Purpose

Stress fractures (SFs) are highly prevalent in female athletes, especially runners (1337%), and result in pain and lost training time. There are numerous risk factors for SFs in athletes; however, the role of bone quality in the etiology of SFs is currently unknown. Therefore, our primary objective was to examine whether there are characteristic differences in bone quality and bone strength in female athletes with lower limb SFs using high-resolution peripheral quantitative computed tomography (HR-pQCT). A secondary objective was to compare muscle strength between SF subjects and controls.

Method

Female athletes with (n=19) and without (n=19) lower limb SFs were recruited from the local community. All SFs were medically confirmed by a physician and subjects were assessed within 1–47 weeks (12.7 13.7) of diagnosis. Controls were age-, training volume- and sport-matched to SF athletes. Bone density and microarchitectural bone parameters such as cortical thickness and porosity, as well as trabecular thickness, separation and number of all subjects were assessed using HR-pQCT at two distal tibia scanning sites (distal, ultra-distal). Finite element (FE) analysis was employed to estimate bone strength and load sharing of cortical and trabecular bone from the HR-pQCT scans. Regional analysis was applied to the HR-pQCT scans to investigate site-specific bone differences between groups. Muscle torque was measured by a Biodex dynamometer as a surrogate of muscle strength. Independent sample t-tests and Mann-Whitney U-tests were used for statistical analyses (p < 0.05).

Purpose

Angiogenesis and osteogenesis are essential for bone growth, fracture repair, and bone remodeling. VEGF has an important role in bone repair by promoting angiogenesis and osteogenesis. In our previous study, endothelial progenitor cells (EPCs) promoted bone healing in a rat segmental bone defect as confirmed by radiological, histological and microCT evaluations (Atesok, Li, Schemitsch 2010); EPC treatment of fractures resulted in a significantly higher strength by biomechanical examination (Li, Schemitsch 2010). In addition, cell-based VEGF gene transfer has been effective in the treatment of segmental bone defects in a rabbit model (Li, Schemitsch et al 2009); Purpose of this study: Evaluation of VEGF gene expression after EPC local therapy for a rat segmental bone defect.

Method

Rat bone marrow-derived EPCs were isolated from the rat bone marrow by the Ficoll-paque gradient centrifuge technique. The EPCs were cultured for 7 to 10 days in endothelial cell growth medium with supplements (EGM-2-MV-SingleQuots, Clonetics). and collected for treatment of the rat segmental bone defect. EPCs were identified by immunocytochemistry staining with primary antibodies for CD34, CD133, FLK-1, and vWF. A total of fifty six rats were studied. A five millimeter segmental bone defect was created in the middle 1/3 of each femur followed by mini plate fixation. The treatment group received 1×106 EPCs locally at the bone defect and control animals received saline only. Seven control and seven EPC treated rats were included in each group at 1, 2, 3 and 10 weeks. Animals were sacrificed at the end of the treatment period, and specimens from the fracture gap area were collected and immediately frozen. Rat VEGF mRNA was measured by reverse transcriptase-polymerase chain reaction (RT-PCR) and quantified by VisionWorksLS. All measurements were performed in triplicate.

Purpose

Up to 70% of the differences in human bone mass have been attributed to genetic background. These differences are associated with alterations in the biomechanical properties, micro-architecture and remodeling of bone as well as its susceptibility to fracture and its capacity for repair. In previous work it was shown that C57Bl6 mice carrying one copy of the parathyroid hormone related protein (PTHrP+/−) gene developed osteopenia by four months of age. The current study was designed to determine if the haploinsufficient phenotype was maintained on a C3H background.

Method

PTHrP+/+ and PTHrP+/− mice on C57Bl6 and C3H backgrounds were euthanised between 6 and 18 months of age. The femurs were harvested, fixed in 4% paraformaldehyde overnight and scanned on a Skyscan 1172 equipped with a 10kV X-ray source and a 10 megapixel camera at a resolution 5μm. The amount and quality of cortical and trabecular bone was quantified from 2D images and 3D reconstructions using CTAn, CTvol and CTVox software. The undecalcified specimens were embedded at low temperature in MMA, sectioned at 5 μm and stained with Von Kossa and Toluidine Blue to distinguish mineralized from unmineralized tissue.

Purpose

The data regarding the effects of noggin on bone morphogenetic protein (BMP)-induced osteogenesis of mesenchymal stem cells (MSCs) are controversial. Most studies performed in rodent cells/models indicated that noggin was a negative regulator of BMP-2-induced osteogenesis; however, one study conducted with human MSCs in culture showed that the addition of noggin induced osteogenesis in vitro. To clear the controversy, we designed this study to evaluate the effects of knocking down noggin gene expression on BMP-2-induced osteogenesis of human bone marrow-derived primary MSCs in vitro.

Method

MSCs were isolated from human tibial bone marrow by density gradient centrifugation. Two noggin small interfering RNAs (siRNAs) were used in this study to knockdown noggin gene expression. There were four study groups: MSCs with no transfection of siRNA (named as NT group), MSCs transfected with non-targeting negative control siRNA (named as control group), MSCs transfected with noggin siRNA1 (named as NOGsi1 group), and MSCs transfected with noggin siRNA2 (named as NOGsi2 group). After transfection, MSCs were induced to undergo osteogenic differentiation by incubating in basal medium containing 0.1 μg/ml BMP-2 for 35 days. The expression levels of osteoblastic marker genes were measured by real-time quantitative PCR on day 14. Also assessed was alkaline phosphatase (ALP) activity by a colorimetric kinetic assay and Fast Blue B staining on day 14. Calcium deposition was determined by the calcium assay on day 35.

Purpose

Internal fixation of fractures in the presence of osteopenia has been associated with a failure rate as high as 25%. Enhancing bone formation and osseointegration of orthopaedic hardware is a priority when treating patients with impaired bone regenerative capacity. Fibroblast Growth Factor (FGF) 18 regulates skeletal development and could therefore have applications in implant integration. This study was designed to determine if FGF 18 promotes bone formation and osseointegration in the osteopenic FGFR3−/− mouse and to examine its effect on bone marrow derived mesenchymal stem cells (MSCs).

Method

In Vivo: Intramedullary implants were fabricated from 0.4 × 10mm nylon rods coated with 300nm of titanium by physical vapour deposition. Skeletally mature, age matched female FGFR3−/− and wild type mice received bilateral intramedullary femoral implants. Left femurs received an intramedullary injection of 0.1μg of FGF 18 (Merck Serono), and right femurs received saline only. Six weeks later, femurs were harvested, radiographed, scanned by micro CT, and processed for undecalcified for histology. In Vitro: MSCs were harvested from femurs and tibiae of skeletally mature age matched FGFR3−/− and wild type mice. Cells were cultured in Alpha Modified Eagles Medium (αMEM) to monitor proliferation or αMEM supplemented with ascorbic acid and sodium beta-glycerophosphate to monitor differentiation. Proliferation was assessed through cell counts and metabolic activity at days 3, 6 and 9. Differentiation was assessed through staining for osteoblasts and mineral deposition at days 6, 9 and 12.

Purpose

Fractures to the distal radius are costly and debilitating injuries. While it is generally accepted that the leading cause of these injuries is a fall onto an outstretched arm, the mechanics of the injury are less well understood. The main limitations of past research are the use of unrealistic loading rates or uncontrolled loading protocols. Therefore, the purpose of this research was to examine the mechanical response of the distal radius pre-fracture and at fracture, under dynamic loads indicative of a forward fall.

Method

Eight cadaveric radius specimens were cleaned of all soft tissues and potted at a 75o angle (representative of the angle between the volar radius and the ground) up to the distal third of the radius. A custom designed pneumatic impact system was used to apply impulsive impacts to the specimen at increasing energy levels until failure occurred. The intra-articular surface of the radius rested against a model scaphoid and lunate made from high density polyethylene (Sawbones) attached to a 5 degree of freedom load cell that in turn was attached to an impact plate. The position of the carpals within the intra-articular surface simulated 45o of wrist extension. Following failure (defined as the specimen being fractured into at least 2 distinct pieces), the specimens were removed from the testing apparatus and the location, type, pattern and severity of injury was noted and classified using the Frykman and Melone classification systems. Energy input and force variables were also collected at failure.

Purpose

Despite enormous progress regarding the genetic regulation of limb development, little attention has been paid to the cellular and tissue mechanisms that govern outgrowth. How does the limb bud acquire its peculiar shape? Previous models have focused on isotropic growth resulting from distally based proliferation. However, recent models and proliferation data and models suggest that differential proliferation cannot explaing the morphogenesis of the limb bud. We tested the possibility that oriented cell behaviours underlie early outgrowth.

Method

We visualised early limb buds in living mouse and zebrafish embryos at cellular resolution by using transgenic subcellular fluorescent labels that mark either the cell nucleus or the cell membrane. We acquired time lapse and static images using a confocal microscope and generated velocity vector fields to track cell movements, and also tracked cell division planes through the entire tissue. To complement the live imaging, we also undertook lineage tracing experiments in chick and zebrafish embryos. The molecular determinants of these cell movements were tested by crossing the reporter transgenes onto mutant backgrounds.

Purpose

Traditionally, the gold standard for bone grafting has been either autografts or allografts. Whilst autografts are still widely used, drawbacks such as donor site morbidity are shifting the market rapidly toward the use of orthobiologic bone graft substitutes. This study investigated the in vivo performance of a novel (W02008096334) collagen-hydroxyapatite (CHA) bone graft substitute material as an osteoinductive tissue engineering scaffold. This highly porous CHA scaffold offers significantly increased mechanical strength over collagen-only scaffolds while still exhibiting an extremely high porosity (≈ 99%), and an osteoinductive hydroxyapatite phase [1]. This study assessed the ability of the CHA scaffolds to heal critical-sized (15 mm) long bone segmental defects in vivo, as a viable alternative to autologous bone grafts.

Method

Collagen-HA (CHA) composite scaffolds were fabricated based on a previously-described freeze-drying technique [1]. After freeze-drying, these scaffolds were subjected to a dehydrothermal treatment and subsequently chemically crosslinked using EDAC. In vivo performance was assessed using a critical size segmental radial defect (15 mm) introduced into 16 young adult New Zealand White Rabbits under Irish Government license. Animals were divided into three groups; (i) an empty defect group (negative control), (ii) an autogenous bone graft group (positive control) and (iii) a CHA scaffold group (CHA). Segmental defect healing in all animals was assessed using plain X-Ray analysis, at four time-points (0, 6, 12 and 16 weeks). MicroCT and histological analysis were carried out at week 16.

Purpose

Alpine skiing is associated with large skeletal loads with distinct patterns of loading rate and direction, and alpine skiers were previously found to have a robust bone structure compared to normally active controls. However, it is not known whether the mechanical stimuli experienced by skiers are also associated with enhanced bone microarchitecture and strength. Thus, the purpose of this study was to use high-resolution peripheral quantitative computed tomography (HR-pQCT) to compare bone macro- and microarchitecture and bone strength between elite alpine skiers and normally active controls.

Method

Participants included 7 female and 12 male members of the Canadian Alpine Ski Team, and 10 female and 16 male normally active control subjects. A whole body dual energy X-ray absorptiometry (DXA) scan was performed to measure lean mass and percent body fat. HR-pQCT (XtremeCT, Scanco) was used to assess bone macro- and microarchitecture including total, cortical and trabecular bone area, total and cortical bone mineral density (BMD), and bone volume ratio (BV/TV) of the dominant distal tibia and radius. Finite element analysis was applied to the HR-pQCT scans to estimate bone strength (failure load, N). Analysis of covariance (ANCOVA) was used to compare outcomes between groups adjusting for body weight (tibia) and height (tibia and radius).

Purpose

Vitamin D is a key regulator of bone homeostasis. The enzyme CYP24A1 is responsible for transforming vitamin D into 24,25(OH)2vitD. The putative biological activity of 24,25(OH)2vitD remains unclear. Previous studies showed an increase in the circulating levels of this metabolite following a fracture in chicks. Our laboratory has engineered a mouse model deficient for the Cyp24a1 gene for studying the role of 24,25(OH)2vitD. We set out to study the role of 24,25(OH)2vitD in endochondral and intramembranous bone formation in fracture repair in this mouse model based on the results of the chick fracture repair study.

Method

Wild-type and mutant Cyp24a1 gene deficient mice were subjected to two different surgical procedures to simulate bone development and fracture repair. To mimic endochondral ossification, we devised a modified technique to perform intramedullary nailing of a mouse tibia followed by an induced fracture. To evaluate intramembranous ossification, we applied distraction osteogenesis to a mouse tibia using a mini Ilizarov external fixator apparatus. Histomorphometric parameters and gene expression differences in fracture repair between the mutant mice and the wild-type controls were measured using micro computed tomography, histology and reverse-transcription quantitative PCR (RT-qPCR) respectively.

Purpose

The recent emergence of autologous blood concentrates, such as platelet rich plasma (PRP), as a treatment option for patients with orthopaedic injuries has led to an extensive debate about their clinical benefit. Our objective was to determine the effectiveness of autologous blood concentrates compared with control therapy in improving pain in patients with orthopaedic bone and soft tissue injuries.

Method

We conducted a systematic review of MEDLINE and EMBASE from 1996 and 1947, respectively, up to July 2010. Additional studies were identified by contacting experts, searching the bibliographies of the included studies as well as orthopaedic meeting archives. We included published and unpublished randomized controlled trials or prospective cohort studies that compared autologous blood concentrates with a control therapy in patients with an orthopaedic injury. Two reviewers, working in duplicate, abstracted data on study characteristics and protocol. Reviewers resolved disagreement by consensus.

Purpose

To describe the geometric variables of the posterosuperior humeral-head (Hill-Sachs) lesion and analyze their relationship with patient clinical variables.

Method

Twenty-eight patients with anteroinferior instability and substantial Hill-Sachs lesions were evaluated using arthro-computer tomography (CT) scans. The images were studied with the OSIRIX software, and the following lesion variables were measured: depth, length, width, volume, surface area, and width/depth ratio. Moreover, the ratio of the humeral heads total volume over the volume under its joint surface was calculated to express the lesions severity as the compromised fraction of the humeral heads articular segment. The above data was statistically analyzed in relation to the total number of instability episodes, the distinction between dislocations and subluxations, and the type of sport played.

Purpose

Glenoid component loosening is a common reason for failed total shoulder arthroplasty. Multiple factors have been suggested as causes for component loosening that may be related to cement technique. The purpose of the study was to compare the load transfer across a polyethylene glenoid bone construct with two different cementing techniques.

Method

Eight cadaveric specimens underwent polyethylene glenoid component implantation. Four had cement around the pegs only (CPEG) and four had cement across the entire back (CBACK) of the implant including around the pegs. Step loading was performed with a pneumatic actuator and a non-conforming humeral head construct capable of applying loads at various angles. Strain gauges were placed at the superior and inferior poles of the glenoid and position trackers were applied to the superior and inferior aspects polyethylene component. Micro CT data were obtained before and after the loading protocol.

Purpose

Twelve case reports of distal femur fractures as post-operative complications after anterior cruciate ligament (ACL) reconstruction have been described in the literature. The femoral tunnel has been suggested as a potential stress riser for fracture formation. The recent increase in double bundle ACL reconstructions may compound this risk. This is the first biomechanical study to examine the stress riser effect of the femoral tunnel(s) after ACL reconstruction. The hypotheses tested in this study are that the femoral tunnel acts as a stress riser to fracture and that this effect increases with the size of the tunnel (8mm versus 10mm) and with the number of tunnels (one versus two).

Method

Femoral tunnels simulating single bundle (SB) hamstring graft (8 mm), bone-patellar tendon-bone graft (10 mm), and double bundle (DB) ACL reconstruction (7mm, 6 mm) were drilled in fourth generation saw bones. These three experimental groups and a control group consisting of native saw bones without tunnels, were loaded to failure.

Purpose

Recent work has shown that joint contracture severity can be decreased with the mast cell stabilizer ketotifen in association with decreased numbers of myofibroblasts and mast cells in the joint capsule of a rabbit model of post-traumatic contractures. Neuropeptides such as Substance P (SP) can induce mast cells to release growth factors. Using a gel contraction assay, we test the hypothesis that joint capsule cell-mediated contraction of a collagen gel can be enhanced with SP, but the effect is magnified in the presence of mast cells.

Method

Anterior elbow joint capsules were obtained at the time of surgical release from 2 men (age 34 and 54) and 1 woman (age 40) with chronic (> 1 year) post-traumatic joint contractures. The human mast cell line HMC-1 (Mayo Clinic, Rochester), SP and the NK1 receptor antagonist RP67580 (Sigma, Oakville, ON) were used. NK1 is the SP receptor.

Neutralized Collagen solution composed with 58% Vitrogen 100 purified collagen mixed with HMC-1 cells only (7.5 105), human capsule cells (2.5 105), or human capsule cells (2.5 105) and 7.5 105 mast cells (1:3) were cast into 24- well tissue culture plates. In some experiments, SP (1 × 10⁻⁵ M) +/− RP67580 (0.5 mM) were added. The gels were maintained with 0.5 ml DMEM composed with 2% BSA and incubated at 37C for 12 h for gelation to occur. The gels were then detached from the wall and the bottom of culture plate wells, and photographed at regular intervals up to 72 hours. Gel contraction studies were carried out on passage 4 and done in triplicate for each patient. The average value of each patients triplicate was combined to give a mean contraction at each time point.

Statistical analysis involved an ANOVA with posthoc Bonferroni correction. P < 0.001 was significant.

Purpose

Capitellum hemiarthroplasty is an emerging concept. The current metallic capitellar implants have spherical surface shapes, but the native capitellum is not spherical. This study evaluated the effect of capitellar implant shape on the contact mechanics of the radiocapitellar joint when articulating with the native radial head.

Method

Eight paired radii and humeri were potted in a custom jig. Articular casts were made with medium-viscosity resin while 85 N of axial load was applied to the reduced radiocapitellar joint at 0, 45, and 90 of elbow flexion, and at neutral, 50 pronation and 50 supination at each flexion angle. The native radiocapitellar articulation was compared to capitellar hemiarthroplasties of two surface designs (anatomical and spherical). Contact area and shape (circularity) were determined. Circularity was defined as the ratio of the minor axis and major axis of the shape.

Purpose

Full-thickness tendon tears of the supraspinatus (SP) are common and can have a significant impact on shoulder function. To optimally treat supraspinatus tendon tears an accurate understanding of its musculotendinous architecture is needed. We have previously shown that the architecture of supraspinatus is complex. It has architecturally distinct regions: anterior and posterior, each of which is further subdivided into superficial, middle and deep parts (Kim et al., 2007). Data of FBL and PA of the torn supraspinatus could enhance clinical decision making and guide rehabilitative treatments (Ward et al., 2006). Currently, however, in vivo US quantification of the fiber bundle architecture of the distinct regions of supraspinatus in subjects with full-thickness tendon tears has not been investigated.

PURPOSE: To quantify architectural parameters within the distinct regions of supraspinatus in subjects with a full-thickness tendon tear using the US protocol that we previously developed (Kim et al., 2010), and to compare findings with age and gender matched normal controls.

Method

Twelve SP from eight subjects, mean age 576.0 years, were scanned using an US scanner (12 MHz). The SP was scanned in relaxed and contracted states. For the contracted state, SP was scanned with the shoulder in neutral rotation and 60 of active abduction. Fiber bundles of the anterior region (middle and deep) and posterior region (deep) could be visualized and measured. Muscle thickness, FBL, and PA were computed from US scans. Data was analyzed using Mann-Whitney and Wilcoxon Signed Rank Tests (P<0.05).

Purpose

The remplissage technique of insetting the infraspinatus tendon and posterior joint capsule into an engaging Hill-Sachs lesion has gained in popularity. However, a standardized technique for suture anchor and suture placement has not been defined for this novel procedure. The purpose of this biomechanical study was to compare three remplissage techniques by evaluating their effects on joint stiffness and motion.

Method

Cadaveric forequarters (n=7) were mounted on a custom active biomechanical shoulder simulator. Three randomly ordered techniques were conducted: T1- anchors in the valley of the defect, T2- anchors in the rim of the humeral head; T3- anchors in the valley with medial suture placement. The testing conditions included: intact, Bankart, Bankart repair, and 15% & 30% HS lesions with repairs (T1, T2, T3). Outcome measures including internal-external range of motion and stability were recorded. Stability was quantified in terms of glenohumeral joint stiffness against an externally applied anterior force of 70N.

Purpose

Radiographs are the most common imaging modality used to guide orthopaedic interventions. Ultrasound (US) imaging offers potential advantages for intraoperative imaging by its portability and ability to produce real-time 2D or 3D images without radiation to either the patient or surgical team. Our objective in this study was to determine in a live emergency room setting, if a newly-developed image processing method for 3D US would allow us to accurately extract (reproduce) the surfaces of fractured bones.

Method

We obtained both CT scans and US images from consenting patients admitted to our Level 1 Trauma Centre for radius or pelvic fractures clinically requiring a CT scan. All US examinations in this clinical study were performed with a GE Voluson 730 machine with a 3D RSP5-12 transducer (a mechanized probe in which a linear array transducer is swept through an arc range of 20). Dorsal, volar, and radial views were obtained in the case of radial fractures and iliac crest views in the case of pelvic fractures.

The bone surfaces on CT were extracted using a thresholding algorithm [1]. Standard, clinical 3D reconstructions were also created using GE Voxtool 4.0.1 to serve as a qualitative comparison.

The US images were processed using the phase-processing algorithm described in [2] then registered to the CT images using a manually-supervised anatomical landmark-based rigid registration algorithm. The quality of the resulting surface matching was evaluated by computing the root mean square distance between the two surface representations [2] and by inter-observer agreement of the registered images to the clinical renderings.

Purpose

Prospective randomized intervention trial to determine whether patients undergoing rotating platform total knee arthroplasty have better clinical outcomes at two years when compared to patients receiving fixed bearing total knee arthroplasty as measured by the WOMAC, SF-36 and Knee Society (KSS) scores.

Method

67 consecutive patients (33 males and 34 females; average age 66 years) were randomized into either receiving a DePuy Sigma rotating platform (RP) total knee arthroplasty (29 patients) or a DePuy Sigma fixed bearing (FB) total knee arthroplasty (38 patients). Inclusion criteria included patients between the ages of 45–75 undergoing single-sided total knee arthoplasty for clinically significant osteoarthritic degeneration.

Pain, disability and well-being were assessed using the WOMAC, KSS, and SF-36 preoperatively and at 6 months, 1 year and 2 years post-operatively. In addition, intraoperative measures were collected. Pre-operative radiographs were analyzed using the Kellgren and Lawrence Score, modified Scotts Scoring and mechanical axis. Post-operative radiographs were collected at 1 and 2 years and analyzed to identify evidence of prosthetic loosening, implant positioning and limb alignment.

Purpose

Femoral nerve block (FNB) following total knee arthroplasty (TKA) has had mixed results with some studies reporting improvement in pain and reduced narcotic exposure while others have not shown substantial differences. The effect of a FNB on rehabilitation indices (quadriceps strength, knee flexion) is also unclear.

The study purpose was to compare the effect of FNB+ a multimodal analgesic protocol (MMA) to MMA only on the 1) development of a complete quadriceps motor block and 2) knee flexion during the first two postoperative days and 3) knee flexion out to 12 weeks after primary TKA. Secondarily, we compared hospital length of stay (LOS), postoperative pain, analgesic use and the incidence of nausea/vomiting.

Method

This was a controlled clinical trial undertaken at two tertiary hospitals that do high annual TJA volumes (>200 cases). Both hospitals followed the same regional clinical pathway for preoperative, perioperative and postoperative care. The pathway started mobilization on the day of surgery with a goal for discharge home on the third postoperative day.

At one site, FNB was used for the first two postoperative days in addition to MMA as needed (FNB group [n=19]) while the other site used standardized MMA (MMA group [n=20]) only.

The presence of a complete quadriceps block, knee flexion, pain, analgesic use, incidence of nausea and vomiting were recorded daily in hospital. Hospital LOS was also recorded and knee flexion and pain were assessed at two, six and 12 weeks post discharge.

Abstract

By next summer the number of patients in the tranexamic acid group will be much higher, probably around 50–60.

Purpose

Tranexamic acid has been extensively studied in single total knee and total hip replacement patients. It has been found to reduce blood loss and transfusion rates, with no increase in the rate of venous thromboembolism.

This study was undertaken to determine whether tranexamic acid reduces blood loss and the rate of blood transfusion after bilateral total knee replacement, which has a much higher transfusion rate.

Purpose

Femoral nerve blockade (FNB) can provide prolonged postoperative analgesia and facilitate rehabilitation following major knee surgery while minimizing opioid-related adverse effects. However, anecdotal data have implicated FNB in post-operative falls, presumably due to a block-related reduction in quadriceps strength. Age, gender and knee replacement surgery have also been previously identified as risk factors for falls in the acute postoperative orthopaedic inpatient setting. We hypothesized that the use of FNB would be an independent predictor of an inpatient fall following total knee replacement (TKR).

Method

We examined a cohort of 2,197 patients who underwent TKR in a single academic institution between October 2003 and March 2010. The start date was based on the separate initiation of both a comprehensive regional anesthesia database and an orthopaedic ward Falls Surveillance Program. Patients undergoing revision TKR or unicompartmental arthroplasty were excluded. Age, simultaneous bilateral TKR, gender, body mass index (BMI), and various regional nerve blocks were considered predictors of post-operative falls in a logistic regression model. The database allowed resolution of the type (i.e. femoral, sciatic) and duration (i.e. single-bolus, indwelling continuous perineural catheter) of nerve blockade. Hospital-standard dosing and insertion techniques were employed.

Purpose

The purpose of this study was to compare the outcomes and complications of normal weight, class one obese (BMI=30-34.9 kg/m2) and superobese (BMI≥50 kg/m2) primary total knee replacement (TKR) patients.

Method

Between January 1995 and December 2005, 4104 primary TKR were performed in our centre. Patients were stratified for their obesity level according the World Health Organisation (WHO) and current surgical literature classification. Sixty-seven superobese patients (group one) were identified. They were matched with normal weight (group two) and class one obese (group three) primary TKR patients for sex, age, side, preoperative diagnosis, implants used, time since surgery and preoperative SF-12 mental component summary score (MCS). Patient clinical outcomes (WOMAC, SF-12 and Knee Society scores), radiographs, complications, readmissions, and revisions rates were compared for normal BMI, class one obese and superobese patients.

Purpose

Unicompartmental knee replacement (UKR) is an established, bone preserving surgical treatment option for medial compartment osteoarthritis (OA). Early revision rates appear consistently higher than those of total knee replacement (TKR) in many case series and consistently in national registry data. Failure with progression of OA in the lateral compartment has been attributed, in part, to surgical technical errors. In this study we used navigation assisted surgery to investigate the effects of improper sizing of the mobile bearing and malrotation of the tibial component on alignment and lateral compartment loading.

Method

A total of eight fresh frozen cadaveric lower limbs were used in the study. After thawing overnight, a Brainlab navigation system with an Oxford (Biomet, Inc) medial UKR module was used to capture the native knee anatomy and alignment using a digitizing probe. Following registration, the case was performed with navigation verified neutral cuts and an ideal insert size was selected to serve as a baseline. The bearing thickness was subsequently increased by 2 mm increments to simulate progressive medial joint overstuffing. Excessive tibial internal rotation of 12 was also simulated at each of the intervals. Knee alignment in varus or valgus was recorded in real time for each surgical scenario with the knee in full extension and at 20 of flexion. Lateral compartment peak pressure was measured using a Tekscan pressure map.

Purpose

Infection following total knee arthroplasty is a devastating complication, requiring considerable effort on the part of the surgeon to eradicate the infection and restore joint function. Two-stage revision is the standard of care in the treatment of peri-prosthetic infection, using a temporary antibiotic-impregnated spacer between procedures. However, controversy remains concerning the use of static versus dynamic spacers, as well as the spacer material. The purpose of this study was to evaluate the clinical outcomes and complications of two-stage revision total knee arthroplasty in patients treated with a metal-on-polyethylene articulating spacer, as compared to those treated with a static antibiotic-impregnated cement spacer at the same centre.

Method

Twenty-seven knees in patients with a mean age of 65 years (range, 40 to 80 years) were treated with two-stage revision of an infected total knee arthroplasty using a metal-on-polyethylene dynamic prosthetic spacer fixed with antibiotic-impregnated cement. Clinical outcomes were evaluated using maximum active knee range of motion, as well as modified Knee Society knee scores and incidence of re-infection at a minimum one-year follow-up. The results were compared to those achieved at similar follow-up in 10 patients treated with a static cement spacer. Demographic profile as measured by age and gender, and pre-operative Knee Society scores and range of motion were similar between the two groups.

Purpose

The patella provides a mechanical advantage to the knee extensor mechanism. Patellectomy, performed for trauma or patellofemoral arthrosis, does not preclude the development of tibiofemoral arthrosis. Total knee arthroplasty is the mainstay of treatment for tibiofemoral arthrosis. The purpose of this study was to evaluate the outcomes of total knee arthoplasty in patients who previously underwent patellectomy.

Method

A retrospective analysis was completed on a prospectively collected database to identify all patients who underwent total knee arthroplasty following a previous patellectomy. Sixty-one total knee arthroplasties in 57 patients were identified. Patient demographics as well as functional outcome scores, including WOMAC and Knee Society Scores, were evaluated.

Purpose

The mobile-bearing total knee arthroplasty was designed to increase the contact area with the polyethylene bearing, through the functional range of motion, and subsequently decrease the wear rate previously seen in fixed-bearing implants. In the literature there is no clear clinical advantage between the different designs in the short to mid-term follow-up.

The purpose of this study was to compare the results between a cruciate retaining mobile-bearing design (SAL II, Sulzer) and two cruciate retaining fixed-bearing designs (AMK, Depuy, and the Genesis II, Smith and Nephew).

Method

Ninety patients were randomised to receive either the mobile-bearing or one of the two fixed-bearing designs between 2000 and 2002. Patients were evaluated preoperatively and postoperatively using the WOMAC and the SF-12, both of which are validated scores.

One patient was withdrawn due to dementia before three months and eleven patients died. Two patients were revised due to infection (both had received the SAL II). One patient was revised for aseptic loosening and one patient was revised for pain (both had received the Genesis II).

Of the 74 patients (77 knees) that remain, they were last seen on average 6.4 years (2–10) after their surgery. Their average age at the surgery was 69.2 years (52–81).

Purpose

Unicompartmental versus total knee arthroplasty has been a debated topic for decades. The purpose of this study was to compare the survivorship and clinical outcomes of a large primary total knee arthroplasty versus unicompartmental knee arthroplasty cohort.

Method

A consecutive series of 6352 TKAs and 296 UKAs with a minimum of one year follow-up were evaluated. Pre-operative scores, latest scores, and change in clinical outcome scores (KSCRS, SF12, WOMAC) were compared and tested for significance using the students t-test.

Purpose

To correlate the initial brace correction with quantity and quality of brace wear within the first 6 months for the treatment of adolescent idiopathic scoliosis (AIS).

Method

Brace treatment for AIS has been debated for years. Prediction of treatment outcomes is difficult as the actual brace usage is generally unknown. As technology became more advanced, electronic devices were able to measure adherence in both quantity (how much time the brace has been worn) and quality (how tightly the brace has been worn) of brace usage without need for patient interaction. The developed adherence monitor consisted of a force sensor and a data acquisition unit. Subjects were monitored within the first 6 months of brace wear. The data sample rate was set to be one sample per minute. Data was downloaded at the patients routine clinical visits. The prescription, first in-brace and first follow-up out-of-brace Cobb angles were measured. Twelve AIS subjects (10F, 2M), age between 9.8 and 14.7 years, average 11.9 1.5 years, who were prescribed a new TLSO and full-time brace wear (23 hours/day) participated. All braces were made by the same orthotist. The force value at the major pressure pad at the prescribed tightness level was recorded as the individualized reference value. The normalized force value (measured force magnitude relative to the individualized reference value) was used for the quality factor. The time of brace usage relative to the prescribed time was used as the quantity factor.

Purpose

Disc degeneration is known to occur early in adult life, but at present there is no medical treatment to reverse or even retard the problem. Development of medical treatments is complicated by the lack of a validated long term organ culture model in which therapeutic candidates can be studied. The objective of this study was to optimize and validate an organ culture system for intact human intervertebral disc (IVD), which could be used subsequently to determine whether synthetic peptide growth factors can stimulate disc cell metabolism and initiate a repair response.

Method

Seventy lumbar IVDs, from 14 individuals, were isolated within 24 h after death. Discs were prepared for organ culture by removing bony endplates but retaining cartilaginous endplates (CEP). Discs were cultured with no external load applied. The effects of glucose and FBS concentrations were evaluated. Dulbeccos Modified Eagle Media (DMEM) was supplemented with glucose, 4.5g/L or 1g/L, referred to as high and low (physiological) glucose, and FBS, 5% or 1%, referred to as high and low FBS, respectively. After a four week culture period, samples were taken across the disc using a 4 mm biopsy punch. Cell viability was analyzed using a live/dead fluorescence assay (Live/Dead, Invitrogen) and visualized by confocal microscopy. CEP discs were also placed in long term culture for four months, and cell viability was assessed. Western bolt analysis for the G1 domain of aggrecan was also performed to assess the effect of nutritional state on disc catabolism.

Purpose

Nucleus pulposus (NP) replacements represent a less invasive alternative for treatment of early stage degenerative disc disease (DDD). Hydrogel based NP replacements are of particular interest as they can be injected/implanted using minimally invasive surgical (MIS) techniques to re-establish mechanical integrity and as a scaffold for regeneration. A thiol-modified hyaluronan elastin-like polypeptide (TMHA/EP) hydrogel crosslinked using polyethylene diacrylate has shown promise as a potential NP replacement for DDD in vitro. This study aims to assess the mechanical properties of this hydrogel when injected into an induced early stage DDD porcine model and to determine the optimal injection method for delivery. It is hypothesized that minimally invasive injection of the TMHA/EP material can restore mechanical behaviour of spinal motion segments in early stage DDD.

Method

Intervertebral disc (IVD) degeneration was enzymatically induced in L2-L3 and L4-L5 lumbar levels in 10 Yorkshire boars using chondroitinase ABC (n=20 discs). An additional three animals served as healthy controls (n=6 discs). Following a four-week degradation period, the TMHA/EP solution (250microL in a 3:1 weight ratio) was injected into the degenerate NP of 16 discs by one of two MIS techniques: A direct 18G needle injection or a modified kyphoplasty technique (MKT) in which a balloon angiocatheter was inserted through an 11G trocar into the IVD and inflated to create a cavitary defect that was then filled with the hydrogel. Excised motion segments were tested in axial compression under a load of 400N and in axial rotation (AR), lateral bending (LB) and flexion/extension (FE) at 5Nm. Range of motion (ROM), neutral zone (NZ) length, NZ stiffness (NZStiff) and axial compressive stiffness (ACStiff) were quantified.

Purpose

Developmental exposure to estrogens has been shown to affect a number of organ systems, including long and short bones. Epigenetic effects of DES exposure have been shown to affect the third generation of progeny. Furthermore, recent studies have shown that environmental exposure to estrogen-like compounds is much higher than originally anticipated. This study aims to discover the effect of in utero exposure to a well-known estrogen agonist, diethylstilbestrol (DES), on lumbar bone, intervertebral disc (IVD), and articular cartilage. Femoral bone was studied to determine the specificity of the effect.

Method

C57bl/6n pregnant mice were dosed orally with vehicle (peanut oil) or 0.1, 1.0 and 10 g/kg/day of DES on gestational days 11–14. Male and female pups were allowed to mature without further treatment until 3 months of age, at which point they were divided into swim and sedentary groups. After sacrifice, bone mineral density (BMD), bone mineral content (BMC), bone area (BA), and trabecular bone area (TBA) of the lumbar vertebrae and femur were measured using a PIXImus Bone Densitometer System (GE Medical Systems). Glycosaminoglycan (GAG) content (proteoglycan) was measured by the DMMB assay. Histological analysis of proteoglycan was performed with Safranin O staining. Intervertebral disc height was measured using NDP software (Leeds, UK). Statistical analysis was performed using analysis of variance (ANOVA) followed by Fisher's Protected Least Significant Difference (PLSD). A p-value of < 0.05 was considered statistically significant.

Purpose

Disc degeneration is known to occur early in adult life, but at present there is no medical treatment to reverse or even retard the problem. Development of medical treatments is complicated by the lack of a validated long term organ culture model in which therapeutic candidates can be studied. The objective of this study was to optimize and validate an organ culture system for intact human intervertebral disc (IVD), which could be used subsequently to determine whether synthetic peptide growth factors can stimulate disc cell metabolism and initiate a repair response.

Method

Seventy lumbar IVDs, from 14 individuals, were isolated within 24 h after death. Discs were prepared for organ culture by removing bony endplates but retaining cartilaginous endplates (CEP). Discs were cultured with no external load applied. The effects of glucose and FBS concentrations were evaluated. Dulbeccos Modified Eagle Media (DMEM) was supplemented with glucose, 4.5g/L or 1g/L, referred to as high and low (physiological) glucose, and FBS, 5% or 1%, referred to as high and low FBS, respectively. After a four week culture period, samples were taken across the disc using a 4 mm biopsy punch. Cell viability was analyzed using a live/dead fluorescence assay (Live/Dead, Invitrogen) and visualized by confocal microscopy. CEP discs were also placed in long term culture for four months, and cell viability was assessed. Western bolt analysis for the G1 domain of aggrecan was also performed to assess the effect of nutritional state on disc catabolism.

Purpose

Maintenance of vertebral mechanical stability is of paramount importance to prevent pathologic fractures and resultant neurologic compromise in individuals with spinal metastases. Current non-surgical treatments for vertebral metastases (i.e. chemotherapy, bisphophonates (BP) and radiation) yield variable responses in the tumour and surrounding bone. Photodynamic therapy (PDT) is a novel, minimally-invasive technology that utilizes a drug activated by light at a specific non-thermal wavelength to locally destroy tumour cells. Previously, we observed that PDT can ablate cancer cells within bone and yield short-term (1-week) improvements in vertebral architecture and biomechanical strength, particularly when combined with BP therapy. This study aims to evaluate the effects of PDT in vertebral bone over a longer (6-week) time period, alone and combined with previous BP treatment, to determine if improvements in skeletal architecture and strength are maintained.

Method

Fourty healthy rnu/rnu rats were randomly assigned to four treatment groups: (i) untreated control, (ii) BP only, (iii) PDT only and (iv) PDT following BP. BP treatments were administered on day 0 via subcutaneous injection of zoledronic acid. PDT was administered on day 7 via an intravenous injection of BPD-MA photosensitizer. A flat-cut optical fiber was inserted percutaneously adjacent to lumbar vertebra L2. After a 15-minute drug-light interval, 75J of light energy was delivered from a 690nm laser. Six weeks later, animals were euthanized. Structural properties of excised L2 vertebral bodies were quantified through semi-automated analysis of micro-CT images. In of the specimens, mechanical properties were evaluated by loading the L2 vertebral body to failure in axial compression. The remaining L2 vertebrae were analyzed for morphology, osteoid formation and osteoclast activity using histological methods.

Purpose

To evaluate whether continuous training and education of posture can help children to improve kyphosis.

Method

A smart harness consisting of a tight-fitting harness and a posture sensing system was developed to measure kyphosis and to provide vibratory feedback during daily activities. The posture sensing system consisted of two sensor units and both units contained a 3-axis accelerometer and a 2-axis gyroscope to calculate the orientation. The dimensions and weight of each unit were 55 mm x 35 mm x 15 mm and 25g, respectively. One unit served as a master (placed at the T3 vertebral level) and the second unit served as a slave (placed at the T12 level) and they communicated wirelessly. The master unit calculated the kyphotic angle, similar to the vertebral centroid method but based on the sagital profile, and provided the vibratory feedback. One volunteer wore the unit and performed different postures and activities (walking, sitting, bending and sudden change from sitting to walking) in a gait analysis laboratory. The posture sensing system was sampled at 30Hz and a gait analysis 8-camera system was sampled at 60Hz. The kyphotic angles captured by the smart harness and camera system were compared. After this validation, the system was tested by 5 normal subjects (M, 25 10 years old) 3 hours per day for 4 consecutive days. For the first 2 days there was no feedback and the last 2 days there was feedback. The system took a sample every 30 seconds. When an undesirable posture was detected, the system switched to a fast sample mode at which time the system took ten measurements with a sample rate of 10 Hz for 1 second to further validate the measured kyphotic angle. These 10 measures were averaged to avoid feedback for postures that lasted only for a very short period of time. Posture orientation data was stored in the sensing unit memory and downloaded for outcomes evaluation.

Purpose

The focus of current management of soft tissue sarcoma on limb preservation often necessitates that patients undergo multimodal treatment, including both surgery and external beam radiotherapy. Pathologic fracture is a serious, late complication of radiotherapy. In patients who have also undergone wide excision of soft tissue sarcoma, nonunion rates of 80–90% persist despite optimal internal fixationMany sequelae of the treatments for soft tissue sarcoma exhibit the potential to perpetuate failure of bony union. Limb salvage surgery is associated with extensive periosteal excision, disruption of vascular supply and eradication of local osteoprogenitor cells. External beam radiotherapy leads to obliterative endarteritis, decreased osteoblast proliferation and reduction in bone matrix production. We hypothesize that the combination of radiotherapy and surgical periosteal stripping leads to greater impairment in the fracture repair process than either intervention alone will produce.

Method

We developed a method for creating a reproducible, low energy, simple femoral fracture in an animal model designed to proceed to nonunion. Female Wistar, retired breeder rats were separated into four treatment groups of 18 animals each: control, radiotherapy, surgery and combination radiotherapy and surgery. Animals were then further randomized to temporal end-points of 21, 28 and 35 days post-fracture. Designated animals first underwent external beam radiotherapy, followed by surgical stripping of the periosteum three weeks later and femoral fracture with fixation after another three weeks. Animals were sacrificed at their randomly assigned end-points.

Purpose

Versican is a member of the large aggregating chondroitin sulfate proteoglycan family. Structurally, it is made up of an N-terminal G1 domain, a glycosamingoglycan attachment region, and a C-terminus containing a selectin-like (G3) domain. Versican is highly expressed in the interstitial tissues at the invasive margins of breast carcinoma and predictive of relapse and overall survival. The purpose of the study to investigate the role of of versican G3 domain in breast cancer bone metastasis.

Method

Mouse mammary tumor cell lines 66c14, 4T07 and 4T1, and human breast cancer cell lines MT-1, MDA-MB-468 and MDA-MB-231 were stably transfected with versican G3. Effects of expression of versican G3 on cell proliferation, migration, invasion, cell cycle progression, and EGFR signaling were observed. The effects of G3 on cell viability in the conditional media of serum free, apoptotic agent C2-ceramide, and chemotherapeutic agents, including Docetaxel, Doxorubicin, Epirubicin were investigated. Colony formation assay and mammosphere formation assay were performed. A syngeneic orthotopic animal model was used to do the in vivo study.

Purpose

To develop a low complexity highly-automated multimodal approach to segment vertebral structure and quantify mixed osteolytic/osteoblastic metastases in the rat spine using a combination of CT and MR imaging. We hypothesize that semi-automated multimodal analysis applied to 3D CT and MRI reconstructions will yield accurate and repeatable quantification of whole vertebrae affected by mixed metastases.

Method

Mixed spinal metastases were developed via intra-cardiac injection of canine Ace-1 luciferase transfected prostate cancer cells in a 3 week old rnu/rnu rat. Two sequential MR images of the L1-L3 vertebral motion segments were acquired using a 1H quadrature customized birdcage coil at 60 m isotropic voxel size followed by CT imaging at a 14m isotropic voxel size. The first MR image was T1 weighted to highlight the trabecular structure to ensure accurate registration with the CT image. The second MR image was T2 weighted to optimize differentiation between bone marrow and osteolytic tumour tissue. Samples were then processed for undecalcified histology and stained with Goldners Trichrome to identify mineralized bone and unmineralized new bone formation.

All images were resampled to 34.9 m and manually aligned to a global axis. This was followed by an affine registration using a Quasi Newton optimizer and a Normalized Mutual Information metric to ensure accurate registration. The whole individual vertebrae and their trabecular centrums were then segmented from the CT images using an extended version of a previously developed atlas based registration algorithm. An intensity-based thresholding method was used to segment the regions corresponding to osteoblastic tumor predominantly attached to the outside of the cortical shell. The whole vertebral segmentation from the CT was warped around the T2 weighted MR to define the bone boundaries. An intensity-based thresholding approach was then applied to the T2 weighted MR segment the osteolytic tumor.

Purpose

Elevated blood metal ions are associated with the early failure of the Hip Resurfacing Arthroplasty. The aim of this study was to analyse our prospective database of Hip Resurfacing Arthroplasty patients, to independently review the outliers with elevated blood metal ions and to determine whether a screening program would be of value at our institution.

Method

In 2004 a ten year prospective longitudinal study was set up to evaluate the clinical effectiveness and safety of Metal on Metal Hip Resurfacings in young, active adults with degenerative hip disease.

Six hundred and four patients have enrolled in this multi-surgeon prospective study with strict inclusion criteria for Hip Resurfacing Arthroplasty. All have received the same implant design. All have completed validated functional outcome questionnaires at baseline, three and six months, then annually. A sub-cohort of 196 patients underwent whole blood chromium and cobalt analysis at the same time periods.

Metal on metal bearings have a running in period of a minimum of six months before a steady state wear pattern is attained. We chose five parts per billion for Cobalt or Chromium as our threshold value. This value corresponds to the workplace exposure limit in the United Kingdom to Cobalt in whole blood. Therefore patients with ion levels greater than five parts per billion after six months were recalled for independent review, including further metal ion analysis.

Purpose

Primary uncemented total hip arthroplasty is the fixation of choice for most patients undergoing hip replacement in North America. Initial stem stability will be detected by the fit and fill of the implant to the bone as well as the overall stem geometry as it relates to its mechanical stability. This study aims to determine the geometric and structural parameters of common cementless tapered femoral stems to better understand their early clinical performance with respect to bony fixation.

Method

Templates for six proximally coated tapered uncemented femoral stems: Accolade (Stryker), Profemur (Wright), Taperloc (Biomet), M/L Taper (Zimmer), Anthology (Smith-Nephew) and Trilock (Depuy) were scanned and saved as images on a PC. Stem sizes were assigned according to AP plane width measurements taken at the most lateral implant shoulder, and images analyzed using ImageJ (US National Institutes of Health). Measurements were made of stem length, and at various locations, the width and thickness of the stem. Coronal plane stiffness was calculated according to beam theory, assuming an elastic modulus of 114 GPa for the Profemur, Taperloc M/L Taper, Anthology and Trilock stems. The Accolade stem has a modulus of 85.5 GPa. due to TMZF alloy which is 25% more flexible. Stem thickness and taper ratios were calculated as a measure of lateral vs. AP fill of the femur. All measurements were plotted as manufacturer-specific curves relative to stem width.

Purpose

The effects of Acetabular Rim Osteophytes (ARO) in Total Hip Arthroplasty (THA), has not been quantified. During THA their presence and location is variable, and the effect on post-operative Range of Motion (ROM) is unknown. The purpose of this study was to evaluate the ROM of a modern hip implant in five cadaver models utilizing computerized virtual surgery, and to analyze the effect of AROs given their location on the acetabulum, and position of the prosthesis during motion.

Method

CT scans of five cadaveric pelvises and femurs were used to create 3-D Models. Surgery, using virtual Stryker components was then performed to restore the natural anatomic offset and leg length. ROM to impingement was evaluated for each model in eight vectors: flexion/extension, internal/external rotation, abduction/adduction, and 90 degrees of flexion with internal/external rotation.

An Osteophyte Impingement Model was then created by elevating the natural acetabular rim by 10 millimeters circumferentially in each virtual cadaver pelvis. Using the same THA components, ROM was then evaluated in this pelvic model and compared to the cadaveric models.

Purpose

Computer navigation for hip resurfacing has been shown to reduce the incidence of technical error during femoral head preparation and provides increased accuracy compared to conventional instrumentation for insertion of the initial femoral guidewire. Limitations to the widespread use of navigation in hip resurfacing include access and cost. A novel, patient specific nylon jig has been developed as a cost effective alternative for placement of the initial guidewire. The purpose of this study was to compare the accuracy of femoral guidewire insertion between imageless navigation, conventional instrumentation and a new type of CT-based custom jig.

Method

Six pairs of cadaveric femora were used in the study. Each pair was divided randomly between a group utilizing firstly a conventional lateral pin jig (BHR, Smith & Nephew Inc.) followed by navigation (Vector Vision SR, BrainLAB) and a group utilizing a CT-based, patient specific custom jig (Visionaire, Smith & Nephew Inc.). A single surgeon inserted all guidewires. The planned guidewire position was approximately 10 degrees of relative valgus to the native neck-shaft angle in the coronal plane and neutral version in the sagittal plane. The same coronal alignment angle was used between paired femora. Femurs were positioned in a draped synthetic foam hip model prepared with a standard posterior approach. Guidewire insertion time and placement accuracy for each of the three alignment methods was assessed. Guidewire placement accuracy for coronal inclination and version was assessed by anteroposterior and lateral digital radiographs and was defined as the mean deviation from the planned alignment value.

Purpose

The literature indicates that the tibial component in total knee arthroplasty (TKA) should be placed in internal rotation not exceeding 18 to the line connecting the geometrical center of the proximal tibia and the middle of the tibial tuberosity. These landmarks may not be easily identifiable intraoperatively. Moreover, an angle of 18 is difficult to measure with the naked eye.

Method

The angle at the intersection of lines from the middle of the tibial tuberosity and from its medial border to the tibial geometric center was measured in 50 patients with normal tibia. The geometric center was determined on an axial CT slice at 10mm below the lateral tibial plateau and transposed to a slice at the level of the most prominent part of the tibial tuberosity.

Similar measurements were performed in 25 patients after TKA in order to simulate the intra operative appearance of the tibia after making its proximal resection.

Purpose

Measurements of patellar kinematics are essential to investigate the link between anterior knee pain following knee arthroplasty and patellar maltracking. A major challenge in studying the patellofemoral (PF) joint postoperatively is that the patellar component is only partially visible in the sagittal and close-to-sagittal radiographs. The narrow angular distance between these radiographs makes the application of conventional bi-planar fluoroscopy impossible. In this study a methodology has been introduced and validated for accurate estimation of the 3D kinematics of the PF joint post-arthroplasty using a novel multi-planar fluoroscopy approach.

Method

An optoelectronic camera (Optotrak Certus) was used to track the motion of an ISO-C fluoroscopy C-arm (Siemens Siremobil) using two sets of markers attached to the X-ray source and detector housings. The C-arm was used in the Digital Radiography (DR) mode, which resembles an ordinary X-ray fluoroscopy image. A previously-developed technique (Cho et al., 2005; Daly et al., 2008) was adapted to find the geometric parameters of the imaging system. Thirty-eight DRs of the calibration phantom were obtained for the 190 of rotation of the C-arm at 5 rotational increments while data from motion markers were recorded continuously at a frequency of 100 Hz. A total knee replacement prosthesis was implanted on an artificial bone model of the knee, and the implant components and bones were rigidly fixed in place using a urethane rigid foam. For the purpose of validation, positions of the implant components were determined using a coordinate measuring machine (CMM). Sagittal and obliquely sagittal radiographs of the model were taken where the patellar component was most visible. For each DR the geometric parameters of the system were interpolated based on the location of the motion markers. The exact location of the projection was then determined in 3D space. JointTrack Bi-plane software (Dr. Scott Banks, University of Florida, Gainesville) was used to conduct 2D-3D registration between the radiographs and the reverse-engineered models of the implant components. Results of the registration were directly compared to the ground-truth obtained from the CMM to calculate the accuracies.

Purpose

The purpose of this study was to assess the biomechanical stability of the a total ankle arthroplasty system using longitudinal migration (LM) and inducible displacement (ID) measures. This study is the first study of its kind to assess total ankle arthroplasty (TAA) implant micromotion using model-based radiostereometric analysis (MBRSA).

Method

Twenty patients underwent TAA that implanted the Mobility(TM) (DePuy, Warsaw IN). The mean (SD) age was 60.4 (12.5) and BMI was 29.1 (2.8) kg/m². One surgeon performed all surgeries. All patients included in this study had given informed consent. Capital Health Research Ethics Board had approved this study.

Uniplanar medial-lateral RSA X-ray exams were taken postop (double exam), at six wk, three mth, six mth, one yr and two yr followup times using a supine, unloaded position. Standing medial-lateral exams were taken at three mth, six mth, one yr and two yr followup intervals.

LM and ID micromotions were assessed using Model-based RSA 3.2 software (Medis specials, Leiden, The Netherlands). Implant micromotions (x, y, z, Rx, Ry, Rz, MTPM) were determined and assessed for each subject using model-based pose estimation, and the implant-based coordinate system. The Elementary Geometric Shapes module from the Model-based RSA 3.2 software was used to assess the micromotion of the tibial component spherical tip due to implant symmetry.

Purpose

To characterize the knee kinematic profiles of total knee arthroplasty patient knees intraoperatively, before implant insertion, using principal component analysis.

Method

Ninety-two patientsreceived Stryker Triathlon total knee arthroplasty (TKA) implants. The Stryker surgical navigation system was used for all surgeries. The system was used to define rigid bodies representing the femur and tibia, and to track the three-dimensional movement of the knee joint during surgery. Each knee was moved through a passive range of knee flexion/extension before and after implantation of the arthroplasty components. The frontal plane (medial-lateral) movement of the knee joint through a range of 10 to 120 degrees of flexion before implantation was calculated for each knee using the joint coordinate system (referred to as the pre-implant knee kinematic curve). Visual inspection of these patterns indicated three predominant curve types: a backward S shape, a backward C shape and a valgus to varus shape. Each curve was subjectively categorized into one of these three categories. Principal component analysis (PCA), a multivariate statistical analysis technique, was applied to the pre-implant knee kinematic pattern data to objectively extract the major patterns of curve types within the 92 knees. Analysis of variance was used to compare the mean differences in PC scores between the curve shape groups to confirm visual categorization.

Purpose

Radiostereometric Analysis (RSA) is a well developed imaging technique used to estimate implant fixation of orthopaedic implants in randomized clinical trials. The precision of RSA depends on a number of factors including image quality related to the individual modality properties. This study assesses the precision of RSA with a novel Digital Radiography (DR) system compared to a CR imaging system using different imaging techniques. Additionally, the study assesses the precision of locating beads embedded in a modified spine pedicle screw.

Method

A modified titanium spinal pedicle screw 4.5 mm diameter, 35 mm length, marked with two 1.0 mm tantalum beads, one inside the head and one near the screw tip was inserted into a bovine tibia segment. Six additional 1.0 mm tantalum beads were inserted into the bone segment – superiorly, distally and adjacent to the pedicle screw. The phantom was placed on a standard clinical diagnostic imaging bed above a custom RSA carbon fiber calibration cage (Halifax Biomedical Inc.). A pair of DR or CR imaging plates were placed below the calibration cage and irradiated 15 times at 100, 125 kV at 2.5 mAs. To determine precision, the standard deviation of 3D vector distances between beads was determined using RSA for each of the different imaging parameters.

Purpose

Aseptic loosening of the tibial component of total knee prosthesis is a common cause of revision surgery. While micromotion at the bone-implant interface can now be accurately measured with Radiostereometric Analysis (RSA), mechanisms responsible for loosening remain poorly understood. The purpose of this study was to investigate the association between bone density in the proximal tibia and post-operative knee implant migration.

Method

Fifty-one subjects who received total knee arthroplasty surgery with the Wright Medical Advance Biofoam (uncemented) implant were recruited. Bone density of seven regions of the proximal tibia (medial, lateral, anterior, posterior, and three regions below implant tip) was measured with DEXA post operatively at two, six, 12 and 24 weeks. RSA exams were also taken immediately post-operatively, and at six, 12 and 24 weeks. Correlations between bone mineral density and RSA migration were examined at 24 weeks post-operatively.

Purpose

Educational handouts designed for patients are promoted as a tool to educate, increase satisfaction, and potentially improve outcome. However, the value of these educational handouts as an adjunct to standard surgical care has not been formally assessed after ankle fracture. The purpose of this study was to compare standard post-operative care following surgically treated rotational ankle fracture to care supplemented with the use of adjunctive educational handouts.

Method

Fifty-one patients who sustained a rotational ankle fracture requiring open reduction and internal fixation were randomized to receive either standard care (group S) for an ankle fracture, or to additionally receive the AAOS handout on ankle fractures and a handout describing appropriate mobilization exercises (group H). Standard care included follow up visits at 2, 6, and 12 weeks postoperatively in a busy orthopaedic fracture clinic, including brief instructions on mobilization exercises. A bulky plaster-reinforced dressing was used for immobilization for the first two weeks following surgery, followed by a removable boot. Range of motion exercises were encouraged after the first two weeks and weight bearing was encouraged six weeks after surgery. Surgeons and outcome assessors were blinded to treatment group.

Patients completed functional outcome assessment (Olerud-Molander ankle score), objective measurement of ankle motion, and visual analog scale questions related to satisfaction at 6 and 12 weeks after surgery.

Purpose

Although multiple surgical options exist for chronic static scapholunate dissociation, no single procedure has been found to be superior clinically or kinematically. We hypothesize that the reduction and association of the scaphoid and lunate (RASL procedure) is a safe and effective procedure that improves function and alleviates pain in the injured wrist. The purpose of this study is to report long-term follow-up of patients undergoing the RASL procedure over a 20-year period.

Method

Between December 1991 and September 2008, the senior author performed 36 RASL procedures for chronic static scapholunate dissociation. This reconstruction involves reduction of the rotational deformity and diastasis between the scaphoid and lunate through a dorsal approach to the wrist. Maintenance of reduction is accomplished with a cannulated, headless, smooth-shafted compression screw directed from the scaphoid to the lunate along the anatomic axis of rotation between the two bones. For the purposes of this study, patients were evaluated by visual analog pain scale (VAS), Disability of the Arm, Shoulder and Hand questionnaire (DASH), SF-36 health survey, physical examination and radiographs.

Purpose

Primary internal fixation of uncomplicated scaphoid fractures offers many advantages compared to conventional casting. However, ideal fixation placement along the central scaphoid axis can be challenging, especially if the procedure is performed percutaneously. Because of the lack of direct visualization, percutaneous procedures demand liberal use of imaging, thereby increasing exposure to harmful radiation.

It has been demonstrated that computer-assisted navigation can improve the accuracy of guidewire placement and reduce X-ray exposure in procedures such as hip fracture fixation. Adapting the conventional computer-assist paradigm, with preoperative imaging and intraoperative registration, to scaphoid fixation is not straightforward, and thus a novel tactic must be conceived.

Method

Our navigation procedure made use of a flatpanel C-arm (Innova, GE Healthcare) to obtain a 3D cone-beam CT (CBCT) scan of the wrist from which volumetrically-rendered images were created. The relationship between the Innova imager and an optical tracking system (OptoTrak Certus, Northern Digital Inc.) was calibrated preoperatively so that an intraoperatively-acquired image could be used for real-time navigation. Optical markers fitted to a drill guide were used to track its orientation, which was displayed on a computer monitor relative to the wrist images for navigation.

Randomized trials were conducted comparing our 3D navigated technique to two alternatives: one using a standard portable C-arm, and the other using the Innova flatpanel C-arm with 2D views and image intensification. A model forearm with an exchangeable scaphoid was constructed to provide consistency between the trials. The surgical objective was to insert a K-wire along the central axis of a model scaphoid.

An exposure meter placed adjacent to the wrist model was used to record X-ray exposure. Procedure time and drill passes were also noted. CT scans of the drilled scaphoids were used to determine the shortest distance from the drill path to the scaphoid surface.

Purpose

One of the current research topics is the aim to produce tissue engineered osteochondral grafts for future treatment of osteochondral lesions (OCL) of the talus. For the exact anatomic reconstruction, the dimensions of the medial and lateral talar dome must be considered.

Sparse data is available regarding the normal anatomic talar dimensions on standard radiographs of ankle joints [1, 2]. The purpose of this study was to describe normal anatomy of different sections of the talar dome on 3D reconstructions of computertomographic (CT) images.

Method

CT data sets (Somatom 10, Siemens Erlangen, Germany) of 82 patients (86 ankles) (28 female, 54 male; average age 41.9y (range 15–76y)) without talar pathologies were included. Measurements were performed with a geometry analysis software (VGStudio MAX 2.0, Volume Graphics, Heidelberg, Germany). To assure measurement reproducibility, the reference planes were defined in a first step. To measure the frontal talar edge radius, circles were fitted into the medial and lateral talar edge on frontal planes. To allow measurement of different segments of the talus, the frontal plane was tilted through the center of the talus (defined as a circle fitted to the talus on sagittal view) at 15 and 30 anteriorly and posteriorly.

To measure the sagittal radius of the medial and talar edge, ircles were fitted into the medial and lateral talar edge on sagittal planes.

Purpose

Coronal plane malalignment at the level of the tibiotalar joint is not uncommon in advanced ankle joint arthritis. It has been stated that preoperative varus or valgus deformity beyond 15 degrees is a relative contraindication and deformity beyond 20 degrees is an absolute contraindication to ankle joint replacement. There is limited evidence in the current literature to support these figures. The current study is a prospective clinical and radiographic comparative study between patients who underwent total ankle arthroplasty with coronal plane varus tibiotalar deformities greater than 10 degrees and patients with neutral alignment, less than 10 degrees of deformity.

Method

Thirty-six ankles with greater than 10 degrees of varus alignment were compared to thirty-six ankles which were matched for implant type, age, gender, and year of surgery. Patients completed preoperative and yearly postoperative functional outcome scores including the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot scores, the Ankle Osteoarthritis Scale (AOS) and the Short Form-36 Standard Version 2.0 Health Survey. Weightbearing preoperative and postoperative radiographs were obtained and reviewed by four examiners (AC, AQ, TD, TT) and measurements were taken of the degree of coronal plane deformity.

Purpose

To compare Radiostereometric Analysis (RSA) and subjective outcomes of Total Knee Arthroplasty (TKA) and Total Ankle Arthroplasty (TAA).

Method

Twenty-five patients were recruited to receive TKA (Zimmer, NexGen LPS Trabecular Metal Monoblock) and 20 patients were recruited to receive TAA (DePuy, Mobility). The tibial component of the TKA and the tibial component of the TAA were followed for two years with RSA with exams postoperatively at six, 12 and 24 months. At two years, inducible displacement RSA at the knee and ankle was also performed. RSA outcomes measured were translations in the anterior-posterior, medial-lateral and distal-proximal directions of both implants. SF-36 outcome questionnaires were completed preoperatively and at each RSA follow-up with the outcome being the mental component score (MCS) and physical component score (PCS). Analysis of variance statistical testing was used to compare RSA outcomes and subjective outcomes.

Purpose

Scaphoid non-unions can result in debilitating wrist problems. This study compared treatment of scaphoid non-unions using either a non vascularised (NVBG) or a vascularised bone graft (VBG).

Method

Twenty one cases of scaphoid non-unions were treated by two surgeons between 2005 and 2008 using either a NVBG from the iliac crest or a VBG from the radius based on a 1,2 intercompartmental supraretinacular artery pedicle.

Purpose

The measurement of radial head translation about the capitellum (in percent): the radio-capitellum ratio (RCR) has proven to have excellent inter- and intra-observer reliabilities when measuring the RCR on a lateral radiological view of elbows at 90° of flexion and in the neutral position of the forearm. However, in the clinical setting, radiographs may be taken with the elbow in different positions. However, the purpose was to validate the RCR measurement method on elbows in different positions in flexion-extension and in different positions of the forearm in pronation-supination.

Method

Fifty-one healthy volunteers were recruited to evaluate the RCR in different elbow positions. Lateral elbow radiographs were taken with the elbow in different magnitude of ROM: maximal extension, maximal flexion, elbow at 90° and forearm in neutral, elbow at 90° and forearm in supination and elbow at 90° and forearm in pronation. The measurements of the RCR were done using the software SliceOmatic. ANOVA and paired T-test were used to assess the difference of the RCR depending on the position of the elbow and of the forearm. Pearson coefficients were calculated to obtain the correlation between the RCR in each different position.

Purpose

Weight loss is often advised to our patients and considered to make a substantial difference in most musculoskeletal symptoms. Patients with end stage ankle arthrosis have severe pain, diminished health related quality of life, and limited physical function.

They frequently refer to increased weight as a simple indicator of decline in their quality loose weight. Patients assume that weight loss will follow after surgery secondary to increased activity with reduced pain and disability.

Method

Changes in the body mass index, mental and physical component of SF36 and Ankle Scale Osteoarthritis of 145 overweight and obese patients after ankle surgery were assessed up to five year after surgery with a mean of 37.1 month follow up from 2002 to 2009.

Purpose

Based on anatomic studies, it appears that the short head (SH) and long head (LH) of the distal biceps tendons have discreet distal attachments on the radial tuberosity. The SH attaches distally and therefore may function as a stronger flexor, whereas the LH attaches more proximal and ulnar which would make it a greater supinator. The contribution of each of the two heads to flexion and supination has not yet been defined. The rationale of this study was to directly measure the contribution of the SH and LH of the biceps to elbow flexion and forearm supination and provide biomechanical evidence for what is inferred in the anatomical studies.

Method

Twelve fresh-frozen cadaveric arms were secured using in vitro elbow simulator, while controlled loads were applied to the individual biceps tendons short and long heads. Isometric supination torque and flexion force were recorded with the forearm in 45 degrees supination, neutral rotation and 45 degrees pronation.

Purpose

A major drawback of current cartilage and intervertebral disc (IVD) tissue engineering is that human mesenchymal stem cells (MSCs) from osteoarthritic (OA) patients express high levels of type X collagen. Type X collagen is a marker of late stage chondrocyte hypertrophy, linked with endochondral ossification, which precedes bone formation. However, it has been shown that a novel plasma-polymer, called nitrogen-rich plasma-polymerized ethylene (PPE:N), is able to inhibit type X collagen expression in committed MSCs. The aim of this study was to determine if the decreased expression of type X collagen, induced by the PPE:N surfaces is maintained when MSCs are removed from the surface and transferred to pellet cultures in the presence of serum and growth factor free chondrogenic media.

Method

Human MSCs were obtained from aspirates from the intramedullary canal of donors undergoing total hip replacement for OA. Cells were expanded for 2–3 passages and then cultured on polystyrene dishes and on two different PPE:N surfaces: high (H) and low (L) pressure deposition. Cells were transferred for 7 additional days in chondrogenic serum free media (DMEM high glucose supplemented with 2 mM L-glutamine, 20 mM HEPES, 45 mM NaHCO3, 100 U/ml penicillin, 100 ug/ml streptomycin, 1 mg/ml bovine serum albumin, 5 ug/ml insulin, 50 ug/ml ascorbic acid, 5 ng/ml sodium selenite, 5 ug/ml transferrin) in pellet culture or on PS cell culture dishes. RNA was extracted using a standard TRIzol protocol. RT-PCR was realized using Superscript II (RT) and Taq polymerase (PCR) with primers specific for type I and X collagen. GAPDH was used as a housekeeping gene and served to normalize the results.

Purpose

In the literature, the hip is near-ubiquitously described as a mechanical ball-and-socket joint. This implies purely rotational motion as well as sphere-on-sphere contact geometry. However, previous works, by several authors, have quantitatively demonstrated asphericity of the articular hip surfaces in a variety of populations. This in turn implies the true kinematics of the hip joint may be more complex than purely rotational motion.

Previously, general ellipsoidal shapes have been used to model the articular surface of the acetabulii of dysplastic hips. This work aims to orient the major axis of these ellipsoids with respect to the anterior pelvic plane (APP).

Method

The source data for this study were CT segmentations done in routine preparation for computer-assisted periacetabular osteotomy (PAO) procedures. Seventeen patients, aged 3510 years, were included in this study. Segmentations were performed manually by skilled technicians using Mimics (Materialize, Belgium) and saved as triangulated surface meshes. These segmentations were manually processed using Magics (Materialize, Belgium) to isolate the acetabulum, removing any non-articular features such as the acetabular ridge and notch, as well as any segmentation artefacts. The vertices of this processed mesh were extracted, and fit to general ellipsoids using Markovskys Adjusted Least Squares (ALS) algorithm. The APP was defined by the left and right anterior superior iliac spines (ASIS) and the midpoint of the pubic tubercles, with the ASIS forming the mediolateral axis. Landmarks were manually chosen mesh vertices, chosen from the approximate centre of the anatomical landmark.

Orthogonal projections of the primary axis of the ellipsoid of best fit were examined in the APP and the two perpendicular planes (pseudo-axial and sagittal).

Purpose

Bone marrow multi-potent stromal cells represent a heterogenous source of cells with great promise in joint cartilage regenerative medicine. However, due to their low numbers upon harvesting, MSCs need to be expanded without compromising their capacity to form chondrocytes (cartilage cells). To date there is no consensus on how to expand MSCs in order to maximize their potential for cartilage repair and nor are there any specific cell signatures of MSCs with chondrogenic propensity. Emerging evidence suggest that marrow stem cells exist in a hypoxic microenvironment. On this basis and in addition to cartilages natural existence in hypoxic environment (1–7% O2), we hypothesized that MSC expansion under hypoxia will result in the enrichment of MSCs with predilection to chondrocytes compared to expansion under the conventional culture conditions of 21% O2.

Method

Bone marrow was harvested from the iliac crest of 4 donors (mean age 43.5 years) post informed consent and local ethical approval. Fifteen million mono-nucleated (MNCs) cells were seeded into T150cm2 culture flasks in the presence of alpha MEM plus 10% FBS and 5 ng/ml FGF2. Similarly, 0.25 million MNCs were seeded in 10cm petri dishes for colony forming unit-fibroblastic (CFU-f) assay. The seeded flasks and petri dishes were cultured under normoxia (21% O2) and hypoxia (3% O2). Petri dished cells were cultured for 14 days and those in flasks were cultured until passage 2 (P2). Developed cell colonies per dish were revealed after crystal violet staining. Colony counts and diameters were recorded. P2 cells were treated with a panel of antibodies for cell surface marker analysis by fluorescent activated cell sorting (FACS) flow cytometry. P2 cell pellets were formed and induced towards cartilage in a defined serum free medium containing TGFβ1. Pellets were cultured for 3 weeks under normoxia and were then processed for histological, biochemical and gene expression analyses.

Purpose

Limb regeneration as it occurs in amphibians has two basic requirements: a source of multipotent cells capable of generating various tissues, and reorganization of those cells to form the one and only pattern of tissue appropriate to restore the missing parts. In the current biomedical world, there is much work dedicated to tissue engineering and to the differentiation of stem cells into various mature cell types. Neither of these approaches however, will by themselves succeed in regenerating a complex structure such as a limb. In our lab, we decided to focus on the pattern organization side of the equation by testing the potential of mammalian limb bud tissue to change its positional identity, and to manipulate that potential.

Method

We used mouse embryos for our mammalian model. Small groups of cells were transplanted from one region of the limb bud into another, and the resulting effect on the positional identity of those cells was assessed using molecular markers of the upper arm, forearm and hand. We knocked out a genetic regulator of cell fate named Ezh2 specifically in the limb bud to test its role in committing cells to a given positional identity along the proximodistal limb axis.

Purpose

Whether the presence of knee effusion in individuals with knee osteoarthritis (OA) affects periarticular neuromuscular control during gait and thus the joint loading environment is unknown. The purpose was to test the hypothesis that knee effusion presence alters periarticular neuromuscular patterns during gait in individuals with moderate knee OA.

Method

40 patients with medial compartment knee OA participated after giving informed consent. Patients were assessed for the presence of effusion using a brush test and were assigned to the knee effusion (n=20) and no knee effusion (n=20) groups. Surface electrodes were placed in a bipolar configuration over the lateral and medial gastrocnemius, vastus lateralis and medialis, rectus femoris and the lateral and medial hamstrings of the affected limb. Five trials of self-selected walking were completed. Electromyograms (EMG) were collected using an AMT-8 EMG system (Bortec Inc.). An Optotrak motion capture system (Northern Digital Inc.) recorded leg motion. Euler rotations were used to derive knee angles. EMG waveforms were low-pass filtered and amplitude normalized to maximal effort voluntary isometric contractions. Quadriceps, gastrocnemius and hamstring strength was measured from torques produced against a Cybex dynamometer. Principal Component Analysis extracted the predominant waveform features and weighting scores were calculated for each measured waveform. Analysis of variance models test for main effects (group, muscle) and interactions (alpha = 0.05). Bonferonni post hoc testing was employed.

Purpose

Traumatic articular cartilage (AC) defects are common in young adults and frequently progresses to osteoarthritis. Matrix-Induced Autologous Chondrocyte Implantation (MACI) is a recent advancement in cartilage resurfacing techniques and is a variant of ACI, which is considered by some surgeons to be the gold standard in AC regeneration. MACI involves embedding cultured chondrocytes into a scaffold that is then surgically implanted into an AC defect. Unfortunately, chondrocytes cultured in a normoxic environment (conventional technique) tend to de-differentiate resulting in decreased collagen II and increased collagen I producing in a fibrocartilagous repair tissue that is biomechanically inferior to AC and incapable of withstanding physiologic loads over prolonged periods. The optimum conditions for maintenance of chondrocyte phenotype remain elusive. Normal oxygen tension within AC is <7%. We hypothesized that hypoxic conditions would induce gene expression and matrix production that more closely characterizes normal articular chondrocytes than that achieved under normoxic conditions when chondrocytes are cultured in a collagen scaffold.

Method

Chondrocytes were isolated from Outerbridge grade 0 and 1 AC from four patients undergoing total knee arthroplasty and embedded within 216 bovine collagen I scaffolds. Scaffolds were incubated in hypoxic (3% O2) or normoxic (21% O2) conditions for 1hr, 21hr and 14 days. Gene expression was determined using Q-rt-PCR for col I/II/X, COMP, SOX9, aggrecan and B actin. Matrix production was determined using glycosaminoglycan (GAG) content relative to cell count determined by DNA quantification. Cell viability and location within the matrix was determined by Live/Dead assay and confocal microscopy. Statistical analysis was performed using a two-tailed T-test.

Purpose

The biomechanical role of the meniscus in the knee joint is a function of its extracellular matrix which consists of type I collagen throughout, type II collagen in the inner meniscus region and glycosaminoglynated (GAG) proteins of which aggrecan is the most prevaleet. Meniscus reparative capacity is limited, particularly when a defect is located in the inner avascular portion, and menisectomy predisposes the joint to osteoarthritis. Using meniscus cells in tissue engineering strategies has been advocated to generate functional meniscus substitutes. However, meniscus cells, like chondrocytes of cartilage, lose their matrix-forming phenotype during culture expansion. Co-culture of chondrocytes with stem cells has been shown to result in enhanced matrix formation. We hypothesized that meniscus cells in co-culture with stem cells will result in increased matrix formation.

Method

Tissue specimens were obtained after approval of the local ethical committee and informed consent. Menisci were obtained from 3 patients undergoing total knee arthroplasty; (53–84; mean age 66.6). Meniscus cells were isolated after digestion of menisci with collagenase II. Isolated meniscus cells were plated for 24–48 hr before use. Bone marrow aspirates were obtained from the iliac crest of 3 donors: 1 female (46) and 2 males (15 and 21) undergoing routine orthopaedic procedures. Plastic adherent bone marrow stromal cell populations were isolated and expanded under normal oxygen tension of 21%O2 in a-MEM growth media plus FGF-2 until passage 2. Cells were mixed at a variety of meniscus cells (Men): BMSC ratio including 5/95, 10/90 and 25/75, respectively. Mixed cells were centrifuged to form spherical pellets followed by culture in a defined serum free chondrogenic differentiation medium. Control groups were pure Men and pure BMSCs. Total cell number per pellet was 25×104. Pellets were cultured for 3 weeks under normal oxygen tension. Thereafter, pellets were processed: biochemically for GAG and DNA content, and histologically for Safranin-O staining of sulphated GAG and immunohistochemical analyses for collagen types I and II. Analysis was performed on a minimum of 2 independent pellets.

Purpose

Whilst it is known that oxidative stress can cause early degenerative changes observed in experimental osteoarthritis and that a major drawback of current cartilage and intervertebral disc tissue engineering is that human mesenchymal stem cells (MSCs) from osteoarthritis (OA) patients express type X collagen, a marker of late-stage chondrocyte hypertrophy (associated with endochondral ossification), little is known whether the expression of type X collagen in MSCs from OA patients can be related to oxidative stress or inflammatory reactions that occur during this disease.

Method

Human MSCs were obtained from aspirates from the intramedullary canal of donors undergoing total hip replacement for OA. Bone marrow aspirates were processed essentially as previously described. Briefly, non-adherent cells were discarded after 72h of culture and the adherent ones were expanded for 2–3 passages. MSCs from normal donor (control) were obtained from Lonza. Cells were then lysed and protein expression was detected by Western blot using specific antibodies directed against type X collagen, as well as the antioxidant enzymes Mn-superoxide dismutase (MnSOD), catalase (CAT) and glutathione peroxidase-1 (GPx-1) and inflammation related proteins cyclooxygenase-1 (COX-1) and intercellular adhesion molecule-1 (ICAM-1). GAPDH was used as a housekeeping gene and served to normalize the results. Correlations between the expressions of the different proteins were realized using the correlation Z test with StatView (SAS Institute).

Purpose

Adenosine triphosphate (ATP) has been implicated as an autocrine/paracrine signal in the mechanotransduction pathway of chondrocytes. In this study, human chondrocytes in a 3D agarose scaffold were cultured with exogenous ATP in varying doses to determine its effect on extracellular matrix synthesis by the cells. Further experiments determined basal ATP release, ATP degradation and expression of P2Y1 and P2Y2 purinoreceptors by the cultured cell constructs.

Method

Human chondrocytes were obtained by enzymatic digestion of cartilage samples obtained at the time of total joint arthroplasty. The chondrocytes were cultured in a 3D agarose scaffold using standard tissue culture techniques. Various concentrations of exogenous ATP were added to the cultures, along with the radioisotopes to assess matrix synthesis. The cultures were harvested after a 24 hr incubation and radioisotope incorporation was determined by scintillation counting to determine proteoglycan ([35S]-sulfate) and collagen ([3H]-proline) synthesis, respectively. DNA content was determined by the Hoescht 33258 binding assay, and the proteoglycan and collagen synthesis were normalized to DNA content. Basal ATP release and degradation of exogenous ATP were determined by luciferase assay and luminometry. Expression of P2Y1 and P2Y2 purinoreceptors were determined by flow cytometry.

Purpose

Based on a structure function relationship, bone density distribution has been described as being representative of skeletal loading. As such, computed tomography (CT) may be used to visualize the structure of femoral head subchondral bone to allow in vivo quantification of joint mechanics without the need for implanted hardware. This study aims to characterize the distribution of subchondral bone density in the femoral head. We hypothesize that a non-uniform distribution of bone density will be observed, with correlation between left and right sides for a given patient.

Method

Femoral head surfaces were created bilaterally for thirty patients through semi-automatic segmentation of reconstructed CT data and used to map bone density, by shrinking them into the subchondral bone and averaging the grey values (linearly related to bone density) within five millimeters of the articular surface. Density maps were then oriented with the center of the head at the origin, the femoral mechanical axis (FMA) aligned with the vertical, and the posterior condylar axis (PCA) aligned with the horizontal. Twelve regions were created by dividing the density maps into three concentric rings at increments of thirty degrees from the horizontal, then splitting into four quadrants along the anterior-posterior and medial-lateral axes. Average bone density within each region was then calculated using histogram analysis. All analysis was performed with AmriaDEV 5.2.2 image analysis software (Visage Imaging, Carlsbad USA).

Purpose

There is no clear definition of a critical sized defect of the tibia. We defined it as a fracture gap at least one centimeter in length and involving over 50% of the cortical diameter. We explored if the presence of a critical-sized defect predicted reoperation, and which other factors predict reoperation in patients with the critical defect. The patient based outcomes of these patients were compared to patients without a critical defect.

Method

Patients enrolled in the SPRINT trial with a critical sized defect were evaluated for secondary interventions to gain union. Other factors predicting the need for reoperation were studied. We also compared the patients with critical sized defects to the larger cohort of patients without a defect with respect to demographics, injury mechanism, fracture characteristics, and patient-based outcome.

Purpose

Incidence of malrotation of femoral fractures after intramedullary nailing is as high as 28%. Prevention of malrotation is superior to late derotation osteotomy. The lesser trochanter (LT) profile has been in use for some time as a radiographic landmark of femoral rotation. One of the authors has previously described a linear regression model that describes the relationship of the LT to rotation. This paper aims to validate the use of this equation in predicting femoral rotation.

Method

A survey was created and circulated online. Twenty images of cadaveric femurs of known rotation were chosen randomly from a large series. Thirty individuals with varying degrees of orthopaedic experience were invited to participate. Participants were asked to take measurements of the LT in a standardized fashion. Inter-observer variation for predicted rotation and the precision of predicted rotation was calculated. Results were grouped into those with the LT readily visible and those with the LT hidden by the femoral shaft.

Purpose

Our hypothesis was that closed tibia fractures treated with intramedullary nails are impacted by surgeon and center volumes.

Method

Data from 813 patients with closed tibia fractures were obtained from the SPRINT study. Using multiple regression, we examined the effect of center and surgeon volume (categorized as high, moderate, or low), and geographic differences by country (Canada, USA, and the Netherlands) on health-related quality-of-life and revision surgeries to gain union at one year. Our measures of quality-of-life were the Short-Form 36 Health Survey Questionnaire (SF-36 PCS) and the Short Musculoskeletal Function Assessment (SMFA).

Purpose

We explored the role of patients beliefs and attitudes towards their likelihood of recovery from severe physical trauma.

Method

We developed and validated an instrument designed to capture the impact of patients beliefs and attitudes towards functional recovery from injury; the Somatic Pre-Occupation and Coping (SPOC) questionnaire. At six weeks post-surgical fixation, we administered the SPOC questionnaire to 359 consecutive patients with operatively managed tibial shaft fractures. We constructed multi-variable regression models to explore the association between SPOC scores and functional outcome at one year, as measured by return to work and Short Form-36 (SF-36) physical component summary (PCS) and mental component summary (MCS) scores.

Purpose

Malrotation of the femur has been documented in as few as 0% and as many as 28% of fractures treated with an intramedullary(IM) nail. Patients with more than 15 degrees of malrotation sometimes require derotation osteotomy. Recognizing malrotation intraoperatively is the most efficient way to avoid corrective surgery. The purpose of this paper is to inform orthopaedic surgeons of the best estimate of incidence of femoral malrotation after IM nailing. This may lead to increased attention toward intraoperative control of malrotation.

Method

A literature search was performed by a library sciences professional. Two authors excluded papers not relevant to the study in two stages with clearly outlined criteria and adjudication. Inter-observer agreement was measured with the kappa statistic. Data extraction was performed by the same two authors with measure of agreement and adjudication from a third author. Data extraction included: incidence of malrotation, method used for measurement of malrotation and use of intraoperative techniques to minimize malrotation.

Purpose

In 2010, the new clinical guideline of Osteoporosis Canada for the diagnosis of osteoporosis, clearly indicates that patients with high-risk of fracture are those that have already sustained a fracture (osteoporotic fracture). Until now, only 12% of the 3,400 fractures that we treat each year receive a treatment for osteoporosis. We are validating an evaluation protocol and a multidisciplinary systematic follow-up approach for osteoporosis. Patients are managed by a clinical nurse specialist. We are recruiting 543 patients with an osteoporotic fracture at Hal du Sacré-Coeur de Montréal. We aim to evaluate: 1) the incidence of a second osteoporotic fracture, 2) the initiation of a treatment and determine the compliance and adherence to treatment and 3) the evaluation of CTX-1 and Osteocalcin at Baseline, 6, 12,18 et 24 months (treatment efficacy) and 4) the functional outcome and quality of life post-fracture.

Method

We've enrolled 153 subjects (men and women) over 40 years of age who were treated for an osteoporotic fracture at the orthopaedic clinic of Hal du Sacré-Coeur de Montréal.

After starting a treatment protocol for osteoporosis, the subjects will be followed for a 24 months period at different time intervals. During these visits, they fill up functional outcome questionnaires, undergo physical exam, blood test, x rays and their compliance to treatment is evaluated.

Purpose

Using utilities and other outcome data collected prospectively on all SPRINT patients and cost data collected from a sample of SPRINT patients, we compared reamed and unreamed intramedullary nailing using a cost-utility analysis.

Method

Participants completed the Health Utility Index 3 (HUI) questionnaire at two weeks after hospital discharge, and three, six, and 12 months post-surgery. We calculated quality adjusted life years (QALYs) for each patient for the first 12 months following intramedullary nailing. A convenience sample of 235 SPRINT patients with similar baseline characteristics provided data on healthcare resource utilization. Costs associated with the healthcare resource utilization were obtained from the 2008 Physicians Schedule of Benefits and a Case Costing System.

Purpose

On January 12th, 2010 a magnitude 7.0 earthquake struck the downtown area of Port au Prince, the capital of the poorest country in the western world. Nearly a quarter of a million people were killed and a million other were injured. Our goal was to provide follow up and acute care to injured Haitain patients.

Method

During an eight day period in June of 2010 a group of three physicians from Memorial University were part of a humanitarian mission to this country in conjunction with the University of Maryland and the humanitarian group Catholic Relief Services (CRS). Attempting to provide orthopedic care six months after such a disaster presented numerous challenges in this part of the world. Security and travel were always a concern due to the rising number of foreign kidnappings that plague the capital city. The heat and humidity made the simplest of tasks exhausting and uncomfortable. Living conditions, although above average for Haiti, consisted of no heated water, diseased mosquitoes, and sleeping of concrete floors. CRS provided us with the means to deal with all of these challenges.

Purpose

Shoulder dislocations account for 50 % of all dislocations, of which 98% are anterior dislocations. Different techniques have been described in literature with variable success, which depends upon type of dislocation, technique used and muscle relaxation.

Method

A retrospective review of data of all shoulder dislocations presented to accident and emergency department over a one-year period was undertaken. Over a 1-year period total of 52 patients presented with mean age of 41 years. Closed reduction was attempted in all patients by accident and emergency department using various techniques and combination of analgesia. Unsuccessful reductions and those with associated fractures were referred to orthopaedics department. This group had closed reduction utilising Sahas zero position technique in accident and emergency department. Post reduction all patients had two views of radiograph to confirm reduction and poly-sling for 2–3 weeks.

Purpose

The measurement of functional outcomes in pelvic fracture patients remains difficult for authors. We aimed to test the construct validity, respondent burden, and patient perception of three previously published pelvic outcome questionnaires.

Method

Subjects completed three pelvic specific, and three general functional outcome instruments. Time for each pelvic instrument was recorded, as was which score the patient felt best addressed their symptoms. Patients stated the three most significant impacts the pelvic fracture had on their life.

Purpose

Electrothermal arthroscopic capsulorrhaphy (ETAC) was a technology introduced for orthopaedic surgery without good scientific clinical evidence supporting its use. This multicentre randomized clinical trial provides the scientific clinical evidence comparing ETAC to Open Inferior Capsular Shift (ICS), by measuring disease-specific quality of life at 2-years post-operatively, in patients with shoulder instability due to capsular redundancy.

Method

Fifty-four subjects (37 females and 17 males; mean age 23.3 years (SD = 6.9; 15–44 years) with multidirectional instability (MDI) or multidirectional laxity with antero-inferior instability (MDL-AII) were randomized intra-operatively to ETAC (n = 28) or Open ICS (n = 26) using concealed envelopes, computer-generated, variable block randomization with stratification by surgeon and type of instability. Outcomes were measured at baseline, 3 and 6 months, 1 and 2 years. The Western Ontario Shoulder Instability (WOSI) Index is a quality of life outcome measure that is scored on a visual analog scale from 0 to 100, where a higher score represents better quality of life. Two functional assessments included the American Shoulder and Elbow Society (ASES) Score and the Constant Score. Post-operative recurrent instability and surgical time were also measured. Analyses included ANOVA of repeated measures with Bonferroni adjustments for multiple comparisons, Chi-square and independent t-tests (p < 0.05).

Purpose

In a previously published multicenter randomized clinical trial it was shown that young patients (16–60 years-old) with displaced mid-shaft clavicle fractures had superior limb specific outcomes when they were treated with primary plate fixation versus non operative treatment at one year follow-up. This study examines the general health status of this cohort of patients at two-years post injury.

Method

We evaluated the general health of a cohort of patients with displaced mid-shaft clavicle fractures comparing non-operative versus plate fixation at two-years after injury. At the conclusion of our study, eighty-nine patients (fifty-four from the operative group and thirty-five from the non-operative group) completed the two-year follow-up. Outcome analysis included the standard clinical follow-up and SF-36 scores.

Purpose

The coronoid process is an integral component for elbow stability. In the setting of a comminuted coronoid fracture, where repair is not possible, a prosthetic device may be beneficial in restoring elbow stability. The hypothesis of this in-vitro biomechanical study was that an anatomic coronoid prosthesis would restore stability to the coronoid deficient elbow.

Method

A metal coronoid prosthesis was designed and developed based on CT-derived images adjusted for cartilage thickness. The kinematics and stability of eight fresh-frozen male cadaveric arms (mean age 77.4 years, range 69–92 years) were quantified in the intact state; after collateral ligament sectioning and repair (control state); after a simulated 40% transverse coronoid fracture; and after implantation of a coronoid prosthesis. Elbow flexion was simulated passively with the arm oriented in the varus position and the forearm in pronation. Varus-valgus angulation (VV) and internal-external rotation (IE) of the ulna relative to the humerus were quantified with an electromagnetic tracking system (Flock of Birds, Ascension Technologies, Burlington, VT, static accuracy: 1.8mm position, 0.5 orientation).

Purpose

Tenodesis of the long head of biceps is an established technique for management of biceps pathology including tears, instability, and chronic tendinosis intractable to non-operative management. Very few studies have reported on clinical outcomes of all-arthroscopic, non-interference, biceps tenodesis techniques. The purpose of this study is to evaluate the functional and quality of life outcomes of patients treated with an all-arthroscopic biceps tenodesis with a suture anchor.

Method

Case Series Level 4 Evidence

Fifty-eight (58) patients with a mean age of 58.5 years were treated with an arthroscopic biceps tenodesis in a single surgeons practice. A single suture anchor was used with a non-interference technique, either in isolation or in association with an arthroscopic rotator cuff repair. A retrospective analysis was performed on prospectively collected outcome measures on patients with a minimum one-year follow-up. Patients were evaluated with an ASES, Constant, and WORC scores pre-operatively and at 6 and 12 months post-operatively. In addition, patients were questioned post-operatively as to whether they experienced any biceps cramping, fatigue, or cosmetic deformity (popeye sign).

Purpose

Controversy exists regarding the optimal technique of subscapularis mobilization during shoulder arthroplasty. The purpose of this multicentre randomized double-blind study was to compare the functional outcomes and healing rates of the lesser tuberosity osteotomy (LTO) to the subscapularis tenotomy (ST).

Method

Patients undergoing shoulder arthroplasty were randomized to receive either a LTO or ST. The primary outcome was to compare subscapularis strength, as measured by an electronic hand-held dynamometer at 12 months. Secondary outcomes included range of motion, WOOS, Constant and ASES scores. A sample size calculation determined that 80 patients provided 80% power with a 50% effect size to detect a significant difference between groups.

Purpose

The coronoid and collateral ligaments are key elbow stabilizers. When repair of comminuted coronoid fractures is not possible, prosthetic replacement may restore elbow stability. A coronoid prosthesis has been designed with an extended tip in an effort to augment elbow stability in the setting of residual collateral ligament insufficiency. The purpose of this biomechanical study, therefore, was to compare an anatomic coronoid replacement with an extended tip implant both with and without ligament insufficiency.

Method

Two coronoid prostheses were designed and developed based on CT-derived images adjusted for cartilage thickness: an anatomical implant and an extended-tip implant. Passive elbow extension was performed in 7 cadaveric arms in the varus and valgus positions. Varus-valgus laxity of the ulna relative to the humerus was quantified with a tracking system with an intact coronoid, a 40% coronoid deficiency, an anatomical prosthesis, and an extended prosthesis, with the collateral ligaments sectioned and repaired.

Purpose

Radial head implant over-lengthening, a common cause of capitellar wear and clinical failure, is difficult to diagnose using radiographs of the injured elbow. The purpose of this study was to determine if a novel measurement technique based on contralateral elbow radiographs, termed the RACER method, could be used to accurately estimate the magnitude of radial head implant over-lengthening. Part I of this study examined the side-to-side consistency of radiographic landmarks used in the measurement technique. Part II of this study validated the technique using simulated radial head implant over-lengthening in a cadaveric model.

Method

Part I: A side-to-side comparison of elbow joint dimensions was performed in 50 patients (100 radiographs). Part II: Radial head prostheses of varying lengths (0,+2mm,+4mm,+6mm,+8mm) were implanted in 4 paired cadaveric specimens (8 elbows). Radiographs were obtained and measurements were performed by 2 examiners blinded to implant size to determine if contralateral radiographs could diagnose and provide a valid estimate of the magnitude of implant over-lengthening. Intra and inter-rater reliability was determined.

Purpose

There have been a number of described techniques for sizing the diameter of radial head implants. All of these techniques, however, are dependent on measurements of the excised native radial head. When accurate sizing is not possible due to extensive comminution or due to a previous radial head excision, it has been postulated that the proximal radioulnar joint (PRUJ) may be used as an intraoperative landmark for correct sizing. The purpose of this study was to: 1) determine if the PRUJ could be used as a reliable landmark for radial head implant diameter sizing when the native radial head in unavailable, and (2) determine the reliability of measurements of the excised radial head.

Method

Twenty-seven fresh-frozen denuded ulnae and their corresponding radial heads (18 males, 9 females) were examined. The maximum diameter (MaxD), minimum diameter (MinD) and dish diameter (DD) of the radial heads were measured twice, 3–5 weeks apart, using digital calipers. Two fellowship-trained upper extremity surgeons, an upper extremity fellow and a senior orthopedic resident were then asked to independently select a radial head implant diameter based on the congruency of the radius of curvature of the PRUJ to that of the radial head trial implants. The examiners were blinded to the native radial head dimensions. This selection was repeated 3–5 weeks later by two of the investigators. Correlation between radial head measurements and radial head implant diameter sizes was assessed using Pearsons correlation coefficient (PCC) and inter and intra-observer reliability were assessed using intra-class correlation coefficient (ICC).

Purpose

The most common procedure for advanced osteoarthritis of the knee is a total knee arthroplasty (TKA). Unicompartmental knee arthroplasty (UKA) has become a popular treatment for isolated medial compartment osteoarthritis. The purpose of this study was to look at the functional outcomes following these two procedures.

Method

Prior to January 1995, 87 Miller-Galante UKAs (MG UKA) were performed in 68 patients. These were compared to a gender, age, BMI matched Anatomic Modular Knee (AMK) cohort of equal size performed during the same time period. Patients were evaluated using a validated clinical outcome score (Knee Society score) and radiographs. Kaplan-Meier survival analysis was performed.

Purpose

The foam metal backed Advance BioFoam Knee Arthroplasty components utilize a porous titanium coating on the underside of the tibial baseplate, intended to promote bone in-growth and provide a more robust bone-implant interface without cement. There is also a version of the Biofoam Advance that incorporates screwed fixation that allows for augmented fixation with up to four titanium screws; however, it is not clear that this augmentation is necessary. The purpose of this study was to employ radiostereometric analysis (RSA) to compare implant migration in a randomized controlled trial of this implant design with or without screw fixation.

Method

Fifty-one patients were randomized to receive a BioFoam total knee replacement (Wright Medical Technologies) with or without screw fixaiton. During surgery, eight tantalum markers, one millimetre in diameter, were inserted into the proximal tibia. Using a calibration box, stereo RSA radiographs were taken post-operatively and then again at six weeks and three, six and 12 months following surgery. Model Based RSA was used with 3D models of the tibial component to measure migration. Health status and functional outcome measures were recorded to quantify functional status of subjects before surgery and at each follow-up interval.

Purpose

Although total knee replacement (TKR) has a high reported success rate, the pain relief and functional improvement after surgery varies. We asked what is the prevalence of patients showing no clinically significant improvement 1-year after TKR, and what are the patient level factors that may predict this outcome.

Method

We reviewed primary TKR registry data that were collected from two academic hospitals: the Toronto Western Hospital (TWH) and the Henderson Hospital(HH) in Ontario. Relevant covariates including demographic data, body mass index, and comorbidity were recorded. Knee joint pain and functional status were assessed at baseline and at 1-year follow-up with the Western Ontario McMaster University Osteoarthritis Index (WOMAC) and Oxford knee score (OKS) to measure the change using the minimal clinically important difference (MCID). Logistic regression modeling was used to identify the predictors of interest.

Purpose

Secondary degenerative changes of the knee are a well recognized complication of Giant Cell Tumor (GCT). Osteoarthritis (OA) may be a consequence of the lesion itself or its treatment. Total Knee Arthroplasty (TKA) is a treatment option for end stage knee arthritis. In the current study we describe the short term follow up of three patients that underwent TKA for treatment of GCT related OA between 2006–2007.

Method

The records of 180 consecutive patients treated for giant cell tumor of the knee between 1989 and 2007 in our institution were reviewed. Three patients were identified that had total knee arthroplasty following treatment of giant cell tumor of the knee, confirmed by tissue biopsy. The review included all clinical notes, pathology and operative reports. Outcomes were assessed based on knee scores and functional scores calculated according to the clinical rating system of The Knee Society, with the assignment of a maximum of 100 points for each. Patient ages range from 29–75 years of age. Assessment occurred pre-operatively as well as post-operatively at six weeks, three months, six months and then yearly. The development of osteoarthritis with severe knee pain was the primary indication for performing TKA.

Purpose

With the advent of newer diagnostic imaging tools, the reported prevalence of acute pulmonary embolism (PE) following total hip (THA) and total knee (TKA) arthroplasty appears to be increasing. However, the true prevalence and clinical relevance of these events are unclear. Our study was designed to evaluate the results of routine multi-detector computed tomography (MDCT) in this patient population in the early postoperative period.

Method

We prospectively performed MDCT scans on 48 consecutive THA/TKA patients on the first postoperative day in 2009. Patients underwent routine postoperative care and data were collected regarding the development of symptoms such as tachycardia, fever, chest pain, or shortness of breath. Scans were kept blinded and read at the end of study recruitment for the diagnosis of acute PE.

Purpose

To evaluate the five year Radiostereometric Analysis (RSA) results of the NexGen LPS Trabecular Metal Tibial Monoblock component (TM) and the NexGen Option Stemmed cemented component (Cemented), (Zimmer, Warsaw IN).

Method

70 patients with osteoarthritis were included in a randomized series to receive either the TM implant or the cemented NG component. Surgery was performed by high volume arthoplasty specialists using standardized procedure. RSA exams were obtained postoperatively, at six months, one year, two years and five years. RSA outcomes were translations, rotations and maximum total point motion (MTPM) of the components. MTPM values were used to classify implants as ‘at risk’ or ‘stable’. Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scores were gathered at all follow-ups.

An analysis of variance was used to test for differences in age, body mass index (BMI), and subjective measures between implant groups. The Kruskal-Wallis test was used to investigate differences in maximum total point motion between implant groups. An analysis of variance was used to test for differences in translations and rotations between groups. Fishers exact test was used to investigate differences in proportions of implants found to be at risk between groups.

Purpose

Two-stage re-implantation after infection of Total Knee Arthroplasty (TKA), remains the gold standard to which other forms of treatment should be compared. The primary purpose of this study was to determine the rates of failure and functional outcome of two stage revision TKA for treatment of infection comparing cemented posterior stabilized compared to constrained condylar implants.

Method

The study group included 25 consecutive patients who had two stage revision TKA to treat infection with an average follow up of 3.25 1.5 years (range 2–6). In all patients the diagnosis of infection was made using standard serum parameters as well as aspiration for joint fluid analysis. Eight patients had posterior stabilized TKAs and 17 patients with had constrained condylar TKAs. Clinical evaluation included the Knee Society Knee Scores (KSKS) at each follow-up visit as well as a detailed record of any difficulties or complications.

Purpose

Total knee arthroplasty (TKA) is the preferred treatment for those with end stage osteoarthritis (OA) and severe functional limitations. With the demographic transition in society, TKA is being offered to a younger patient population. Younger patients are generally more active requiring an increased range of motion, and place greater physiological demands on the prosthesis than typical older patients. The mobile bearing (MB) total knee prosthesis has theoretically been designed to meet these demands. We conducted a meta-analysis and systematic review of randomized controlled trials comparing outcomes of MB and fixed bearing (FB) TKA.

Method

After testing for publication bias and heterogeneity, the data were aggregated by fixed effects modelling. Our searches identified 14 studies for reporting our primary outcome of Knee Society Scores (KSS). We also pooled data for post-operative range of motion (ROM) and Hospital for Special Surgery scores (HSS).

Purpose

The outcome following isolated liner exchange for revision knee arthroplasty, while an attractive option for its simplicity, has a mixed outcome reported in the literature. We report our experience in patients who had a minimum of two years follow-up.

Method

From our database we identified 44 cases in 41 patients who had an isolated liner exchange for a failed primary knee replacement. Twenty were female and the mean body mass index was 33 (range 20 to 49). The mean time to revision from their index procedure was 76 months (range 8 to 152). The mean age at revision was 69 years (range 45 to 90). Patients were assessed by use of validated quality of life questionnaires: Oxford-12, UCLA Activity Level, WOMAC and SF-12. Patients current scores were compared to pre-operative scores in 19 cases. Radiographs were assessed for polyethylene wear, osteolysis and alignment with respect to the mechanical axis. Intra-operative findings were compared to radiographic findings.

Purpose

Patients with anterior cruciate ligament (ACL) deficiency and symptomatic medial compartment osteoarthritis (OA) present a challenge in management. These are often younger than typical primary OA patients and aspire to remain athletically active beyond simple ADLs. Combined ACL reconstruction and valgus tibial osteotomy (ACLHTO) is a well documented surgical option for patients deemed wither too young or too active for total knee arthroplasty. Unicompartmental knee arthroplasty (UKA) is an established surgical treatment for symptomatic medial osteoarthritis of the knee refractory to conservative management. A commonly cited contraindications is symptomatic ACL deficiency because of previous reports detailing premature failure through loosening of the tibial component. Improved results and endoscopic ACL reconstructive procedures have led to an enticing concept of combining ACL reconstruction with medial unicompartmental knee arthroplasty (ACLUKR) for those ACL-deficient medial osteoarthritic (OA) knees. We sought to compare the outcomes in 2 cohorts of patients who underwent either ACLHTO or ACLUKR for this clinical problem.

Method

Patients presenting with symptomatic bone on bone medial compartment OA and concomitant ACL deficiency (clinical or asymptomatic) were evaluated for surgery after exhausting non operative management. Patients who were under 40 or had plans to return to high impact loading sports and/or who had more moderate OA were offered combined ACL – medial opening wedge tibia osteotomy as a surgical procedure of choice. Patients were considered for combined ACL Oxford replacement if they were primarily seeking pain relief and were not engaged or aspiring to return to high impact or pivoting sports. All cases but one were concurrent ACL with either HTO or UKR with autogenous hamstring grafts used in all but 2 cases

Purpose

The prevalence of focal chondral lesions reported inthe literature during knee arhroscopy can be as high as 63%. Of these, more than half are either grade III or grade IV lesions (Outerbridge). Full thickness cartilage lesions ranging from 2cm2 to 10cm2 are the most challenging to treat. To goal of this study was to evaluate clinical outcomes of pain, function and quality of life, along with radiological outcomes of cartilage repair using microfracture, autologous minced cartilage and polymeric scaffold.

Method

A cohort of thirty-eight patients with Outerbridge grade III or IV cartilage injuries larger than 2cm2 in the knee's femoral condyle, trochlea or patella were prospectively folowed since 2008. They were all treated with microfracture, fresh minced autologous cartilage grafting and a polymeric scaffold technique through mini-arthrotomy of the knee. Autografts and scaffolds were secured to subchondral bone using fibrin glue and tran-sosseous resorbable sutures. Patients were evaluated pre and postoperatively using VAS scores for pain, WOMAC and IKDC scores for knee function and SF-36 questionnaire for quality of life. Clinical evaluations were done by physical examination, and imaging was done using X-Rays, MRI and arthro-CT

Purpose

Factors that contribute to early and late re-operation after cruciate reconstruction (CR) have not been evaluated on a population level in a public health system. After surgery patients are at risk for knee stiffness, infection or early graft failure prompting revision. Long-term, ipsilateral revision CR, contralateral CR and potentially even joint replacement may occur. Population research in total joint replacement surgery has demonstrated an inverse relationship between complication/failure rates and surgeon procedural volume. We hypothesized that in Ontario, younger patient age and lower surgeon volume would increase the risk of short and long-term re-operation after CR.

Method

Billing, procedural and diagnostic coding from administrative databases (Ontario Health Insurance Plan, Canadian Institutes of Health Research) were accessed through the Institute for Clinical Evaluative Sciences to develop the cohort of all Ontario residents aged 14 to 60 who underwent anterior or posterior CR from July 1992 to April 2008. Logistic regression analysis was used to calculate the odds ratio for patient (age, gender, comorbidity, income, concurrent knee surgery) and provider (surgeon volume, teaching hospital status) factors for having a surgical washout of the knee, manipulation for stiffness or repeat of the index event within six months. A cox proportional hazards survivorship model was used to calculate the hazard ratio of the same covariates for repeat CR and partial/total knee arthroplasty from inception until end of 2009.

Purpose

Anterior knee pain has been relieved by resection of the infrapatellar plica (IPP). The question is: How? The hypothesis is: the IPP acts as an intra-articular ligament, a mechanical link between the forces of knee motion, the fat pad (FP) and the distal femur, holding the FP captive through the arc of motion. Release of the IPP severs this link, allowing the highly innervated FP to move freely. This may allow any underlying pathologic process to heal.

Method

Anatomic dissection: In 12 knees, the extensor apparatus was released from the femur and retracted distally allowing relationships to be examined.

Cadaver studies: Lateral fluoroscopy was used as well as direct arthroscopic visualization to control implantation of tantalum beads or radiographic contrast material in the FP and IPP. The knee was taken through the arc of motion repeatedly. The femoral attachment of the IPP was then released and knee motion repeated. Traction on the extensor apparatus simulated active motion.

In-Vivo Study: The IRB approved study of 12 volunteers undergoing planned knee arthroscopy under local anesthesia. Contrast was placed in the FP and IPP under lateral fluoroscopic control. Passive, then active motion then a quads-set manoeuvre was performed. The IPP was resected and knee motion again recorded.

Purpose

Elective ACLR is indicated for symptomatic instability of the knee. Despite being a common procedure, there are numerous surgical techniques, graft and fixation choices. Many have been directly compared in randomized trials and meta-analyses. The typical operation is arthroscopic-assisted, uses autograft tendon and screw fixation. Research in elective joint replacement surgery has demonstrated an inverse relationship between surgeon volume and revision and complication rates. How patient demographics, provider characteristics and graft/fixation choices influence ACLR revision rates has not been reported on a population level. We hypothesized that ACLR using tendon autograft and screw fixation performed by high volume surgeons will have the lowest rate of revision. In contrast, the risk of contralateral ACLR in the same cohort will be influenced only by patient factors.

Method

All ACLR performed in Ontario from July 2003 to March 2008 on Ontario residents aged 14 to 60 were identified using physician billing, procedural and diagnostic codes from administrative databases. Data was accessed through the Institute for Clinical Evaluative Sciences. The main outcomes were revision and contralateral ACLR sought from inception until end of 2009. Patient factors (age, gender, income, co-morbidity), surgical choices (allograft or autograft tendon; screw, biodegradable or endobutton/staple fixation) and associated procedures (meniscal repair, collateral ligament surgery) were entered as covariates in a cox proportional hazards survivorship model. Mean cohort patient characteristics were chosen as reference groups. Surgical options and associated procedures were analyzed in a binary fashion (yes/no).

Purpose

Successful outcome after opening wedge high tibial osteotomy (HTO) has been correlated with obtaining and maintaining angular correction while achieving union. Magnitude of correction, type of fixation and use of bone graft have been implicated as variables which can affect maintenance of correction.

The purpose of this study was to determine whether loss of coronal plane correction occurs over time following opening wedge HTO using our standard surgical techniques (unlocked plate with allograft). Our aim was also to correlate clinical outcome measures and radiographic findings. Our hypothesis was that no significant loss of correction would occur.

Method

We conducted a retrospective case series with prospectively obtained clinical and radiographic follow-up. The study population was drawn from surgical data bases of 4 fellowship trained surgeons and included all patients who underwent opening wedge HTO between 2007 and 2009, allowing a minimum of 1 year follow-up. Chart data collected included the model and size of opening wedge fixation plate, type of bone graft, concomitant procedures performed as well as patient factors such as smoking status, medical co-morbidities and body mass index (BMI).

Patients underwent follow-up including documentation of complications and physical examination for range of motion and stability. Outcome scores obtained included the validated, disease-specific KOOS score (5 domains measured out of 100) and the SF-36 as a validated assessment of health related quality of life (8 domains averaged and reported using norm based scoring with population mean = 50). Full length weight bearing X-rays were obtained and measured and then compared with pre-operative and early post-operative X-rays. Measurements were performed with PACS digital imaging software.

Purpose

The majority (73%) of orthopaedic surgeons in Canada prefer using semitendinosus-gracilis (STG) autograft for ACL reconstruction. However, there is large variation in tendon size between individuals which makes pre-operative estimation of graft size unpredictable. Inadequate graft size may require an alternative source of graft tissue that should be planned prior to surgery. The purpose of this study is to determine if clinical anthropometric data and MRI measurements of STG tendons can be used to predict hamstring graft size.

Method

One-hundred and fourteen patients with ACL deficiency awaiting reconstruction using hamstring autograft were retrospectively evaluated. The following information was obtained from patient charts: height, weight, body mass index (BMI), age, and gender. Cross-sectional area (CSA) of gracilis (G) and semitendinosus (ST) tendons were determined from pre-operative MRI scans using NIH ImageJ analysis software. Actual STG graft diameters were obtained from operative reports. Correlations between patient height, weight, BMI, age, gender, ST-CSA, G-CSA, STG-CSA and intraoperative graft size were calculated to determine the association between these variables. Multiple stepwise regression was performed to assess the predictive value of these variables to intraoperative graft diameter. In addition, three investigators with no radiological experience made independent measurements of the ST and G tendons to determine the inter-rater reliability (ICC) of MRI measurements.

Purpose

The Purpose of this study was to evaluate hamstring strength after autogenous hamstring anterior cruciate ligament(ACL) reconstruction with emphasis on deeper knee flexion angles. A comparison of hamstring strength between patients undergoing ACL reconstruction using semitendinosus(ST), and those with semitendinosus and Gracilis(STG) tendons was conducted.

Method

Sixty patients were prospectively followed after undergoing ACL reconstruction surgery. Forty patients received a ST graft, and 20 patients had a STG graft. All patients had standard IKDC subjective knee evaluation completed, and had bilateral hamstring strengths tested using isokinetic testing with a Cybex Orthotron machine. In addition, a hand held Microfet dynamometer was used to measure hamstring strengths at deeper knee flexion angles at six, 12, and 24 months.

Purpose

No knee-specific outcome measures have demonstrated reliability, validity or responsiveness in patients with multiligament knee injuries. Furthermore, the content validity of existing questionnaires has been challenged and remains unknown for patients with concomitant neurovascular injury. As a first step in developing a disease-specific outcome measure, the objective of this study was to identify items from existing knee questionnaires pertinent to patients with multiligament knee injuries using established a priori criteria.

Method

Eighty-five consecutive patients from a level one trauma centre were mailed a questionnaire comprising 124 items from 11 knee-specific instruments. They rated the frequency and importance for each item on a five-point Likert scale. Criteria for item selection included a mean importance rating (MIR) ≥ 3.5 and frequency < 30% for the response never experienced. The World Health Organization International Classification of Functioning, Disability and Health (ICF) framework was used to support the content.

Purpose

Dislocation after revision total hip is a common complication. The purpose of this study was to assess whether a large femoral head (36/40mm) would result in a decreased dislocation rate compared to a standard head (32mm).

Method

A randomized clinical trial was undertaken to assess the effect of large femoral heads on dislocation after revision total hip. Patients undergoing revision hip arthroplasty at seven centers were randomized to 32mm head or 36/40mm head. Patients were stratified according to surgeon. Primary endpoint was dislocation. Rates were compared with Fishers exact test. Secondary outcome measures were quality of life: WOMAC, SF-36 and satisfaction. One hundred eighty four patients were randomized: 92 in the 32mm head group and 92 in the large head group. Baseline demographics were similar in the two groups. Patients were followed from two to five years postoperatively

Purpose

This prospective randomised controlled trial aims to compare the clinical and radiological outcomes of ceramic on ceramic, cobalt chrome on ultra-high molecular weight polyethylene, and cobalt chrome on highly cross-linked polyethylene bearing surfaces at a minimum of five years.

Method

One hundred and two primary total hip replacements were performed in ninety one patients between February 2003 and March 2005. All patients were younger than 65 (mean 52.7, 19–64). They were randomised to receive one of the three bearing surfaces. All patients had 28mm articulations with a Reflection uncemented acetabular component and a Synergy stem (Smith & Nephew, Memphis, Tennessee). Patients were followed up periodically up to at least sixty months following surgery. Outcome measures included WOMAC and SF12 scores. Radiological assessment included implant position, evidence of osteolysis and measurement of linear wear.

Purpose

Transfusion rates after primary total hip has been reported up to 39.2%. The purpose of our study was to evaluate the efficacy of TXA in minimizing risk of allogeneic blood transfusion after primary total hip and hip resurfacing arthroplasty.

Method

Retrospective data on a cohort of 88 patients undergoing total hip arthroplasty and 44 who undergoing hip resurfacing arthroplasty who received a single pre-operative bolus of 1g TXA was compared with a control group matched for starting haemoglobin (Hg), body mass index (BMI), age, gender, blood loss, surgical time, and surgeon. All procedures were completed at a single institution with standardized post-operative care. Endpoints included allogeneic blood transfusion rate, post operative day one Hg, and overall Hg decrease.

Purpose

There is a postulated association between increased serum metal ions and pseudotumour formation in patients with metal-on-metal hip replacements. The primary aim of this study was to assess the prevalence of pseudotumour in 31 asymptomatic patients with a large femoral head (LFH) metal-on-metal hip implant. This was compared to the prevalence of pseudotumour in 20 matched asymptomatic patients with a hip resurfacing (HRA) and 24 matched asymptomatic patients with a standard metal-on-polyethylene (MOP) total hip. A secondary objective was to assess possible correlation between increased serum metal ions and pseudotumour formation

Method

Ultrasound examination of the three groups was performed at a minimum follow up of two years. Serum metal ions were measured in the metal-on-metal LFH and HRA groups at a minimum of two years.

Purpose

Despite the increasing interest and subsequent published literature on hip resurfacing arthroplasty, little is known about the prevalence of its complications and in particular the less common modes of failure. The aim of this study was to identify the prevalence of failure of hip resurfacing arthroplasty and to analyse the reasons for it.

Method

From a multi-surgeon series (141 surgeons) of 5000 Bimingham hip resurfacings we have analysed the modes, prevalence, gender differences and times to failure of any hip requiring revision surgery.

Purpose

Primary total hip arthroplasty (THA) has been a very successful surgical intervention for the management of end-stage arthritis in geriatric patients (> age 65). The mid- to long-term results have been less satisfactory however, in younger patients primarily due to the wear of the acetabular liner and loosening of the femoral component.

The primary study purpose was to compare pain, function and stiffness over the first five years in a population less than 60 years of age who received either an alumina liner/alumina femoral head (alumina group) or a crossfire UHMWPE liner/alumina head (Poly group) following primary THA. Secondarily, we compared re-operation rates over five years between these two groups.

Method

This was a randomized, controlled clinical trial of subjects with non-inflammatory OA who were booked for primary THA and consented to participate in the study. Subjects were evaluated pre-operatively and again at one and five years post-operatively by an evaluator who was blinded to group allocation. At each assessment, subjects completed the WOMAC Osteoarthritis Index (WOMAC); complications and re-operations were also recorded. All analyses were performed on an intention to treat basis.

Purpose

The purpose of this study was to determine the functional outcome, imaging and complications of conversion of hip fusion to uncemented total hip replacement.

Method

The study group comprised eighteen patients who had undergone conversion of unilateral hip fusion to total hip replacement between 1996 and 2007. There were five men and 13 women. The diagnosis prior to fusion was traumatic injury in eight patients, developmental dysplasia in three patients, and septic arthritis in seven patients. Four of the patient who had septic arthritis in childhood had spontaneous hips fusion while the other underwent surgical arthrodesis.

The mean age at the time of conversion was 53 years (range, 21–77) and the mean time between fusion and conversion to hip replacement was 33 years (range, 11–60). Mean follow up was five years (range 2–15 years).

Data was collected by retrospective review of a prospective database. Uncemented acetabular components were used in all cases and uncemented femoral components were used in all but two patients. In three patients with abductor and soft tissue deficiency an intraoperative decision was made to use a constrained acetabular liner.

Purpose

The purpose of this study was to compare and evaluate the cost-effectiveness of the MIS Anterolateral Approach to that of the MIS Posterolateral and MIS Direct Lateral Approach.

Method

A prospective randomized control trial was designed and conducted to compare the MIS Anterolateral Approach to that of the MIS Posterolateral and MIS Direct Lateral Approach. Contemporary methods for economic evaluation were used to ascertain direct and indirect costs (in Canadian dollars) along with clinical effectiveness outcomes (SF6D and Pat5D utility measures). University and hospital ethics was obtained and patients were recruited and consented to participate in the RCT resulting in the assignment of 130 patients MIS hip arthroplasty procedures. Baseline patient demographics, comorbidity, quality of life, and utility were obtained for all patients. In-hospital costing data was obtained including operating room and patient room costs as well as medication, rehab and complications. Post-discharge costs were calculated from direct and indirect costs of medication, rehab, medical costs and complications until one year post-operatively. Clinical effectiveness measures were administered at intervals until one year post-operatively.

Purpose

The Birmingham Mid-Head Resection (BMHR) is a bone-conserving, short-stem alternative to hip resurfacing for patients with compromised femoral head anatomy. It is unclear, however, if an uncemented, metaphyseal fixed stem confers a mechanical advantage to that of a traditional hip resurfacing in which the femoral prosthesis is cemented to the prepared femoral head. Thus, we aimed to determine if a metaphyseal fixed, bone preserving femoral component provided superior mechanical strength in resisting neck fracture compared to a conventional hip resurfacing arthroplasty.

Method

Sixteen matched pairs of human cadaveric femurs were divided evenly between specimens receiving a traditional epiphyseal fixed hip resurfacing arthroplasty (BHR) and those receiving a metaphyseal fixed BMHR. Pre-preparation scaled digital radiographs were taken of all specimens to determine anatomical parameters as well as planned stem-shaft angles and implant sizes. A minimum of 10 degrees of relative valgus alignment was planned for all implants and the planned stem-shaft angles and implant sizes were equal between femur pairs. Prior to preparation, bone mineral density scans of the femurs were obtained. Prepared specimens were potted, positioned in single-leg stance and tested to failure using a mechanical testing machine. Load-displacement curves were used to calculate construct stiffness, failure energy and ultimate failure load.

Purpose

The pros and cons of general anesthesia versus spinal anesthesia in total hip arthroplasty has been a long debated topic. The purpose of this study was to compare the surgical times, blood loss and transfusion requirements between anesthetic types in patients undergoing primary total hip arthroplasty.

Method

A consecutive series of 1600 THA procedures with complete preoperative and postoperative data were evaluated. Twenty eight percent of procedures were performed with a general anesthetic (GA), 67% with a spinal anesthetic (SP) and 5% with a combination of the two. Outcomes were compared and tested for significance using the Independent Samples Kruskal Wallis or Pearson Chi-Square analysis.

Purpose

The patient-physician relationship is a complex interaction and the importance of effective communication is well documented. The importance and implications of effective physician-patient communication is highlighted by the implementation of Communication Skills as a core competency by ACGME. The purpose of this study was to evaluate anonymous surveys completed by orthopaedic clinic patients to assess their visit experiences and whether they would recommend their physician to a friend or family member.

Method

Data were collected from patients exiting SIUs Division of Orthopaedic Surgery outpatient clinics through the completion of an anonymous survey. The survey was distributed on a sample of days between 2002 and 2004 and again in 2009. Responders were asked to complete the survey and return it prior to leaving the office. Participating surgeons were aware of the project occurring but did not know the dates on which surveys would be collected from their clinic patients. All surveys were scanned for data entry and if there was any difficulty with the scanning process then the data was entered manually.

Purpose

Case logs have been utilized as a means of assessing residents surgical exposure and involvement in cases. It can be argued that the degree of involvement in operative cases is as important as absolute number of cases logged. A log which contains accurate information on actual participation in surgical cases in addition to self reported competency, is a powerful tool in obtaining a true reflection of surgical experience. Thus a prerequisite for a valuable log is the ability to perform an accurate self-assessment. Numerous studies have shown mixed results when examining residents ability to perform self-assessment on varying tasks. The purpose of the study was to examine the correlation between residents self-assessment and staff surgeons evaluation of surgical involvement and competence in performing primary hip and knee arthroplasty surgery.

Method

Self assessment data from 65 primary hip and knee arthroplasty cases involving 17 residents and 17 staff surgeons (93% response rate) was analyzed. Interobserver agreement between residents self perception and staff surgeons assessment of involvement was evaluated using the Intraclass Correlation Coefficient (ICC). An assessment of competency was performed utilizing a categorical global scale and evaluated with the Kappa statistic (k). Furthermore, a structured surgical skills assessment form was piloted as an objective appraisal of resident involvement and comparisons were made to resident and staff perception.

Purpose

Students attend operating room sessions throughout their medical school training and are often given the opportunity to scrub and assist during the surgery. Many students have no or very little formal teaching in operating room etiquette, which leads to last minute on the job training from operating room staff. This study aimed to identify if there was any difference between the students knowledge, technique and competency in operating room etiquette skills between two groups of students who received different methods of teaching.

Method

Thirty three 2nd year medical students, that had no previous exposure to operating room etiquette, were recruited for this study. There was variation in their age 18 to 27 years (mean SD years; 19.7 1.9). All students were initially observed scrubbing, gowning and gloving using their baseline knowledge. Their technique was scored using the Dundee University Assessment Sheet and each students knowledge was tested using a spot the mistake quiz. The students were ranked on initial competency then using randomised stratification, separated into two groups. Group One received traditional teaching by operating room staff. Group Two was taught using the new operating room etiquette course, which includes a power point presentation, a video and a practical session. Both groups knowledge and practical skills were reassessed following their teaching. The assessment was repeated at 3 months using the same method, to measure longer-term learning.

Purpose

Residency programs are continually attempting to predict the performance of both current and potential residents. Previous studies have supported the use of USMLE Step 1 and 2 as predictors of Orthopaedic In-Training Examination and eventual American Board of Orthopaedic Surgery board success, while others show no significant correlation. A strong performance on OITE exams does correlate with strong residency performance, and some believe OITE scores are good predictors of future written board success. The current study was designed to examine potential differences in resident assessment measures and their predictive value for written boards.

Method

A retrospective review of resident performance data was performed for the past 10 years. Personalized information was removed by the residency coordinator. USMLE Step 1, USMLE Step 2, in-training exams (from first to fifth years of training), and written orthopaedic specialty board scores were collected. Subsequently, the residents were separated into two groups, those scoring above the 35th percentile on in-training examinations and those scoring below. Data were analyzed using correlation and regression analyses to compare and contrast the scores across all tests.

Purpose

The development of skills in arthroscopic surgery is essential to the training of modern orthopedic surgeons. Few validated, objective tools exist which track improvement in arthroscopic skills. The purpose of this study was to validate an objective global assessment of arthroscopic skills employing videotape footage of diagnostic arthroscopy performed by participants of various skill levels on a cadaveric knee.

Method

A total of 22 participants with varying arthroscopic experience performed a recorded diagnostic knee arthroscopy on a cadaveric knee. Recorded footage of the procedures from an arthroscopic and external view was assessed by five blinded evaluators and scored on a global skills evaluation and checklist evaluation form. Interclass correlation coefficient analyses were used to determine the inter-rater reliability. Mean scores of novice and experienced residents and practicing arthroscopists (based on rank and experience) were compared using a students t-test.

Abstract

This project was funded by “start-up” funds by the Department of Surgery, Division of Orthopaedics, University of Toronto

Purpose

The purpose of this study was to determine the impact of an interactive workshop pertaining to optimizing learning in orthopaedics, on academic performance and changed behaviour towards learning during orthopaedic residency training. Themes included: 1) what makes learning orthopaedic surgery unique? 2) creating the learning environment and; 3) preparation for specific milestones.

Purpose

Hip fractures are the most common injury requiring hospitalization in both men and women over the age of 65. There is significant mortality associated with hip fracture and delay to surgical treatment increases this rate. We undertook an ethnographic study exploring organizational barriers to timely hip fracture surgery.

Method

Using purposive sampling, over 30 interviews were conducted at a large teaching hospital with various professionals involved in the process of getting a patient from ED to surgery and to surgical discharge. This included anaesthetists, surgeons, emergency and internal medicine physicians, nurses, social workers and senior administrative personnel. An additional twelve patient interviews were conducted and reported separately. Following transcription of each tape, a small study team met over the course of several months to read and discuss each transcript in detail. A coding template was developed and each transcript coded with emerging themes noted.

Purpose

Surgical complications are common and frequently preventable. The introduction of the WHO Surgical Safety Checklist has improved surgical outcomes. WHO guidelines reduce, but do not prevent errors. Successful arthroplasty surgery requires strict infection control measures. We observed a single surgical team to see if errors caused by operating room personnel were covered by the WHO Checklist.

Method

Two independent observers studied compliance of WHO Checklists and operating room etiquette, for one surgical team. All operating room personnel were observed during thirteen arthroplasties (hips and knees) from induction to recovery. All Personnel were blinded to the purpose of this study. Data was categorised into errors with WHO checklists and operating room etiquette.

Purpose

The ability to correctly interpret quantitative results is a crucial skill developed in medical school and surgical residency. It demands a basic understanding of epidemiological principles and modes of presenting data. Yet, there has been little investigation into the efficacy of current teaching methods and areas of difficulty among orthopaedic residents.

Method

Forty orthopaedic residents attended a research course provided by the main author in preparation for this assessment. Immediately after formal teaching, these residents were administered a survey that assessed residents perceived and actual level of understanding of basic modes of presenting results including number needed to treat (NNT), relative risk (RR), odds ratio (OR), and absolute risk reduction (ARR). Residents were given a multiple choice clinical case scenario of fracture nonunion and asked to choose which result would be most efficacious at reducing nonunion. An All are equally efficacious option was given for each question. The multiple choice answers were purposefully identical with regard to effect size but answers differed in the way they were presented.

Purpose

Current practice requires all post-operative hip and knee arthroplasty patients complete a series of clinical questionnaires at each visit. The patients responses to these questionnaires are used as a clinical evaluation tool for the surgeons to assess functionality, satisfaction and pain at routine pre and post-operative visits. The recent installation of 4 touch screen computer terminals, located in the patient waiting area, has created the opportunity to have the patients complete these questionnaires by using only the touch screen entry system. This eliminates the need for clinic staff to manually enter the patients responses into the clinics database, eliminate potential data entry errors, and will significantly reduce the amount of time and paper required to prepare questionnaires for each patient. In addition to possibly increasing the volume of data we can collect in our clinic, this also allows the surgeon to have immediate access to the patients responses which can be reviewed prior to seeing the patient in the office. Our goal was to determine the overall level of patient satisfaction with using the new touch screen direct entry system, the efficiency of completion and the quality of data entry occurring from the direct entry system.

Method

During the month of April, 2010, a consecutive series of 100 patients entering the orthopaedic clinic, were directed to the touch screen kiosks to complete the required questionnaires (SF-12, Oxford Knee/Hip, Harris Hip/Knee Society Score, and the Patient Satisfaction Survey). Once the patients completed the touch screen questionnaires they were asked to complete a paper copy of the Touch Screen Satisfaction Questionnaire. This questionnaire asked 6 questions regarding their satisfaction with the touch-screen system, the ease/difficulty of use, and which method they would prefer to complete such questionnaires if given a choice.

Purpose

The ideal timing for a Total Hip Arthroplasty (THA) remains a highly controversial topic in the treatment of displaced acetabular fractures in the elderly with damage to the articular surface of the acetabulum or femoral head. Acute THA offers early rehabilitation but a high incidence of heterotopic ossification has been reported. Its incidence and consequences on the patient's function are not clear.

The goal of this study is to compare the incidence of heterotopic ossification following acute THA of acetabular fractures compared to delayed THA, and to evaluate its functional effects on the patient.

Method

In this retrospective consecutive case series of acetabular fractures; 20 patients were treated with acute THA and 20 patients were treated with delayed THA after failed conservative or surgical treatment. The incidence of heterotopic ossification (using Brooker's classification) was obtained and functional outcomes were evaluated using SF-12, WOMAC, Harris Hip Score surveys.

Purpose

Traditional recommendations suggest that open fractures require urgent surgical debridement to reduce infection. Although many papers comparing early vs late debridement have found no difference in infection rates, these papers have not taken into account important confounding factors. We attempt to answer whether delay between injury and surgical debridement in open fractures is associated with a higher infection rate after accounting for these important confounders.

Method

Five hundred and twenty three open extremity fractures in 417 patients were identified using the Sunnybrook trauma and orthopaedic department registries. Thirty patients (36 fractures) did not have complete follow-up. Seven patients were excluded due to incomplete data (complete follow-up rate=91%). A further 14 patients died during their hospitalization. A total of 459 fractures in 364 patients were reviewed. Data was collected on demographics, ISS score, ASA, time to initial operative debridement, timing of antibiotic administration, mechanism of injury, presence of significant contamination, and Gustillo-Anderson fracture grade. Deep infection was defined as an unplanned return to the operating room for treatment of infection. The influence of time to initial debridement was examined in an unadjusted analysis as a continuous variable and at thresholds of 6 and 12 hours of delay. A multivariable logistic regression was used to analyze the effect of delay while controlling for important confounding variables.

Purpose

Management of compound fractures, which have a higher infection risk than closed fractures, currently depends on surgeon training and past practice rather than evidence based practice. Some centres use delayed closure involving a second surgery with repeat debridement and wound closure 48 hours after initial debridement and fixation. Other centres use primary closure in the absence of gross contamination or major soft tissue deficits, where debridement, fixation and wound closure occur during the initial surgery. Delayed closure was used at our centre until January 2009 when the standard of care evolved to primary closure where appropriate. Primary closure allows more efficient OR utilization due to fewer OR visits, but it is unknown if primary closure increases the risk of infection, which can, in turn, lead to fracture non-union. The purpose of this pilot study was to complete a safety analysis of infection rates in the first 40 patients undergoing primary closure of a compound fracture; enrolment is ongoing and updated results will be presented.

Method

Patients admitted in 2010 with a long bone(femur, tibia/fibula, humerus, radius/ulna) Gustilo grade I-IIIA compound fracture, without the following: gross organic contamination, compartment or crush syndrome, amputation, or gunshot wound, were eligible for primary closure at fracture fixation, and thus for study inclusion.

The analysis compared primary closure subjects with matched delayed closure subjects taken from a previous prospective cohort study of >700 subjects. Subjects were matched at a one:two ratio(i.e. one primary closure:two delayed closure patients) on fracture location, Gustilo grade of fracture, age(within five years), significant comorbidities(diabetes, kidney disease and osteoporosis) and social factors(smoking and alcohol abuse). The outcomes were 1) any infection and 2) deep infection within six weeks of surgery. Time on antibiotics and length of hospital stay(LOS) was also recorded.

Purpose

Blood transfusions cause morbidity and complications in hip fracture patients. This includes increased risk of bacterial infection, potentially increased mortality, and higher hospital costs. Factors such as delay from admission to surgery, fracture pattern, method of fixation, operating time, age, and gender, may affect transfusion requirements. The purpose of this study was to evaluate the effect of patient and operative factors on blood loss and transfusion requirements.

Method

A retrospective analysis of 631 hip fracture patients between October 2005 and February 2010 was performed. Patients were reviewed for demographics, fracture type, fixation method, delay from admission to surgery and operating time. Patients receiving post operative blood transfusions were recorded. A logistic regression analysis was performed to establish a relationship between all independent variables and transfusion requirements.

Purpose

Open reduction and plate fixation of displaced mid-shaft clavicle fractures has gained significant popularity following a recent multi-center randomized control trial. The purpose of this study is to describe the incidence of reoperation following plate fixation of displaced mid-shaft clavicle fractures. The secondary objective is to determine if plate design influences the incidence of reoperation.

Method

A retrospective search of our hospital database was performed to identify subjects treated with plate fixation for a displaced clavicle fracture between 2001 and 2009. Radiographs and medical records were used to identify demographic data, fracture classification, plate design, and reoperation events. Only mid-shaft (AO/OTA 15-B) fractures treated with either a Low-Contact Dynamic Compression (LCDC) plate or Pre-contoured Locking (PCL) plate were included.

Purpose

Anterior column screw fixation has been a useful tool in the management of acetabular fractures, either alone or in combination with other fixation techniques. Percutaneous insertion may be advantageous by limiting surgical dissection but little has been reported on its safety. The purpose of this study is to report on the efficacy and safety of percutaneous anterior column stabilization.

Method

In a consecutive series of 122 operatively treated acetabular fractures, 56 patients were treated with antegrade percutaneous anterior column stabilization either alone or in combination with other fixation techniques by a single surgeon (JY). The technique was selected when the anterior column portion of the fracture was undisplaced or could be reduced via indirect methods. Intraoperative fluoroscopy was used to guide the placement of either a 6.5 mm or 7.3 mm cannulated antegrade anterior column lag screw. Postoperative radiographs (anteroposterior and Judet views) were obtained in the recovery room, prior to discharge and at clinic follow up.

Purpose

To evaluate the use of cutaneous marking of the sacrum for percutaneous iliosacral screw fixation. Iliosacral screw placement is dependent upon spatial perception, multiplanar fluoroscopic imaging, and an appreciation of pelvic anatomy which often makes learning the technique difficult for residents. Cutaneous marking of the sacrum may facilitate iliosacral screw insertion by providing additional cues to the orientation of the sacrum.

Method

A cross-over study design was used for placing iliosacral screws in whole cadaver specimens using standardized operative and imaging techniques with and without cutaneous sacral markings. Lateral fluoroscopic imaging and a radio-opaque straight edge were used to trace the lateral profile of the sacrum with a marking pen. Total procedure time and fluoroscopy time were recorded. A total of 14 residents (6 seniors and 8 juniors) each placed two iliosacral screw guide-wires in a total of seven whole cadavers (14 SI joints). Group 1 performed the procedure first with no markings and then with markings. Group 2 performed the procedure first with markings and then without markings. Statistical analysis included T test, Wilcoxon Rank Sum Test, and Signed-Rank Test for Difference (p = 0.05). Participants also reported their opinions on each technique.

Purpose

Conservative treatment of minimally displaced distal radius fractures (DFR) remains controversial. Circumferential casting (CC) in the acute setting is believed to supply superior support compared to splinting, but is generally cautioned due to the limited capacity of a cast to accommodate ongoing limb swelling possibly leading to complications. However, there is no conclusive data on which to base these beliefs. Moreover, the appropriate management of cast complications while minimizing risk to fracture integrity remains unclear.

This retrospective study of distal radius fractures treated conservatively with circumferential cast in the acute setting aims to: A. Determine demographic, fracture dependant or management risk factors for CC complications. B. Determine the natural history for both patients with CC and those with CC necessitating cast modification.

Method

Hospital records and radiographic data of 316 patients with DRFs treated with CC at a tertiary-care university hospital between the years 2006 to 2009 were reviewed. Our primary outcome was to access risk factors for cast complications including swelling, pressure sores, neuropathies and loss of cast immobilization. Our secondary outcome accessed reduction stability in patients undergoing cast re-manipulation.

Purpose

The SPRINT trial randomized 1226 patients with tibial shaft fractures treated by intramedullary (IM) nailing to reamed versus unreamed groups. Using data from this trial, we completed a subgroup analysis of those patients who required two or more reoperations following the initial IM fracture stabilization.

Method

We identified 44 patients with tibial shaft fractures who required two or more reoperations following IM nailing. We considered those that were reamed vs unreamed, open vs closed, those that were planned for reoperation after the 12 month follow up, and the indications for reoperation.

Purpose

The prevention of a subsequent, contralateral hip fracture is targeted as an avoidable event in the elderly. Fall prevention and bone strengthening measures have met with limited success and the urgency of their effect is undetermined. Our objective was to evaluate the time to second hip fracture (the time between a first and a subsequent, contralateral fracture) in elderly patients, using a population-based administrative health data set.

Method

The 58,286 records of persons older than 60 yrs and hospitalized for a hip fracture between 1985 and 2005 were obtained from a Provincial administrative health database. We excluded non-traumatic cases and identified the care episodes related to a subsequent hip fracture for each patient using unique identifiers. We used a 5 year “wash-out period” to avoid counting a second fracture as a first one.

We calculated the proportion of first and second fractures and sex distribution over time (fiscal years) and quantified the time between first and second fracture, while correlating it to age, sex and fracture type.

Purpose

There are concerns with regard to the physiological effects of reamed intramedullary femoral fracture stabilisation in patients who have received a pulmonary injury. This large animal study used invasive monitoring techniques to obtain sensitive cardiopulmonary measurements and compared the responses to Early Total Care (reamed intramedullary femoral fracture fixation) to Damage Control Orthopaedics (external fixation), after the induction of acute lung injury. We hypothesised a greater cardiopulmonary response to intramedullary fracture fixation.

Method

Acute lung injury (PaO2/FiO2 < 200 mmHg) was induced in 12 invasively monitored and terminally anaesthetised male sheep via the infusion of oleic acid into the right atrium. Each animal underwent surgical femoral osteotomy and fixation with either reamed intramedullary (n=6) or external fixation (n=6). Simultaneous haemodynamic and arterial blood-gas measurements were recorded at baseline and at 5, 30 and 60 minutes after fracture stabilisation.

Purpose

Evaluate the demographics, stages and outcomes in Myxoid (ML) and Round Cell liposarcoma (RCL). Establish the incidence of local recurrence and metastases. Outline the use and benefits of radiotherapy and chemotherapy. Provide guidelines for future management of these rare tumors

Method

Multicentric retrospective study of 421 cases of MRCLS primarily managed by multidisciplinary sarcoma teams in Canada. Data were collected in each centers through a standardized database and statistically analysed.

Purpose

Mesenchymal stromal cells (MSCs) are an attractive choice for regenerative medicine. We previously showed that MSCs enhance wound healing in animals after radiotherapy. The effect of MSCs on tumor growth is not well understood. The potential use of MSCs to enhance wound healing after radiotherapy (RT) and resection of soft tissue sarcoma (STS) is dependent on a satisfactory safety profile to ensure that tumor proliferation does not occur and recurrence is not increased.

Method

Primary cell lines (human myxofibrosarcoma and undifferentiated sarcoma) derived from sarcoma bearing patients and a commercialized human fibrosarcoma cell line (HT1080) were used. Cell line proliferation assay after co-culture with MSCs was done using flow cytometry (CFSE) and bioluminescence emission (BLI) (using eGFP/Fluc transduced cell lines).

Five xenograft models were developed with NOD/SCID gc-null mice (n=164) harbouring primary tissue lines obtained from patients biopsies (myxofibrosarcoma and three pleomorphic undifferentiated sarcoma [PUS A, B and C]) and a a fibrosarcoma cell line previously transduced with eGFP/Fluc. Tumors were passaged to three mouse generations before a tissue line was established and the model was then used. For the fibrosarcoma model, eGFP/Fluc HT1080 were injected under the dorsal skin. When tumors reached 1cm in diameter, they received localized RT and 48hr later were resected. MSCs (n=82) or medium alone (n=82) was injected subcutaneously adjacent to the wound after tumor resection. Histological and in vivo BLI analysis were performed 3 and 12 weeks after surgery.

Purpose

The consequences of infection in orthopedic oncology patients are well known. Methicillin sensitive- and resistant Staphylococcus aureus (MSSA and MRSA, respectively) are common infecting organisms which may colonize patients pre-operatively. The prevalence of colonization in orthopedic oncology patients is unknown. We sought to prospectively establish the prevalence of MSSA and MRSA colonization in an orthopedic oncology patient population.

Method

Beginning in September 2009, all oncology patients of a single surgical service were prospectively screened pre-operatively for MSSA and MRSA colonization using PCR nasal swabs as part of an infection control protocol. Patients identified as carriers underwent decolonization treatment peri-operatively.

Purpose

Due to the aging population, an increasing proportion of elderly patients with soft tissue sarcoma are presenting to cancer centers. This population appears to have a worse prognosis but the reasons for this has not been studied in depth. The purpose of this study is to examine the effect of age on the outcome of patients with extremity and trunk soft tissue sarcoma.

Method

This is a multicenter study including 2071 patients with median age at operation of 57 years (1st quartile–3rd quartile: 42–70). The endpoints considered were local recurrence and metastasis with death as a competing event. Cox proportional hazards models were used to estimate hazard ratios across the age ranges with and without adjustment for known confounding factors.

Purpose

Ewings Sarcoma (ES) and Osteosarcoma (OS) behave and respond differently to chemotherapy and any interpretation of diagnostics tests to predict a patients response to treatment must consider this. We reviewed 18F-FDG PET imaging characteristics of consecutive series of ES and OS patients to determine if any differences in PET imaging existed between them.

Method

A retrospective review was performed of 31 patients with ES and OS who received all their treatment by our group and who had pre- and post-chemotherapy 18F-FDG PET scans at the Peter MacCallum Cancer Centre from Jan 1, 1999 to December 1, 2009 (Table 1). Patients who did not have both their pre- and post-chemotherapy PET scans done at Peter MacCallum Cancer Centre were excluded from the study to remove bias from having different PET scanning protocols. Patients received neoadjuvant chemotherapy according to standard protocols, all starting within 2 weeks after the initial pre-chemotherapy PET scans (PET1). The PET scan taken after the last cycle of chemotherapy prior to surgery was considered as the post-chemotherapy scan (PET2). The ratio between pre and post-chemotherapy for each PET parameter was then associated with the histology response for both ES and OS, and positive (PPV) and negative predicting values (NPV) of each parameter were calculated.

Purpose

Rotationplasty was first described in 1930 by Borggreve for treatment of limb shortening with knee ankylosis after tuberculosis. In 1948, Van Nes described its use for management of congenital defects of the femur and in the 1980s, Kotz and Salzer reported on patients with malignant bone tumors around the knee treated by rotationplasty as an alternative to above-knee amputation. Currently, rotationplasty is one of the options for surgical management of lower extremity bone sarcomas in skeletally immature patients but alternative limb salvage techniques, such as the use of expandable endoprosthesis, are also available. Despite rather satisfactory functional results have been uniformly associated with rotationplasty, concern still exists about the potential psychological impact of the new body imagerelated to the strange appearance of the rotated limb. Results of rotationplasty for sarcomas of the distal femur over a 20-year period were analyzed, focusing on long-term survival, function, quality of life and mental health.

Method

Retrospective study of 73 children who had a rotationplasty performed at two institutions between 1984 and 2007 for a bone sarcoma of the distal femur; 42 males and 31 females, mean age at surgery 8.7 yrs (range 3–17). Four patients were converted to transfemoral amputation due to early vascular complication; 25 eventually died of their disease (mean survival 34 months, range 4–127). The 46 remaining survivors were evaluated for updated clinical outcome, MSTS score, gait analysis, SF-36 score, quality of life interview and psychological assessment at mean follow-up of 15 yrs (range 3–23).

Purpose

The main predictors in the literature of local control for patients operated on for a soft tissue sarcoma are age, local presentation status, depth, grade, size, surgical margins and radiation. However, due to the competing effect of death (patients who die are withdrawn from the risk of local recurrence), the influence of these predictors on the cumulative probabilities may have been misinterpreted so far. The objective of the study was to interpret the influence of known predictors of local recurrence in a competing risks setting.

Method

This single center study included 1519 patients operated on for a localized soft tissue sarcoma of the extremity or trunk. Cox models were used to estimate the cause specific hazard of known predictors on local recurrence. Cumulative incidences were estimated in a competing risks scenario.

Purpose

Durable fixation may be difficult to achieve when significant bone loss is present, as it occurs in pelvic sarcoma resection and revision surgery of tumor implants. Purpose of this study was to review clinical results of primary and revision surgery of the pelvis and lower extremity in the setting of severe bone loss following limb salvage procedures for bone sarcoma using modular porous tantalum implants.

Method

Retrospective study of 15 patients (nine females, six males) undergoing primary or revision pelvic reconstruction (five patients) or revision surgery of a tumor implant of the hip (five patients), knee (four patients), and ankle (one patient) using porous tantalum implants was undertaken. Reason for the tumor implant was resection of bone sarcoma in 13 cases and tumor-like massive bone loss in the remaining two cases. Cause for revision was aseptic failure (nine patients) or deep infection (six patients); average age at the time of surgery was 31 years (16–61 yrs). Revision was managed in a staged fashion in all the six infected cases. All patients presented severe combined segmental and cavitary bone defects. Bone loss was managed in all patients using porous tantalum implants as augmentation of residual bone stock and associated with a megaprosthesis in eight cases (five proximal femur, two distal femur, one proximal tibia). Average follow-up was 4.5 years for hip/knee implants and 2.5 yrs for pelvic reconstructions (range 1–6.8 yrs). Minimum follow-up of two years was available in 11 cases.

Purpose

The traditional management of pediatric aneurysmal bone cysts involves the application of intralesional resection principles that are used to treat benign aggressive tumors in general. Alternatively, some are treated by injections of sclerosing agents. The risks of these approaches include growth arrest, additional bony destruction necessitating the restoration of structural integrity, and soft tissue necrosis. We wished to evaluate the effectiveness of treating aneurysmal bone cysts in children by percutaneous curettage as a means to avoid these risks.

Method

A retrospective cohort study of pediatric, histologically proven aneurysmal bone cyst patients treated either by percutaneous curettage or by open intralesional resection with two years follow up was undertaken. Those cysts judged as uncontained and requiring restoration of structural bony integrity underwent open intralesional resection and reconstruction. Contained cysts judged as not requiring immediate structural restoration were treated percutaneously. This group was uniformly treated on an outpatient basis using angled curettes under image guidance followed by intralesional evacuation using a suction trap. None in this group had insertion of any substance into the cyst cavity. Short-term casting or immobilization was undertaken in most cases. The primary outcome evaluated was radiographic resolution, persistence or recurrence at two years according to the Neer/Cole classification. Complications were noted.

Purpose

While treating fracture sequelae (FS) with unconstrained prostheses has been shown to give inferior or unpredictable outcomes, the literature is still scant regarding their treatment with reverse shoulder arthroplasty (RSA). This study was performed to determine the suitability of RSA as a solution for FS with severe tuberosity malunion/nonunion and rotator cuff dysfunction, and to identify any useful preoperative prognostic factors.

Method

Between 1997 and 2007, RSA was performed in 26 cases for FS of type 4 according to the classification of Boileau et al., previously treated either operatively or nonoperatively. Prior treatment with hemiarthroplasty was an exclusion criteria, as was follow-up of less than two years, leaving 20 patients who had undergone an average of one surgery prior to the index RSA (range, 1–3) and were followed up for a mean of 4.8 years. Preoperatively, the mean global fatty degeneration index (GFDI) was 1.8 (range, 0.7–2.9), and almost half the patients had an atrophic or ruptured teres minor. The mean age at surgery was 70 years (range, 50–91). Clinical evaluation was performed by two independent observers with the help of the Constant score (CS) and Subjective Shoulder Value (SSV).

Purpose

Displaced midshaft clavicular fractures are a common injury with a high occurrence rate in young, active individuals. Non-operative care has traditionally been the standard of care for such fractures, but more recent studies have suggested benefits following primary operative fixation. The purpose of this study was to review the literature on displaced midshaft clavicle fractures, identify randomized controlled trials of operative versus non-operative treatment, and pool the functional outcome and complication rates (including nonunion and symptomatic malunion), to arrive at summary estimates of these outcomes.

Method

A systematic review of the literature was performed to identify studies of randomized controlled trials comparing operative versus non-operative care for displaced midshaft clavicle fractures. Meeting abstracts were also searched and included in this study.

Purpose

There is minimal information on outcome of glenohumeral debridement for treatment of shoulder osteoarthritis (OA). The purpose of this study was to examine the outcome of this procedure with or without acromioplasty /resection of clavicle in subjective perception of disability and functional range of motion and strength at one year following surgery.

Method

Prospectively collected data of patients with advanced OA of the glenohumeral joint who were not good candidates for shoulder arthroplasty due to young age, high activity level, or desire to avoid major surgery at the time of assessment were included. Arthroscopic debridement included removal of loose bodies, chondral flaps, and degenerative tissue. Resection of the lateral end of the clavicle or acromioplasty was performed as clinically indicated for management of osteoarthritis of the Acromioclavicular (AC) joint or subacromial impingement respectively. Disability at 12 months following surgery was measured by the American Shoulder and Elbow Surgeons (ASES) assessment form, Constant-Murley score (CMS), strength, and painfree range of motion in four directions.

Purpose

The management of moderate to large engaging Hill-Sachs lesions is controversial and surgical options include remplissage, allograft reconstruction, and partial resurfacing arthroplasty. Few in-vitro studies have quantified their biomechanical characteristics and none have made direct comparisons. The purpose of this study was to compare joint stability and range of motion (ROM) among these procedures using an in-vitro shoulder simulator. It was hypothesized that all procedures would prevent defect engagement, but allograft and partial resurfacing would most accurately restore intact biomechanics; while remplissage would provide the greatest stabilization, possibly at the expense of motion.

Method

Eight cadaveric shoulders were tested on an active in-vitro shoulder simulator. Each specimen underwent testing in 11 conditions: intact, Bankart lesion, Bankart repair, and two unrepaired Hill-Sachs lesions (30% & 45%) which were then treated with each of the three techniques. Anterior joint stability, ROM in extension and internal-external rotation, and glenohumeral engagement were assessed. Stability was quantified as resistance, in N/mm, to an anteriorly applied load of 70N.

Purpose

Pain and stiffness from elbow arthritides can be reliably improved with arthroscopic osteocapsular ulnohumeral arthroplasty (OUA) in selected patients. Post-operative continuous passive motion (CPM) may be helpful in reducing hemarthrosis, improving soft-tissue compliance and maintaining the range of motion (ROM) established intra-operatively. There is only one published series of arthroscopic OUA and CPM was used in a minority of those patients. We hypothesized that a standardized surgical and post-operative CPM protocol would lead to rapid recovery and sustained improvement in ROM.

Method

Thirty patients with painful elbow contractures underwent limited open ulnar nerve decompression and arthroscopic OUA at our institution by a single fellowship trained upper limb reconstruction surgeon. All patients underwent CPM for three days in-hospital with a continuous peripheral nerve block, followed by gradual weaning of CPM at home over two weeks. ROM using a goniometer was assessed at discharge, cessation of CPM (2 weeks) and final follow-up. The main outcome was elbow flexion, extension and total arc of motion. Paired students t-test was used to compare pre and post-operative ROM.

Purpose

Controversy exists regarding the optimal technique for arthroscopic rotator cuff repair. The purpose of this multicentre randomized double-blind controlled study was to compare the functional outcomes and healing rates of double-row suture techniques with single row repair.

Method

Patients undergoing arthroscopic rotator cuff repair were randomized to receive either a double row (DR) or single row (SR) repair. The primary objective was to compare the WORC score at 24 months. Secondary objectives included anatomical outcomes by MRI or ultrasound, the Constant, and ASES scores. A sample size calculation determined that 84 patients provided 80% power with a 50% effect size to detect a statistical difference between groups.

Purpose

Limited information is available regarding the functional outcomes of radial head fractures managed with open reduction and internal fixation (ORIF). The purpose of this study was to determine the functional outcomes of radial head fractures treated with ORIF.

Method

Fifty-two patients, with a mean age of 4412 years, who were treated with radial head ORIF were evaluated at a mean of 4.42.4 years. Thirty were isolated radial head fractures (Group A), 13 (Group B) were associated with a complex fracture-dislocation (terrible triad variants), and 5 (Group C) were associated with a proximal ulnar fracture (Monteggia/trans-olecranon variants). Fourty-four were partial articular fractures and 8 were complete articular fractures. Outcomes were assessed with physical and radiographic examination, and validated self-reported questionnaires.

Purpose

Glenoid version has been correlated with tears within the rotator cuff. Cuff tear arthropathy is an evolution of multiple unhealed tendons ultimately resulting in pseudoparalysis. Although several factors are critical to allow tendon healing, we have observed that there is less glenoid version in patients with cuff tear arthropathy. This was compared to those with osteoarthritis where rotator cuff tears are uncommon. We hypothesize that patients undergoing inverse prosthesis generally have a near neutral glenoid.

Method

A single surgeons practice (JPW) was retrospectively reviewed for all cuff tear arthropathy and osteoarthritis patients undergoing primary shoulder arthroplasty. (Zimmer, Warsaw, IN). Glenoid version was measured by 2 fellowship trained shoulder surgeons. Inter and intra-class correlation was measured.

Purpose

The remplissage procedure may be performed as an adjunct to Bankart repair to address an engaging Hill-Sachs defect. Clinically, it has been reported that the remplissage procedure improves joint stability but that it may also restrict shoulder range of motion. The purpose of this biomechanical study was to examine the effects of the remplissage procedure on shoulder motion and stability. We hypothesized that the remplissage procedure would improve stability and prevent engagement but may have a deleterious effect on motion.

Method

Eight cadaveric forequarters were mounted on a custom biomechanical testing apparatus which applied simulated loads independently to the rotator cuff muscles and to the anterior, middle and posterior deltoid. The testing conditions included: intact shoulder, Bankart defect, Bankart repair, 2 Hill-Sachs defects (15%, 30%) with and without remplissage. Joint range of motion and translation were recorded with an optical tracking system. Outcomes measured were internal-external rotation range of motion in adduction and 90 combined abduction, extension range of motion and stability, quantified in terms of joint stiffness and engagement, in abduction.

Purpose

The introduction of alternate care provider roles is at the forefront of many new health human resource strategies and is one of the key approaches in reducing orthopaedic wait times in Canada. The present study was part of a formal evaluation of an expanded role for physiotherapists which included referral triage, comprehensive assessment and development of a management plan and post-surgical follow-ups. Specifically, we examined the efficacy and role of an Advanced Practice Physiotherapist (APP) with respect to reduction in wait times to care for patients with shoulder complaints referred to an orthopaedic surgeon with subspecialty in shoulder reconstruction.

Method

We used data of 100 consecutive patients seen by an APP in 2010 to examine the following: 1) type of diagnosis, 2) number of new investigations ordered, percentage of patients who needed a consultation with the surgeon, 3) and indication for surgery. Patients who were sent for a second surgical opinion, had a failed surgery in the affected side, had a motor vehicle accident or were a surgical candidate for stabilization or superior labral repairs were not included in the study and were directly booked for the orthopaedic surgeon. To compare change in waiting times, a random sample of 100 charts of patients seen in 2008 by an orthopaedic surgeon with a subspecialty in shoulder reconstruction were reviewed. The following time frames were compared between the surgeon and APP: T1: time from date of referral to date of consultation, T2: time from date of consultation to date of final diagnostic test, T3: time from date of consultation to confirmed diagnosis. Parametric and non-parametric analyses were performed as indicated by the distribution of data.

Purpose

To determine whether there is a difference in the metal ion levels among three different metal-on-metal total hip systems: two monoblock large heads and one modular metal-on-metal total hip replacement system in patients who received these implants in our region.

Method

A group of 56 patients were recruited that had either undergone total hip replacement (THR) with a Birmingham resurfacing socket, the Durom resurfacing socket, or a Pinnacle metal-on-metal bearing surface. All patients recruited were at least one year following their surgery in order that their ion levels had reached a steady state.

We reviewed every patient clinically, radiographically as well as biochemically. Blood was obtained for cobalt (Co) and chromium (Cr) levels. Current radiographs were arranged to assess the stability and mechanics of the total hip systems. All patients signed an informed consent and completed three questionnaires, The Western Ontario and McMaster Universities (WOMAC) index, the Short Form 36 (SF36) and UCLA activity score. A Harris Hip score was completed in order to assess individual hip function. Statistical analysis was performed on the collected data to assess whether there were any other potential influence on the mean levels of Co and Cr.

Purpose

To determine if minimally invasive surgery (MIS) for primary hip replacement surgery increases the risk of long term aseptic loosening as predicted by implant micromotion measured with radiostereometric analysis (RSA).

Method

Ninety patients undergoing primary THA for osteoarthritis (exclusion criteria: post-traumatic arthritis, rheumatoid arthritis, hip dysplasia, previous hip infection) were randomized to undergo THR surgery utilizing the standard direct lateral approach (n=45; 24 male; age=58 yrs; BMI=27) or MIS via a one-incision direct lateral approach using specific instrumentation (n=45; 23 male; age=55; BMI=29). Uncemented acetabular and femoral (ProfemurZ) components were used with ceramic on ceramic bearings. The femur was marked with 9 tantalum beads placed in the greater trochanter, lesser trochanter, and femoral shaft distal to the tip of the prosthesis. Post-operative care was be standardized according to the care maps at our institution. Primary outcome measure was femoral stem MTPM (maximum total point motion) measured using Model-based RSA. Stereo supine X-rays were taken before weight bearing and 3, 6, and 12 months postoperatively. At the same time intervals Harris Hip Score, Oxford-12, WOMAC, and SF36 questionnaires were administered. Rates of infection, dislocation and revision were recorded.

Purpose

Use of a large femoral head metal-on-metal bearing in total hip arthroplasty may offer an advantage in terms of dislocation rates and more natural joint kinematics. The acetabular component is more rigid however in these prostheses and if not placed accurately can lead to increased levels of metal ion release. A prospective randomized controlled trial was conducted to quantify bone mineral density on the acetabular side, as well as compare metal ion levels from a standard metal-on-polyethylene bearing to a large head metal-on-metal bearing in primary total hip arthroplasty.

Method

Fifty patients were randomized to receive total hip arthroplasty with either the CONSERVE A-Class Total Hip with BFH femoral head or the Lineage acetabular component with polyethylene insert and cobalt chrome femoral head. There were 27 females (11 BFH) and 23 males (14 BFH), with a mean overall age of 61.6 (range 47.7–73.2). Serum levels of cobalt, chromium, and titanium were measured at regular intervals up to two years. Harris Hip Score, WOMAC, UCLA, and RAND-36 were completed at these same intervals. Standard radiographs as well as periprosthetic BMD were performed.

Purpose

Cross-linking of polyethylene greatly reduces its wear rate in hip simulator studies. We conducted a systematic review and meta-analysis of randomized controlled trials comparing cross-linked to conventional polyethylene liners for total hip arthroplasty to determine if there is a clinical reduction of: 1) wear rates, 2) radiographic osteolysis, and 3) need for total hip revision.

Method

A systematic search of MEDLINE, EMBASE, and COCHRANE databases was conducted from inception to May 2010 for all trials involving the use of cross-linked polyethylene for total hip arthroplasty. Eligibility for inclusion in the review was: use of a random allocation of treatments; a treatment arm receiving cross-linked polyethylene and a treatment arm receiving conventional polyethylene for total hip arthroplasty; and use of radiographic wear as an outcome measure. Eligible studies were obtained and read in full by two co-authors who then independently applied the Checklist to Evaluate a Report of a Nonpharmacological Trial to each study. Pooled mean differences were calculated for the following continuous outcomes: bedding-in, linear wear rate, three dimensional linear wear rate, volumetric wear rate, and total linear wear. Pooled risk ratios were calculated for radiographic osteolysis and revision hip arthroplasty.

Purpose

To review prospectively collected data on patients undergoing primary total hip arthroplasty utilizing two different cementless acetabular components.

Method

All patients undergoing primary total hip replacement surgery at our institution are entered prospectively into a database which includes history and physical examination, radiology, WOMAC and SF-36 scores. The patients are re-examined, re-x-rayed and re-scored at 3 months, 6 months and 1 year after surgery and yearly thereafter.

Using this database we are able to identify patients who have undergone total hip replacement using one of two geometric variants of the acetabular component. The first design is hemispherical and the second design has a peripheral rim expansion designed to increase initial press-fit stability.

Purpose

Metal-on-metal (MoM) articulations in total hip replacement (THR) have become an attractive option for young, active patients. Short-term reports have demonstrated elevated systemic metal ion levels in the blood and urine. Disseminated concentrations of cobalt and chromium have raised concern regarding cellular toxicity, chromosomal damage and adverse local soft tissue reactions.

Long-term studies are required to support the increased use of MoM bearings in younger patients given their potential deleterious effects. The purpose of the current study was to report the seven to 13 year clinical, radiographic, and metal ion results in patients following MoM THR.

Method

We prospectively followed 165 patients (196 hips) after second-generation MoM THR between July 1997 and November 2003. Functional outcome was measured using the Harris Hip Score (HHS) and the University of California Los Angeles (UCLA) Activity Score. Radiographic analysis was performed using Einzel-Bild-Roentgen-Analyse (EBRA) by two of the authors blinded to the study. Cobalt and chromium metal ions were measured from whole blood and analyzed using inductively coupled plasma-mass spectrometry as previously described.

Purpose

Femoroacetabular impingement (FAI) may contribute to the development of early onset hip osteoarthritis (OA). A cam lesion (or pistol grip deformity) of the proximal femur reduces head-neck offset resulting in cam type FAI. The alpha angle is a radiographic measurement recommended for diagnosis of cam type FAI. The purpose of this study was to determine if patients that develop end stage hip OA prior to 55 years of age have radiographic evidence of cam type FAI.

Method

The anteroposterior (AP) pelvis and lateral hip radiographs of 244 patients (261 hips) who presented to our institution for hip arthroplasty or hip fracture fixation between 2006 and 2008 were retrospectively reviewed. Three cohorts were compared: 1) patients with end stage hip OA < 55 years old (N=76); 2) patients with end stage hip OA > 55 years old (N=84); 3) hip fracture patients > 65 years old without radiographic evidence of hip arthritis were used as controls (N=101). Patients with inflammatory arthritis, avascular necrosis and post-traumatic hip OA were excluded. Alpha angles were measured on the AP pelvis and lateral radiographs by three coauthors using ImageJ 1.43 software (National Institutes of Health, USA). For patients with end stage hip OA, AP alpha angles were measured on both the hip with OA and the contralateral hip. Lateral alpha angles were measured only on the hip with OA. For patients with hip fracture, AP alpha angles were measured on the non-fractured hip and lateral alpha angles were measured on the fractured hip. A one-way ANOVA with post hoc Tukeys HSD test was used to compare the AP and lateral alpha angles for the three cohorts.

Purpose

Tape blisters after hip surgery are frequent. There are source of pain, an obstacle for rapid rehabilitation and an open door for infection. Previous studies have shown a reduction up to 10% according to the type of bandage. A previous survey in our hospital demonstrated more than 50% of patients presenting tape blisters with the use of Hypafix. The purpose of this prospective study was to compare the prevalence of blisters with the use of three different kinds of bandages.

Method

Between April and December 2009, 150 patients admitted for hip surgery (THR, hip fractures) were randomized in three groups: Hypafix (control group), silicone gel (Mepilex Border), perforated plaster (Mepore Pro). Groups were similar for demographic datas and type of surgery. Main outcome is tape blisters during hospital stay. Additional observations were duration of hospital stay, costs related to bandages and nursing cares. Outpatient records were completed by nurses and patients and returned to research team after complete wound healing.

Purpose

The purpose of the study was to determine the rate of conversion from RSA to THR in a number of Canadian centers performing resurfacings

Method

Retrospective review was undertaken in 12 Canadian Centers to determine the rate of revision and reason for conversion from RSA to THR. Averages and cross-tabulation with Chi-Squared analysis was performed. kaplan Meier survivorship was calculated.

Purpose

This prospective, expertise-based randomized clinical trial compares arthroscopic to open shoulder stabilization by measuring the disease-specific quality of life outcome in patients with traumatic unidirectional anterior shoulder instability, and determining the incidence of recurrent instability at 2-years post-operatively.

Method

One hundred and ninety-six patients were randomly allocated to arthroscopic (n=98) or open (n=98) repair using an expertise-based approach with a surgeon specializing in one type of surgery. Randomization was performed using computer-generation, variable block sizes and concealed envelopes. Outcomes were measured at baseline, 3 and 6 months, 1 and 2 years post-operatively. These outcomes included the Western Ontario Shoulder Instability (WOSI) Index quality of life outcome and the American Shoulder and Elbow Society (ASES) functional outcome. Both outcomes were measured on a visual analog scale from 0 to 100, where a higher score represents better quality of life or function. Recurrent instability was categorized as traumatic/atraumatic, and as a subluxation/dislocation. Analyses included ANOVA of repeated measures and independent t-tests. Bonferroni adjustments for pairwise contrasts were made for multiple comparisons. Chi-squared analyses were performed on recurrence. Statistical significance was reported at p < 0.05.

Purpose

Platelet-derived growth factor-BB (PDGF-BB) is a well characterized wound healing protein known to be chemotactic and mitogenic for cells of mesenchymal origin, including osteoblasts and chondrocytes. Biocompatible scaffolds, combined with growth factors such as PDGF-BB, have potential to stimulate regeneration and repair of osseous and cartilaginous tissues. The purpose of this study was to determine the efficacy and safety of recombinant human PDGF-BB (rhPDGF-BB) combined with a collagen implant to augment healing of osteochondral defects.

Method

A single osteochondral defect (8mm x 8mm) was created in the medial femoral condyle of 32 adult goats. Collagen implants(8.5mm x 8mm) hydrated with four doses of rhPDGF-BB (0g, 15g, 75g, 500g) were press-fit into the defect. Defects in four animals were left untreated. All goats were sacrificed 12 weeks postoperatively. Macroscopic evaluation and quantitative CT analyses were performed. Histologic sections were stained with Safranin O/Fast Green and assessed with a modified ODriscoll scoring scale for cartilage and bone repair. Significance was determined by One-Way ANOVA or nonparametric Kruskal-Wallis.

Purpose

Management of massive, degenerative, and irreparable rotator cuff tears is challenging. Excessive re-tear rates and poor clinical outcome after standard repair have led to alternative methods of treatment. Tendon transfers and shoulder arthroplasty have had mixed results; both are invasive procedures with high potential morbidity. We began performing rotator cuff augmentation and replacement using GraftJacket allograft acellular human dermal matrix as a biologic minimally invasive alternative in this difficult population almost 6 years ago. This article highlights our preferred arthroscopic technique and early results.

Method

From January 2004 to June 2007, 45 patients (36 men, 9 women) with massive rotator cuff tears were treated arthroscopically with the GraftJacket allograft. All patients completed a preoperative University of California, Los Angeles (UCLA) score. Follow-up was a minimum of 2 years (range, 24–68 months) and patients completed UCLA, Western Ontario Rotator Cuff (WORC), and American Shoulder and Elbow Surgeons (ASES) scores.

Purpose

The presence of a Hill-Sachs lesion is a major contributor to failure of surgical intervention following anterior shoulder dislocation. The relationship between lesion size, measured on pre-operative MRI, and risk of recurrent instability after surgery has not previously been defined.

Hypothesis: We hypothesized that the size of Hill-Sachs lesions on pre-op MRI would be greater among patients who failed soft tissue stabilization when compared to patients who did not fail. We also hypothesized that the existence of a glenoid lesion would lead to failure with smaller Hill-Sachs lesions.

Method

Nested case-control analysis of 114 patients was performed to evaluate incidence of failure after soft tissue stabilization. Successful follow-up of at least 24 months was made with 91 patients (80%). Patients with recurrent instability after surgery were compared to randomly selected age and sex matched controls in a 1:1 ratio. Pre-operative sagittal and axial MRI series were analyzed for presence of Hill-Sachs lesions, and maximum edge-to-edge length and depth as well as location of the lesion related to the bicipital groove (axial) and humeral shaft (sagittal) were measured.