Background. Post-operative acute kidney injury is significant complication following surgery. Patients who develop AKI have an increased risk for progression into chronic kidney disease, end-stage renal failure and increased mortality risk. The patient outcomes following total knee replacement (TKR), who develop AKI has been a topic of interest in recent years as it may have patient and medicolegal implications. Nevertheless, there are no studies looking at the incidence, risk factors and outcomes of AKI following bilateral TKRs at the same sitting. Objectives. To determine the incidence, risk factors and outcomes of post-operative AKI following bilateral TKRs surgery at the same sitting. Methods. This was a retrospective single-centre study performed at the Princess Royal Hospital, which performed a total of 25 BTKR. The incidence, Surgical and patient risk factors were recorded and analysed. Results. The incidence of AKI as defined by NICE guidelines following bilateral TKRs was 20%. 16% (4 patients) had stage 1 and 4% (1 patient) had stage 2 AKI. The mean change in Creatinine between pre- and post-operative blood tests was +19μmol/L. There was a strong significant correlation between CKD and AKI (r=0.75, P<0.05). Furthermore, a moderate correlation was found between higher BMI and pre-operative Charlson index and AKI. AKI did not have an effect on the length of inpatient stay with the mean inpatient length of stay for patients who had an AKI of 10 days compared to 11days for those who did not. All AKIs were resolved within 72 hours. There were no associated mortalities with AKI. Conclusion. The incidence of AKI following bilateral TKR was 20%. Pre-operative chronic kidney disease as well as having a higher BMI were identified as risk factors for developing AKI. Pre-operative CKD optimisation and careful adequate hydration intra-operatively should be considered in these patients. AKI was not associated with an increased length of stay or mortality in our study

Background. The current average tariff of a total knee replacement (TKR) is £5500. The approximate cost of each knee prosthesis is £2500. Therefore, length of patient stay (LOS) and the cost of patient rehabilitation influence the total costs significantly. Previous studies have shown a mean LOS of between 5 and 9.4 days for patients undergoing primary unilateral TKR but none looked at the factors influencing length of stay following bilateral primary total knee replacements (BTKR) at the same sitting. Objectives. To identify significant factors that influence the LOS following BTKR at the same sitting in a single centre in the UK. Methods. This was a retrospective single-centre study performed at the Princess Royal Hospital which performed a total of 25 BTKR. Surgical and patient factors that may influence LOS were recorded and analysed. Results. The mean LOS was 10 days with a median of 9 days. 64% were discharged within 10 days. Those staying longer were classified as long stayers. Being a female (0.65, p< 0.05), having a higher Charlson index (0.68, p< 0.05) and having a post-operative blood transfusion (0.59, p< 0.05) were the only significant factors that influenced LOS. Post-operative acute kidney injury (AKI), underlying diagnosis such as rheumatoid arthritis, BMI, age, worse pre-operative oxford knee scores and type of implant did not influence LOS. Conclusion. Factors influencing LOS following BTKR shown in our study seems to be the same as those influencing unilateral TKRs as identified in the literature. This should be taken into consideration when comparing unilateral versus bilateral TKR results as well as when planning a local arthroplasty service

Total temporomandibular joint (TMJ) replacements reduce pain and improve quality of life in patients suffering from end-stage TMJ disorders, such as osteoarthritis and trauma. Jaw kinematics measurements following TMJ arthroplasty provide a basis for evaluating implant performance and jaw function. The aim of this study is to provide the first measurements of three-dimensional kinematics of the jaw in patients following unilateral and bilateral prosthetic TMJ surgeries. Jaw motion tracking experiments were performed on 7 healthy control participants, 3 unilateral and 1 bilateral TMJ replacement patients. Custom-made mouthpieces were manufactured for each participant's mandibular and maxillary teeth, with each supporting three retroreflective markers anterior to the participant's lip line. Participants performed 15 trials each of maximum jaw opening, lateral and protrusive movements. Marker trajectories were simultaneously measured using an optoelectronic tracking system. Laser scans taken of each dental plate, together with CT scans of each patient, were used to register the plate position to each participant's jaw geometry, allowing 3D condylar motion to be quantified from the marker trajectories. The maximum mouth opening capacity of joint replacement patients was comparable to healthy controls with average incisal inferior translations of 37.5mm, 38.4mm and 33.6mm for the controls, unilateral and bilateral joint replacement patients respectively. During mouth opening the maximum anterior translation of prosthetic condyles was 2.4mm, compared to 10.6mm for controls. Prosthetic condyles had limited anterior motion compared to natural condyles, in unilateral patients this resulted in asymmetric opening and protrusive movements and the capacity to laterally move their jaw towards their pathological side only. For the bilateral patient, protrusive and lateral jaw movement capacity was minimal. Total TMJ replacement surgery facilitates normal mouth opening capacity and lateral and inferior condylar movements but limits anterior condylar motion. This study provides future direction for TMJ implant design

To report the case of an asymptomatic simultaneous bilateral neck of femur fracture following vitamin D deficiency which was missed, misdiagnosed and treated for coexisting severe bilateral osteoarthritis knee. A male aged 62 years presented with severe osteoarthritis of both knee joints confining him to bed about eight weeks prior to presentation. The patient did not have any complaints pertaining to his hip joints/axial skeleton. Examination of the hip joints revealed only crepitus with absence of straight leg rising. Radiological survey showed bilateral displaced fracture neck of femur. He had elevated serum alkaline phosphatase; 119IU/L(N:39–117IU/L), decreased Serum 25 (OH) Vit D level;6.03ng/ml(N:7.6–75ng/ml), decreased spot urinary calcium;78mg/day(N:100–300mg/day) with normal serum calcium, phosphorus and highly raised parathormone levels;142.51pg/ml(N:12–72pg/ml). Tc-99 Bone scan showed increased radiotracer uptake in both the hip joints and knee joints. Bone Mineral Density was in favour of osteoporosis. Biopsy fromthe heads of both femurs also revealed osteoporosis. Bilateral staged total hip arthroplasty was done and he was put on Vitamin D replacement therapy. Patient was on regular monthly follow-up for intial one year and three monthly follow-up thereafter. At present with three year follow-up patient is community ambulant with a walking frame. Despite medical advice patient had denied total knee arthroplasty for osteoarthritis of his knee joints. Asymptomatic simultaneous bilateral neck of femur fracture is a rare injury and poses a diagnostic challenge to the treating orthopaedic surgeon with its bizarre clinical picture. Similar presentation of metabolic bone disease can be easily missed without a proper screening, keeping in mind a high index of suspicion for the above disorders. Besides proper clinical examination of both hip and knee joint should be performed in patients presenting with bilateral knee pain. A good functional outcome may be achieved with prompt surgical intervention and medical treatment

Introduction. Recurrent patellar dislocation is often reported in bilateral knees in young active individuals. The medial patellofemoral ligament (MPFL) tear is the attributable cause behind many of them and warrants reconstruction of the ligament to stabilize the patellofemoral joint. Besides, trochleoplasty and Fulkerson's osteotomy are some other procedures that are performed to treat this problem. This study aimed to compare the clinical and functional outcomes in a cohort of patients with single-stage bilateral realignment procedures vs staged procedures. Methods. It was a retrospective matched cohort study with prospectively collected data. A total of 36 patients (mean age-26.9 years, range 13 years to 47 years) with recurrent patellar dislocations, who underwent a surgical correction in both the knees, were divided into two matched groups (age, sex, follow-up, and type of procedure). Among them, 18 patients had surgeries in one knee done at least six months later than the other knee. The remaining 18 patients had surgical interventions for both knees done in a single stage. Lysholm, Kujala, Tegner, and subjective knee scores of both groups were compared and analyzed. The rate of complications and return to the theatre were noted in both groups. Results. With a mean follow-up of 7.3 years (2.0 years to 12.3 years), there was a significant improvement in PROMS observed in both the groups (p<0.05). No significant difference could be found between the two groups in terms of the Lysholm, Kujala, and subjective knee scores (p> 0.05). The rate of complication and the re-operation rate was comparable in both the groups (p>0.05). Conclusion. The outcomes of staged vs simultaneous surgeries for bilateral patellofemoral instability are comparable. Our results indicate that simultaneous bilateral surgical correction is safe. This can potentially be an option to reduce the surgical cost and perioperative morbidity. However, careful selection of cases, choice of the patient, and the scope of rehabilitation facilities are some of the other factors that should be considered

Abstract. Objectives. Although hip replacement and resurfacing procedures both aim to restore mobility, improve joint function, and relieve pain, it is unclear how each differ in terms of gait mechanics and if they are affected by varying walking speeds. We compared limb symmetry and ground reaction force (GRF) profiles between bilateral total hip arthroplasty patients (THA), bilateral hip resurfacing arthroplasty patients (HRA), and healthy control participants (CON) during level-treadmill walking at different speeds. Methods. Bilateral THA and bilateral HRA patients (nTHA = 15; nHRA = 15; postoperative 12–18 months), and age-, mass-, and height-matched CON participants (nCON = 20) underwent gait analysis on an instrumented treadmill. Walking trials started at 4 km/h and increased in 0.5 km/h increments until top walking speed (TWS) was achieved. Gait symmetry index (SI = 0% for symmetry) was assessed between limbs during weight-acceptance, mid-stance and push-off phases of gait; and vertical GRFs were captured for the normalised stance phase using statistical parametric mapping (SPM; CI = 95%). Results. THA had a significantly lower TWS (6.51 ± 0.06 km/h) compared to HRA (7.09 ± 0.07 km/h, p = 0.01) and CON (7.15 km/h ± 0.06, p = 0.02). There were no SI differences between groups nor between walking speeds (SI < 5%). There were no GRF differences between groups at slower walking speeds (4.0–5.0 km/h). However, at 5.5 and 6 km/h, THA had lower GRF at the push-off phase (0.88 ± 0.09 N/BW), compared to HRA (1.06 ± 0.08 N/BW, p = 0.01) and CON (1.04 ± 0.02 N/BW, p = 0.01). Conclusions. The main finding was that HRA patients demonstrated restored gait function and similar walking profiles to CON participants at any speed. With a diverging gait profile, walking speeds over 5.5 km/h provided a functional challenge for THA patients

Summary. Data of 663 patients with three different pathologies were examined. We found that using patients with significant symptoms and functional difficulty in the opposite shoulder will not bias the results of observational studies if outcomes are based on routine disability measures such as ASES or Constant-Murley scores. Introduction. Recently, using patients with bilateral limb problems as independent cases has raised concerns in orthopaedic research due to violating the assumption of independence. If observations are too similar in characteristics, they become highly correlated which leads to lowering the variance and biasing the results. Type of pathology (impingement, cuff tear, osteoarthritis) and aging are expected to affect the incidence of bilateral shoulder complaints and should be considered when examining potential bias in this area. In addition, the impact of dominant side pathology has not been investigated primarily in patients with shoulder problems. The objectives of this study were: 1) to examine the incidence of bilateral shoulder complaints and pathology on the dominant side in patients with impingement syndrome, rotator cuff tear and osteoarthritis of the glenohumeral joint, 2) to explore the role of sex and age in developing bilateral shoulder complaints, and 3) to examine the impact of bilaterality and hand dominance on pre and one year post-operative disability. Patients and Methods. This study involved review of data of patients with a diagnosis of impingement syndrome, rotator cuff tears and osteoarthritis (OA) of the gleno-humeral joint who had undergone surgery and had returned for their one year follow-up. Two outcome measures were used; the American Shoulder & Elbow Surgeons (ASES) and the Constant Murley score (CMS). Results. Data of 663 patients (317 females; 269 impingement syndrome, 290 rotator cuff tear, 104 osteoarthritis) were included in the analysis. There was a difference in the incidence of bilateral symptoms in patients with different pathologies: osteoarthritis 46%, impingement 26%, and rotator cuff tears 23% (p<0.0001). The incidence of dominant side involvement was 70%, 68% and 50% in patients with rotator cuff tear, impingement syndrome and osteoarthritis (p=0.003). Neither bilaterality nor dominant arm pathology had a negative impact on disability (p>0.05). Discussion/Conclusion. Type of pathology and aging affect the incidence of bilateral shoulder symptoms. Rotator cuff related pathologies affect the dominant side more frequently. The most interesting finding of this study was related to lack of influence of bilateral symptoms or dominant side pathology on reported disability in three different pathology groups with different prevalence of disease

Summary Statement. Supercritical fluid (SCF) sterilization produces clean and osteoconductive allograft bone capable of healing a critical-sised bony defect. SCF treated graft induces an increased anabolic response and decreased catabolic reponse compared to gamma irradiated graft. Introduction. Clinically, allogeneic bone graft is used extensively because it avoids the donor site morbidity associated with autograft. However, there are concerns over the optimal sterilization method to eliminate immunological risks whilst maintaining the biological efficacy of the graft. This study compared the effect of Supercritical fluid (SCF) sterilization and gamma irradiation on the osteoconductivity of allograft bone in a bilateral critical-sised defect rabbit model. Methods. Cortical-cancellous allograft bone was milled, defatted and terminally sterilised with either gamma irradiation at 25kGy or SCF treatment. The graft was then implanted bilaterally into a critical-sised metaphyseal defect in 10 New Zealand White rabbits (n=5 sites per time point per group). Osteoconductivity was evaluated at 2 and 4 weeks to measure the early inflammatory response and early new bone formation respectively, using X-ray, CT, and both qualitative and quantitative histology and immunohistochemistry (Alkaline Phosphatase and Cathepsin-K). Results. Both grafts were well tolerated and osteoconductive. At 2 weeks, there were significant reductions in bone volume and density in the gamma irradiated graft compared to the SCF treated graft as measured by CT. Inside the defect this corresponded with a greater inflammatory response in the gamma irradiated graft, with a less organised fibrous tissue infiltration and mild granuloma reaction. Conversely, the SCF group had a highly organised and densely packed fibrous tissue infiltration around the allograft chips. Immunohistochemistry results supported these findings with an up-regulation in the expression and distribution of Cathepsin-K in the gamma irradiation group; while Alkaline Phosphatase expression was higher in the SCF group. At 4 weeks, resorptive behavior predominated in both groups. Radiographic and CT results detected no significant difference between groups. Histology at 4 weeks showed larger bone chips were undergoing substantial remodeling with areas of simultaneous osteoclastic resorption and osteoblastic new bone formation. Smaller allograft chips and areas of new bone formation were infiltrated by fibrous tissue and undergoing osteoclastic resorption. Quantitative immunohistochemistry showed an up-regulation of Cathepsin-K expression in both groups from 2 to 4 weeks. At both time points Cathepsin-K expression was higher in the gamma irradiated graft compared to the SCF group. This was greatest at 2 weeks where there was a substantial 82% increase in expression which was reduced to a 38% discrepancy at 4 weeks. Alkaline Phosphatase expression was greater in the SCF group at both time-points. Discussion/Conclusion. Allograft bone sterilised with either gamma irradiation or SCF treatment was osteoconductive and capable of healing a critical-sised defect in a rabbit. Gamma irradiated allografts elicited an acute inflammatory reaction when implanted which increased the amount graft resorption compared to the SCF treated bone. Increased osteoclastic resorption may be a concern for structural graft applications leaving the graft more susceptible to premature failure. SCF sterilization produced a clean, highly biocompatible graft with increased anabolic activity compared to gamma irradiation which may facilitate earlier healing clinically. These results suggest that SCF sterilization has considerable expediency for allograft processing and may facilitate more optimal extraction of the inherent properties of the graft compared to current practices

Biphasic calcium phosphate (BCP) with a characteristic needle-shaped submicron surface topography (MagnetOs) has attracted much attention due to its unique bone-forming ability which is essential for repairing critical-size bone defects such as those found in the posterolateral spine. Previous in vitro and ex-vivo data performed by van Dijk LA and Yuan H demonstrated that these specific surface characteristics drive a favorable response from the innate immune system. This study aimed to evaluate and compare the in vivo performance of three commercially-available synthetic bone grafts, (1) i-FACTOR Putty. ®. , (2) OssDsign. ®. Catalyst Putty and (3) FIBERGRAFT. ®. BG Matrix, with that of a novel synthetic bone graft in a clinically-relevant instrumented sheep posterolateral lumbar spine fusion (PLF) model. The novel synthetic bone graft comprised of BCP granules with a needle-shaped submicron surface topography (MagnetOs) embedded in a highly porous and fibrillar collagen matrix (MagnetOs Flex Matrix). Four synthetic bone grafts were implanted as standalone in an instrumented sheep PLF model for 12 weeks (n=3 bilateral levels per group; levels L2/3 & L4/5), after which spinal fusion was determined by manual palpation, radiograph and µCT imaging (based on the Lenke scale), range-of-motion mechanical testing, and histological and histomorphological evaluation. Radiographic fusion assessment determined bilateral robust bone bridging (Lenke scale A) in 3/3 levels for MagnetOs Flex Matrix compared to 1/3 for all other groups. For µCT, bilateral fusion (Lenke scale A) was found in 2/3 levels for MagnetOs Flex Matrix, compared to 0/3 for i-FACTOR Putty. ®. , 1/3 for OssDsign. ®. Catalyst Putty and 0/3 for FIBERGRAFT. ®. BG Matrix. Fusion assessment for MagnetOs Flex Matrix was further substantiated by histology which revealed significant graft resorption complemented by abundant bone tissue and continuous bony bridging between vertebral transverse processes resulting in bilateral spinal fusion in 3/3 implants. These results show that MagnetOs Flex Matrix achieved better fusion rates compared to three commercially-available synthetic bone grafts when used as a standalone in a clinically-relevant instrumented sheep PLF model

Pelvic bone defect in patients with severe congenital dysplasia of the hip (CDH) lead to abnormalities in lumbar spine and lower limb alignment that can determine total hip arthroplasty (THA) patients' outcome. These variables may be different in uni- or bilateral CDH. We compared the clinical outcome and the spinopelvic and lower limb radiological changes over time in patients undergoing THA due to uni- or bilateral CHD at a minimum follow-up of five years. Sixty-four patients (77 hips) undergoing THA due to severe CDH between 2006 and 2015 were analyzed: Group 1 consisted of 51 patients with unilateral CDH, and group 2, 113 patients (26 hips) with bilateral CDH. There were 32 females in group 1 and 18 in group 2 (p=0.6). The mean age was 41.6 years in group 1 and 53.6 in group 2 (p<0.001). We compared the hip, spine and knee clinical outcomes. The radiological analysis included the postoperative hip reconstruction, and the evolution of the coronal and sagittal spinopelvic parameters assessing the pelvic obliquity (PO) and the sacro-femoro-pubic (SFP) angles, and the knee mechanical axis evaluating the tibio-femoral angle (TFA). At latest follow-up, the mean Harris Hip Score was 88.6 in group 1 and 90.7 in group 2 (p=0.025). Postoperative leg length discrepancy of more than 5 mm was more frequent in group 1 (p=0.028). Postoperative lumbar back pain was reported in 23.4% of the cases and knee pain in 20.8%, however, there were no differences between groups. One supracondylar femoral osteotomy and one total knee arthroplasty were required. The radiological reconstruction of the hip was similar in both groups. The PO angle improved more in group 1 (p=0.01) from the preoperative to 6-weeks postoperative and was constant at 5 years. The SFP angle improved in both groups but there were no differences between groups (p=0.5). 30 patients in group 1 showed a TFA less than 10º and 17 in group 2 (p=0.7). Although the clinical outcome was better in terms of hip function in patients with bilateral CDH than those with unilateral CDH, the improvement in low back and knee pain was similar. Patients with unilateral dysplasia showed a better correction of the PO after THA. All spinopelvic and knee alignment parameters were corrected and maintained over time in most cases five years after THA

Lateral lumbar interbody fusion (LLIF) has biomechanical advantages due to the preservation of ligamentous structures (ALL/PLL), and optimal cage height afforded by the strength of the apophyseal ring. We compare the biomechanical motion stability of multiple levels LLIF (4 segments) utilising PEEK interbody 26mm cages to stand-alone cage placement and with supplemental posterior fixation with pedicle screw and rods. Six lumbar human cadaver specimens were stripped of the paraspinal musculature while preserving the discs, facet joints, and osteoligamentous structures and potted. Specimens were tested under 5 conditions: intact, posterior bilateral fixation (L1-L5) only, LLIF-only, LLIF with unilateral fixation and LLIF with bilateral fixation. Non-destructive testing was performed on a universal testing machine (MTS Systems Corp) to produce flexion-extension, lateral-bending, and axial rotation using customized jigs and a pulley system to define a non-constraining load follower. Three-dimensional spine motion was recorded using a motion device (Optotrak). Results are reported for the L3-L4 motion segment within the construct to allow comparison with previously published works of shorter constructs (1-2 segments). In all conditions, there was an observed decrease in ROM from intact in flexion/extension (31%-89% decrease), lateral bending (19%-78%), and axial rotation (37%-60%). At flexion/extension, the decreases were statistically significant (p<0.007) except for stand-alone LLIF. LLIF+unilateral had similar decreases in all planes as the LLIF+bilateral condition. The observed ROM within the 4-level construct was similar to previously reported results in 1-2 levels for stand-alone LLIF and LLIF+bilateral. Surgeons may be concerned about the biomechanical stability of an approach utilizing stand-alone multilevel LLIF. Our results show that 4-level multilevel LLIF utilizing 26 mm cages demonstrated ROM comparable to short-segment LLIF. Stand-alone LLIF showed a decrease in ROM from the intact condition. The addition of posterior supplemental fixation resulted in an additional decrease in ROM. The results suggest that unilateral posterior fixation may be sufficient

The purpose of this study was to compare the outcomes of arthroscopic unilateral surgery and simultaneous bilateral surgery for posterior ankle impingement syndrome (PAIS) in athletes and to evaluate the usefulness of simultaneous bilateral surgery. A total 48 hindfeet of 41 athletes (14 hindfeet of 14 males, 34 hindfeet of 27 females) who underwent arthroscopic surgery for PAIS were studied. Japanese society for surgery of the foot (JSSF) score and visual analogue scale (VAS) were compared before and after surgery, using Wilcoxon signed-rank test. The operation time and the time to return to sports activity were compared in 10 hindfeet of 5 patients who underwent simultaneous bilateral surgery and 38 hindfeet of 36 patients who underwent unilateral surgery, using Wilcoxon rank sum test. Classic ballet was the most common type of sport that caused PAIS (59%, 24/41 athletes). Soccer (10%, 4/41 athletes), baseball (10%, 4/41 athletes), badminton (5%, 2/41 athletes), volleyball (5%, 2/41 athletes), and athletics (5%, 2/41 athletes) followed. The JSSF score improved significantly from 72.7 preoperatively to 98.9 postoperatively in unilateral surgery, and significantly improved from 75.2 preoperatively to 99.0 postoperatively in simultaneous bilateral surgery. VAS significantly decreased from 64.7 preoperatively to 4.8 postoperatively in unilateral surgery, and significantly decreased from 72.7 preoperatively to 1.0 postoperatively in simultaneous bilateral surgery. The operating time was 53.7 minutes on average for unilateral surgery and 101.0 minutes for simultaneous bilateral surgery, significantly longer in bilateral simultaneous surgery. The mean time to return to sports activity was 4.8 weeks for unilateral surgery and 9.6 weeks for simultaneous bilateral surgery, significantly longer in simultaneous bilateral surgery. Both unilateral and simultaneous bilateral surgeries for PAIS in athletes were useful. It should be noted that the operating time and the time to return to sports will be longer. However, considering the 2 times hospitalizations and 2 times surgeries, simultaneous bilateral surgery is one of the treatment options for PAIS

Meniscal tears are the most common injury in the knee, affecting 66/100,000 people/year. Surgical treatment includes arthroscopic meniscectomy or meniscal repair. Little is known regarding medium-term outcomes following these procedures in isolated meniscal tears. This study aims to quantitatively evaluate patients with meniscal tears, and those who have undergone meniscectomy and meniscal repair using validated patient reported outcome measures (PROMs), further exploring factors which affect surgical outcomes. This observational study screened 334 patients who underwent arthroscopic surgery at South Tyneside Hospital since August 2013. 134 patients with isolated meniscal tears were invited to complete postal PROMs. A combination of patient notes and radiological imaging was used to collect information of interest including age, gender, knee-laterality, injured meniscus, tear pattern, procedure performed, complications, and associated injuries. A total of 115 patients (pre-operative patients with current meniscal tear (n=36), meniscectomy (n=63), meniscal repair (n=16)) were included in the analysis with 96% successful PROM completion. Both meniscectomy and meniscal repairs (mean 55-months follow-up) showed better outcomes than pre-operative patients with meniscal tears. Meniscal repairs demonstrated superior outcomes across all PROMs when compared to meniscectomy, with a greater mean overall KOOS score of 17.2 (p=0.009). Factors including higher pre-operative Kellgren-Lawrence Grade, pre-operative articular cartilage lesions and bilateral meniscectomies were shown to negatively influence outcomes. Both meniscectomy and meniscal repair maintain clinical benefit at mean 55-months follow-up, affirming their use for treatment of meniscal tears. When feasible, meniscal repair should be performed preferentially over meniscectomy in isolated meniscal tears. Identified predictive factors allow adequate treatment stratification in specific patient groups

Renal Osteodystrophy is a type of metabolic bone disease characterized by bone mineralization deficiency due to electrolyte and endocrine abnormalities. Patients with chronic kidney disease (CKD) are more likely to experience falls and fractures due to renal osteodystrophy and the high prevalence of risk factors for falls. Treatment involves medical management to resolve the etiology of the underlying renal condition, as well as management (and prevention) of pathological fractures. A 66-year-old female patient, with severe osteoporosis and chronic kidney disease undergoing haemodialysis, has presented with multiple fractures along the years. She was submitted to bilateral proximal femoral nailing as fracture treatment on the left and prophylactically due to pathological bone injury on the right, followed by revision of the left nail with a longer one after varus angulation and fracture distal to the nail extremity. Meanwhile, the patient suffered a pathological fracture of the radial and cubital diaphysis and was submitted to conservative treatment with cast, with consolidation of the fracture. Posteriorly, she re-fractured these bones after a fall and repeated the conservative treatment. Clinical management: There is a multidisciplinary approach to manage the chronic illness of the patient, including medical management to resolve the etiology and consequences of her chronic kidney disease, pain control, conservative or surgical fracture management and prevention of falls. The incidence of chronic renal disease is increasing and the patients with this condition live longer than previously and are more physically active. Thus, patients may experience trauma as a direct result of increased physical activity in a setting of weakened pathologic bone. Their quality of life is primarily limited by musculoskeletal problems, such as bone pain, muscle weakness, growth retardation, and skeletal deformity. A multidisciplinary approach is required to treat these patients, controlling their chronic diseases, managing fractures and preventing falls

A novel EP4 selective agonist (KMN-159) was developed [1] and has been proven that it can act as an osteopromotive factor to repair critical-size femoral bone defects in rats at a dose-dependent manner [2]. Based on its osteopromotive properties, we hypothesized that KMN-159 could also aid in bone formation for spinal fusion. Therefore, the aim of this study was to investigate its spinal fusion effect in a dorsolateral spinal fusion model in rats. This study was performed on 192, 10-week-old male Wistar rats. The rats were randomized into 8 groups (n = 12 per group): 1) SHAM (negative control), 2) MCM (scaffold only), 3) MCM + 20 µg BMP-2 (positive control), 4-8) MCM + 0.2, 2, 20, 200 or 2000 µg KMN-159. A posterolateral intertransverse process spinal fusion at L4 to L5 was performed bilaterally by implanting group dependent scaffolds (see above) or left empty in the SHAM group (protocol no. 25-5131/474/38). Animals were euthanized after 3 weeks and 6 weeks for µCT and biomechanical testing analysis. The results showed that KMN-159 promoted new bone formation in a dose-dependent manner at 3 weeks and 6 weeks as verified by µCT. The biomechanical testing showed that the dose of 20, 200 and 2000 µg KMN-159 groups obtained comparable strength with BMP-2 group, which higher than SHAM, MCM and lower doses of 0.2 and 2 µg KMN-159 groups. In conclusion, KMN-159 could be a potential replacement of BMP-2 as a novel osteopromotive factor for spinal fusion. Acknowledgements: We are grateful to Ulrike Heide, Anna-Maria Placht (assistance with surgeries) as well as Suzanne Manthey & Annett Wenke (histology)

Osteoarthritis (OA) of the knee joint is a complex peripheral joint disorder with multiple risk factors. We aimed to examine the relationship between the grade of knee OA and anterior thigh length (ATL). A total of 64 geriatric patients who had no total hip or knee replacement with a BMI of ≥30 were evaluated. Patients' OA severity was determined by two independent experts from bilateral standing knee radiographs according to the Kellgren-Lawrence (KL) grade. Joint cartilage structure was assessed using ultrasonography (US). The ATL, the gastrocnemius medialis (GC), the rectus femoris (RF) and the rectus abdominis (RA) skeletal muscle thicknesses as well as the RF cross-sectional area (CSA) were measured with US. Sarcopenia was diagnosed using the handgrip strength (HGS), 5× sit-to-stand test (5xSST) and bioelectrical impedance analysis. The median (IQR) age of participants was 72 (65–88) years. Seventy-one per cent of the patients (n=46) were female. They were divided into the sarcopenic obese (31.3 %) and the non-sarcopenic obese (68.8%) groups. KL grade of all patients correlated negatively with the ATL (mm) and the thickness of GC (mm) (r= -0,517, p<0.001 and r= -0.456, p<0.001, respectively). In the sarcopenic obese and the non-sarcopenic obese groups, KL grade of the all patients was negatively correlated with ATL (mm) and thickness of GC (mm) (r= -0,986, p<0.001; r= -0.456, p=0.05 and r= -0,812, p=0.002; r= −0,427, p=0.006). KL grade negatively correlated with the RF thickness in the sarcopenic obese group (r= -0,928, p=0.008). In conclusion, OA risk may decrease as the lower extremity skeletal muscle mass increases. Acknowledgments: Feza Korkusuz MD is a member of the Turkish Academy of Sciences (TÜBA)

The lateral wall thickness (LWT) in trochanteric femoral fractures is a known predictive factor for postoperative fracture stability. Currently, the AO/OTA classification uses a patient non-specific measure to assess the absolute LWT (aLWT) and distinguish stable A1.3 from unstable A2.1 fractures based on a threshold of 20.5 mm. This approach potentially results in interpatient deviations due to different bone morphologies and consequently variations in fracture stability. Therefore, the aim of this study was to explore whether a patient-specific measure for assessment of the relative LWT (rLWT) results in a more precise threshold for prediction of unstable fractures. Part 1 of the study evaluated 146 pelvic radiographs to assess left-right symmetry with regard to caput-collum-angle (CCD) and total trochanteric thickness (TTT), and used the results to establish the rLWT measurement technique. Part 2 reevaluated 202 patients from a previous study cohort to analyze their rLWT versus aLWT for optimization purposes. Findings in Part 1 demonstrated a bilateral symmetry of the femur regarding both CCD and TTT (p ≥ 0.827) allowing to mirror bone's morphology and geometry from the contralateral intact to the fractured femur. Outcomes in Part 2 resulted in an increased accuracy for the new determined rLWT threshold (50.5%) versus the standard 20.5 mm aLWT threshold, with sensitivity of 83.7% versus 82.7% and specificity 81.3% versus 77.8%, respectively. The novel patient-specific rLWT measure can be based on the contralateral femur anatomy and is a more accurate predictor of a secondary lateral wall fracture in comparison to the conventional aLWT. This study established the threshold of 50.5% rLWT as a reference value for prediction of fracture stability and selection of an appropriate implant for fixation of trochanteric femoral fractures

Acute syndesmotic ankle injuries continue to impose a diagnostic dilemma and it remains unclear whether weighbearing or external rotation should be exerted rotation during the imaging process. Therefore, we aimed to implement both axial load (weightbearing) and external rotation in the assessment of a clinical cohort of patients with syndesmotic ankle injuries syndesmotic using weightbearing CT imaging. In this retrospective comparative cohort study, patients with an acute syndesmotic ankle injury were analyzed using a WBCT (N= 20; Mean age= 31,64 years; SD= 14,07. Inclusion criteria were an MRI confirmed syndesmotic ankle injury imaged by a bilateral WBCT of the ankle during weightbearing and combined weightbearing-external rotation. Exclusion criteria consisted of fracture associated syndesmotic ankle injuries. Three-dimensional (3D) models were generated from the CT slices. Tibiofibular displacement and Talar Rotation was quantified using automated3D measurements (Anterior TibioFibular Distance (ATFD), Alpha Angle, Posterior TibioFibular Distance (PTFD) and Talar Rotation (TR) Angle) in comparison to a cohort of non-injured ankles. Results. The difference in neutral-stressed Alpha° and ATFD showed a significant difference between patients with a syndesmotic ankle lesion and healthy ankles (P = 0.046 and P = 0.039, respectively) The difference in neutral-stressed PTFD and TR° did not show a significant difference between patients with a syndesmotic ankle lesion and healthy ankles (P = 0.492; P = 0.152, respectively). Conclusion. Application of combined weightbearing-external rotation reveals a dynamic anterior tibiofibular widening in patients with syndesmotic ankle injuries. This study provides the first insights based on 3D measurements to support the potential relevance of applying external rotation during WBCT imaging. However, to what extent certain displacement patterns are associated with syndesmotic instability and thus require operative treatment strategies has yet to be determined in future studies

Osteoporotic fracture has become a major problem in ageing population and often requires prolonged healing time. Low Intensity Pulsed Ultrasound (LIPUS) can significantly enhance fracture healing through alteration of osteocyte lacuno-canalicular network (LCN). DMP1 in osteocytes is responsible for maintaining LCN and mineralisation. This study aims to investigate osteocyte-specific DMP1's role in enhanced osteoporotic fracture healing in response to mechanical stimulation. Bilateral ovariectomy was performed in 6-month-old female SD rats to induce osteoporosis. Metaphyseal fracture was created at left distal femur using oscillating micro-saw. Rats were randomised to groups: (1) DMP1 KD, (2) DMP1 KD + LIPUS, (3) Control, or (4) Control + LIPUS, where KD stands for knockdown by injection of shRNA into marrow cavity 2 weeks before surgery. Assessments included weekly radiography, microCT and immunohistochemistry on DMP1, E11, FGF23 and sclerostin. DMP1 KD significantly impaired LIPUS-accelerated fracture healing when comparing KD + LIPUS group to Control + LIPUS group. The X-ray relative opacity showed less tissue growth at all timepoints (Week 1, 3 & 6; p=0.000, 0.001 and 0.003 respectively) and the bone volume fraction was decreased after DMP1 KD at Week 3 (p=0.006). DMP1 KD also significantly altered the expression levels of osteocyte-specific DMP1, E11, FGF23 and sclerostin during healing process. The lower relative opacity and bone volume fraction in DMP1 KD groups indicated that knockdown of DMP1 was associated with poorer fracture healing process compared to non-knockdown groups. The similar results between knockdown group with and without LIPUS showed that blockage of DMP1 would negate LIPUS-induced enhancement on fracture healing. Acknowledgment: General Research Fund (Ref: 14113018)

Digital Ventilated Cages (DVC) offer an innovative technology to obtain accurate movement data from a single mouse over time [1]. Thus, they could be used to determine the occurrence of a tendon damage event as well as inform on tissue regeneration [2,3]. Therefore, using the mouse model of tendon experimental damage, in this study it has been tested whether the recovery of tissue microarchitecture and of extracellular matrix (ECM) correlates with the motion data collected through this technology. Mice models were used to induce acute injury in Achilles tendons (ATs), while healthy ones were used as control. During the healing process, the mice were housed in DVC cages (Tecniplast) to monitor animal welfare and to study biomechanics assessing movement activity, an indicator of the recovery of tendon tissue functionality. After 28 days, the AT were harvested and assessed for their histological and immunohistochemical properties to obtain a total histological score (TSH) that was then correlated to the movement data. DVC cages showed the capacity to distinguish activity patterns in groups from the two different conditions. The data collected showed that the mice with access to the mouse wheel had a higher activity as compared to the blocked wheel group, which suggests that the extra movement during tendon healing improved motion ability. The histological results showed a clear difference between different analyzed groups. The bilateral free wheel group showed the best histological recovery, offering the highest TSH score, thus confirming the results of the DVC cages and the correlation between movement activity and structural recovery. Data obtained showed a correlation between TSH and the DVC cages, displaying structural and movement differences between the tested groups. This successful correlation allows the usage of DVC type cages as a non-invasive method to predict tissue regeneration and recovery. Acknowledgements: This research is part of the P4FIT project ESR13, funded by the H2020-ITN-EJD MSCA grant agreement No.955685