, or fail to integrate the repair tissue with host tissue, and therefore there is great interest in developing biological approaches to cartilage repair. We have shown previously that platelet-rich plasma (PRP) can enhance cartilage tissue formation. PRP is obtained from a patient's own blood, and is an autologous source of many growth factors and other molecules which may aid in healing. This raised the question as to whether PRP could enhance cartilage integration. We hypothesise that PRP will enhance integration of bioengineered cartilage with native cartilage.

Chondrocytes were isolated from bovine metacarpal-phalangeal joints, seeded on a porous bone substitute (calcium polyphosphate) and grown in the presence of FBS to form an in vitro model of osteochondral-like tissue. After 7 days, the biphasic constructs were soaked in PRP for 30 minutes prior to implantation into the core of a ring-shaped biphasic explant of native bovine cartilage and bone. Controls were not soaked in PRP. The resulting implant-explant construct was cultured in a stirring bioreactor in serum free conditions for 2 weeks. The integration zone was visualised histologically. A push-out test was performed to assess the strength of integration. Matrix accumulation at the zone of integration was assessed biochemically and the gene expression of the cells in this region was assessed by RT-PCR. Significance (p<0.05) was assessed by a student's t-test or one-way ANOVA with tukey's post hoc.

PRP soaked bioengineered implants, integrated with the host tissue in 73% of samples, whereas control bioengineered implants only integrated in 19% of samples based on macroscopic evaluation (p<0.05). The integration strength, as determined by the normalised maximum force to failure, was significantly increased in the PRP soaked implant group compared to controls (219 +/− 35.4 kPa and 72.0 +/− 28.5 kPa, respectively, p<0.05). This correlated with an increase in glycosaminoglycan and collagen accumulation in the region of integration in the PRP treated implant group, compared to untreated controls after 2 weeks (p<0.05). Immunohistochemical studies revealed that the integration zone was rich in collagen type II and aggrecan. The cells at the zone of integration in the PRP soaked group had a 2.5 fold increase in aggrecan gene expression (p=0.05) and a 3.5 fold increase in matrix metalloproteinase 13 expression (p<0.05) compared to controls.

PRP soaked bio-engineered cartilage implants showed improved integration with native cartilage compared to non-treated implants, perhaps due to the increased matrix accumulation and remodeling at the interface. Further evaluation is required to determine if PRP improves integration in vivo.

Bone marrow-derived mesenchymal stromal stem cells (BMSCs) are a promising cell source for treating articular cartilage defects. Quality of cartilaginous repair tissue following BMSC transplantation has been shown to correlate with functional outcome. Therefore, tissue-engineering variables, such as cell expansion environment and seeding density of scaffolds, are currently under investigation. The objectives of this study were to demonstrate chondrogenic differentiation of BMSCs seeded within a collagen I scaffold following isolation and expansion in two-dimensional (2D) and three-dimensional (3D) environments, and assess the impact of seeding density on in vitro chondrogenesis. It was hypothesised that both expansion protocols would produce BMSCs capable of hyaline-like chondrogenesis with an optimal seeding density of 10 million cells/cm3.

Ovine BMSCs were isolated in a 2D environment by plastic adherence, expanded to passage two in flasks containing expansion medium, and seeded within collagen I scaffolds (6 mm diameter, 3.5 mm thickness and 0.115 ± 0.020 mm pore size; Integra LifeSciences Corp.) at densities of 50, 10, 5, 1, and 0.5 million BMSCs/cm3. For 3D isolation and expansion, bone marrow aspirates containing known quantities of mononucleated cells (BMNCs) were seeded on scaffolds at 50, 10, 5, 1, and 0.5 million BMNCs/cm3 and cultured in expansion medium for an equivalent duration to 2D expansion. All cell-scaffold constructs were differentiated in vitro in chondrogenic medium containing transforming growth factor-beta three for 21 days and assessed with RT-qPCR, safranin O staining, histological scoring using the Bern Score, collagen immunofluorescence, and glycosaminoglycan (GAG) quantification.

Two dimensional-expanded BMSCs seeded at all densities were capable of proteoglycan production and displayed increased expressions of aggrecan and collagen II mRNA relative to pre-differentiation controls. Collagen II deposition was apparent in scaffolds seeded at 0.5–10 million BMSCs/cm3. Chondrogenesis of 2D-expanded BMSCs was most pronounced in scaffolds seeded at 5–10 million BMSCs/cm3 based on aggrecan and collagen II mRNA, safranin O staining, Bern Score, total GAG, and GAG/DNA. For 3D-expanded BMSC-seeded scaffolds, increased aggrecan and collagen II mRNA expressions relative to controls were noted with all densities. Proteoglycan deposition was present in scaffolds seeded at 0.5–50 million BMNCs/cm3, while collagen II deposition occurred in scaffolds seeded at 10–50 million BMNCs/cm3. The highest levels of aggrecan and collagen II mRNA, Bern Score, total GAG, and GAG/DNA occurred with seeding at 50 million BMNCs/cm3.

Within a collagen I scaffold, 2D- and 3D-expanded BMSCs are capable of hyaline-like chondrogenesis with optimal cell seeding densities of 5–10 million BMSCs/cm3 and 50 million BMNCs/cm3, respectively. Accordingly, these densities could be considered when seeding collagen I scaffolds in BMSC transplantation protocols.

With the growing number of individuals with asymptomatic cam-type deformities, elevated alpha angles alone do not always explain clinical signs of femoroacetabular impingement (FAI). Differences in additional anatomical parameters may affect hip joint mechanics, altering the pathomechanical process resulting in symptomatic FAI. The purpose was to examine the association between anatomical hip joint parameters and kinematics and kinetics variables, during level walking.

Fifty participants (m = 46, f = 4; age = 34 ± 7 years; BMI = 26 ± 4 kg/m²) underwent CT imaging and were diagnosed as either: symptomatic (15), if they showed a cam deformity and clinical signs; asymptomatic (19), if they showed a cam deformity, but no clinical signs; or control (16), if they showed no cam deformity and no clinical signs. Each participant's CT data was measured for: axial and radial alpha angles, femoral head-neck offset, femoral neck-shaft angle, medial proximal femoral angle, femoral torsion, acetabular version, and centre-edge angle. Participants performed level walking trials, which were recorded using a ten-camera motion capture system (Vicon MX-13, Oxford, UK) and two force plates (Bertec FP4060–08, Columbus, OH, USA). Peak sagittal and frontal hip joint angles, range of motion, and moments were calculated using a custom programming script (MATLAB R2015b, Natick, MA, USA). A one-way, between groups ANOVA examined differences among kinematics and kinetics variables (α = 0.05), using statistics software (IBM SPSS v.23, Armonk, NY, USA); while a stepwise multiple regression analysis examined associations between anatomical parameters and kinematics and kinetics variables.

No significant differences in kinematics were observed between groups. The symptomatic group demonstrated lower peak hip abduction moments (0.12 ± 0.08 Nm/kg) than the control group (0.22 ± 0.10 Nm/kg, p = 0.01). Sagittal hip range of motion showed a moderate, negative correlation with radial alpha angle (r = −0.33, p = 0.02), while peak hip abduction moment correlated with femoral neck-shaft angle (r = 0.36, p = 0.009) and negatively with femoral torsion (r = −0.36, p = 0.009). With peak hip abduction moment in the stepwise regression analysis, femoral torsion accounted for a variance of 13.3% (F(1, 48) = 7.38; p = 0.009), while together with femoral neck-shaft angle accounted for a total variance of 20.4% (R² change = 0.07, F(2, 47) = 6.01; p = 0.047).

Although elevated radial alpha angles may have limited sagittal range of motion, the cam deformity parameters did not affect joint moments. Femoral neck-shaft angle and femoral torsion were significantly associated with peak hip abduction moment, suggesting that the insertion location of the abductor affects muscle's length and its resultant force vector. A varus neck angle, combined with severe femoral torsion, may ultimately influence muscle moment arms and hip mechanics in individuals with cam FAI.

Fracture or resection of the radial head can cause unbalance and long-term functional complications in the elbow. Studies have shown that a radial head excision can change elbow kinematics and decrease elbow stability. The radial head is also important in both valgus and varus laxity and displacement. However, the effect of radial head on ulnohumeral joint load is not known. The objective of this experimental study was to compare the axial loading produced at the ulnohumeral joint during active flexion with and without a radial head resection.

Ten cadaveric arms were used. Each specimen was prepared and secured in an elbow motion simulator. To simulate active flexion, the tendons of the biceps, brachialis, brachioradialis, and triceps were attached to servo motors. The elbow was moved through a full range of flexion. To quantify loads at the ulnohumeral joint, a load cell was implanted in the proximal ulna. Testing was conducted in the intact then radial head resected case, in supination in the horizontal, vertical, varus and valgus positions.

When comparing the average loads during flexion, the axial ulnar load in the horizontal position was 89±29N in an intact state compared to 122±46N during radial head resection. In the vertical position, the intact state produced a 67±16N load while the resected state was 78±23N. In the varus and valgus positions, intact state resulted in loads of 57±26N and 18±3N, respectively. Conversely, with a radial head resection, varus and valus positions measured 56±23N and 54±23N loads, respectively. For both joint configurations, statistical differences were observed for all flexion angles in all arm positions during active flexion (p=0.0001). When comparing arm positions and flexion angle, statistical differences were measured between valgus, horizontal and vertical (p<0.005) except for varus position (p=0.64).

Active flexion caused a variation in loads throughout flexion when comparing intact versus radial head resection. The most significant variation in ulnar loading occurred during valgus and horizontal flexion. The vertical and varus position showed little variation because the position of the arm is not affected by the loss of the radial head. However, in valgus position, the resected radial head creates a void in the joint space and, with gravity, causes greater compensatory ulnar loading. In the horizontal position, the forearm is not directly affected by gravitational pull and cannot adjust to counterbalance the resected radial head, therefore loads are localised in the ulnohumeral joint. These findings prove the importance of the radial head and that a radial head resection can overload the ulnohumeral side.

Wrist motion is achieved primarily via rotation at the radiocarpal and midcarpal joints. The contribution of each carpal bone to total range of motion has been previously investigated, although there is no consensus regarding the influence of each structure to global wrist motion. The objective of this comprehensive in-vitro biomechanical study was to determine the kinematics of the capitate, scaphoid and lunate during unconstrained simulated wrist flexion-extension. In addition, this study examined the effect of motion direction (i.e. flexion or extension) on the kinematics and contribution of the carpal bones.

Seven fresh frozen cadaveric upper limb specimens (age: 67±18 yrs) were amputated mid-humerus, and the wrist flexors/extensors were exposed and sutured at their musculotendinous junctions. Each specimen was mounted on a wrist motion simulator in neutral forearm rotation with the elbow at 90° flexion. Passive flexion and extension motion of the wrist was simulated by moving a K-wire, inserted into the third metacarpal, through the flexion/extension motion arc at a speed of ∼5 mm/sec under muscle tone loads of 10N. Carpal kinematics were captured using optical tracking of bone fixated markers. Kinematic data was analysed from ±35° flexion/extension.

Scaphoid and lunate motion differed between wrist flexion and extension, but correlated linearly (R^2=0.99,0.97) with capitate motion. In wrist extension, the scaphoid (p=0.03) and lunate (p=0.01) extended 83±19% & 37±18% respectively relative to the capitate. In wrist flexion, the scaphoid (p=1.0) and lunate (p=0.01) flexed 95±20% and 70±12% respectively relative to the capitate. The ratio of carpal rotation to global wrist rotation decreased as the wrist moved from flexion to extension. The lunate rotates on average 46±25% less than the capitate and 35±31% less than the scaphoid during global wrist motion (p=0.01). The scaphoid rotates on average 11±19% less than the capitate during wrist flexion and extension (p=0.07). There was no difference in the contribution of carpal bone motion to global wrist motion during flexion (p=0.26) or extension (p=0.78).

The capitate, lunate and scaphoid move synergistically throughout planar motions of the wrist. Our study found that both the scaphoid and lunate contributed at a greater degree during wrist flexion compared to extension, suggesting that the radiocarpal joint plays a more critical role in wrist flexion. Our results agree with previous studies demonstrating that the scaphoid and lunate do not contribute equally to wrist motion and do not function as a single unit during planar wrist motion. The large magnitude of differential rotation observed between the scaphoid and lunate may be responsible for the high incidence of scapholunate ligament injuries relative to other intercarpal ligaments. An understanding of normal carpal kinematics may assist in developing more durable wrist arthroplasty designs.

Periprosthetic femoral shaft fractures are a significant complication of total hip arthroplasty. Plate osteosynthesis with or without onlay strut allograft has been the mainstay of treatment around well-fixed stems. Nonunions are a rare, challenging complication of this fixation method. The number of published treatment strategies for periprosthetic femoral nonunions are limited. In this series, we report the outcomes of a novel orthogonal plating surgical technique for addressing nonunions in the setting of Vancouver B1 and C-type periprosthetic fractures that previously failed open reduction internal fixation (ORIF).

A retrospective chart review of all patients from 2010 to 2014 with Vancouver B1/C total hip arthroplasty periprosthetic femoral nonunions was performed. All patients were treated primarily with ORIF. Nonunion was defined as no radiographic signs of fracture healing nine months post-operatively, with or without hardware failure. Exclusion criteria included open fractures and periprosthetic infections. The technique utilised a mechanobiologic strategy of atraumatic exposure, resection of necrotic tissue, bone grafting with adjuvant recombinant growth factor and revision open reduction internal fixation. Initially, compression was achieved using an articulated tensioning device and application of an anterior plate. This was followed by locked lateral plating. Patients remained non-weight bearing for eight weeks.

Six Vancouver B1/C periprosthetic femoral nonunions were treated. Five patients were female with an average age of 80.3 years (range 72–91). The fractures occurred at a mean of 5.8 years (range 1–10) from their initial arthroplasty procedure. No patients underwent further revision surgery; there were no wound dehiscence, hardware failures, infections, or surgical complications. All patients had a minimum of nine months follow up (mean 16.6, range 9–36). All fractures achieved osseous union, defined as solid bridging callus over at least two cortices and pain free, independent ambulation, at an average of 24.4 weeks (range 6.1–39.7 weeks).

To our knowledge, this is the first case series describing 90–90 locked compression plating using modern implants for periprosthetic femoral nonunions. This is a rare but challenging complication of total hip arthroplasty and we present a novel solution with satisfactory preliminary outcomes. Orthogonal locked compression plating utilising an articulated tensioning device and autograft with adjuvant osteoinductive allograft should be considered in periprosthetic femur fractures around a well-fixed stem. Further biomechanical and clinical research is needed to improve our treatment strategies in this population.

Large bearing surfaces are appealing in total hip arthroplasty (THA) as they may help create a greater range of impingement free motion and reduce the risk of dislocation. However, attempts to achieve this with a metal bearing surface have been blighted by adverse reactions to metal debris. Ceramic bearings have a good long-term track record in more conventional head sizes, and manufacturing techniques now permit the use of larger ceramic bearing surfaces using monoblock uncemented acetabular components. In this study, we are reviewing the early results of the Maxera® acetabular component (Zimmer, Indiana) at our institution.

All data was collected prospectively. Maxera® acetabular component is a Titanium (Ti) shell with plasma sprayed Ti for the osteointegrative surface. Delta ceramic liner is inserted & locked into the cup shell by the manufacturer (non-modular). With the Maxera cup system, the bearing diameter is dictated by the acetabular component size. Acetabular components (AC) of 46 and 48 mm have a bearing diameter (BD) of 36 mm, AC of 50 and 52 mm: have a 40 mm BD, AC of 54 and 56 mm: have a BD of 44 mm and AC of 58–64: have a 48mm BD. Delta ceramic femoral head size of 44 and 48 mm have a modular Ti sleeve between the head and femoral stem trunnion. Femoral head sizes of 36 and 40 mm have no Ti sleeve. All THA had an uncemented femoral stem. Implants were inserted with a posterior approach. Patients were reviewed at 6 weeks, 6 months and then annually with radiographs. Clinical function was evaluated using WOMAC and UCLA scores along with joint perception questionnaires.

Five hundred components have been implanted in 442 patients (250 women, 192 men) with a mean age of 55, (min 17, max 80) and a mean BMI of 26.9 (min 17.8, max 51). The mean acetabular size was 54 (min 46, max 64), leading to a mean femoral head size of 44. At a minimum of two years follow-up (mean 3.8 years): 5 patients have been revised, 4 secondary to undetected intraoperative fracture of the femur and only one due to early displacement of a Maxera® cup (0.2%). Five patients reported a mild squeaking; two reported clicking and one patient presented with a symptomatic heterotopic ossification. The WOMAC score improved significantly post-operatively, (57.4 compared to 4.4 post-operatively, p<0.001). The mean post-operative UCLA score was 6.9. Sixty percent (60.6%) of patients rated their joint perception as either “natural” or “artificial without limitation”. two patients (0.4%) suffered a dislocation after high velocity trauma without recurrence after closed reduction. No ceramic component fracture was recorded.

This prospective study shows that this monoblock acetabular component provides an easy implantation with minimal complications. The ceramic bearing surface provides good clinical function and joint perception. Bearing surfaces of this design may provide an alternative to large head metal on metal (MoM) implants without the side effects of metal debris/ions.

Tranexamic acid (TEA), an antifibrinolytic agent, is routinely used for reduction of blood loss in total hip arthroplasty (THA). However, use of intravenous (IV) TEA has been questioned due to safety concerns and a lack of biochemical data in the arthroplasty literature. Tranexamic acid given topically as a periarticular solution is a promising alternative route of administration. The purpose of this study is to identify differences in systemic absorption for intravenous and topical TEA administered during primary THA.

In a blinded randomised controlled trial of patients undergoing primary cementless total hip arthroplasty, 29 participants received a weight-based bolus infusion of intravenous TEA (20 mg/kg) 10 minutes prior to skin incision. Conversely, 15 participants received a 1.5 g bolus dose of TEA administered topically into the periarticular region of the operative hip at the time of arthrotomy closure. A blood sample was drawn one hour post-administration for measurement of serum TEA concentration (µg/mL) by tandem mass spectrometry. In addition to comparing mean concentration levels for both treatment arms, each sample concentration was referenced to a pre-determined TEA concentration threshold of 10 µg/mL, a value known to represent 80% tissue plasminogen activator (tPA) inhibition in vivo.

Those participants receiving topical TEA had four-fold lower TEA levels at one hour postoperatively (mean 12.44 ± 17.59 versus 52.54 ± 23.94 µg/mL, p<0.05).

These results demonstrate significantly lower circulating TEA at one hour after topical administration. Intravenous TEA must travel through the intravascular compartment in order to reach the operative hip. Topical administration of TEA targets bleeding tissues within the surgical field without necessitating parenteral administration. This results in less inhibition of tPA away from the operative site, potentially decreasing the risk of developing a pro-thrombotic state postoperatively. Correlating these results with outcomes from clinical efficacy trials comparing intravenous and topical TEA use in THA will further clarify optimal dosing strategies.

Trunnionosis in modular hip arthroplasty has recently been recognised to be clinically important. Gaining an understanding of how the material interface at the head-trunnion affects the tribology at the modular junctions has current clinical implications as well as an implication on future implant selection and material choice. This matched-cohort study aims to compare tribocorrosion between ceramic and cobalt-chromium trunnions and to investigate other factors that contribute to the difference in tribocorrosion if present.

All hip prostheses retrieved between 1999 and 2015 at one centre were reviewed. Fifty two ceramic heads were retrieved, and these were matched to a cobalt-chromium cohort according to taper design, head size, neck length and implantation time in that order. The two cohorts were similar in male:female ratio (p=0.32) and body mass index (p=0.15) though the ceramic group was younger than the cobalt-chromium group (56.6 (+/−)13.5 years for ceramic group vs 66.3 (+/−14.4) years for cobalt-chromium group; p=0.001). There was no significant difference in the reasons for revision between the two groups (p=0.42). The femoral head trunnions were examined by two independent observers using a previously published 4-point scoring technique. The trunnions were divided into three zones: apex, middle and base. The observers were blinded to clinical and manufacturing data where possible.

Ceramic head trunnions demonstrated a lower median fretting and corrosion score at the base zone (p<0.001), middle zone (p<0.001) and in the combined score (p<0.001). In a subgroup analysis by head size, ceramic heads had a lower fretting and corrosion score at 28mm head diameter (p<0.001). Within the ceramic group, taper design had a significant effect on fretting and corrosion in the apex zone (p=0.04). Taper design also had a similar effect in the cobalt-chromium group in the apex zone (p=0.03). For the ceramic trunnions, the largest effect was contributed by the difference between the 11/13 taper and the 12/14 taper. For the cobalt-chromium trunnions, the largest effect was contributed by the difference between the 5 degree 38′ 37″ taper and type 1 taper.

Ceramic head trunnions showed a significantly lower fretting and corrosion score as compared to cobalt-chromium trunnions. Ceramic heads had a lower score than cobalt-chromium heads at 28mm head diameter. Taper design had an effect on fretting and corrosion within each cohort.

Total joint arthroplasty is commonly associated with post-operative anemia. Blood conservation programs have been developed to optimise patients prior to surgery. Epoetin Alfa (Eprex) or intravenous (IV) iron transfusions are two modalities that can be used pre-operatively to optimise hemoglobin and ferritin levels. There are, however, potential complications and increased costs associated with their use. Oral iron is a less costly option for those undergoing surgery but requires more time to take effect. There are no studies to date that examine the effects of an early screening program utilising oral iron supplementation prior to total joint arthroplasty. The purpose of this study is to evaluate the effect of implementing early pre-operative oral iron supplementation on patients prior total joint arthroplasty.

A retrospective review of patients undergoing total joint arthroplasty was performed using our institution clinical informatics database. We identified all patients seen in pre-admission clinic (PAC) between Jan 1, 2009 and March 31, 2010 representing our control group. We then identified all patients seen in PAC between October 1, 2012 and December 31, 2013. Patients in this cohort received screening blood work when booked for surgery, and oral iron supplementation was given to patients with hemoglobin of less than 135g/L or ferritin less than 100ug/L, thus representing our treatment group. Patients undergoing revision, uni-compartment knee arthroplasty and bilateral arthroplasties were excluded from the study. Pearson Chi-Square tests were used to calculate significance between groups with main outcomes including pre-admission hemoglobin, and pre-operative requirements for Eprex or IV iron.

In our control group, we identified 354 patients (25.6%) with hemoglobin less than 130 g/L at time of pre-admission clinic. In our treatment group, this number dropped significantly to only 16.4% of patients (p<0.005).

Implementation of an early screening program using oral iron supplementation resulted in a decrease in the number of patients with hemoglobin lower than 130 g/L at the time of pre-admission clinic. There was also a significant decrease in the use of Eprex and IV iron pre-operatively in the patients in the early screening program. These results encourage the use of early oral iron supplementation for patients with hemoglobin less than 135 g/L or ferritin less than 100ug/L in order to optimise patients prior to total joint arthroplasty.

Studies that have previously examined the relationship between inclination angle and polyethylene wear have shown increased wear of conventional polyethylene with high inclination angles. To date, there have been no long term in vivo studies examining the correlation between cup position and polyethylene wear with highly crosslinked polyethylene.

An institutional arthroplasty database was used to identify patients who had metal-on-highly crosslinked polyethylene primary total hip arthroplasty (THA) using the same component design with a minimum follow up of 10 years ago. A modified RSA examination setup was utilised, recreating standard anteroposterior (AP) and cross-table lateral exams in a single biplane RSA acquisition. Three dimensional head penetration was measured using the centre index method. The same radiographs were used to measure inclination angle and anteversion. Spearman correlation was used to show an association between the parameters of acetabular position and wear rate.

A total of 43 hips were included for analysis in this study. Average follow-up was 12.3 ± 1.2 years. The average linear wear rate was calculated to be 0.066 ± 0.066 mm/year. Inclination angle was not correlated with polyethylene wear rate (p=0.82). Anteversion was also not correlated with polyethylene wear rate (p=0.11). There was no statistical difference between wear rates of hips within Lewinnek's “safe zone” and those outside this “safe zone” (p=0.11). Males had a higher wear rate of 0.094 ± 0.089 mm/year compared to females with a wear rate of 0.046 ± 0.032 mm/year (p=0.045).

At long term follow up of greater than 10 years, highly cross linked polyethylene has very low wear rates. This excellent tribology is independent of acetabular position, but gender did impact wear rates. Due to the low wear rates, follow-up of even longer term is suggested to examine variables affecting wear.

Enhanced Recovery After Surgery (ERAS) is a multimodal perioperative care pathway designed to achieve early recovery for patients undergoing major surgery. ERAS allows for the incorporation of evidence based practices and incorporated a comprehensive assessment of the patient's journey through the surgical process from pre-operative screening through to post-operative care. The purpose of this study was to determine if optimisation of ERAS protocol with pre-operative screening and incorporating patient-specific factors into their post operative care would improve length of stay (LOS) and readmission rates following total joint arthroplasty (TJA) in a Canadian community hospital setting.

The study collected clinical, demographic data and the physical status perioperative using the American Society of Anaesthesiologists (ASA) classification on 508 patients who underwent TJA between January and August 2015 and compared similar data from the same time frame in the previous calendar year prior to implementation of the pathway. Cohorts were analysed for length of stay (LOS), readmission rates, Pre-operative assessments (completed by anaesthesia, nursing and pharmacy), relevant labs, patient history (surgery, medical, social), and patient values were all considered when developing a specific patient plan for care post-operatively. A post-operative management tool was used to optimise pain control, post-operative nausea and vomiting, bowel management, diabetes blood glucose control, venous thromboembolism prophylaxis, as well as monitoring parameters specific to patient medical history (e.g. respiratory, cardiac). While in hospital, physiotherapy and nursing were consulted by the pharmacist to assess whether patient's post op management needed to be altered to optimise mobilisation and recovery in hospital. The average patient's LOS and readmission rates in 30 days was analysed to assess the change after implementation of the post-operative management tool based on patient specific factors.

A total of 508 patients (mean age: 66 years), ASA classification was 3 or greater for 430 patients. The patients were assessed for LOS, readmission rates in 30 days. The mean LOS decreased from 3.6 to 3.3 days after optimisation of the ERAS protocol (student t test p=0.021). The 30-day readmission rate decreased from 2.9% to 1.4% post intervention (z test p=0.087) when compared to the same time period in the previous calendar year prior to protocol implementation. Overall, the cost savings to optimising the ERAS protocol for the hospital is substantial; with approximately $238 saved per patient.

Pre-operative screening and incorporating patient-specific factors into an individualised care plan to optimise the ERAS protocol for TJA reduced mean length of stay without a concomitant increase in readmission rates with significant cost saving.

Modular total hip arthroplasty (MTHA) stems were introduced in order to provide increased intra-operative flexibility for restoring hip biomechanics, improving stability and potentially reducing revision risk. However, the additional interface at the neck-body junction provides another location for corrosion or mechanical failure of the stem. To delineate the mid term revision risk of MTHA stems, we examined data from the Canadian Joint Replacement Registry (CJRR) at the Canadian Institute for Health Information (CIHI).

Kinectiv, Profemur and Rejuvenate modular stems were identified from CJRR records submitted between 2004 and 2014. Revision status was determined by examining the discharge abstract database (DAD) also housed by CIHI, which collects information on all revisions, regardless of whether the procedure was submitted to CJRR.

A total of 2446 modular stems were identified with a mean follow up of 4.2 years (range 0 to 10). Their usage peaked in 2012 (the first year of mandatory CJRR form submission for BC, ON and MB), and dropped rapidly thereafter. A total of 155 (6.3%) were revised. This consisted of 5/301 Kinectiv (1.7%), 141/2050 ProFemur (6.9%), and 9/96 Rejuvenate (9.4%) stems. As a group, this falls below the National Institute for Clinical Excellence (NICE) guidelines of 95% survival at 10 years.

While MTHA stems were introduced to improve outcomes and reduce revision risk, our findings of a 6.3% revision risk at a mean follow up of 4.2 years does not appear to support this.

The advent of highly cross-linked polyethylene has resulted in improved wear rates and reduced osteolysis with at least intermediate follow-up when compared to conventional polyethylene. However, the role of alternative femoral head bearing materials in decreasing wear is less clear. The purpose of this study was to determine in-vivo polyethylene wear rates across ceramic, Oxinium, and cobalt chrome femoral head articulations.

A review of our institutional database was performed to identify patients who underwent a total hip arthroplasty using either ceramic or oxidised zirconium (Oxinium) femoral head components on highly cross-linked polyethylene between 2008 and 2011. These patients were then matched on implant type, age, sex and BMI with patients who had a cobalt chrome bearing implant during the same time period. RSA analysis was performed using the centre index method to measure femoral head penetration (polyethylene wear). Secondary quality of life outcomes were collected using WOMAC and HHS Scores. Paired analyses were performed to detect differences in wear rate (mm/year) between the cobalt chrome cohorts and their matched ceramic and Oxinium cohorts. Additional independent group comparisons were performed by analysis of variance with the control groups collapsed to determine wear rate differences between all three cohorts.

A total of 68 patients underwent RSA analysis. Fifteen patients with a ceramic femoral head component and 14 patients with an Oxinium femoral head component along with the same number of matched patients with cobalt chrome femoral head component were included in the analysis. The time in vivo for the Oxinium (5.17 +/− 0.96 years), Oxinium matched cohort (5.13 +/− 0.72 years), ceramic (5.15 +/− 0.76 years) and ceramic matched cohort (5.36 +/− 0.63 years) were comparable. The demographics of all bearing surface cohorts were similar. The paired comparison between the Oxinium and cobalt chrome cohorts (0.33 vs. 0.29 mm/year, p=0.284) and ceramic vs cobalt chrome cohorts (0.26 vs. 0.20 mm/year, p=0.137) did not demonstrate a significant difference in wear rate. The independent groups analysis revealed a significantly higher wear rate of Oxinium (0.33 mm/year) compared to cobalt chrome (0.24 mm/year) (p = 0. 038). There were no differences in HHS and WOMAC scores between the Oxinium and cobalt chrome cohorts (HHS: p = 0.71, WOMAC: p=0.08) or the ceramic and cobalt chrome cohorts (HHS: p=0.15, WOMAC: p=023).

This study presents evidence of a greater wear rate (mm/year) of the Oxinium femoral head component compared to a cobalt chrome femoral head component. This difference was not demonstrated in the ceramic femoral head component. Despite this difference, there were no clinical differences as measured by the HHS and WOMAC. Future research should focus on factors that may contribute to the higher wear rate seen in the Oxinium cohort.

Total hip arthroplasty (THA) has become one of the most commonly performed elective procedures. Today, there are nearly 50 000 annual hospitalisations for hip replacement surgery in Canada. This number is projected to increase significantly with the aging population. Periprosthetic joint infection (PJI) is the 3rd leading cause of failure following THA and is reported to occur at an incidence of 1–3%. A two-stage re-vision THA is the current gold standard treatment and this has a tremendous economic impact on the healthcare system. The purpose of this study is to create an accurate cost estimate of two-stage revision THA and, in turn, evaluate the economic burden of PJI as it compares to primary THA in a Canadian healthcare context.

We conducted a retrospective review of primary THA cases and two-stage revision THA for PJI at our institution. Patients were matched for age and BMI. We recorded all costs associated with each procedure, including: OR time, equipment, length of hospital stay, readmission rates, and any other inpatient resource use. Unit costs were obtained using administrative data from the case costing department at London Health Sciences Centre. Billing fees associated with the procedure were obtained from the Ontario Schedule of Benefits. Descriptive statistics were used to summarise the demographic characteristics of patients, hospital costs and resource use data. Patients with PJI were compared to the matched cohort of primary THA using the t-test (for continuous variables), and the chi-square test (for categorical variables).

Twenty consecutive cases of revision THA were matched to 20 patients who underwent uncomplicated primary THA between 2006 and 2014. Periprosthetic infection was associated with a significant increase in hospital stay (26.5 vs. 2.0; p<0.001), clinic visits (9.5 vs. 3.8; p<0.001), readmission rates (12 vs. 1; p<0.001) and overall cost ($39 953 vs. $7 460; p<0.001) in comparison to the primary arthroplasty cohort.

Two-stage revision for infected THA is a significant economic burden to the healthcare system. Our data suggests a 5-fold increase in healthcare cost when compared to primary THA. This may be an important consideration when distributing resources among Canadian tertiary care centres.

The philosophy of cemented total hip arthroplasty (THA) femoral components has become polarised. At one extreme are polished, collarless, tapered devices that are expected to subside; at the other extreme are roughened, non-tapered implants with a collar designed not to subside. Radiostereometric analysis (RSA) allows the accurate measurement of implant movement and has been extensively used for measurement of the in vivo migration of implants. The degree of migration as measured by RSA during the first years after surgery has been shown to correlate with the long-term performance of cemented femoral implants. The purpose of this study was to review the two-year RSA results of two different designs of primary cemented THA stems.

Data from two previous prospective RSA trials with two-year follow-up were pooled. The first group included 36 patients who received a Spectron (Smith & Nephew, Memphis, USA) cemented stem. The second group included 13 patients who received an Exeter (Stryker, Mahwah, USA) cemented stem, and 15 patients who received a CPCS (Smith & Nephew, Memphis, USA) cemented stem. All patients underwent RSA examinations shortly post-operation, at 6 weeks, 3 months, 6 months, 1 years, and 2 years. Migration and rotation of the femoral stems was measured at each time point relative to the post-operative exam, and compared between the two groups.

There was no difference in age at surgery (Spectron 78 ± 6 years, Exeter/CPCS 77 ± 5 years, p = 0.43), BMI (Spectron and Exeter/CPCS 28 ± 5 kg/m2, p = 0.92), or percentage of male patients (Spectron 23% male, Exeter/CPCS 21% male) between the implant groups. Subsidence was significantly greater (p < 0.0001) at all time points from three months to two years for the Exeter and CPCS stems (0.94 ± 0.39 mm at two years) compared to the Spectron stem (0.05 ± 0.16 mm at two years). There was no significant difference between the stem types for medial-lateral translation (p = 0.07) or anterior-posterior translation (p = 0.49), or for anterior-posterior tilt (p = 0.15), internal-external rotation (p = 0.89), or varus-valgus rotation (p = 0.05).

Implant material, design, and surface finish are all factors in the long-term performance of cemented femoral hip implants. In this study, both femoral stem designs had a magnitude of sub-sidence that was within the limits of what is considered to be safe with respect to long-term performance. The continuous subsidence of the Exeter and CPCS stems is consistent with previous reports in the literature.

Calcification of the intervertebral disc (IVD) has been correlated with degenerative disc disease (DDD), a common cause of low back pain. The appearance of calcium deposits has been shown to increase with age, and its occurrence has been associated with several other disorders such as hyperparathyroidism, chondrocalcinosis, and arthritis. Trauma, vertebral fusion and infection have also been shown to increase the incidence of IVD calcification. The role of IVD calcification in the development DDD is unknown. Our preliminary data suggest that ionic calcium content and expression of the extracellular calcium-sensing receptor (CaSR), a G protein-coupled receptor (GPCR) and regulator of calcium homeostasis, are increased in the degenerated discs. However, its role in DDD remains unclear.

IVD Cells: Bovine and normal human IVD cells were incubated in PrimeGrowth culture medium (Wisent Bioproducts, Canada; Cat# 319–510-CL, −S1, and S2) and supplemented with various concentrations of calcium (1.0, 1.5, 2.5, 5.0 mM), a CaSR agonist [5 µM], or IL-1β [10 ng/ml] for 7 days. Accumulated matrix protein was quantitated for aggrecan and type II collagen (Col II) by Western blotting. Conditioned medium was also collected from cells treated for 24h and measured for the synthesis and release of total proteoglycan using the DMMB assay and Western blotting for Col II content. IVD Cultures: Caudal IVDs from tails of 20–24 month old steers were isolated with the PrimeGrowth Isolation kit (Wisent Bioproducts, Canada). IVDs were cultured for 4 weeks in PrimeGrowth culture medium supplemented with calcium (1.0, 2.5, or 5.0 mM), or a CaSR agonist [5 µM]. Cell viability was measured in NP and AF tissue using Live/Dead Imaging kit (ThermoFisher, Waltham, MA), to determine if Ca2+ effects cell viability end the expression of aggrecan and Col II was evaluated in the IVD tissue by Western blotting. Histological sections were prepared to determine total proteoglycan content, alkaline phosphatase expression and degree of mineralisation by von Kossa staining.

The accumulation of aggrecan and Col II decreased dose-dependently in IVD cells following supplementation with calcium or the CaSR agonist. Conditioned medium also demonstrated decreases in the synthesis and release of proteoglycan and collagen with increasing Ca2+ dose or direct activation of the CaSR with agonist. A similar phenomenon was observed for total proteoglycan and aggrecan and Col II in IVDs following calcium supplementation or the CaSR agonist. In addition to decreases in Col II and aggrecan, increases in alkaline phosphatase expression and mineralisation was observed in IVDs cultured in elevated Ca2+ concentrations without affecting cell viability.

Our results suggest that changes in the local concentrations of calcium are not benign, and that activation of the CaSR may be a contributing factor in IVD degeneration. Determining ways to minimise Ca2+ infiltration into the disc may mitigate disc degeneration.

Strain is a robust indicator of bone failure initiation. Previous work has demonstrated the measurement of vertebral trabecular bone strain by Digital Volume Correlation (DVC) of µCT scan in both a loaded and an unloaded configuration. This project aims to improve previous strain measurement methods relying on image registration, improving resolution to resolve trabecula level strain and to improve accuracy by applying feature based registration algorithms to µCT images of vertebral trabecular bone to quantify strain. It is hypothesised that extracting reliable corresponding feature points from loaded and unloaded µCT scans can be used to produce higher resolution strain fields compared to DVC techniques.

The feature based strain calculation algorithm has two steps: 1) a displacement field is calculated by finding corresponding feature points identified in both the loaded and unloaded µCT scans 2) strain fields are calculated from the displacement fields. Two methods of feature point extraction, Scale Invariant Feature Transform (SIFT) and Skeletonisation, were applied to unloaded (fixed) and loaded (moving) µCT images of a rat tail vertebra. Spatially non-uniform displacement fields were generated by automatically matching corresponding feature points in the unloaded and loaded scans. The Thin Plate Spline method and a Moving Least Squares Meshless Method were both tested for calculating strain from the displacement fields. Verification of the algorithms was performed by testing against known artificial strain/displacement fields. A uniform and a linearly varying 2% compressive strain field were applied separately to an unloaded 2D sagittal µCT slice to simulate the moving image.

SIFT was unable to reliably match identified feature points leading to large errors in displacement. Skeletonisation generated a more accurate and precise displacement field. TPS was not tolerant to small displacement field errors, which resulted in inaccurate strain fields. The Meshless Methods proved much more resilient to displacement field errors. The combination of Skeletonisation with the Meshless Method resulted in best performance with an accuracy of −405µstrain and a detection limit of 1210µstrain at a strain resolution of 221.5µm. The DVC algorithm verified using the same validation test yielded a similar detection limit (1190µstrain), but with a lower accuracy for the same test (2370µstrain) for a lower resolution strain field (770µm) (Hardisty, 2009).

The Skeletonisation algorithm combined with the Meshless Method calculated strain at a higher resolution, but with a similar detection limit, to that of traditional DVC methods. Future improvements to this method include the implementation of subpixel feature point identification and adapting this method of strain measurement into a 3D domain. Ultimately, a hybrid DVC/feature registration algorithm may further improve the ability to measure trabecular bone strain using µCT based image registration.

Testing potential therapeutics in the regeneration of the disc requires the use of model systems. Although several animal models have been developed to test intervertebral disc (IVD) regeneration, application becomes costly when used as a screening method. The bovine IVD organ culture system offers an inexpensive alternative, however, in the current paradigm, the bony vertebrae is removed to allow for nutrient diffusion to disc cells. This provides limitations on the conditions and strategies one can employ in investigating IVD regeneration and mechanisms in degenerative disc disease (i.e. complex loading). Although one method has been attempted to extend the survival of bovine vertebrae containing IVDs (vIVD) cell viability declined after two weeks in culture. Our goal was to develop and validate a long-term organ culture model with vertebral bone, which could be used subsequently for studying biological repair of disc degeneration and biomechanics.

Preparation of vIVDs: Bovine IVDs from the tails of 22–28-month-old steers were prepared for organ culture by parallel cuts through the adjacent vertebral bodies at 1cm from the endplates using an IsoMet®1000 Buehler precision sectioning saw. vIVDs were split into two groups: IVDs treated with PrimeGrowth Media kit (developed by Intervertech and licensed to Wisent Bioproducts) and IVDs with DMEM. The PrimeGrowth group was incubated for 1h in PrimeGrowth Isolation Medium (Cat# 319–511-EL) and the DMEM group for 1h in DMEM. After isolation, IVDs were washed in PrimeGrowth Neutralisation Medium (Cat# 319–512-CL) while the other IVDs were washed in DMEM. The discs isolated with PrimeGrowth and DMEM were cultured for up to 5 months in sterile vented 60 ml Leakbuster™ Specimen Containers in PrimeGrowth Culture Medium (Cat# 319–510-CL) and DMEM with no mechanical load applied. Live/Dead Assay: vIVDs cultured for 1 or 5 months were dissected and cell viability was assessed in different regions by confocal microscopy using Live/Dead® (Invitrogen) fluorescence assay. Glucose Diffusion: After one month of culture, vIVDs were incubated for 72h in diffusion medium containing PBS (1x), CaCl2 (1mM), MgCl2 (0.5mM), KCl2 (5mM), 0.1% BSA and 150µM 2-NDBG, a D-glucose fluorescent analogue. Discs were dissected and IVD tissues were incubated in guanidinium chloride extraction buffer. Extracts were measured for fluorescence.

After 5 months in culture, vIVDs prepared with PrimeGrowth kit demonstrated approximately 95% cell viability in all regions of the disc. However, dramatic reductions (∼90%) in vIVD viability were measured in DMEM group after 1 month. vIVD viability was related to the amount of 2-NDBG incorporated into the disc tissue.

We have developed a novel method for isolating IVDs with vertebral bone capable of long-term viability. This method may not only help in the discovery of novel therapeutics in disc regeneration, but could also advance our understanding on complex loading paradigms in disc degeneration.

Most long-term follow-up studies report retrospective data, the quality of which remains limited due to their inherent biases. Prospective databases may overcome these limitations, however, feasibility and costs limit their application. To date there exists a paucity of evidence-based literature on which recommendations can be made for the ideal length of follow-up for spinal deformity research. Therefore, our aim was to evaluate the added value of follow-up of patients beyond 2 years following surgery for AIS.

A database registry evaluating surgical outcomes for all consecutive AIS patients with post-op data-points of 6 months, 1 year, 2 year, and 5 year was analysed. Surgeon-reported complications, SRS-22 scores, and radiographic data were evaluated. Complications requiring surgical or medical intervention were compared between patients in whom complications developed within 2 years to those in which newly developed complications occurred between >2–5 years.

536 patients were analysed. SRS-22 scores significantly improved at 2 years post-op with no change at 5-year follow-up. Overall complication rate was 33.2% with majority occurring within 2 years (24.8%). The rate of complications occurring >2–5 years requiring intervention was significantly lower than those requiring intervention within 2 years of surgery (4.7% vs 9.7%, p=0.000), however was not negligible. The most common newly observed complication beyond 2 years was pain (1.9%), followed by surgical site infection (SSI) (1.3%) and implant issues (0.56%). There were no significant differences in the rates of crankshaft (p=0.48), implant issues (p=0.56), pseudarthrosis (p=0.19), and SSI (p=0.13) between the 2 time points.

Although majority of complications following AIS surgery occurs within 2 years, a non-negligible rate of newly observed complications occur at >2–5 years post-op. Specifically crankshaft, pseudarthrosis, implant issues, and SSI have similar rates of occurrence at these 2 time points.

Referral patterns in spine clinic of young patients with suspected scoliosis is suboptimal with 19% of late referrals and 42% of inappropriate referrals. Patients' triage and prioritisation in spine clinic is a strategy to ensure that health care allocation is done according to the level of health needs, favoring effective management and efficient use of health care resources use. The objective of the study is to elaborate a model for triage and prioritisation of young patients in spine clinic based on expert consensus and literature on best practices.

This projects was structured in three parts: 1)We documented best evidence. We conducted a review of empirical studies evaluating triage and prioritisation initiatives in order to identify key components for intervention success. 2)We elaborate a model of health care delivery with the professionals of a local paediatric spine clinic. In this model, the triage and prioritisation algorithm was developed from list of potential factors (demographics, signs and perceived symptoms, provisional diagnoses and known co-morbidities, results of preliminary physical examination and radiological findings) that was submitted to five paediatric orthopaedic surgeons for rating according to their potential relevance to orient prioritisation decisions. 3) We compared the professionals' model of health care delivery to the literature synthesis in order to propose the best model.

Seven key components of triage and prioritisation systems were identified: centralised review of referral requests, list of consensual objectives criteria for triage, fast track evaluation of urgent cases, selection of cases for management at point of triage, cases prioritisation to main consultant, multidisciplinary evaluation and alternatives pathways. The consensual decision algorithm confirmed that cases who should be seen in priority are immature patients presenting with a significant trunk deformity. In addition, presence of persisting neurological symptoms, severe incapacitating pain or night pain, as well as abnormal scan or MRI findings were considered as urgent/PI priority. Cases characteristics for evaluation by nurse practitioners as well as alternative pathways of management were defined. Acceptability, compatibility, clinical relevance and discriminant capacity of the new model of health care delivery were satisfactorily demonstrated.

Consensus was easily reached between the five respondents on factors supporting decisions to prioritise patients in spine clinic for suspected spinal deformity. Refinements to the initially proposed model according the identified key features from the literature, led to a final model of health care delivery that is evidence-base, feasible and coherent with the local context. Future implementation of this model should facilitate timely and appropriate health care delivery and best use of health care resources according to patients' needs.

The objective of this paper is to demonstrate the difference in post-operative complication rates between Computer-assisted surgery (CAS) and conventional techniques in spine surgery. Several studies have shown that the accuracy of pedicle screw placement significantly improves with use of CAS. Yet, few studies have compared the incidence of post-operative complications between CAS and conventional techniques.

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients that underwent posterior lumbar fusion from 2011 to 2013. Multivariate analysis was conducted to demonstrate the difference in post-operative complication rates between CAS and conventional techniques in spine surgery.

Out of 15,222 patients, 14,382 (95.1%) were operated with conventional techniques and 740 (4.90%) were operated with CAS. Multivariate analysis showed that patients in the CAS group had less odds to experience adverse events post-operatively (OR 0.57, P <0.001).

This paper examined the complications in lumbar spinal surgery with or without the use of CAS. These results suggest that CAS may provide a safer technique for implant placement in lumbar fusion surgeries.

Adverse events (AEs) following spine surgery are very common. It is important to monitor the incidence of AEs to ensure that appropriate practices are implemented to minimise AEs and improve patient outcomes. The Spine Adverse Events Severity System (SAVES) is a validated AE recording tool specifically designed for spine surgery and the Orthopaedic Surgical Adverse Events Severity System (OrthoSAVES) is a similar tool intended for general orthopaedic surgery. The main objective was to prospectively collect AE data from spine surgery patients using SAVES and OrthoSAVES and compare their viability and applicability for use. The longterm objective is to enhance patient safety by tracking AEs with a view towards potentially changing future healthcare practices to eliminate the risk factors for AEs.

For a 10-week period in June-September 2015, three spine surgeons used SAVES to record AEs experienced by any elective spine surgery patients. In addition, a trained independent clinical reviewer with access to electronic records, medical charts, and allied health professionals (e.g. nurses, physioterhapists) used SAVES and OrthoSAVES to record AEs for the same patients. At discharge, the SAVES forms from the surgeons and SAVES and OrthoSAVES forms from the independent reviewer were collected and all AEs were recorded in a database.

In 48 patients, the independent reviewer recorded a total of 45 AEs (4 intra-operative, 41 post-operative), compared to the surgeons who recorded a total of 8 AEs (2 intra-operative, 6 post-operative) (P2) were recorded by both the independent reviewer and surgeons. OrthoSAVES had the capacity to directly record 3 additional AEs that had to be included in the “Other” section on SAVES.

SAVES and OrthoSAVES are valuable tools for recording AEs. Use of SAVES and OrthoSAVES has the potential to enhance patient care and safety by ensuring AEs are followed by the surgeon during their in-hospital stay and prior to discharge. Independent reviewers are more effective at capturing AEs following spine surgery, and thus, could be recruited in order to capture more AEs and maximise different complication diagnoses in alignment with proposed diagnosis-based funding models. The next step is to analyse AE data identified by the hospital discharge abstract to determine whether retrospective administrative coding can adequately record AEs compared to prospectively-collected AE data with SAVES/OrthoSAVES.

Cervical spine fusion have gained interest in the literature since these procedures are now ever more frequently being performed in an outpatient setting with few complications and acceptable results. The purpose of this study was to assess the rate of blood transfusion after cervical fusion surgery, and its effect, if any on complication rates.

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients that underwent cervical fusion surgery from 2010 to 2013. Univariate and multivariate regression analysis was used to determine post-operative complications associated with transfusion and cervical fusion.

We identified 11,588 patients who had cervical spine fusion between 2010 and 2013. The overall rate of transfusion was found to be 1.47%. All transfused patients were found to have increased risk of: venous thromboembolism (TBE) (OR 3.19, CI: 1.16–8.77), myocardial infarction (MI) (OR 9.12, CI: 2.53–32.8), increased length of stay (LOS) (OR 28.03, CI: 14.28–55.01) and mortality (OR 4.14, CI: 1.44–11.93). Single level fusion had increased risk of: TBE (OR 3.37, CI: 1.01–11.33), MI (OR 10.5, CI: 1.88–59.89), and LOS (OR 14.79, CI: 8.2–26.67). Multilevel fusion had increased risk of: TBE (OR 5.64, CI: 1.15–27.6), surgical site infection (OR 16.29, CI: 3.34–79.49), MI (OR 10.84, CI: 2.01–58.55), LOS (OR 26.56, CI: 11.8–59.78) and mortality (OR 10.24, CI: 2.45–42.71). ACDF surgery had an increased risk of: TBE (OR 4.87, CI: 1.04–22.82), surgical site infection (OR 9.73, CI: 2.14–44.1), MI (OR 9.88, CI: 1.87–52.2), LOS (OR 28.34, CI: 13.79–58.21) and mortality (OR 6.3, CI: 1.76–22.48). Posterior fusion surgery had increased risk of: MI (OR 10.45, CI: 1.42–77.12) and LOS (OR 4.42, CI: 2.68–7.29).

Our results demonstrate that although cervical fusions can be done as outpatient procedures special precautions and investigations should be done for patients who receive transfusion after cervical fusion surgery. These patients are demonstrated to have higher rate of MI, DVT, wound infection and mortality when compared to those who do not receive transfusion.

Although patient-reported outcomes (PROs) have become increasingly important in the evaluation of spine surgery patients, interpretability may be limited by a patient's ability to recall pre-intervention impairment. The accuracy of patient recall of preoperative back pain, leg pain, and disability after spine surgery remains unknown. We sought to characterise the accuracy of patient recall of preoperative symptoms in a cohort of lumbar spine surgery patients.

We analysed consecutive patients undergoing lumbar decompression or decompression and fusion for lumbar radiculopathy by a single surgeon over a four-year period. Using standardised questionnaires, we recorded back and leg numeric pain scores (NPS) and Oswestry Disability Indices (ODI) preoperatively and asked patients to recall their preoperative status at a minimum of one-year following surgery. We then statistically compared and characterised patient recall of their pre-operative status and their actual pre-operative status. Patients with incomplete follow up or diagnoses other than degenerative lumbar stenosis were excluded.

Sixty-seven patients with a mean age of 66.1 years (55% female) were included in the final analysis. All cases were either posterior or combined anterior/ posterior procedures. Mean levels of surgery was 1.7 and 93.8% of all cases were instrumented. Mean duration of preoperative symptoms was 44.5 months (3.7 years). Preoperative vs postoperative PROs improved with regards to NPS back (5.2 vs 2.2, p= to 2 point difference), exceeding the minimal clinical important difference (MCID) for NPS. This pattern was maintained across age, gender, and duration of preoperative symptoms. We also observed cases of symptom minimisation recall bias, and cases in which back and leg pain predominance were switched in severity during recall bias.

Significant recall bias of preoperative symptoms exists in patients undergoing spine surgery, potentially limiting accurate assessment and interpretation of PROs. An understanding of PROs and their limitations is essential to assess treatment efficacy of spinal procedures.

Natural history of AIS >30° in skeletally mature patients is poorly defined. Studies reporting rates and risk factors for progression are predominantly of large curves in immature patients. Our aim was to determine the rate of curve progression in AIS following skeletal maturity, any associated changes in SRS-22 scores, and identify any potential predictors of curve progression.

Patients enrolled in a prospective, longitudinal, multicentre non-surgical AIS database were evaluated. All patients had minimum 2 year follow-up, idiopathic scoliosis >30°, and were skeletally mature. SRS-22 functional outcome scores and radiographic data were compared at baseline and 2-year follow-up. Patients were divided into 3 groups based on curve size: A=30°-39°, B=40°-49°, C= >50°. Curve progression was defined as any change in curve magnitude.

There were 80 patients, majority females (93.8%) with a mean age of 16.5+/−0.16. Mean BMI was 21+/−0.31 with 15.1% overweight. Mean major cobb at baseline was 38.3°+/−0.88°. At 2 year follow-up 46.3% of curves had progressed an average 3.4°+/−0.38°. Of curves that progressed, patients in group A had the largest mean rate of progression followed by group B. SRS-22 scores on average declined significantly over 2 years in this cohort (4.23 to 4.08; p=0.002). Patients who progressed had on average a more significant decline in SRS outcome scores compared to those that did not (p=0.018, p=0.041 respectively), with the most significant change noted in the Self-Image domain (p=0.03). There was no significant difference in the change in SRS scores over 2 years based on curve size. Univariate analysis did not identify any factors predictive of curve progression in this cohort.

Skeletally mature patients with AIS >30°may continue to have a risk of progression at a mean rate of 1.7°/yr and significant decline in SRS-22 outcome scores, in particular Pain and Self-Image, over time.

Hemorrhage and transfusion requirements in spine surgery are common. This is especially true for thoracic and lumbar fusion surgeries. The purpose of this papersi to determine predictive factors for transfusion and their effect on short-term post-operative outcomes for thoracic and lumbar fusions.

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients that underwent lumbar or thoracic fusion surgery from 2010 to 2013. Univariate and multivariate regression analysis was used to determine predictive factors and post-operative complications associated with transfusion.

A total of 14,249 patients were included in this study; 13,586 had lumbar fusion and 663 had thoracic fusion surgery. The prevalence of transfusion was 35% for thoracic fusion and 17.5% for lumbar fusion. The multivariate analysis showed that age between 50–60 (OR 1.38, CI: 1.23–1.54), age between 61–70 (OR 1.65, CI: 1.40–1.95), dyspnea (OR 1.11, CI: 1.02–1.23), hypertension (OR 1.14, CI: 1.02–1.27), ASA class (OR 1.73, 1.18–1.45), pre-operative blood transfusion (OR 1.91, CI: 1.04–3.49), and extended surgical time (OR 4.51, CI: 4.09–4.98) were predictors of blood transfusion requirements for lumbar fusion. While only pre-operative BUN (OR 1.04, CI: 1.01–1.06) and extended surgical time (OR 4.70, CI: 3.12–6.96) were predictors of transfusion for thoracic fusion. In contrast, higher pre-operative hematocrit was protective against transfusion. Patients transfused who underwent lumbar fusion had an increased risk to develop superficial wound infection, deep wound infection, venous thromboembolism, myocardial infarction and had longer length of hospital stay. Patients transfused who underwent thoracic fusion were more likely to have venous thromboembolism and extended length of hospital stay. However, mortality was not associated with blood transfusion.

This study used a large database to characterise the incidence, predictors and post-operative complications associated with blood transfusion in thoracic and lumbar fusion surgeries. Pre- and post-operative planning for patients deemed to be at high-risk of requiring blood transfusion should be considered to reduce post-operative complication in this population.

Clinical pathways are optimal patient care processes that have been developed to improve the quality of care for patients. Anecdotal evidence has suggested that patients presenting to the healthcare system with rotator cuff tears experience less than ideal quality care plagued by lengthy wait times, challenges in coordinating care, and inefficient use of healthcare resources. Therefore, diagnosis and treatment of patients with rotator cuff tears are in need of quality improvement through evidence-informed decision making. The purpose of this study is to develop a clinical pathway for patients presenting to the healthcare system with rotator cuff tears.

The following steps were taken in developing the clinical pathway: 1) a multidisciplinary expert panel was formed; 2) goals of the clinical pathway were identified by the panel; 3) the literature and current clinical practices for best practice were reviewed; 4) recommendations for treatment algorithms were developed using consensus methods.

The panel consisted of fourteen experts representing the two largest cities in Alberta, Canada (Edmonton and Calgary). The team consisted of at least one member from the clinical domains of sport medicine, orthopaedic surgery, athletic therapy, and physiotherapy. The first goal of the clinical pathway was to standardise screening, diagnosis, and physical examination of the patient. The second goal was to provide recommendations for appropriate investigations. The final goal was to map steps in the patients' care pathway including sequencing and timing recommendations for treatment and interventions. Best practices were reviewed by the panel and using a modified Delphi method, clinical pathways for three types of rotator cuff tears (acute, chronic, and acute-on-chronic) were developed.

A clinical pathway that reflected best practices was developed from the literature and experts. The clinical pathway for diagnosis and treatment of patients with rotator cuff pathology will help to standardised patient care, improve patient flow, reduce unnecessary interventions, reduce healthcare utilisation and costs, and improve the quality of patient care.

The traditional treatment for a primary anterior shoulder dislocation has been immobilisation in a sling with the arm in adduction and internal rotation. The recurrence rates after the initial traumatic event range from 20% to 94%. However, recent results have suggested that recurrent instability after primary shoulder dislocation may be reduced with immobilisation in external rotation. Since then, controversy exists regarding the position of immobilisation following these injuries. The objective of the present study was to compare immobilisation in internal and external rotation after a primary anterior shoulder dislocation.

Fifty patients presenting to our fracture clinic with a primary traumatic anterior dislocation of the shoulder were randomly assigned to treatment with immobilisation in either internal rotation (IR; 25 patients) or external rotation (ER; 25 patients) for three weeks. In addition of a two-years clinical follow-up, patients underwent a magnetic resonance imaging (MRI) of the shoulder with intra-articular contrast within four days following the traumatic event, and then at three months of follow-up. The primary outcome was a recurrent dislocation within 24 months of follow-up. The secondary outcome was the healing rate of the labral lesion seen on MRI (if present) within each immobilisation group.

The follow-up rate after two years was 92% (23 of 25) in the IR group and 96% (24 of 25) in the ER group. The recurrence rate in the IR group (11 of 23; 47.8%) was higher than that in the ER group (7 of 24; 29.2%) but the difference did not reach statistical significance (p=0.188). However, in the subgroup of patients aged 20–40 years, the recurrence rate was significantly lower in the ER group (3 of 17; 6.4%) than that in the IR group (9 of 18; 50%, p<0,01). In the subgroup of patients with a labral lesion present on the initial MRI, the healing rate of the lesion was 46.2% (6 of 13) in the IR group and 60% (6 of 10) in the ER group (p=0.680). Overall, the recurrence rate among those who showed healing of the labrum (regardless of the immobilisation group) was 8.3% (1 of 12), but patients who did not healed their labrum had a recurrence rate of 45.5% (5 of 11; p=0.069).

This study suggests that immobilisation in ER reduces the risk of recurrence after a primary anterior shoulder dislocation in patients aged between 20 and 40 years. At two years follow-up, the recurrence rate is lower in patients who demonstrated a healed labrum at three months, regardless of the position of immobilisation. Future studies are required in order to identify factors that can improve healing of the damaged labrum following a traumatic dislocation of the shoulder.

The optimal approach to arthroscopic repair of the rotator cuff is controversial, and both single row and double row fixation methods are commonly used. Which construct yields the highest efficacy is not clear. Given the current era of increasing costs in which health care delivery models are aiming for improved efficiencies and optimal outcomes, a cost-effectiveness study was performed to inform the decision making process of the utilisation of single versus double row repair. The purpose of this study was to evaluate the cost-effectiveness of single row versus double row constructs in patients undergoing arthroscopic rotator cuff repair.

A cost-utility analysis was performed. Health resource use and outcome data were obtained from a previous prospective randomised controlled trial in which 90 patients were randomised to two treatment arms, single row rotator cuff repair (n=48) and double row (n=42). The patients were followed over a two-year span from the time of initial surgery. Unit cost data were captured using case costs collected from the hospital database and the Ontario Schedule of Benefits. Utility values were derived from published literature. The incremental cost effectiveness ratio (ICER), defined as the difference in cost between the two types of rotator cuff fixation divided by the difference in quality adjusted life years (QALY), was determined.

Double row fixation was more costly ($2,279.94 versus $1,587.37) but was more effective than the single row method (QALY of 4.073 versus 4.055). An incremental cost-effectiveness ratio was estimated to be $38,504.92 per QALY for double row fixation relative to single row. This is well below the commonly used willingness to pay threshold of $50,000/QALY. Subgroup analysis demonstrated that patients with larger rotator cuff tears (>3cm) had a lower ICER, suggesting that double-row fixation may be more cost-effective in more severe tears.

Double row rotator cuff fixation is a cost-effective option compared to single row rotator cuff repair with an ICER of $38,504.92/QALY, well within the accepted willingness to pay threshold of $50,000/QALY. Furthermore, the ICER between single and double row fixation improved with larger rotator cuff tears (>3cm), suggesting an additional benefit of a double row construct in those cases.

Rotator cuff repair is performed to treat shoulder pain and disability. Failure of the tendon repair site is common; one strategy to improve healing is to enforce a period of post-operative immobilisation. Immobilisation may have unintended effects on tendon healing. Tenocytes under uniaxial strain form more organised collagen and up regulate expression of proliferative genes. Vitamin C (ascorbic acid), an anti-oxidant that is a co-factor for collagen synthesis, has also been reported to enhance collagen deposition and organisation. The purpose of this study was to compare human tenocyte cultures exposed to uniaxial cyclical strain with or without slow-release ascorbic acid (ascorbyl-2 phosphate) to determine their individual and combined effects on tissue remodelling and expression of tissue repair genes.

Rotator cuff tissues were collected from degenerative supraspinatus tears from eight patients. Tenocytes were incorporated into 3D type I collagen culture matrices. Cultures were divided into four groups: 1) ascorbic acid (0.6mMol/L) + strain (1%–20% uniaxial cyclic strain at 0.1 Hz), 2) ascorbic acid unstrained, 3) strain + vehicle 4) unstrained + vehicle. Samples were fixed in paraffin, stained with picrosirius red and analysed with circular polarising light. A second set of cultures were divided into three groups: 1) 0.5mM ascorbic acid, 2) 1mM ascorbic acid, 3) vehicle cultured for 24, 72, 120 and 168 hours. Cell-free collagen matrix was used as a control. Tenocyte proliferation was assessed using the water soluble tetrazolium-1 (WST1) assay and f tissue repair gene expression (TGFB1, COL1A1, FN1, COLIII, IGF2, MMP1, and MMP13), were analysed by qPCR. The data were analysed using a Split model ANOVA with contrast and bonferroni correction and a one-way ANOVAs and Tukey's test (p<0.05 was significant).

Our results indicated that unstrained cultures with or without exposure to slow release ascorbic acid exhibited greater picrosirius red birifringency and an increase in collagen fiber deposition in a longitudinal orientation compared to strained tenocytes. We found that slow release ascorbic acid promoted significant dose and culture-time dependent increases in tenocyte proliferation (p<0.05) but no obvious enhancement in collagen deposition was evident over cultures without ascorbic acid supplementation.

Based on these data, applying strain to tenocytes may result in less organised formation of collagen fibers, suggestive of fibrotic tissue, rather than tendon remodelling. This may indicate that a short period of immobilisation post-rotator cuff repair is beneficial for the healing of tendons. Exposure to slow release ascorbic acid enhanced tenocyte proliferation, suggesting that supplementation with Vitamin C may improve tendon repair post-injury or repair. Future studies will assess levels of tissue repair-associated proteins as well as comparing traumatic and degenerative rotator cuff tears to healthy uninjured rotator cuff tissue.

The majority of studies reporting sensitivity and specificity data for imaging modalities and physical examination tests for long head of biceps (LHB) tendon pathology use arthroscopy as the gold standard. However, there is little published data to validate this as an appropriate benchmark. The aim of this study was to determine the maximum length of the LHB tendon that can be seen at glenohumeral arthroscopy and whether it allows adequate visualisation of common sites of pathology.

Seven female cadaveric specimens were studied. Mean age was 74 years (range 44–96 years). Each specimen underwent arthroscopy in lateral decubitus (LD) and beach chair (BC) positions. The LBH-tendon was tagged with a suture placed with a spinal needle marking the intra-articular length and the maximum excursions achieved using a hook and a grasper in both LD and BC positions. T-tests were used to compare data.

The mean intra-articular and extra-articular lengths of the tendon were 23.9 mm and 82.3 mm respectively. The mean length of tendon that could be visualised by pulling it into the joint with a hook was significantly less than with a grasper (LD: hook 29.9 mm, grasper 33.9 mm, mean difference 4 mm, p=0.0032. BC: hook 32.7 mm, grasper 37.6 mm, mean difference 4.9 mm, p=0.0001). Using the BC position allowed visualisation of a significantly greater length than the LD position when using either a hook (mean difference 2.86 mm, p=0.0327) or a grasper (mean difference 3.7 mm, p=0.0077). The mean length of the extra-articular part of the tendon visualised using a hook was 6 mm in LD and 8.9 mm in BC. The maximum length of the extra-articular portion visualised using this technique was 14 mm (17%).

Pulling the tendon into the joint with a hook does not allow adequate visualisation of common distal sites of pathology in either LD or BC. Although the BC position allows a significantly greater proportion of the tendon to be visualised this represents a numerically small value and is not likely to be clinically significant. The use of a grasper also allowed greater excursion but results in iatrogenic tendon injury which precludes its use. The reported incidence of pathology in Denard zone C (distal to subscapularis) is 80% and in our study it was not possible to evaluate this zone even by using a grasper or maximum manual force to increase excursion. This is consistent with the extremely high rate of missed diagnoses reported in the literature. Surgeons should be aware that the technique of pulling the LHB-tendon into the joint is inadequate for visualising distal pathology and results in a high rate of missed diagnoses. Furthermore, efforts to achieve greater excursion by “optimum” limb positioning intra-operatively do not confer an important clinical advantage and are probably unnecessary.

Estimated to affect 2–5% of the population, adhesive capsulitis is a common cause of shoulder pain and dysfunction. The objective of this study is to determine if arthrographic injection of the shoulder joint with steroid, local anesthetic and contrast is an effective treatment modality for adhesive capsulitis and whether it is superior to arthrographic injection with local anesthetic and contrast alone.

This is a double-blinded RCT of patients with a diagnosis of adhesive capsulitis who were randomly assigned to receive an image guided arthrographic glenohumeral injection with either triamcinalone (steroid), lidocaine (local anesthetic) and contrast or lidocaine and contrast alone. Outcome measures included active and passive shoulder range of motion (ROM) and functional outcomes assessed using the Shoulder Pain and Disability Index (SPADI), the Constant Score and a Visual Analog Scale for pain. Post-operative evaluation occurred at 3 weeks, 6 weeks and 12 weeks. Descriptive statistics were utilised to summarise patient demographics and other study parameters. One-way ANOVAs compared the VAS, Constant and SPADI scores across the different time points for both study groups. The post hoc Bonferroni correction was used to adjust for multiple comparisons.

There were 37 shoulders injected with follow-up visits at 12 weeks. Twenty shoulders were randomised to receive local plus steroid and 17 shoulders received local anesthetic only. There were 21 females and 14 males with an average age of 54 years (range, 42–70). VAS scores for both patient groups were significantly improved (p<0.05) at all follow-up times. Goniometric testing demonstrated significant improvements in forward flexion and internal rotation at 90 degrees in the local group and only abduction in the local plus steroid group. There were no significant changes in the Constant scores for the local group (p=0.08), however, the Constant scores showed significant improvement for the local plus steroid group (p=0.003) at all follow-up time points. The local group showed significant improvement in their SPADI pain scores at the 12 week follow-up only (p=0.01). There were no significant differences in their SPADI disability scores (p=0.09). The local plus steroid group had significant improvement in SPADI pain and disability scores at all follow-up time points (p=0.001).

The optimal treatment for adhesive capsulitis remains unclear. Our study demonstrated that patients receiving an arthrographic injection of either steroid and local anesthetic or local anesthetic alone had significantly improved post-injection pain scores. However, only the steroid and local anesthetic group demonstrated improved SPADI disability and Constant scores. Thus, we believe that either treatment may be a good option for patients with adhesive capsulitis and can reliably relieve pain, but we would recommend the steroid with local anesthetic over the local anesthetic alone as it may provide improved function.

This is largest collection of outcomes of distal biceps reconstruction in the literature. 8 subjects prospectively measured pre and post reconstruction Strength deficit in patients with chronic tendon deficit is described.

To describe outcomes for 53 chronic distal biceps reconstructions with tendon graft. Clinical outcomes as well as strength and endurance in supination and flexion are reported. To examine eight patients measured pre- and post-reconstruction. To identify deficit in supination and flexion in chronic reconstruction.

53 reconstructions of chronic distal biceps with tendon graft were carried out between 1999 and 2015. 26 subjects agreed to undergo strength testing after minimum one year follow up. Eight subjects were tested both before and after reconstruction. Primary outcomes were strength in elbow flexion and forearm supination. Strength testing of supination and flexion included maximum isokinetic power and endurance performed on a Biodex. Clinical outcomes measures included pre-operative retraction severity, surgical fixation technique, postoperative contour, range of motion, subjective satisfaction, SF-12, DASH, MAYO elbow score, ASES and pain VAS Non-parametric data was reported as median (interquartile range), while normally-distributed data was reported as mean with 95% Confidence Limits. Hypothesis testing was performed according to two-tailed, paired t-tests.

Median time from index rupture to reconstructions 9.5 (range 3–108) months. Strength measurements were completed at a median follow-up time of 29 (range 12–137) months on 26 subjects. The proportion of patients that achieved 90% strength of the contralateral limb post-reconstruction was 65% (17/26) for peak supination torque, and 62% (16/26) for peak flexion torque. Supination and flexion endurance was 90% of the contralateral arm in 81% (21/26) and 65% (17/26) of subjects, respectively. Ten subjects (39%) achieved 90% strength of the contralateral arm on at least four of five strength tests. Eight of the 26 patients were evaluated pre- and post-surgery. As compared to the contralateral limb, chronic distal biceps rupture was found to have a mean [95%CI] deficit in peak supination torque of 31.0 [21.0, 42.9]% (p=0.002). Mean deficit in peak flexion torque of 34.2 [23.1, 45.4]% (p <0.001). Reconstruction resulted in an increase in peak supination torque of 33.5 [8.7, 58.3]% (p=0.0162), increase in peak flexion torque of 35.0 [6.4, 63.6]% (p=0.023), increase in isometric strength of 57.6 [36.1, 79.1]% (p<0.001), increase in supination endurance of 0.6 [-22.2, 23.4]% (p=0.668), and a decrease in flexion endurance of 4.8 [-23.3, 13.7](p=0.478). Ninety-six percent of the patients (25/26) were satisfied, or very satisfied with the overall outcome of the surgery, while median Mayo score post-reconstruction was 100 (range: 55–100).

Chronic distal biceps tendon rupture results in less supination loss and greater flexion loss than previously reported. Reconstruction with tendon graft results in a significant, but incomplete recovery of peak supination and flexion torque, but no significant change in endurance. Clinical patient satisfaction with surgical outcomes is high.

Recent literature has demonstrated that conventional arthroscopic techniques do not adequately visualise areas of predilection of pathology of the long head of biceps (LHB) tendon and are associated with a 30–50% rate of missed diagnoses. The aim of this study was to evaluate the safety, effectiveness and ease of performing biceps tenoscopy as a novel strategy for reducing the rate of missed diagnoses.

Five forequarter amputation cadaver specimens were studied. The pressure in the anterior compartment was measured before and after surgical evaluation. Diagnostic glenohumeral arthroscopy was performed and the biceps tendon was tagged to mark the maximum length visualised by pulling the tendon into the joint. Biceps tenoscopy was performed using 3 different techniques (1. Flexible video-endoscopy, 2. Standard arthroscopy via Neviaser portal. 3. Standard arthroscope via antero-superior portal with retrograde instrumentation). Each was assessed for safety, ease of the procedure and whether the full length of the extra-articular part of the LHB tendon could be visualised. The t-test was used to compare the length of the LHB tendon visualised at standard glenohumeral arthroscopy vs that visualised at biceps tenoscopy. An open dissection was performed after the arthroscopic procedures to evaluate for an iatrogenic injury to local structures.

Biceps tenoscopy allowed visualisation to the musculotendinous junction in all cases. The mean length of the tendon visualised was therefore significantly greater at biceps tenoscopy (104 mm) than at standard glenohumeral arthroscopy (33 mm) (mean difference 71 mm, p<0.0001). Biceps tenoscopy was safe with regards to compartment syndrome and there was no difference between pre- and post-operative pressure measurements (mean difference 0 mmHg, p=1). No iatrogenic injuries were identified at open dissection.

Biceps tenoscopy allows excellent visualisation of the entire length of the LHB tendon and therefore has the potential to reduce the rate of missed diagnoses. This study did not demonstrate any risk of iatrogenic injury to important local structures or any risk of compartment syndrome. Clinical evaluation is required to further validate this technique.

Studies have shown that the trees minor plays an important role after total (TSA) and reverse (RSA) shoulder arthroplasty, as well as in maintenance of function in the setting of infraspinatus wasting. In this regard, teres minor hypertrophy has been described as a compensatory change in response to this infraspinatus wasting, and has been suggested that this compensatory hypertrophy may mitigate the loss of infraspinatus function in the patient with a large rotator cuff tear. The purpose of this study was to determine the prevalence of teres minor hypertrophy in a cohort of patients undergoing rotator cuff repair, and to determine its prognostic effect, if any, on outcomes after surgical repair.

Over a 3 year period, all rotator cuff repairs performed in a single practice by 3 ASES member surgeons were collected. Inclusion criteria included both preoperative and postoperative validated outcomes measures (minimum 2 year), and preoperative Magnetic Resonance Imaging (MRI) scanning. 144 patients met all criteria. MRIs were evaluated for rotator cuff tear tendon involvement, tear size, and Goutallier changes of each muscle. In addition, occupational ratios were determined for the supraspinatus, infraspinatus, and teres minor muscles. Patients were divided into 2 groups, based upon whether they had teres minor hypertrophy or not, based on a previously established definition. A 2 way ANOVA was used to determine the effect of teres minor hypertrophy(tear size by hypertrophy) and Goutallier

Teres minor hypertrophy was a relatively common finding in this cohort of rotator cuff patients, with 51% of all shoulders demonstrating hypertrophy. Interestingly, in patients without an infraspinatus tear, teres minor hypertrophy was still present in 19/40 (48%) of patients. Teres minor hypertrophy had a significant, negative effect ASES scores after rotator cuff repair in patients with and without infraspinatus tearing, infraspinatus atrophy, and fatty infiltrative changes (P<0.05). In general, the presence of teres minor hypertrophy showed 10–15% less improvement (Figure 1) than when no hypertrophy was present, and this was consistent across all tear sizes, independent of Goutallier changes.

Teres minor hypertrophy is a common finding in the setting of rotator cuff tearing, including in the absence of infraspinatus tearing. Contrary to previous publications, the presence of teres minor hypertrophy in patients with rotator cuff repair does not appear to be protective as a compensatory mechanism. While further study is necessary to determine the mechanism or implication of teres minor hypertrophy in setting of rotator cuff repair, our results show it is not a positive of outcomes following rotator cuff repair.

The purpose of this study was to examine five-year outcomes of patients previously enrolled in a non-operative rotator cuff study.

Patients with chronic, full-thickness rotator cuff tears (demonstrated on imaging) who were referred to one of two senior shoulder surgeons were enrolled in the study between October 2008 and September 2010. Patients participated in a comprehensive non-operative, home-based treatment program. After three months patients were defined as “successful” or “failed”. “Successful” patients were essentially asymptomatic and did not require surgery. “Failed” patients were symptomatic and consented to surgical repair. All patients were followed up at one year, two years, and five-plus years.

Original results of our study showed that 75% of patients were treated successfully with non-operative treatment, while 25% went on to surgery. These numbers were maintained at two-year follow-up (previously reported) and five-year follow-up. At five+ years, 88 patients were contacted for follow-up. Fifty-eight (66%) responded. The non-operative success group had a mean RC-QOL score of 80 (SD 18) at previously reported two-year follow-up. At five-year follow-up this score did not decrease (RCQOL = 82 (SD 16)). Furthermore, between two and five years, only two patients who had previously been defined as “successful” became more symptomatic and underwent surgical rotator cuff repair. From the original cohort of patients, those who failed non-operative treatment and underwent surgical repair had a mean RC-QOL score of 89 (SD 12) at five-year follow-up. The operative and non-operative groups at five-year follow-up were not significantly different (p = 0.07).

Non-operative treatment is an effective and lasting option for many patients with a chronic, full-thickness rotator cuff tear. While some may argue that non-operative treatment delays inevitable surgical fixation, our study shows that patients can do extremely well over time.

The purpose of this study was to determine the effect of sectioning the relevant soft tissues and a TKA on the medial and lateral knee joint gap.

Twelve intact lower extremity cadaveric specimens (mean (SD) age 76.5 (11.6) years) were tested. A custom designed knee tensioner was developed that allowed the separate application of forces to the medial and lateral components of the knee. The distance between the bottom of the load cell and the top of a compression rod was measured with digital calipers (precision = 0.1mm). Loads of 100N and 200N were then applied to each compartment and the resulting displacement was measured. The two loads were applied to the knee in the following conditions: i) All soft tissues intact; ii) an arthrotomy; iii) ACL sectioned; iv) PCL sectioned; v) release of the mid-coronal tissues; and vi) TKA. Finally, tensions were applied for all conditions from 90° to 0° of knee flexion in 30° increments.

There was a significant effect of soft tissue release on the magnitude of the gap at the 100N load application, such that there was an increase in the when the mid-coronal MCL release was performed compared to the intact (2.2mm) and arthrotomy (1.75mm) conditions. With respect to the 200N load application there was a statistically significant tissue release effect, where differences were detected between the mid-coronal MCL release and intact (3.04mm) and arthrotomy conditions (2.31mm). At the 100N load there was a significance increase in the gap compared to the intact knee. There was also a significant condition by knee angle interaction where the gap was approximately 4mm larger following the TKA compared to the intact condition when the knee was flexed at 90°. Furthermore, there was a statistically significant 4.8mm and 3.8mm difference between 90° and 0° and 60° and 0° of knee flexion respectively, for the TKA condition only. At the 200N load application the gap width increased significantly by 2.5mm following the TKA. Finally, there was a significant condition by knee angle interaction where the change in gap width increased significantly from the intact (7.54mm) to the TKA condition (13.88mm) at 90° of knee flexion. There was a statistically significant difference in the TKA condition between 60° and 0° of knee flexion.

Releasing the soft tissues increases the gap between the tibia and femur, when compared to the intact condition, with significance occurring only following the mid-coronal release. Furthermore, the TKA did not return the knee to its intact state as was evident by the significant difference between the TKA and intact conditions. This suggests that the resulting kinematics may not accurately match those pre-surgery resulting in un-physiological motion patterns and the possibility of early failure and revision.

Complications involving the patellofemoral joint are a source of anterior knee pain, instability, and dysfunction following total knee arthroplasty. “Overstuffing” the patello-femoral joint refers to an increase in the thickness of the patellofemoral joint after a total knee replacement compared to the preoperative thickness. While biomechanical studies have indicated that overstuffing the patellofemoral joint may lead to adverse clinical outcomes, limited clinical evidence exists to support this notion. The purpose of this study is to evaluate the effect of changing the thickness of the patellafemoral joint on functional outcomes following total knee arthroplasty.

Our institutional arthroplasty database was used to identify 1347 patients who underwent a primary total knee arthroplasty between 2006 and 2012 with the same component design. Standard preoperative and postoperative anteroposterior, lateral, and skyline radiographs were collected and measured for patello-femoral overstuffing. These measurements included anterior patellar displacement, anterior femoral offset, and anteroposterior femoral size. These measurements were correlated with patient outcome data using WOMAC, KSS scores, and postoperative range of motion. Multiple linear regression analysis was used to assess the association between stuffing and functional outcomes.

A total of 1031 patients who underwent total knee arthroplasty were included. Increased anterior patellar displacement, a measure of patellofemoral joint thickness, was associated with decreased WOMAC scores (p=0.02). Anterior femoral offset (p=0.210) and anteroposterior femoral size (p=0.091) were not significantly associated with patient functional outcomes. Postoperative range of motion (ROM) was not associated with patellofemoral stuffing (p=0.190).

The current study demonstrated that functional outcomes are adversely affected by patellofemoral overstuffing. Based on these results, caution is encouraged against increasing the thickness of the patellofemoral joint, particularly on the patellar side of the joint.

With the introduction of new technology in orthopaedics, surgeons must balance anticipated benefits in patient outcomes with challenges or complications associated with surgical learning curve for the technology. The purpose of this study was to determine whether surgeon learning curve with a new multi-radius primary TKA system and instruments designed to improve surgical team ease would impact clinical outcomes, surgical time, and complications.

From November 2012 to July 2015, 2369 primary TKAs were prospectively enrolled in two multicentre studies across 50 sites in 14 countries with a new knee system (NEW-TKA) evenly balanced across four configurations: cruciate retaining or posterior stabilised with either fixed bearing or rotating platform (CRFB, CRRP, PSFB, PSRP). 2128 knees had a<1 year visit and 1189 had a minimum 1 year visit. These knees were compared to a reference dataset of 843 primary TKAs from three manufacturers in the same four configurations with currently available products (CA-TKA). Demographics for NEW-TKA and CA-TKA were similar and typical for primary TKA. Operative times, clinical outcomes and a series of five patient reported outcomes were compared for NEW-TKA vs. CA-TKA. The first 10 New-TKA subjects for each surgeon were defined as learning curve cases (N=520) and were compared to all later subjects (N=1849). Patient reported outcome measure and clinical outcome analyses were covariate adjusted for patient demographics, pre-op assessment and days post-op.

Mean (SD) surgical time for NEW-TKA learning curve cases was 79.1 (24.3) minutes, which reduced thereafter to 73.6 (24.3) (p=0.002). Beyond 10 cases, there was a continued reduction in NEW-TKA surgical time (R-Squared = 0.031). After 10 cases, surgical time was on par with the mean (SD) 71.9 (21.6) for CA-TKA (p=0.078). PROM outcomes of the first 10 learning curve cases for NEW-TKA were not statistically different from later cases at less than 1 year or later when adjusted for relevant covariates including configuration, patient demographics, pre-op functional status, and time post-op (p-values > 0.01). PROM outcomes for NEW-TKA vs. CA-TKA under the same covariate adjustments showed a trend favoring KOOS ADL, Symptoms, and Sport and Recreation subscores at minimum 1 year (p-values < 0.01). The incidence of intraoperative operative site complications was 1.3% for the NEW-TKA learning curve cases which was similar to the 0.6% rate for historical CA-TKA (p=0.231) and the intraoperative complication rate for the NEW-TKA later cases was consistent with learning curve cases (p=0.158).

The introduction of new implants into the market place needs to have adequate data to support that they are safe and effective. Except for a minor increase in surgical time during the first 10 patients, this study found that surgeon learning curve with this new primary TKA system does not adversely affect patient short term outcomes and complication rates.

The posterior tibial slope angle (PTS) in posterior cruciate retaining total knee arthroplasty influences the knee kinematics, knee stability, flexion gap, knee range of motion (ROM) and the tension of the posterior cruciate ligament (PCL). The current technique of using an arbitrary (often 3–5 degrees) PTS in all cases seldom will restore native slope in cruciate retaining TKA. Questions/Purposes: The primary objective was to determine if we could surgically reproduce the native PTS in cruciate-retaining total knee arthroplasty. The second objective was to determine if reproduction of native slope was significant – ie influenced clinical outcome.

We evaluated the radiographic and clinical outcomes of a series of consecutive total knee arthroplasties using the PFC sigma cruciate-retaining total knee system in 215 knees. The tibial bone cut was planned to be parallel to the patient's native anatomical slope in the sagittal plane. An “Angel Wing” instrument was placed on the lateral tibial plateau and the slope of the cutting guide adjusted to make the cutting block parallel to the patient's native tibial slope. All true lateral radiographs of the knee were measured for PTS using a picture achieving and communication system (PACS). PTSs were measured with reference to the proximal tibial medullary canal (PTS-M) and the proximal tibial anterior cortex (PTS-C). The knee ROM, Knee Society Score, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and SF-12 at the last follow-up were evaluated as clinical outcomes.

The mean preoperative PTS-M was 6.9±3.3 degrees and the mean postoperative PTS-M was 7±2.4 degrees. The mean preoperative PTS-C was 12.2±4.2 degrees and the mean postoperative PTS-M was 12.6±3.4 degrees. There was no significant difference form the preoperative and postoperative PTS measurement in both techniques (p>0.05). We used an arbitrary 3 degrees as an acceptable range for PTS-M reproduction. The PTS-M was reproduced within 3 degrees in 144 knees (67%); designated as Group A. The 71 knees with a difference more than 3 degrees in (33%) were designated as Group B. Group A showed significantly larger gain in ROM compared with group B (p=0.04). Group A also had significantly better improvement in Knee society score and WOMAC score and SF-12 physical score when compare with group B (p<0.01).

Our modification of standard surgical technique reliably reproduced the native tibial slope in cruciate-retaining total knee arthroplasty. More importantly, reproduction of the patient's native PTS within 3 degrees resulted in better clinical outcomes manifested by gain in ROM and knee functional outcome scores.

An outpatient TKA program was developed by integrating advances in analgesia, rehabilitation, and minimally invasive surgical techniques with the objective of improving value in elective total knee arthroplasty (TKA) while maintaining quality standards. Previous studies have established the safety of outpatient TKA in selected populations, but the literature is devoid of outcome measures in these patients. Our goal was to investigate the quality of recovery, patient satisfaction, and safety profile in the first 90 days undergoing outpatient TKA.

One hundred TKAs in 93 consecutive patients with end-stage arthritis of the knee candidate for primary TKA were enrolled in this prospective matched cohort study. Patients that underwent inpatient TKA (47 TKAs) were compared with patients that underwent planned outpatient TKA (53 TKAs). The following 28 day post-operative scores were recorded: quality of recovery (QoR-18) and pain scores by Numerical Rating Scale (NRS-11). Satisfaction with pain control (0 to 10) and quantity of opioid use was collected. Secondary outcome measures of 90-day complications, readmissions, and emergency department (ED) visits were recorded.

Ninety-six percent of patients planned for outpatient TKA met our defined multidisciplinary criteria for same-day discharge. QoR-18 at post-operative day one was statistically higher in the outpatient TKA group. Otherwise, outcome measures were not statistically different between the 2 groups. Two patients required overnight admission: 1 for extended motor-block and 1 for vasovagal syncope. There were 7 ED visits in the in the outpatient group and 4 in the inpatient group. One outpatient was admitted for irrigation and debridement with liner exchange for an acute infection 2 weeks post-operatively. One inpatient required manipulation under anesthesia at six weeks post-operatively.

Outpatient TKA in selected patients produced a post-operative quality of recovery and patient satisfaction similar to that of inpatient TKA. Our results support that outpatient TKA is a safe alternative that should be considered due to its potential cost-savings and comparable recovery.

Modifying Knee anatomy during mechanical Total Knee Arthroplasty (TKA) may impact ligament balance, patellar tracking and quadriceps function. Although well fixed, patients may report high levels (20%) of dissatisfaction. One theory is that putting the knee in neutral mechanical alignment may be responsible for these unsatisfactory results. Kinematic TKA has gained interest in recent years; it aims to resurface the knee joint and preservation of natural femoral flexion axis about which the tibia and patella articulate, recreating the native knee without the need for soft tissue relaease. That's being said, it remains the question of whether all patients are suitable for kinematic alignment. Some patients' anatomy may be inherently biomechanically inferior and recreating native anatomy in these patients may result in early implant failure. The senior author (PAV) has been performing Kinematic TKA since 2011, and has developed an algorithm in order to better predict which patient may benefit from this technique.

Lower limb CT scans from 4884 consecutive patients scheduled for TKA arthroplasty were analysed. These exams were performed for patient-specific instrumentation production (My Knee®, Medacta, Switzerland). Multiple anatomical landmarks used to create accurate CT-based preoperative planning and determine the mechanical axis of bone for the femur and tibia and overall Hip-knee-Ankle (HKA). We wanted to test the safe range for kinematic TKA for the planned distal resection of the femur and tibia. Safe range algorithm was defined as the combination of the following criteria: – Independent tibial and femoral cuts within ± 5° of the bone neutral mechanical axis and HKA within ± 3°. The purpose of this study is to verify the applicability of the proposed safe range algorithm on a large sample of individual scheduled for TKA.

The preoperative tibial mechanical angle average 2.9 degrees in varus, femoral mechanical angle averaged 2.7 degrees in valgus and overall HKA averaged of 0.1 in varus. There were 2475 (51%) knees out of 4884, with femur and tibia mechanical axis within ±5° and HKA within ±3° without need for bony corrections. After applying the algorithm, a total of 4062 cases (83%) were successfully been evaluated using the proposed protocol to reach a safe range of HKA ±3° with minimal correction. The remaining 822 cases (17%) could not be managed by the proposed algorithm because of their unusual anatomies and were dealt with individually.

In this study, we tested a proposed algorithm to perform kinematic alignment TKA avoiding preservation/restoration of some extreme anatomies that might not be suitable for TKA long-term survivorship. A total of 4062 cases (83%) were successfully eligible for our proposed safe range algorithm for kinematic TKA. In conclusion, kinematically aligned TKA may be a promising option to improve normal knee function restoration and patient satisfaction. Until we have valuable data confirming the compatibility of all patients' pre arthritic anatomies with TKA long-term survivorship, we believe that kinematically alignment should be performed within some limits. Further studies with Radiostereometry or longer follow up might help determine if all patients' anatomies are suitable for Kinematic TKA.

Total knee arthroplasty (TKA) is recognised as an effective treatment for end-staged knee osteoarthritis. Up to 20% of these patients is unfortunately unsatisfied due to anterior knee pain from unknown origin (Bourne and al. 2010). The aim of this study is to compare knee 3D kinematics during gait of patients with anterior knee pain after TKA to an asymptomatic TKA group. Our hypothesis is that the painful TKA group would exhibit known kinematics characteristics during gait that increase patellofemoral (PF) stresses (i.e. dynamic flexion contracture, valgus alignment, valgus collapse or a quick internal tibial rotation movement) compared to the TKA asymptomatic group.

Thirty-eight patients (45 knees) were recruited 12–24 months post-surgery done by one of three experienced orthopaedic surgeons (31 unilateral TKA and seven bilateral TKA, all using the same knee implant). Patients were divided according to their KOOS pain score (with a cut-off at 6/20 to be included in the painful group). The KOOS questionnaire was also used to assess activities of daily living, symptoms, sports and quality of life. A complete clinical and radiological work up was done on the painful group to exclude those with known explanation for pain (i.e. loosening, malrotation, infection and clinical instability). 3D knee kinematics during treadmill walking was captured and computed using the KneeKGTM system.

For the painful and asymptomatic groups, demographic results show respectively: age of 64.4 ± 7.6 and 69.8 ± 8.3 years, BMI of 31.9 ± 5.0 and 28.1 ± 3.6 kg.m−2, speed of 1.8 ± 0.6 and 1.67 ± 0.5 miles/h., and 50% of women in each group. Only age and BMI showed to be statistically different between groups. The painful TKA group exhibited a valgus alignment when walking (at initial contact and during stance, p<0.001). No significant difference has been put forward for the flexion/extension and internal/external tibial rotation.

Since a higher valgus alignment increases the Q angle, which lateralise the patella and increases PF stresses, results provide new insight on origin of symptoms. Conservative treatments for PF pain syndrome have shown to address the valgus alignment and improve symptoms, therefore the next step will be to assess the impact on pain level and alignment during gait of a personalised conservative management for the painful TKA group. Additionally, a study assessing the change in the radiological and dynamic alignment from pre to post surgery could bring valuable insight on the impact of surgical procedure on anterior knee pain.

The use of spinal anesthesia with adjuvant intra-thecal opioids has been commonly used in total knee arthroplasty without documented clinical benefit. It has been associated with a potential increase in side effects, including nausea, vomiting, pruritus, urinary retention and oxygen usage. This double-blinded RCT investigated whether the addition of epimorph to spinal anesthesia in patients undergoing total knee arthroplasty resulted in superior pain control and decreased narcotic consumption without also causing an increase in postoperative complication rates.

We performed a prospective double-blind trial in patients undergoing primary total knee arthroplasty (TKA). Patients were randomised to receive either spinal anesthesia alone or spinal anesthesia with epimorph (150 ug). All patients received infiltration of a local anesthetic cocktail intraoperatively. Both the study patients and staff measuring outcomes were blinded to the experimental treatment received during data collection. Postoperatively, visual analogue scale (VAS) for pain was recorded at 6, 12, 18, 24, 36 and 48hrs and a final value at 1 week. Narcotic use, Foley insertion, oxygen requirements, nausea, vomiting and pruritus were recorded during the course of hospitalisation.

Forty-one patients were randomised into each of the spinal with epimorph and spinal alone treatment arms. The groups showed no significant differences in BMI, age, and gender distribution. In the first 12 hours postoperatively there was no difference in VAS for pain between the two groups, however there were significantly lower pain scores in the spinal alone patients at 18 hours (p=0.002), 24 hours (p=0.04) and 48 hours (p = 0.03) compared to the spinal with epimorph group. Narcotic usage was greater in the spinal group during the first 6 hours postoperatively, but beyond this time point narcotic usage was similar between the two groups. Additionally, there was a statistically significant increase in rate of complications with spinal epimorph including nausea (p=0.037) and pruritus (p=0.024). The incidence of urinary retention was greater in the spinal epimorph group, however this did not reach statistical significance.

This study demonstrates no clinical benefit with the addition of intra-thecal opioids to spinal anesthetic in primary TKA. In addition to a failing to reduce VAS pain scores and overall narcotic consumption, increased complication rates were seen. For these reasons, this study does not support the use of epimorph in addition to spinal anesthesia for pain control in TKA.

Many hospitals and orthopaedic surgery teams across Canada have instituted quality improvement (QI) programs for hip and knee arthroplasty. One of the common goals is to reduce hospital length of stay (LOS) in order to improve operational efficiency, patient flow and, by achieving this, provide improved access for patients to arthroplasty surgery. A common concern among surgeons and care providers is that hospital readmission rates will increase if LOS is significantly reduced. This study assesses the relationship between LOS and readmission rates in Alberta over a six year period during a focused QI initiative targeting LOS.

Data from all patients undergoing primary elective total hip or knee arthroplasty in Alberta between 2010 and 2015 was captured through a provincial QI program. Patient characteristics captured included age, gender, joint replaced, and pre-surgical co-morbidities. Patient LOS and all-cause hospital readmissions within thirty days from the initial discharge were captured through provincial data repositories, including the Discharge Abstract Database (DAD), operating room information systems, electronic medical records, and comorbidity risk grouper (CRG) data. Three longitudinal analyses were performed: 1) the crude and risk adjusted length of stay and 30-day readmission rates were calculated, 2) the population was grouped into two 3-year subsets and compared using t-test (acute LOS) and chi-square (30-day readmission), and 3) a multivariable regression analyses was performed to determine the rate of change and statistical significance in acute LOS and 30-day readmission between the two time periods.

The number of patients undergoing elective lower extremity arthroplasty in the province during the six-year study period (2010–2015) was 48,760 patients. Fifty-nine percent were female and forty-one percent were male. Mean age of the cohort was 66.9 years. Thirty-nine percent of patients had a total hip arthroplasty and 61% had a total knee arthroplasty. Forty-five percent of patients had no pre-surgical risk factors, 27% had one risk factor, and 28% of the patients had 2 or more risk factors. During the quality improvement program risk-adjusted length of stay improved from a mean of 4.82 days (in 2010–2012) to 3.90 days (in 2013–2015) (p<0.01). Controlling for differences in age, sex, joint replaced, and pre-surgery risk factors, the acute LOS declined by 0.32 days between the two time periods (p<0.001).

Quality improvement programs that target reduced LOS can avoid increasing 30-day hospital readmission rates. This has significant implications for inpatient resource utilisation for lower extremity arthroplasty surgery and for improving patient flow.

Pain immediately following total knee arthroplasty (TKA) is often severe and can inhibit patients' rehabilitation. Recently, adductor canal blocks have been shown to provide adequate analgesia and spare quadriceps muscle strength in the early postoperative period. We devised a single injection motor sparing knee block (MSB) by targeting the adductor canal and lateral femoral cutaneous nerve with a posterior knee infiltration under ultrasound. Our primary objective was to evaluate the analgesia duration of the MSB in comparison to a standard periarticular infiltration (PAI) analgesia using patients' first rescue analgesia as the end point. Secondary outcomes measured were quadriceps muscle strength and length of stay.

We randomised 82 patients scheduled for elective TKA to receive either the preoperative MSB (0.5% ropivacaine, 2.5ug/ml epinephrine, 10mg morphine, and 30mg ketorolac) or intraoperative periarticular infiltration (0.3% ropivacaine, 2.5ug/ml epinephrine, 10mg morphine, and 30mg ketorolac). Duration of analgesia, postoperative quadriceps power, and length of stay were evaluated postoperatively.

Analgesic duration was found to be significantly different between groups. The MSB had a mean duration of 18.06 ± 1.68 hours while the PAI group had a mean duration of 9.25 ± 1.68 hours for a mean difference of 8.8 hours (95% CI 3.98 to 13.62), p<0.01. There were no significant differences between groups in quadriceps muscle strength power at 20 minutes (p=0.91) or 6 hours (p=0.66) after block administration. Length of stay was also not significantly different between the groups (p=0.29).

Motor sparing blocks provide longer analgesia than patients receiving periarticular infiltration while not significantly reducing quadriceps muscle strength or increasing length of hospital stay.

Computer assisted surgery (CAS) has gained popularity in orthopaedics for both total knee (TKA) and total hip arthroplasty (THA) in the past decades as a stereotactic device that provides the surgeon with real-time feedback on implant position based on electromagnetic or infrared based instruments. The purpose of this study was to assess the effect of CAS on 30-day complication rates following THA and TKA.

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify all patients that underwent THA and TKA from 2011 to 2013, as well as any complication they had within 30-days of their surgery. Univariate and multivariate regression analysis was used to compare the post-operative complications in patients whose surgery involved the use of CAS with those by conventional surgical techniques.

We identified 104,550 patients who had THA (42,275 patients) and TKA (62,275 patients) procedures in the database between 2011 and 2013. Computer Assisted Surgery was used in 1,120 THA and 2,173 TKA procedures. There were higher overall adverse events (OR 1.40, CI: 1.22–1.59) in the Conventional group when compared to CAS for TKA. The rate of overall minor events (OR 1.38, CI: 1.21–1.58) and requirements for blood transfusion (OR 1.44, CI: 1.25–1.67) were higher in the Conventional group compared to the CAS group for TKA. However, rate of re-operation was significantly higher in the CAS group for TKA (OR 1.60, CI: 1.15–2.25). The results also showed higher overall adverse events (OR 2.61, CI: 2.09–3.26) in the Conventional group when compared to CAS for THA. The rate of overall minor events (OR 2.72, CI: 2.16–3.42) and requirements for blood transfusion (OR 3.27, CI: 2.52–4.25) was higher in the Conventional group whereas superficial wound infections (OR 0.46, CI: 0.46–0.81) were shown to be higher in the CAS group. The result also showed slightly longer operative times in CAS for both THA and TKA.

This study analysed a large patient database involving multiple institutions and surgeons and found that, overall, the use off CAS in primary total hip and total knee arthroplasty reduced the number of adverse events in the first 30-days postoperatively, compared to conventional surgical techniques. However, CAS was associated with an increased number of reoperations, superficial infections and operating time. The clinical benefits and disadvantages of CAS should be considered by arthroplasty surgeons when determining the potential benefit-cost ratio of this technology.

This aim of this study was to identify common factors in patients with the shortest length of hospital stay following total hip arthroplasty (THA). This would then allow a means of targeting suitable patients to reduce their length of stay.

This was a retrospective cohort study of all patients undergoing primary THA at our institution between September 2013 and August 2014. Demographic data were collected from the patient record. The cohort was divided into those discharged to home within two days of operation and the rest of the THA population. The demographics (age, gender, ASA grade, body mass index (BMI), primary diagnosis, socioeconomic status (Scottish Index of Multiple Deprivation, SIMD and SIMD health domain) were compared between groups. In addition for the early discharge group information on comorbidities, family support at home and independent transport were collected.

The study cohort was 1292 patients. 119 patients were discharged home on the first post-operative day. Those discharged earlier were on average younger (p<0.0001), more likely to be male (p<0.0001) and had a lower ASA grade (p<0.00001). Other demographics did not differ between groups. Patients who were discharged early also appeared to have few comorbidities (Diabetes 5.9%, Cardiac disease 7.6%, Respiratory disease 9%), high levels of family support at home (95%) and high levels of independent transport arrangements (97%).

Factors associated with those patients with the shortest lengths of stay were identified. Such factors could be used to target patients who are suitable for streamlined recovery programmes aimed at early discharge after THA and assist with service planning.

Total hip arthroplasty (THA) is a common and extremely beneficial procedure that is being performed more often as the population ages. Current THA follow-up guidelines require large amounts of resources and may not justify their cost with increased patient outcomes. Most problems that would require THA revision will cause symptoms. Late-presenting asymptomatic THAs that are found to require revision are complicated and expensive to address and often lead to poor patient outcomes. Follow-up visits for THA patients are essentially a screening tool to identify asymptomatic THAs that require revision. The rate of asymptomatic THA revision and the subsequent cost of screening for them is not well reported in the literature. Given the relative shortage of orthopaedic resources, efficient use of clinic time should be a priority and inefficient practices should be identified and changed.

We calculated the rate of asymptomatic hip revisions over the first twenty years of THA ownership. We further calculated the cost of a single visit to the orthopaedic clinic for follow up of a THA. Finally, we calculated the cost savings of decreasing the follow-up schedule to a total of three visits.

The cost savings of foregoing the screening to identify one asymptomatic THA requiring revision is CAD $1.2 million.

Asymptomatic THAs requiring revision are rare and, as such, require a large amount of follow up to diagnose. As a screening tool, regular orthopaedic follow up of THA is an inefficient use of resources. Current follow-up guidelines are cost-prohibitive and should be made much less frequent in order to save resources.

To identify the differences in inflammatory profiles between hip OA, knee OA and non-OA control cohorts and investigate the association between cytokine expression and clinical outcome measurements, specifically pain.

A total of 250 individuals were recruited in three cohorts (100 knee OA, 50 hip OA, 100 control). Serum was collected and inflammatory profiles analysed using the Multiplex Human Cytokine Panel (Millipore) on the Luminex 100 platform (Luminex Corp., Austin, TX). The pain, physical function and activity limitations of hip OA cohort were scored using the WOMAC, SF-36, HHS and UCLA scores. All cytokine levels were compared between cohorts individually using Mann–Whitney–Wilcoxon (MWW) test with Bonferroni multiple comparison correction. Within hip OA cohorts, the effect of hip alignment (impingement and dysplasia) and radiographic grade (Kellgren and Lawrence grade, K/L grade) on cytokine levels were accessed by MWW test. Spearman's rank correlation test used to assess the association between cytokines and pain levels.

The three cohorts showed distinct inflammatory profiles. Specifically, EGF, FGF-2, MCP-3, MIP-1a, IL-8 were significant different between knee and hip OA; FGF-2, GRO, IL-8, MCP-1, VEGF were significant different between hip OA and control; Eotaxin, GRO, MCP-1, MIP-1b, VEGF were significant different between knee OA and control (p-value < 0.0012). For hip OA cohorts, cytokines do not differ between K/L grade three and K/L grade four or between patients that displayed either impingement or dysplasia. Three cytokines were significant associated with pain: IL-6 (p-value = 0.045), MDC (p-value = 0.032) and IP-10 (p-value = 0.038).

We have demonstrated that differences in serum inflammatory profiles exist between hip and knee OA patients. These differences suggest that OA may include different inflammatory subtypes according to affected joints. We also identified that the cytokine IL-6, MDC and IP-10 are associated with pain level in hip OA patients. These cytokines might help explain the inconsistent of presentation of pain with radiographical severity of OA joints. Future studies are needed to validate our findings and then to understand the following questions: (1) how differently affected joints are reflected in systematic biomarkers; (2) how these cytokines are biologically involved in the OA pain pathway.

Total hip arthroplasty (THA) is the most effective treatment modality for severe arthritis of the hip. Patients report excellent clinical and functional outcomes following THA, including subjective improvement in gait mechanics. However, few studies in the literature have outlined the impact of surgical approach on gait kinetics and kinematics. The purpose of this study was to determine the impact of surgical approach for THA on quantitative gait analysis.

Thirty patients undergoing THA for primary osteoarthritis of the hip were assigned to one of three surgical approaches (10 anterior, 10 posterior, and 10 lateral). A single surgeon performed each individual approach. Each patient received standardised implants at the time of surgery (cementless stem and acetabular component, cobalt chrome femoral head, highly cross-linked liner). Patients underwent 3D gait analysis pre-operatively, and at 6- and 12-weeks following the procedure. At each time point, temporal gait parameters, kinetics, and kinematics were compared. Statistical analysis was performed using one-way analysis of variance.

All three groups were similar with respect to age (p=0.27), body mass index (p=0.16), and the Charlson Comorbidity Index (p=0.66). Temporal parameters including step length, stride length, gait velocity, and percent stance and swing phase were similar between the groups at all time points. The lateral cohort had higher pelvic tilt during stance on the affected leg than the anterior cohort at 6-weeks (p=0.033). Affected leg ipsilateral trunk lean during stance was higher in the lateral group at 6-weeks (p=0.006) and 12-weeks (p=0.037) compared to the other cohorts. The anterior and posterior groups demonstrated an increased external rotation moment at 6-weeks (p=0.001) and 12-weeks (p=0.005) compared to the lateral group.

Although temporal parameters were similar across all groups, some differences in gait kinematics and kinetics exist following THA using different surgical approaches. However, the clinical relevance based on the small magnitude of the differences remains in question.

Patients undergoing Joint Arthroplasty received a significant proportion of blood transfusions. In this study, we compared the risk of Deep Infection, and Superficial Infection post operation following Primary Total Hip or Knee replacement in blood-transfused and non-blood-transfused patients.

Cohort of patients who underwent primary total Hip or Knee Arthroplasty from April 2012 to March 2015 in Alberta. Patient characteristics, comorbidity, received blood transfusion were collected from electronic medical records, operating room information systems, discharge abstract database, provincial clinical risk grouper data. Deep Infection and Superficial Infection were captured from Provincial Surgical Site Infection Surveillance data. Deep Infection include deep incisional and organ/space infections. Logistic regression analysis were used to compare Deep Infection and Superficial Infection in blood-transfused and non-blood-transfused cohorts, and risk-adjusted for age, gender, procedure type, and co-morbidities.

Our study cohort contains 27891 patients, with mean of age at admission was 66.3±10.4, 57.5% female, 49.3% had 1 or more comorbidities. 58.8% underwent Knee Replacement. 11.1% received blood transfusion during hospital stay (Total Hip Replacement (THR) =13.1% and Total Knee Replacement (TKR) =9.7%,). 1.1% had Deep Infection (THR=1.4% and TKR=0.9%) and 0.5% had Superficial Infection (THR=0.5% and TKR=0.5%). Blood-transfused patients got 1.7% Deep Infection and 1.0% Superficial infection. Non-blood-transfused patients got 1.0% Deep Infection and 0.5% Superficial infection. Controlling for age, gender, procedure type, and co-morbidities, the odds of Deep Infection were 1.6 times higher for blood-transfused patients than for non-blood-transfused patients (adjusted odds ratio [OR]=1.6, 95% confidence interval [CI] [1.2–2.2], p=0.004). The odds of Superficial Infection were 2.0 times higher for transfused patients (adjusted OR=2.0, 95% CI [1.3–3.0], p=0.002).

Blood transfusion increases Deep Infection and Superficial Infection post-surgery following Primary Total Knee or Hip Replacement. This finding suggests to reduce the unnecessary blood transfusion for patients considering Joint Arthroplasty. Reducing the blood transfusion will save the inpatient cost and decrease the infective complications post-surgery in Hip or Knee Arthroplasty patients.

Cam-type femoral acetabular impingement (FAI), is a common structural hip deformity and thought to be a leading cause of early hip osteoarthritis. Although patients who undergo surgical correction notice improved clinical function it is unclear what impact this has on the overall health of the cartilage. T1rho MRI cartilage mapping has been shown to be a reliable imaging technique to assess the proteoglycan (PG) content potentially serving as a biomarker. This study analyses post surgical changes in T1rho levels in hip joints treated with cam FAI.

Eleven patients with a mean age of 38 (all males) underwent pre and post T1Rho Cartilage mapping of their hips at a mean time of 20 months post surgical intervention. The acetabulum was spatially divided into 4 main regions of interest (ROI), with levels of T1Rho in cartilage quantified as a whole and in each spatial segment. T1Rho signal is inversely correlated with level of PG content.

All patients demonstrated loss of PG content on pre-op imaging with a T1Rho of 33.5ms+2.6ms. Preop T1rho levels were found to significantly correlated with the difference between pre-op and post-op T1rho in entire hip cartilage (R: 0.73; p=0.016). This correlation was reflected both in the anterolateral quadrant (R: 0.86; p=0.002), and in the posteriosuperior quadrant (R:0.70; p=0.035). Additionally, significant correlation was found between improvement of WOMAC pain score over time, and difference of T1rho values over time in the most lateral 3mm slice of the anterolateral quadrant (R: 0.81; p=0.045). Significant correlation was found between pre-op alpha angle at 1:30 and difference between pre-op and post-op total cartilage T1rho content (R: −065;p=0.038).

T1Rho Cartilage mapping of the hip is a useful biomarker in the assessment of the surgical management of Cam type FAI. This preliminary data provides some evidence that surgical correction of the deformity can help minimise disease progression.

The direct anterior (DA) approach for total hip arthroplasty (THA) has become increasingly popular in North America. With experience, exposure of both the acetabulum and femur can be achieved similar to those in other approaches. In cases of difficult femoral exposure, the conjoint tendon of the short external rotators can be released to improve visualisation. The effect of conjoint tendon release has not been previously explored in regards to overall outcomes, or postoperative pain. The goal of this study was to evaluate 1) the length of stay and inpatient pain medication requirements of patients undergoing DA THA on the basis of conjoint tendon release, and 2) whether conjoint tendon release influenced functional outcomes.

We conducted a retrospective chart review of all cases of primary DA THAs conducted by single surgeon at LHSC University between August 2012 and July 2015. Patient demographics, bilateral THA cases, intraoperative conjoint tendon or other soft tissue releases, intra-operative complications, and length of stay (LOS) were evaluated for all cases. Inpatient pain medication data was available for all cases from Apr 2014 onwards. One year functional outcome scores, including WOMAC and Harris Hip Scores (HHS), were evaluated for all cases before August 2014. Six-week and three-month functional outcome scores were available and evaluated for a subset of cases. All data was analysed with multiple linear regression.

Three hundred and twelve cases of primary DA THAs were identified, of which 29 were concurrent bilateral THAs. One hundred and eighty cases included a conjoint tendon release, while 29 cases had other soft tissue releases (tensor fascia lata). Mean age and BMI were 64.9±11.5 years and 29.0±5.3 respectively. Mean LOS was 1.3±1.1 days, with age, bilateral THA, non-conjoint tendon soft tissue release, and intra-operative complications being predictive of LOS (p<0.05). Pain medication data was available for 107 cases, of which 11 were concurrent bilateral THAs. Sixty four cases included a conjoint tendon release, while one case had other soft tissue releases. Mean daily morphine equivalent dose (MED) narcotic use was 43.2±48.2mg, with age being a negative predictor of narcotic use (p<0.05). BMI was a negative predictor of one year HHS pain, HHS total, and all WOMAC subcategory scores, while age was a negative predictor of one year HHS function and HHS total scores (p<0.05). None of the variables were predictive of six-week and three-month functional outcome scores. Conjoint tendon release was not predictive of LOS, inpatient pain medication requirements, or outcome scores.

Conjoint tendon release did not affect postoperative pain, LOS, or functional outcomes. Given that conjoint release improves femoral exposure, intraoperative thresholds for conjoint release should be low. The effect of intraoperative release of other soft tissues is uncertain, as this increased LOS but not postoperative pain.