Aims. The gluteus minimus (GMin) and gluteus medius (GMed) have unique structural and functional segments that may be affected to varying degrees, by end-stage osteoarthritis (OA) and normal ageing. We used data from patients with end-stage OA and matched healthy controls to 1) quantify the atrophy of the GMin and GMed in the two groups and 2) describe the distinct patterns of the fatty infiltration in the different segments of the GMin and GMed in the two groups. Methods. A total of 39 patients with end-stage OA and 12 age- and sex frequency-matched healthy controls were prospectively enrolled in the study. Fatty infiltration within the different segments of the GMin and the GMed was assessed on MRI according to the semiquantitative classification system of Goutallier and normalized cross-sectional areas were measured. Results. The GMin was smaller in the OA-group (p < 0.001) compared to the control group, but there was no group difference in the size of the GMed (p = 0.101). Higher levels of fatty infiltration were identified in the anterior segment of the GMin (p = 0.006) and the anterior (p = 0.006) and middle (p = 0.047) segments of the GMed in the OA group. All subjects in the control group had fatty infiltration of the anterior segment of the GMin, but all except one had no fatty infiltration in the entire GMed. Conclusion. End-stage OA was associated with significant atrophy of the GMin and higher levels of fatty infiltration, particularly in the anterior segments of the GMin and GMed. Minor fatty infiltration of the anterior segment of GMin appears to be a normal part of ageing. Our study has demonstrated different patterns of atrophy and fatty infiltration between patients with end-stage OA and healthy matched peers. Cite this article: Bone Jt Open 2021;2(1):40–47

Aims

This study aims to determine the proportion of patients with end-stage knee osteoarthritis (OA) possibly suitable for partial (PKA) or combined partial knee arthroplasty (CPKA) according to patterns of full-thickness cartilage loss and anterior cruciate ligament (ACL) status.

From a prospective, cross-sectional survey of 402 patients who had a total hip (THR) or a total knee (TKR) replacement for idiopathic osteoarthritis (OA) at a major centre, we determined the prevalence of these replacements for idiopathic OA in their 1171 siblings and 376 spouses. Using spouses as controls, the relative risk of THR in siblings was 1.86 (95% CI 0.93 to 3.69). The relative risk for TKR in siblings v spouses was 4.8 (95% CI 0.64 to 36.4) whereas the risk for the combined outcome measure of THR or TKR was 2.32 (95% CI 1.22 to 4.43) when siblings and spouses over 64 years of age were compared. Using a threshold liability model (Falconer), the heritability of end-stage OA of the hip was estimated at 27%.

The increased risks of joint replacement for severe, idiopathic OA which we found in siblings suggest that genetic influences are important in end-stage OA of the hip and knee.

To determine the risk of total knee replacement (TKR) for primary osteoarthritis (OA) associated with overweight/obesity in the Australian population.

This population-based study analyzed 191,723 cases of TKR collected by the Australian Orthopaedic Association National Joint Registry and population data from the Australian Bureau of Statistics. The time-trend change in incidence of TKR relating to BMI was assessed between 2015-2018. The influence of obesity on the incidence of TKR in different age and gender groups was determined. The population attributable fraction (PAF) was then calculated to estimate the effect of obesity reduction on TKR incidence.

The greatest increase in incidence of TKR was seen in patients from obese class III. The incidence rate ratio for having a TKR for obesity class III was 28.683 at those aged 18-54 years but was 2.029 at those aged >75 years. Females in obesity class III were 1.7 times more likely to undergo TKR compared to similarly classified males. The PAFs of TKR associated with overweight or obesity was 35%, estimating 12,156 cases of TKR attributable to obesity in 2018. The proportion of TKRs could be reduced by 20% if overweight and obese population move down one category.

Obesity has resulted in a significant increase in the incidence of TKR in the youngest population in Australia. The impact of obesity is greatest in the young and the female population. Effective strategies to reduce the national obese population could potentially reduce 35% of the TKR, with over 10,000 cases being avoided.

Purpose: Femoral and tibial shaft malunion may predispose to knee osteoarthritis but may also pose a problem for knee reconstruction; malposition of total knee prostheses being a known cause of early failure. Limb realignment may prove to be beneficial prior to proceeding with arthroplasty. The purpose of this study was to evaluate the outcome and effect of shaft osteotomy prior to total knee arthroplasty (TKA).

Method: A search of the trauma database between 1987 and 2006 was conducted. Twenty-two osteotomies were performed on 21 patients with femoral or tibial shaft malunion who had been considered for TKA. Mean age at osteotomy was 54 years and mean follow-up 86 months. Time intervals between surgical procedures and Knee Society scores were calculated. Patients were surveyed regarding pain relief and functional improvement.

Results: Femoral osteotomy improved mean Knee Society knee scores from 47 to 76 and function scores from 34 to 61. Tibial osteotomy improved knee scores from 53 to 82 and function scores from 28 to 50. Four osteotomies were complicated by nonunion and required further intervention. Osteotomy subjectively improved pain and function for a mean of 56 months. Femoral and tibial shaft osteotomy delayed TKA in 45% (10 cases) for a mean period of just over 6.5 years (89 and 73 months for femoral and tibial osteotomy respectively). Pre and post Knee society scores were: Femur: knee 56 to 88, function 41 to 72; Tibia: knee 65 to 85, function 25 to 57. One TKA was revised after 11 months due to valgus malalignment and was complicated by a wound infection. There were no other infections or wound complications. The procedure additionally relieved pain and improved function in the remaining 12 joints, not yet requiring arthroplasty.

Conclusion: Femoral and tibial shaft osteotomy may delay and possibly avoid TKA, relieve pain and improve function in patients who present with malunion and end-stage knee arthritis. The complication rate and clinical results of TKA following shaft osteotomy appear to be similar to primary TKA. This treatment strategy should be considered in younger patients with post traumatic osteoarthritis where significant femoral or tibial deformity is present.

Aims. Treatment of end-stage anteromedial osteoarthritis (AMOA) of the knee is commonly approached using one of two surgical strategies: medial unicompartmental knee arthroplasty (UKA) or total knee arthroplasty (TKA). In this study we aim to investigate if there is any difference in outcome for patients undergoing UKA or TKA, when treated by high-volume surgeons, in high-volume centres, using two different clinical guidelines. The two strategies are ‘UKA whenever possible’ vs TKA for all patients with AMOA. Methods. A total of 501 consecutive AMOA patients (301 UKA) operated on between 2013 to 2016 in two high-volume centres were included. Centre One employed clinical guidelines for the treatment of AMOA allowing either UKA or TKA, but encouraged UKA wherever possible. Centre Two used clinical guidelines that treated all patients with a TKA, regardless of wear pattern. TKA patients were included if they had isolated AMOA on preoperative radiographs. Data were collected from both centres’ local databases. The primary outcome measure was change in Oxford Knee Score (OKS), and the proportion of patients achieving the patient-acceptable symptom state (PASS) at one-year follow-up. The data were 1:1 propensity score matched before regression models were used to investigate potential differences. Results. The matched cohort included 400 patients (mean age 67 years (SD 9.55), 213 (53%) female, mean BMI 30.2 kg/m. 2. , 337 (84%) American Society of Anesthesiologists grade ≤ 2). We found a mean adjusted difference in change score of 3.02 points (95% confidence interval (CI) 1.41 to 4.63; p < 0.001) and a significantly larger likeliness of achieving PASS (odds ratio 3.67 (95% CI 1.73 to 8.45); p = 0.001) both in favour of the UKA strategy. Conclusion. UKA and TKA are both good strategies for treating end-stage AMOA. However, when compared as a strategy, UKA achieved larger improvements in OKS, and were more likely to reach the PASS value at one-year follow-up. Cite this article: Bone Jt Open 2022;3(5):441–447

Aims. Instability is a common cause of failure after total hip arthroplasty. A novel reverse total hip has been developed, with a femoral cup and acetabular ball, creating enhanced mechanical stability. The purpose of this study was to assess the implant fixation using radiostereometric analysis (RSA), and the clinical safety and efficacy of this novel design. Methods. Patients with end-stage osteoarthritis were enrolled in a prospective cohort at a single centre. The cohort consisted of 11 females and 11 males with mean age of 70.6 years (SD 3.5) and BMI of 31.0 kg/m. 2. (SD 5.7). Implant fixation was evaluated using RSA as well as Western Ontario and McMaster Universities Osteoarthritis Index, Harris Hip Score, Oxford Hip Score, Hip disability and Osteoarthritis Outcome Score, 38-item Short Form survey, and EuroQol five-dimension health questionnaire scores at two-year follow-up. At least one acetabular screw was used in all cases. RSA markers were inserted into the innominate bone and proximal femur with imaging at six weeks (baseline) and six, 12, and 24 months. Independent-samples t-tests were used to compare to published thresholds. Results. Mean acetabular subsidence from baseline to 24 months was 0.087 mm (SD 0.152), below the critical threshold of 0.2 mm (p = 0.005). Mean femoral subsidence from baseline to 24 months was -0.002 mm (SD 0.194), below the published reference of 0.5 mm (p < 0.001). There was significant improvement in patient-reported outcome measures at 24 months with good to excellent results. Conclusion. RSA analysis demonstrates excellent fixation with a predicted low risk of revision at ten years of this novel reverse total hip system. Clinical outcomes were consistent with safe and effective hip replacement prostheses. Cite this article: Bone Jt Open 2023;4(5):385–392

Aims. The aim of this study was to investigate the distribution of phenotypes in Asian patients with end-stage osteoarthritis (OA) and assess whether the phenotype affected the clinical outcome and survival of mechanically aligned total knee arthroplasty (TKA). We also compared the survival of the group in which the phenotype unintentionally remained unchanged with those in which it was corrected to neutral. Methods. The study involved 945 TKAs, which were performed in 641 patients with primary OA, between January 2000 and January 2009. These were classified into 12 phenotypes based on the combined assessment of four categories of the arithmetic hip-knee-ankle angle and three categories of actual joint line obliquity. The rates of survival were analyzed using Kaplan-Meier methods and the log-rank test. The Hospital for Special Surgery score and survival of each phenotype were compared with those of the reference phenotype with neutral alignment and a parallel joint line. We also compared long-term survival between the unchanged phenotype group and the corrected to neutral alignment-parallel joint line group in patients with Type IV-b (mild to moderate varus alignment-parallel joint line) phenotype. Results. The most common phenotype was Type I-b (mild to moderate varus alignment-medial joint line; 27.1% (n = 256)), followed by Type IV-b (23.2%; n = 219). There was no significant difference in the clinical outcomes and long-term survival between the groups. In Type IV-b phenotypes, the neutrally corrected group showed higher 15-year survival compared with the unchanged-phenotype group (94.9% (95% confidence interval (CI) 92.0 to 97.8) vs 74.2% (95% CI 98.0 to 100); p = 0.020). Conclusion. Constitutional varus was confirmed in more than half of these patients. Mechanically aligned TKA can achieve consistent clinical outcomes and long-term survival, regardless of the patient’s phenotype. The neutrally corrected group had better long-term survival compared with the unchanged phenotype group. Cite this article: Bone Joint J 2024;106-B(5):460–467

Aims. This study reports updates the previously published two-year clinical, functional, and radiological results of a group of patients who underwent transfibular total ankle arthroplasty (TAA), with follow-up extended to a minimum of five years. Methods. We prospectively evaluated 89 patients who underwent transfibular TAA for end-stage osteoarthritis. Patients’ clinical and radiological examinations were collected pre- and postoperatively at six months and then annually for up to five years of follow-up. Three patients were lost at the final follow-up with a total of 86 patients at the final follow-up. Results. A total of 86 patients were evaluated at a mean follow-up of 65.4 months (60 to 90). At five-year follow-up, statistically significant improvements (p < 0.001) were found in the mean American Orthopaedic Foot & Ankle Society Ankle Hindfoot Score (from 33.8 (SD 14.3) to 86.1 (SD 8.8)), visual analogue scale for pain (from 8.5 (SD 1.7) to 1.5 (SD 1.2)), Short Form-12 Physical and Mental Component Scores (from 29.9 (SD 6.7) and 43.3 (SD 8.6) to 47.3 (SD 7.5) and 52.2 (SD 8.0), respectively), and mean ankle dorsiflexion and plantarflexion (from 6.2° (SD 5.5°) and 9.6° (SD 5.8°) to 23.9° (SD 7.7°) and 16.9° (SD 7.2°), respectively). Radiologically, the implants maintained neutral alignment without subsidence. Tibial or talar radiolucency was found in eight patients, but none of these patients was symptomatic. At five-year follow up, 97.7% of implants (95% confidence interval 91.2 to 99.4) were free from revision or removal with 84 implants at risk. We recorded two cases (2.3%) of failure for septic loosening. Conclusion. Transfibular TAA is safe and effective with a high survival rate at mid-term follow-up and satisfactory clinical and radiological results. Further studies are required to determine the long-term performance of these implants. Cite this article: Bone Joint J 2022;104-B(4):472–478

Background. It is technically challenging to restore hip rotation center exactly in total hip arthroplasty (THA) for patients with end-stage osteoarthritis secondary to developmental dysplasia of the hip (DDH) due to the complicated acetabular morphology changes. In this study, we developed a new method to restore hip rotation center exactly and rapidly in THA with the assistance of three dimensional (3-D) printing technology. Methods. Seventeen patients (21 hips) with end-stage osteoarthritis secondary to DDH who underwent THA were included in this study. Simulated operations were performed on 3-D printed hip models for preoperative planning. The Harris fossa and acetabular notches were recognized and restored to locate acetabular center. The agreement on the size of acetabular cup and bone defect between simulated operations and actual operations were analyzed. Clinical and radiographic outcomes were recorded and evaluated. Results. The sizes of the acetabular cup of simulated operations on 3-D printing models showed a high rate of coincidence with the actual sizes in the operations(ICC value=0.930) There was no significant difference statistically between the sizes of bone defect in simulated operations and the actual sizes of bone defect in THA(t value=0.03 P value=0.97). The average Harris score of the patients was improved from (38.33±6.07) preoperatively to the last follow-up (88.61±3.44) postoperatively. The mean vertical and horizontal distances of hip rotation center on the pelvic radiographs were restored to (15.12 ± 1.25 mm and (32.49±2.83) mm respectively. No case presented dislocation or radiological signs of loosening until last follow-up. Conclusions. The application of 3-D printing technology facilitates orthopedists to recognize the morphology of Harris fossa and acetabular notches, locate the acetabular center and restore the hip rotation center rapidly and accurately

Introduction. The changes in sagittal spino-pelvic balance from standing to sitting in patients with end-stage osteoarthritis (OA) of the hip remain poorly characterized. Our aim was to 1) investigate the contribution of sagittal spino-pelvic movement and hip flexion when moving from a standing to sitting posture in patients with hip OA; 2) determine the proportion of OA-patients with stiff, normal or hypermobile spino-pelvic mobility and 3) identify radiographic parameters correlating with spino-pelvic mobility. Methods. This prospective diagnostic cohort study followed 116 consecutive patients with end-stage osteoarthritis awaiting THR. All patients underwent preoperative standardized radiographs (lateral view) of the lumbar spine, pelvis and proximal femur using EOS© in standing position and with femurs parallel to the floor in order to achieve a 90°-seated position. Radiographic measurements performed included lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI) and pelvic-femoral-angle (PFA). The difference in PT between standing and seated allowed for patient classification based on spino-pelvic mobility into stiff (<±10°), normal (±10–30°), or hypermobile (>±30°). Results. From the standing to the sitting position, the pelvis tilted backwards by a mean of 19.1° (SD 12.8) and the hip was flexed by a mean of 56.6° (SD 17.2). Change in pelvic tilt correlated inversely with change in hip flexion (r=−0.68; P<0.01; r. 2. =0.47). Thirty-two patients (28%) had stiff, 68 (58%) normal and 16 (14%) hypermobile spino-pelvic mobility. Multivariate regression analysis adjusted for patient age, BMI, static LL, SS, PI, PT and PFA showed a correlation for static standing SS and the change in PT (p=0.03; β=2.31; r. 2. =0.34). Conclusion. Hip flexion contributes on average 75% (25–100%) of the motion required to sit upright. Pre-operative assessment would identify patients with spino-pelvic hypermobility (associated greater change in cup orientation) or stiffness (associated increased hip range-of-movement), which would be at greater risk of dislocation

Demand for total knee arthroplasty (TKA) is increasing as it remains the gold-standard treatment for end-stage osteoarthritis (OA) of the knee. While magnetic-resonance imaging (MRI) scans of the knee are not indicated for diagnosing knee OA, they are commonly ordered prior to the referral to an orthopaedic surgeon. The purpose of this study was to determine the proportion of patients who underwent an MRI in the two years prior to their primary TKA for OA. Secondary outcomes included determining patient and physician associations with increased MRI usage. This is a population-based cohort study using billing codes in Ontario, Canada. All patients over 40 years-old who underwent a primary TKA between April 1, 2008 and March 31, 2017 were included. Statistical analyses were performed using SAS and included the Cochran-Armitage test for trend of MRI prior to surgery, and predictive multivariable regression model. Significance was set to p<0.05. There were 172,689 eligible first-time TKA recipients, of which 34,140 (19.8%) received an MRI in the two years prior to their surgery. The majority of these (70.8%) were ordered by primary care physicians, followed by orthopaedic surgeons (22.5%). Patients who received an MRI were younger and had fewer comorbidities than patients who did not (p<0.001). MRI use prior to TKA increased from 15.9% in 2008 to 20.1% in 2017 (p<0.0001). Despite MRIs rarely being indicated for the work-up of knee OA, nearly one in five patients have an MRI in the two years prior to their TKA. Reducing the use of this prior to TKA may help reduce wait-times for surgery

Aims. The aim of this study was to compare a bicruciate-retaining (BCR) total knee arthroplasty (TKA) with a posterior cruciate-retaining (CR) TKA design in terms of kinematics, measured using fluoroscopy and stability as micromotion using radiostereometric analysis (RSA). Methods. A total of 40 patients with end-stage osteoarthritis were included in this randomized controlled trial. All patients performed a step-up and lunge task in front of a monoplane fluoroscope one year postoperatively. Femorotibial contact point (CP) locations were determined at every flexion angle and compared between the groups. RSA images were taken at baseline, six weeks, three, six, 12, and 24 months postoperatively. Clinical and functional outcomes were compared postoperatively for two years. Results. The BCR-TKA demonstrated a kinematic pattern comparable to the natural knee’s screw-home mechanism in the step-up task. In the lunge task, the medial CP of the BCR-TKA was more anterior in the early flexion phase, while laterally the CP was more posterior during the entire movement cycle. The BCR-TKA group showed higher tibial migration. No differences were found for the clinical and functional outcomes. Conclusion. The BCR-TKA shows a different kinematic pattern in early flexion/late extension compared to the CR-TKA. The difference between both implants is mostly visible in the flexion phase in which the anterior cruciate ligament is effective; however, both designs fail to fully replicate the motion of a natural knee. The higher migration of the BCR-TKA was concerning and highlights the importance of longer follow-up. Cite this article: Bone Joint J 2023;105-B(1):35–46

Arthrodesis of the first metatarsophalangeal joint (MTPJ) is the most reliable surgical option, for hallux rigidus from end-stage osteoarthritis. The aim of the study was to compare the functional outcomes of memory nickel-titanium staples versus a compression plate with a cross screw construct for first MTPJ arthrodesis using the Manchester–Oxford Foot Questionnaire (MOXFQ). Patients who underwent MTPJ arthrodesis using either memory nickel-titanium staples or a compression plate with a cross screw construct were identified from the surgical lists of two orthopaedic consultants. Pre and post-operative MOXFQ questionnaire, a validated patient-reported outcome measure, was administered, and responses were analysed to derive the MOXFQ summary index. The study included 38 patients (staple group N=12 and plate and cross screw group N=26). 23 patients were female and 15 were male. Mean age was 64.8 years (SD 9.02; 40 to 82). Initial analysis showed no significant difference in preoperative MOXFQ scores between the groups (p = 0.04). Postoperatively, the staple group exhibited a mean improvement of 36.17, surpassing the plate group's mean improvement of 23. Paired t-test analysis revealed a statistically significant difference (t-score= 2.5, p = 0.008), favouring the use of staples. The findings indicate that the use of staples in MTPJ arthrodesis resulted in a significantly greater improvement in MOXFQ scores compared to plates. Further research is needed to explore the underlying factors contributing to this difference and to evaluate long-term effects on patient outcomes

Abstract. Introduction. Articular cartilage degradation is a defining feature of osteoarthritis. Synovium is a reactive tissue with synovial villae, neoangiogenesis and intimal hyperplasia common to many joint pathologies. The consequences of cartilage debris in osteoarthritis impacting the synovial intima is not well understood. We analysed the immunohistology of synovium from 16 patients with osteoarthritis and 17 patients undergoing knee surgery for non-arthritic pathologies. This data was integrated with imaging and functional scores to correlate synovitis in osteoarthritis. Methodology. Formalin-fixed paraffin embedded synovial biopsy sections were cut in serial sequence and processed for routine staining (H&E or CD3, CD68, CD20, Vimentin, vWF and PCNA IHC) using standardised Dako monoclonal mouse anti-human antibodies. Digital images scanned at x20 were evaluated for fragments of cartilage and aggregates of inflammatory cells. Clinical data (gender, BMI, KL grade, WOMAC & SF-12 scores) was aligned with histopathological data. Results. Cartilage fragments were seen in the synovial intimal layer from end-stage osteoarthritis especially those with BMI<30kg/m2. Macrophages, T-cells and B-cells were identified surrounding cartilage inclusions. Inflammatory aggregates of T-cells, B-cells and macrophages were located peri-cartilage in the intima and peri-vascular in the sub-intimal layer of the synovium. Worse synovitis and function scores were significantly associated with both cartilage inclusions and inflammatory aggregates. X-ray features linked to longer duration of symptoms were associated with inflammatory aggregates. Conclusion. The histological features of the synovium clearly reflect deteriorating joint structures and compromised clinical function

Aims. Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity. Methods. Patients who underwent TKA from September 2020 to September 2021 were prospectively included. Inclusion criteria were primary end-stage osteoarthritis (Kellgren-Lawrence stage IV) of the knee. Exclusion criteria were missed follow-up visit, post-traumatic pathologies of the foot, and neurological disorders. Radiological angles measured included the mTFA, hindfoot alignment view angle, and TT. The Foot Function Index (FFI) score was assessed. Gait analyses were conducted to measure mediolateral changes of the gait line and ankle laxity was tested using an ankle arthrometer. All parameters were acquired one week pre- and three months postoperatively. Results. A total of 69 patients (varus n = 45; valgus n = 24) underwent TKA and completed the postoperative follow-up visit. Of these, 16 patients (23.2%) reported the onset or progression of ankle symptoms. Varus patients with increased ankle symptoms after TKA had a significantly higher pre- and postoperative TT. Valgus patients with ankle symptoms after TKA showed a pathologically lateralized gait line which could not be corrected through TKA. Patients who reported increased ankle pain neither had a decreased ROM of the subtalar joint nor increased ankle laxity following TKA. The preoperative mTFA did not correlate with the postoperative FFI (r = 0.037; p = 0.759). Conclusion. Approximately one-quarter of the patients developed ankle pain after TKA. If patients complain about ankle symptoms after TKA, standing radiographs of the ankle and a gait analysis could help in detecting a malaligned TT or a pathological gait. Cite this article: Bone Joint J 2023;105-B(11):1159–1167

Objectives. The aim of this study was to investigate the structural integrity of torn and non-torn human acetabular labral tissue. Methods. A total of 47 human labral specimens were obtained from a biobank. These included 22 torn specimens and 25 control specimens from patients undergoing total hip arthroplasty with macroscopically normal labra. The specimens underwent dynamic shear analysis using a rheometer to measure storage modulus, as an indicator of structural integrity. Results. There was a significant difference in the storage modulus between torn (mean modulus = 2144.08 Pa) and non-torn (3178.1 Pa) labra (p = 0.0001). Conclusion. The acetabular labrum of young patients with a tear has significantly reduced structural integrity compared with a non-torn labrum in older patients with end-stage osteoarthritis. This study contributes to the understanding of the biomechanics of labral tears, and the observation of reduced structural integrity in torn labra may explain why some repairs fail. Our data demonstrate that labral tears probably have a relatively narrow phenotype, presenting a basis for further investigations that will provide quantifiable data to support their classification and a means to develop a standardized surgical technique for their repair. This study also demonstrates the value of novel biomechanical testing methods in investigating pathological tissues of orthopaedic interest. Cite this article: A. K. Woods, J. Broomfield, P. Monk, F. Vollrath, S. Glyn-Jones. Dynamic shear analysis: a novel method to determine mechanical integrity of normal and torn human acetabular labra: Implications for prediction of outcome of repair. Bone Joint Res 2018;7:440–446. DOI: 10.1302/2046-3758.77.BJR-2017-0282.R2

Total hip replacement (THR) for end-stage osteoarthritis is a commonly performed cost-effective procedure, which provides patients with significant clinical improvement. Estimating the future demand for joint replacement is important to identify the healthcare resources needed. We estimated the number of primary THRs that will need to be performed up to the year 2060. We used data from The National Joint Registry for England, Wales, Northern Ireland and the Isle of Man on the current volume of primary THR (n=94,936) performed in 2018. We projected future numbers of THR using a static estimated rate from 2018 applied to population growth forecast data from the UK Office for National Statistics up to 2060. By 2060, primary THR volume would increase from 2018 levels by an estimated 37.7% (n=130,766). For both males and females demand for surgery was also higher for patients aged 70 and over, with older patients having the biggest relative increase in volume over time: 70–79 years (144.6% males, 141.2% females); 80–89 years (212.4% males, 185.6% females); 90 years and older (448.0% males, 298.2% females). By 2060 demand for THR is estimated to increase by almost 40%. Demand will be greatest in older patients (70 years+), which will have significant implications for the health service that requires forward planning given morbidity and resource use is higher in this population. There is a backlog of current demand with cancellation of elective surgery due to seasonal flu pressures in 2017 and now Covid-19 in 2020. Orthopaedics already has the largest waiting list of any speciality. These issues will negatively impact the health services ability to deliver timely joint replacement to many patients for a number of years and require urgent planning

Introduction. The degree of cartilage degeneration assessed intraoperatively may not be sufficient as a criterion for patellar resurfacing in total knee arthroplasty (TKA). However, single-photon emission tomography/computed tomography (SPECT/CT) is useful for detecting osteoarthritic involvement deeper in the subchondral bone. The purpose of the study was to determine whether SPECT/CT reflected the cartilage lesion underneath the patella in patients with end-stage osteoarthritis (OA) and whether clinical outcomes after TKA without patellar resurfacing differed according to the severity of patellofemoral (PF) OA determined by visual assessment and SPECT/CT findings. Methods. This study included 206 knees which underwent TKA. The degree of cartilage degeneration was graded intraoperatively according to the International Cartilage Repair Society grading system. Subjects were classified into four groups according to the degree of bone tracer uptake (BTU) on SPECT/CT in the PF joint. The Feller's patella score and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were assessed preoperatively and postoperative 1 and 2 years. Results. The increased BTU in the PF joint was associated with more severe degenerative cartilage changes underneath the patella (P < 0.001). The risk for the presence of denudated cartilage was greater in the high uptake group (odds ratio = 5.89). There was no association between clinical outcomes and visual grading of patellar cartilage degeneration or the degree of BTU on SPECT/CT. Discussion and Conclusions. The visual assessment of the degree of cartilage degeneration underneath the patella and preoperative SPECT/CT evaluation of the PF joint were not predictive of clinical outcome after TKA with unresurfaced patella

Aims. The aim of this study was to observe the implications of withholding total joint arthroplasty (TJA) in morbidly obese patients. Patients and Methods. A total of 289 morbidly obese patients with end-stage osteoarthritis were prospectively followed. There were 218 women and 71 men, with a mean age of 56.3 years (26.7 to 79.1). At initial visit, patients were given information about the risks of TJA in the morbidly obese and were given referral information to a bariatric clinic. Patients were contacted at six, 12, 18, and 24 months from initial visit. Results. The median body mass index (BMI) at initial visit was 46.9 kg/m. 2. (interquartile range (IQR) 44.6 to 51.3). A total of 82 patients (28.4%) refused to follow-up or answer phone surveys, and 149 of the remaining 207 (72.0%) did not have surgery. Initial median BMI of those 149 was 47.5 kg/m. 2. (IQR 44.6 to 52.5) and at last follow-up was 46.7 kg/m. 2. (IQR 43.4 to 51.2). Only 67 patients (23.2%) went to the bariatric clinic, of whom 14 (20.9%) had bariatric surgery. A total of 58 patients (20.1%) underwent TJA. For those 58, BMI at initial visit was 45.3 kg/m. 2. (IQR 43.7 to 47.2), and at surgery was 42.3 kg/m. 2. (IQR 38.1 to 46.5). Only 23 patients (39.7%) of those who had TJA successfully achieved BMI < 40 kg/m. 2. at surgery. Conclusion. Restricting TJA for morbidly obese patients does not incentivize weight loss prior to arthroplasty. Only 20.1% of patients ultimately underwent TJA and the majority of those remained morbidly obese. Better resources and coordinated care are required to optimize patients prior to surgery. Cite this article: Bone Joint J 2019;101-B(7 Supple C):28–32

Aims. Despite advances in the treatment of paediatric hip disease, adolescent and young adult patients can develop early onset end-stage osteoarthritis. The aims of this study were to address the indications and medium-term outcomes for total hip arthroplasty (THA) with ceramic bearings for teenage patients. Methods. Surgery was performed by a single surgeon working in the paediatric orthopaedic unit of a tertiary referral hospital. Databases were interrogated from 2003 to 2017 for all teenage patients undergoing THA with a minimum 2.3 year follow-up. Data capture included patient demographics, the underlying hip pathology, number of previous surgeries, and THA prostheses used. Institutional ethical approval was granted to contact patients for prospective clinical outcomes and obtain up-to-date radiographs. In total, 60 primary hips were implanted in 51 patients (35 female, 16 male) with nine bilateral cases. The mean age was 16.7 years (12 to 19) and mean follow-up was 9.3 years (2.3 to 16.8). Results. The most common indication for teenage hip arthroplasty was avascular necrosis secondary to slipped upper femoral epiphysis (31%; n = 16). Overall, 64% of patients (n = 33) had undergone multiple previous operations. The survival at follow-up was 97%; two patients required revision for aseptic loosening (one femoral stem, one acetabular component). Both patients had fused hips noted at the time of arthroplasty. A further two patients had radiolucent lines but were asymptomatic. At latest follow-up the mean Oxford Hip Score was 44 (31 to 48) and a Visual Analogue Scale measurement of 1.5, indicating satisfactory function. Conclusion. Operating on this cohort can be complicated by multiple previous surgeries and distorted anatomy, which in some cases require custom-made prostheses. We have demonstrated a good outcome with low revision rate in this complex group of patients. Cite this article: Bone Joint J 2020;102-B(11):1491–1496

Introduction. Patients undergoing total knee arthroplasty (TKA) with end-stage osteoarthritis of knee have secondary foot and ankle pathology. Some compensatory changes occur at ankle and subtalar joint secondary to malalignment and deformity at the knee joint. Purpose was to evaluate the changes in hindfoot malalignment and foot deformities in patients with advanced osteoarthritis of knee requiring TKA and effect of correction of knee deformities post TKA on foot/Ankle alignment. Methods. 61 consecutive patients with Kellgren-Lawrence grade IV osteoarthritis knee undergoing TKA were enrolled in a prospective blinded study. Demographic data, deformities at knee and ankle, hindfoot malalignment and functional outcome scores such as VAS, KSS, WOMAC scores, Foot and Ankle Disability Index (FADI) and Foot posture index (FPI) were recorded preoperatively and postoperatively at 6, 12 weeks and final follow up (range: 6–21 months; mean: 14.2months). Results. Statistically significant improvement was observed in KSS score, WOMAC score, FADI and FPI after TKA. There was improvement in ankle valgus after correction of knee varus deformity. Hind foot changes mainly occured at subtalar joint. Hallux valgus (10 patients), and Pesplanus (5 patients) were associated with advanced osteoarthritis of knee. Gait profile score and Gait deviation index improved significantly after TKA. There was increased stance phase and decreased stride length in knee osteoarthritis patients which improved after TKA. Conclusion. Hind foot malalignment with foot deformities (hind foot valgus) occur secondary to knee malalignment and deformities (varus deformity) in advanced osteoarthritis of knee which subsequently improve following TKA

Background. Total hip arthroplasty (THA) has been and continues to be the gold standard for treatment of end-stage osteoarthritis. With each year, implant characteristics are evolving to increase patient-reported outcomes and decrease complications. Purpose: to report minimum 2-year outcomes and complications in patients who underwent robotic-arm assisted THA using Corin versus Stryker-type implants. Methods. Data were prospectively collected on patients who underwent THA with Corin-type implants (both cup and stem) and THA using Stryker implants between June 2011 and July 2016. A 1:1 propensity match was performed using the following 5 covariates: age, body mass index, gender, Charlson score and smoking status. Surgical outcomes were assessed at minimum 2-year follow-up using the Forgotten Joint Score (FJS), Harris Hip Score (HHS), Veterans RAND 12-item physical and mental health survey, Short Form 12 physical and mental health survey, Visual Analog Score (VAS), and patient satisfaction. The exclusion criteria were previous hip condition/surgery, workers compensation, or were unwilling. Results. Of the eligible 774 cases, 645 patients (83.3%) had minimum 2-year follow-up and met inclusion and exclusion criteria. Of the 645 patients, 323 had Corin implants, and 155 had Stryker implants. The 1:1 propensity match successfully yielded 290 patients (145 per implant group) which had a minimum 2-year follow-up at a mean 38.3 months (range, 24.1–65.3 months). Average age was 59.9 (range, 34.92–79.89 Stryker group, 30.65–75.92 Corin group) for each group and average BMI were 30.0 (range, 19.05–49.33) kg/m. 2. for the Stryker group and 29.77 (range, 20.15–55.37) kg/m. 2. for the Corin group. FJS (P=0.0388) and patient satisfaction (P=0.0019) were significantly higher in the Stryker implant group than the Corin implant group. There were nine cases of postoperative thigh numbness or paresthesias, three cases of wound infection, and one case of nonunion in the Corin-implant group. There were four cases of postoperative thigh numbness or parasthesias and six cases of wound infection in the Stryker-implant group. Conclusion. At minimum 2-year follow-up, patients who had undergone THA with Stryker-type implants had significantly higher FJS and satisfaction and a trend toward decreased complications than patients with Corin-type implants. These results can help guide decision making for surgical instrumentation by arthroplasty surgeons

Total hip replacements (THRs) provide pain relief and improved function to thousands of patients suffering from end-stage osteoarthritis, every year. Over 800 different THR constructs were implanted in the UK in 2017. To ensure reliable implants are used, a NICE revision benchmark of 5% after 10 years exists. Given the 10-year cumulative mortality of patients under 55 years of age receiving THRs is only 5% and that a recent study suggests 25-year THR survival of 58%, we aim to produce revision estimates out to 30 years that may guide future long-term benchmarks. The local database of the Princess Elizabeth Orthopaedic Centre (PEOC), Exeter, holds data on over 20,000 patients with nearly 30-years follow-up with contemporary prostheses. A previous study suggests that the results of this centre are generalisable if comparisons restricted to the same prostheses. Via flexible parametric survival analysis, we created an algorithm using this database, for revision of any part of the construct for any reason, controlling for age and gender. This algorithm was applied to 664,761 patients in the NJR who have undergone THR, producing a revision prediction for patients with the same prostheses as those used at this centre. Using our algorithm, the 10-year predicted revision rate of THRs in the NJR was 2.2% (95% CI 1.8, 2.7) based on a 68-year-old female patient; well below the current NICE benchmark. Our predictions were validated by comparison to the maximum observed survival in the NJR (14.2 years) using restricted mean survival time (P=0.32). Our predicted cumulative revision estimate after 30 years is 6.5% (95% CI 4.5, 9.4). The low observed and predicted revision rate with the prosthesis combinations studied, suggest current benchmarks may be lowered and new ones introduced at 15 and 20 years to encourage the use of prostheses with high survival

Introduction and Objective. Total joint replacement (TJR) is indicated for patients with end-stage osteoarthritis (OA) where conservative treatment has failed. Approximately 1.3 million primary hip replacement surgeries have been recorded in the United Kingdom since 2003 and this number is set to rise due to an increase in obesity as well as an ageing population. Total hip replacement (THR) has a survival rate of 85% at 20 years; the most common reason for failure is aseptic loosening which often occurs secondary to osteolysis caused by immune-mediated inflammation responses to wear debris generated from the materials used in the THR implant. Therefore, by understanding the biological steps by which biomaterials cause immune-mediated reactions it should be possible to prevent them in the future thereby reducing the number of costly revision surgeries required. Materials and Methods. The human osteoblast-like cell line (MG-63) was seeded at a density of 100,000 cell per well of a 6-well plate and treated with and increasing doses (0.5, 5, and 50mm. 3. per cell) of cobalt-chromium (CoCr) particles generated on a six-station pin-on-plate wear generator or commercially available ceramic oxide nanopowders (Al. 2. O. 3. and ZrO. 2. ) for 24 hours. TNF-alpha was used as a positive control and untreated cells as a negative control. Cells were then analysed by transmission electron microscopy (TEM) to determine whether the osteoblasts were capable of phagocytosing these biomaterials. MG-63 cells were used in conjunction with trypan blue and the XTT Cell Proliferation II Kit to assess cytotoxicity of the biomaterials investigated. Cells supernatants were also collected and analysed by enzyme-linked immunosorbant assay (ELISA) to investigate changes in pro-inflammatory protein secretion. Protein extracted from lysed cells was used for western blotting analysis to investigate RANKL protein expression to determine changes to osteolytic activation. Lysed cells were also used for RNA extraction and subsequent cDNA synthesis for real-time quantitative polymerase chain reaction (RT-qPCR) in order to assess changes to pro-inflammatory gene expression. Results. There was no significant change to cellular viability or proliferation in the osteoblasts treated with CoCr, Al. 2. O. 3. or ZrO. 2. when compared to the untreated negative control. TEM images showed clear and distinct intracellular vesicles within the cell cytoplasm which contained CoCr, Al. 2. O. 3. and ZrO. 2. RANKL expression increased at 5 and 50mm. 3. per cell CoCr and 50mm. 3. per cell Al. 2. O. 3. and ZrO. 2. Pro-inflammatory protein secretion of CXCL10, IL-8, and IL-6 all significantly increased at 50mm. 3. per cell CoCr, Al. 2. O. 3. , and ZrO. 2. Similarly to the protein secretion, CXCL10, IL-8, and IL-6 gene expression was significantly upregulated at 50mm. 3. per cell CoCr, Al. 2. O. 3. , and ZrO. 2. Conclusions. Increased in vitro RANKL expression in response to CoCr, Al. 2. O. 3. , and ZrO. 2. may result in disruption of bone metabolism and lead to osteolysis which can contribute to aseptic loosening in vivo. Significant increases in IL-6 are particularly important because as well as being a pro-inflammatory cytokine, IL-6 is also secreted by osteoblasts in order to stimulate mature osteoclast formation to mediate bone breakdown. CXCL10 and IL-8 are chemotactic cytokines and increased secretion in response to implant biomaterials can contribute to ongoing pro-inflammatory responses through the recruitment of monocytes and neutrophils respectively. This is interesting as in vivo data demonstrates increased cellular infiltrate in patients experiencing responses to implant materials. Overall, these findings show clear immune activation as well as altered metabolism of MG-63 osteoblast cells in response to implant wear debris which is in agreement with in vivo clinical reports

Spinopelvic mobility describes the change in lumbar lordosis and pelvic tilt from standing to sitting position. For 1° of posterior pelvic tilt, functional cup anteversion increases by 0.75° after total hip arthroplasty (THA). Thus, spinopelvic mobility is of high clinical relevance regarding the risk of implant impingement and dislocation. Our study aimed to 1) determine the proportion of OA-patients with stiff, normal or hypermobile spino-pelvic mobility and 2) to identify clinical or static standing radiographic parameters predicting spinopelvic mobility. This prospective diagnostic cohort study followed 122 consecutive patients with end-stage osteoarthritis awaiting THA. Preoperatively, the Oxford Hip Score, Oswestry Disability Index and Schober's test were assessed in a standardized clinical examination. Lateral view radiographs were taken of the lumbar spine, pelvis and proximal femur using EOS© in standing position and with femurs parallel to the floor in order to achieve a 90°-seated position. Radiographic measurements were performed for the lumbar lordosis angle (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI) and pelvic-femoral-angle (PFA). The difference in PT between standing and seated allowed for patient classification based on spino-pelvic mobility into stiff (±30°). From the standing to the sitting position, the pelvis tilted backwards by a mean of 19.6° (SD 11.6) and the hip was flexed by a mean of 57° (SD 17). Change in pelvic tilt correlated inversely with change in hip flexion. Spinopelvic mobility is highly variable in patients awaiting THA and we could not identify any clinical or static standing radiographic parameter predicting the change in pelvic tilt from standing to sitting position. In order to identify patients with stiff or hypermobile spinopelvic mobility, we recommend performing lateral view radiographs of the lumbar spine, pelvis and proximal femur in all patients awaiting THA. Thereafter, implants and combined cup inclination/anteversion can be individually chosen to minimize the risk of dislocation. No predictors could be identified. We recommend performing sitting and standing lateral view radiographs of the lumbar spine and pelvis to determine spinopelvic mobility in patients awaiting THA

While total joint replacement (TJR) is considered as an effective intervention to relieve pain and restore joint function for end-stage osteoarthritis (OA) patients, a significant proportion of the patients are dissatisfied with their surgery outcomes. The aim of this study was to identify genetic factors that can predict patients who do or do not benefit from these surgical procedures by a genome-wide association study (GWAS). Study participants were derived from the Newfoundland Osteoarthritis Study (NFOAS) which consisted of 1086 TJR patients. Non-responders to TJR was defined as patients who did not reach the minimum clinically important difference (MCID) based on the self administered Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) in terms of pain reduction or function improvment. DNA was extracted from the blood samples of the study participants and genotyped by Illumina GWAS genotyping platform. Over two million single nucleotide polymorphisms (SNPs) across the genome were genotyped and tested for assocition with non-responders. 39 non-responders and 44 age, sex, and BMI matched responders were included in this study. Four chromosome regions on chromosomes 5, 7, 8, and 12 were suggested to be associated with non-responders with p < 1 0–5. The most promising one was on chromosome 5 with the lead SNP rs17118094 (p=1.7×10–6) which can classify 72% of non-responders accurately. The discriminatory power of this SNP alone is very promising as indicated by an area under the curve (AUC) of 0.72 with 95% confidence interval of 0.63 to 0.81, which is much better than any previously studied predictors mentioned above. All the patients who carry two copies of the G allele (minor allele) of rs17118094 were non-responders and 75% of those who carry one copy of the G allele were non-responders. The discriminatory ability of the lead SNPs on chromosomes 7 and 12 were comparable to the one on chromosome 5 with an AUC of 0.74, and 88% of patients who carry two copies of the A allele of rs10244798 on chromosome 7 were non-responders. Similarly, 88% of patients who carry two copies of the C allele of rs10773476 on chromosome 12 were non-responders. While the discriminatory ability of rs9643244 on chromosome 8 was poor with an AUC of 0.26, its strong association with non-responders warrants a further investigation in the region. The study identified four genomic regions harboring genetic factors for non-responders to TJR. The lead SNPs in those regions have great discriminatory ability to predict non-responders and could be used to create a genetic prediction model for clinical unitilty and application

Objectives. Numerous complications following total knee replacement (TKR) relate to the patellofemoral (PF) joint, including pain and patellar maltracking, yet the options for in vivo imaging of the PF joint are limited, especially after TKR. We propose a novel sequential biplane radiological method that permits accurate tracking of the PF and tibiofemoral (TF) joints throughout the range of movement under weightbearing, and test it in knees pre- and post-arthroplasty. Methods. A total of three knees with end-stage osteoarthritis and three knees that had undergone TKR at more than one year’s follow-up were investigated. In each knee, sequential biplane radiological images were acquired from the sagittal direction (i.e. horizontal X-ray source and 10° below horizontal) for a sequence of eight flexion angles. Three-dimensional implant or bone models were matched to the biplane images to compute the six degrees of freedom of PF tracking and TF kinematics, and other clinical measures. Results. The mean and standard deviation for the six degrees of freedom of PF tracking and TF kinematics were computed. TF and PF kinematics were highly accurate (< 0.9 mm, < 0.6°) and repeatable. Conclusions. The developed method permitted measuring of in vivo PF tracking and TF kinematics before and after TKR throughout the range of movement. This method could be a useful tool for investigating differences between cohorts of patients (e.g., with and without pain) impacting clinical decision-making regarding surgical technique, revision surgery or implant design

The goals of a total knee arthroplasty include approximation of the function of a normal knee and achievement of balance post-surgery. Accurate bone preparation and the preservation of natural ligaments along with a functional knee design, holds the potential to provide a method of restoring close to normal function. Although conventional knee arthroplasty is considered a successful intervention for end-stage osteoarthritis, some patients still experience reduced functionality and in some cases, require revision procedures. With conventional manual techniques, accurate alignment of the tibial component has been difficult to achieve. Even in the hands of skilled knee surgeons, outliers beyond 2 degrees of the desired alignment may occur in as many as 40%-60% of cases using conventional methods, and the range of component alignment varies considerably. Similarly, for total knee replacement outliers beyond 2 degrees of the desired alignment may occur in as many as 15% of cases in the coronal plane, going up to 40% of unsatisfactory alignment in the sagittal plane. Robotics-assisted arthroplasty has gained increasing popularity as orthopaedic surgeons aim to increase accuracy and precision of implant positioning. With advances in computer generated data, with image free data, surgeons have the ability to better predict and influence surgical outcomes. Based on planned implant position and soft tissue considerations, robotics-assisted systems can provide surgeons with virtual tools to make informed decisions for knee replacement, specific to the needs of the patient. Here, for the first time in a live surgical setting, we assess the accuracy and technique of a novel imageless semiautonomous handheld robotic surgical technique in bi-cruciate retaining total knee arthroplasty (Navio, Smith and Nephew). The system supports image-free anatomic data collection, intraoperative surgical planning and execution of the plan using a combination of robotic burring and saw cut guides

Total joint arthroplasty (TJA) is often utilized to improve pain and dysfunction associated with end-stage osteoarthritis. Previous research has suggested that depression may negatively impact patient reported pain and function. The purpose of this study was to determine the effect of pre-operative depressive symptoms, using the Center for Epidemiologic Scale for Depression (CES-D) scale, on patient reported function and pain at one, three and six months following TJA, after controlling for the impact of age, sex, pain, joint replaced, and other comorbidities. This was a secondary analysis of a prospective cohort of 710 patients aged 40 years and older who underwent elective primary TJA in the Edmonton zone. Participants were recruited pre-operatively and reported socio-demographics, comorbid conditions and medications (including depression medications where appropriate), each participant also completed the Western Ontario McMaster (WOMAC) Osteoarthritis Index and the CES-D scale preoperatively. Participants then completed the WOMAC and CES-D scale again at one, three, and six months postoperatively. Risk-adjusted longitudinal data analysis using a linear mixed regression model was performed, controlling for age, sex, joint replaced, chronic pain, comorbidity, social support and employment status. THA participants had a mean age of 65.9±10.1 years and included 175 (57%) female while TKA participants had a mean age of 67.9±10.1 years and included 249 (61%) females. ‘Possible’ depressive symptoms (CES-D score 16–19) were identified in 58 (8.1%) participants while ‘probable’ depressive symptoms (CES-D score ≥20) were identified in 68 (9.6%) participants. The mean WOMAC pain and function scores, when analyzed using the linear mixed regression model, demonstrated improvement from baseline at one, three, and six months (p < 0 .001 for both pain and function models as well as over time). However, in the patients with possible and probable depressive symptoms, WOMAC pain scores were 7.6±1.5 and 11.7±1.3 worse respectively than those without depressive symptoms after controlling for age, sex, joint replaced, chronic pain, comorbidities and social support. Similarly, WOMAC function scores in the patients with possible and probable depressive symptoms were 8.8±1.4 and 14.2±1.2 worse respectively than those without depressive symptoms after controlling for age, sex, joint replaced, comorbidities and employment status. Depressive symptoms negatively affect postoperative pain and function measured using WOMAC scales even after risk adjustment up to six-months post TJA. Screening for depressive symptomology both pre- and postoperatively may provide an opportunity to identify and manage depressive symptoms to improve postoperative pain and function

The aim of this retrospective cohort study was to identify any difference in femoral offset as measured on pre-operative anteroposterior (AP) radiographs of the pelvis, AP radiographs of the hip and corresponding CT scans in a consecutive series of 100 patients with primary end-stage osteoarthritis of the hip (43 men and 57 women with a mean age of 61 years (45 to 74) and a mean body mass index of 28 kg/m. 2. (20 to 45)). Patients were positioned according to a standardised protocol to achieve reproducible projection and all images were calibrated. Inter- and intra-observer reliability was evaluated and agreement between methods was assessed using Bland-Altman plots. In the entire cohort, the mean femoral offset was 39.0 mm (95% confidence interval (CI) 37.4 to 40.6) on radiographs of the pelvis, 44.0 mm (95% CI 42.4 to 45.6) on radiographs of the hip and 44.7 mm (95% CI 43.5 to 45.9) on CT scans. AP radiographs of the pelvis underestimated femoral offset by 13% when compared with CT (p < 0.001). No difference in mean femoral offset was seen between AP radiographs of the hip and CT (p = 0.191). Our results suggest that femoral offset is significantly underestimated on AP radiographs of the pelvis but can be reliably and accurately assessed on AP radiographs of the hip in patients with primary end-stage hip osteoarthritis. We, therefore, recommend that additional AP radiographs of the hip are obtained routinely for the pre-operative assessment of femoral offset when templating before total hip replacement

Total joint arthroplasty (TJA) is often utilized to improve pain and dysfunction associated with end-stage osteoarthritis. Previous research has suggested that depression may negatively impact patient reported pain and function. The purpose of this study was to determine the effect of preoperative depressive symptoms, using the Center for Epidemiologic Scale for Depression (CES-D) scale, on patient reported function and pain at one, three and six months following TJA, after controlling for the impact of age, sex, pain, joint replaced, and other comorbidities. This was a secondary analysis of a prospective cohort of 710 patients aged 40 years and older who underwent elective primary TJA in the Edmonton zone. Participants were recruited pre-operatively and reported socio-demographics, comorbid conditions and medications (including depression medications where appropriate), each participant also completed the Western Ontario McMaster (WOMAC) Osteoarthritis Index and the CES-D scale preoperatively. Participants then completed the WOMAC and CES-D scale again at one, three, and six months postoperatively. Risk-adjusted longitudinal data analysis using a linear mixed regression model was performed, controlling for age, sex, joint replaced, chronic pain, comorbidity, social support and employment status. THA participants had a mean age of 65.9±10.1 years and included 175 (57%) female while TKA participants had a mean age of 67.9±10.1 years and included 249 (61%) females. ‘Possible’ depressive symptoms (CES-D score 16–19) were identified in 58 (8.1%) participants while ‘probable’ depressive symptoms (CES-D score ≥20) were identified in 68 (9.6%) participants. The mean WOMAC pain and function scores, when analyzed using the linear mixed regression model, demonstrated improvement from baseline at one, three, and six months (p < 0 .001 for both pain and function models as well as over time). However, in the patients with possible and probable depressive symptoms, WOMAC pain scores were 7.6±1.5 and 11.7±1.3 worse respectively than those without depressive symptoms after controlling for age, sex, joint replaced, chronic pain, comorbidities and social support. Similarly, WOMAC function scores in the patients with possible and probable depressive symptoms were 8.8±1.4 and 14.2±1.2 worse respectively than those without depressive symptoms after controlling for age, sex, joint replaced, comorbidities and employment status. Depressive symptoms negatively affect postoperative pain and function measured using WOMAC scales even after risk adjustment up to six-months post TJA. Screening for depressive symptomology both pre- and postoperatively may provide an opportunity to identify and manage depressive symptoms to improve postoperative pain and function

Limited strong data exists in current literature comparing the 90-day morbidity and mortality following general or spinal anesthetic in patients who underwent total hip or knee arthroplasty, especially between matched cohorts. Because of this, there continues to be an ongoing debate regarding the risks and benefits of using general versus spinal anesthetic for patients undergoing elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) for end-stage osteoarthritis. The Alberta Bone and Joint Health Institute (ABJHI) database was searched to identify all patients who underwent either primary THA or TKA between April 2005 and December 2015. Those identified were matched 1:1 based on age, sex, type of joint replacement (THA or TKA), American Society of Anesthesiologists (ASA) score, and anesthetic type. Patients were stratified into two groups based on whether they received a general anesthesia (GA) or a spinal anesthesia (SA) at the time of their index surgery. Perioperative complications (medical events, mechanical events, deep infection, need for blood transfusion), length of stay (LOS), 30-day readmission, and 90-day mortality were compared between cohorts. Included in this study are 5,580 patients who underwent THA and 7,712 patient who underwent TKA. All were successfully matched based on similar categorical criteria (THA, 2,790 matched-pairs, TKA, 3,856 matched-pairs). Following stratifications of cohorts, no statistical differences were appreciated between patient baseline demographics. Patients who underwent GA showed a trend towards higher 90-day mortality, however no statistical differences were found between anesthetic type on rates of 90-day mortality following either THA or TKA (THA, p = 0.290, TKA, p = 0.291). Considering this, patients who underwent THA with SA experienced fewer 90-day complications (medical events, p = 0.022, mechanical events, p = 0.017), needed fewer blood transfusions (p < 0 .001), and required shorter LOS (p = 0.038). Moreover, patient who underwent TKA with SA had fewer blood transfusion (p < 0 .001), 30-day readmission rates (p = 0.011), and fewer deep infections (p = 0.030) that required additional surgery compared to those in the GA cohort. Regardless of surgery performed, patients in the SA cohorts were more commonly discharged home without requiring additional support (i.e. home care). General anesthesia during THA and TKA appears to be associated with increased 90-day morbidity and more frequent need for allogenic blood transfusion. No statistical difference in 90-day mortality is reported between cohorts for either THA or TKA, yet a trend is appreciated favoring SA. Surgeons who commonly perform these surgeries should consider the added benefits of spinal anesthesia for those patients who are candidates

Introduction. Total hip arthroplasty (THA) is a highly successful procedure achieving excellent clinical outcomes beyond 10 years post-surgery. With exception of periprosthetic infection, dislocation is the most common cause of failure in THA. A novel reverse total hip (RTH) replacement has been developed to address dislocation through reversal of the typical THA articulation in which a femoral cup and acetabular ball interlock at the extremes of motion to enhance mechanical stability in all planes. The purpose of this study was to assess the safety and efficacy of this novel RTH in a series of 22 patients and to monitor implant fixation using radiostereometric analysis (RSA). Methods. Twenty two patients with end-stage osteoarthritis of the hip were enrolled between 2017 and 2019 at a single center. All surgeries were performed by a group of four high-volume fellowship-trained arthroplasty surgeons. All patients received at least 1 acetabular cup screw and RSA markers inserted into the acetabulum and proximal femur. Follow-up time points were 6 weeks, 6, 12 and 24 months and included patient reported outcome measures (HOOS, Oxford-12, Harris Hip Score, SF-36 and Satisfaction) as well as RSA assessment. Results. The patient cohort consisted of 11 females and 11 males with mean age of 70.8 years and body mass index 31.3 kg/m. 2. At the time of writing, 21, 15 and 3 patients had completed their 6-month, 1- and 2-year clinical follow-ups, respectively. There was a significant improvement in function and pain with the RTH between pre-operative and six and twelve month follow up as collected by the HOOS, Oxfrod-12, HHS, WOMAC, EQ-5D and SF-36 PCS with p<0.001 for all. The sole exception was the SF-36 MCS which had a non-statistical improvement. Eighteen of 20 patients were satisfied or very satisfied with the outcome of surgery. Average vertical migration of the acetabular cup at 6 and 12 months was 0.082 mm and 0.110 mm, respectively. Average distal migration of the femoral stem at 6 and 12 months was 0.015 mm and 0.035 mm, respectively. Conclusions. Early results indicate acceptable safety and efficacy of this novel RTH for treating osteoarthritis of the hip. The femoral and acetabular components both appear well fixed at near-term follow-up, as assessed with RSA. Further follow-up will determine if these results are maintained at 24 months post-surgery. Additional patient enrollment will assess acetabular cup fixation without the use of screws. For any figures or tables, please contact authors directly

Not all degenerative knees need a total knee replacement. Over the last few decades we have shifted our surgical treatment of end-stage osteoarthritis (OA) of the knee to a “compartmental approach” resulting in approximately half of end-stage OA knees receiving a partial knee replacement. Of these an emerging procedure is isolated lateral compartment replacement with the indications being isolated bone-on-bone osteoarthritis or avascular necrosis of the lateral compartment of the knee. Associated significant patellofemoral disease and inflammatory arthritis are contraindications. The purpose of this study is to present the indications, surgical technique, and early outcome of lateral partial knees from our institution. From Aug 2011 until June 2017 we have performed 3,548 knee arthroplasties. Of these 147 were fixed bearing lateral partial knee replacements via a lateral parapatellar approach (4%), 1,481 medial partial knee replacements (42%), and 1,920 total knee replacements (54%). The average age was 66 years old and 76% were female. Average follow-up in the lateral partials was 1.3 years (range 0.5 years to 6 years). Knee Society Scores improved from 41 (pre-op) to 86 points (post-op). Range of motion improved from 6 – 113 degrees (pre-op) to 0 – 123 degrees (post-op). No knees were revised to a TKA. One knee required I&D for traumatic wound dehiscence. This is the largest single center series of lateral partial knee replacements. We have observed this cohort to have more female patients and gain additional range of motion compared to our historic cohorts of TKA's. Longer-term follow-up is needed for determination of implant and unreplaced compartment survivorship. We believe the lateral partial knee replacement to be a viable option for isolated lateral compartment disease in approximately 4% of patients

Introduction. A total knee arthroplasty (TKA) is the standard of care treatment for end-stage osteoarthritis (OA) of the knee. Over the last decade, we have observed a change in TKA patient population to include younger patients. This cohort tends to be more active and thus places more stress on the implanted prothesis. Bone cement has historically been used to establish fixation between the implant and host bone, resulting in two interfaces where loosening may occur. Uncemented fixation methods provide a promising alternative to cemented fixation. While vulnerable during the early post-operative period, cementless implants may be better suited to long-term stability in younger patient cohorts. It is currently unknown whether the surgical technique used to implant the cementless prostheses impacts the longevity of the implant. Two different surgical techniques are commonly used by surgeons and may result in different load distribution across the joint, which will affect bone ingrowth. The overall objective of the study is to assess implant migration and in vivo kinematics following cementless TKA. Methods. Thirty-nine patients undergoing a primary unilateral TKA as a result of OA were recruited prior to surgery and randomized to a surgical technique based on surgeon referral. In the gap balancing surgical technique (GB) soft tissues releases are made to restore neutral limb alignment followed by bone cuts (resection) to balance the joint space in flexion and extension. In the measured resection surgical technique (MR) bone cuts are first made based on anatomical landmarks and soft tissue releases are subsequently conducted with implant components in-situ. Patients returned 2 weeks, 6 weeks, 12 weeks, 24 weeks, and 52 weeks following surgery for radiographic evaluation. Kinematics were assessed 52 weeks post-operatively. Results. No significant difference was observed between groups in maximum total point motion (MTPM) at any time point during the first post-operative year. MTPM of both the tibial and femoral component did not significantly change between the six month and one year follow up visits for both the GB (6 mths=0.67 ±0.34mm, 1 yr=0.65 ±0.52, p=0.71) and MR (6 mths= 0.79 ±0.53mm, 1 yr= 0.82 ±0.43mm, p=0.56) cohorts. MTPM for both components over the follow up period is displayed in Figure 1. No significant difference was observed in contact location or pattern on the medial condyle during deep flexion (Figure 2A). A significant difference (p=0.01) was observed, however, between surgical techniques in the lateral contact location at full extension (Figure 2B). No significant difference was observed in the magnitude of AP excursion for both the medial and lateral condyles within and between groups. Conclusion. Surgical technique did not impact the MTPM of an uncemented TKA design during the first post-operative year. By the six month post-operative period tibial and femoral MTPM plateaus indicating that osseointegration between the host bone and implanted components has occurred. Kinematic evaluation indicates contact locations anterior to the midline of the sagittal plane, paradoxical anterior translation, and a lateral pivot point, regardless of surgical technique

Successful nonarthroplasty solutions for the treatment of osteonecrosis of the femoral head continued to be sought. However, no definitive nonarthroplasty solutions have to date been found. Hence, even in the best of hands a large number of patients with osteonecrosis end up with debilitating end-stage osteoarthritis. In the inception of total hip arthroplasty (THA), the results of treatment of femoral head osteonecrosis by THA were inferior to total hip replacement performed for osteoarthritis. Reasons for this included the young age of many osteonecrosis patients, the high numbers of comorbidities in this population (SLE, sickle cell anemia, alcoholism), and the poor bone quality at the time of surgery. Arthroplasty considerations included bipolar replacement, hemiresurfacing, resurfacing (non metal-on-metal and later metal-on-metal), cemented total hip arthroplasty and cementless total hip arthroplasty. Previous to the use of cementless arthroplasty, all of these procedures had a relatively high 5 to 10 year failure rate of 10–50%. Even our own 10-year results using contemporary cementing techniques demonstrated 10% failure compared to 1–2% failure in our nonosteonecrosis patients. For this reason, it made sense to continue exploring nonarthroplasty solutions for osteonecrosis of the hip. The introduction of cementless fixation for total hip arthroplasty changed the entire thinking about hip osteonecrosis treatment for many of us. Although initially we were concerned about whether bone would grow into the prosthesis in the environment of relatively poor bone, the early results demonstrated that it can and does. Most recently, with the use of crosslinked polyethylene, the cementless construct gives many of us hope that with cementless fixation, the treatment of many patients including the young (especially if followed closely to exchange bearing surfaces if necessary) will last a lifetime with THA being the only and definitive procedure. Our most recent 10-year results demonstrated a femoral stem revision rate of 1.5% will all other stems (other than the stem revised) bone ingrown. Acetabular fixation was also 100% and although 6% required liner exchange, our own and others' results with crosslinked polyethylene would suggest that this problem should be markedly reduced

Knee osteoarthritis (OA) is a progressive and debilitating condition that is estimated to account for over 80% of the osteoarthritis burden. In cases of end-stage osteoarthritis, surgical intervention is the desired option, however, less severe cases may warrant the use of nonoperative modalities. Knee braces are becoming increasingly popular as an adjunct to the standard treatment and have shown promising results in reducing pain, improving function, and mitigating disease progression. Moreover, bracing has the added benefit of being able to include other noninvasive modalities as a means to augment recovery and delay the need for surgery. Prior studies have demonstrated that the medial compartment of the knee joint sustains 62% of loading forces during the stance phase of regular gait, whereas the lateral compartment receives the remaining 38%. It is hypothesised that this distribution of loading forces is why the medial joint compartment is more frequently damaged relative to the lateral compartment. Reduction of these stresses can be accomplished by the use of medial compartment unloader braces, which incorporate distraction forces and rotation with the purpose of increasing the medial joint space and providing pain relief. These devices have the potential to correct the characteristic gait changes associated with knee OA and enhance patients' functional status. Therefore, our main purpose is to assess the efficacy of the various types of knee braces used for the treatment of osteoarthritic knee pain as well as offer perspective regarding the use of knee braces at our institution

Knee osteoarthritis (OA) is a debilitating and progressive condition that accounts for over 80% of the total osteoarthritis burden. Surgical intervention is the suitable option in end-stage osteoarthritis, however, in cases of less severe disease, it may be warranted to use non-operative methods. Knee braces have recently become a popular option as an addition to conventional treatment, and have displayed good results in improving function, reducing pain, and attenuating disease progression. Furthermore, other non-invasive modalities can be supplemented to bracing as a means to improve recovery and delay the need for surgery. Studies have indicated that the medial compartment of the knee sustains 62% of loading forces during the stance phase of regular gait, meanwhile the lateral compartment receives the remaining 38%. It is postulated that this distribution of knee loading forces is the reason why the medial compartment is more frequently deteriorated as compared to the lateral joint compartment. The use of medial compartment unloader braces can reduce these stresses by the means of distraction and rotation of the knee joint with the goal of increasing the medial joint space and producing pain relief. Knee bracing has the capability to enhance patients’ functional status, and even correct the gait changes associated with knee OA. Therefore, our goal is to assess: 1) the use of knee braces at our institution, and 2) the effectiveness of the various types of knee braces in treating OA associated knee pain

Purpose. To update current surgical management of knee osteoarthritis. Methods. A literature review was done using standard keyword search. Articles were scrutinized by the investigators to ensure relevancy to the purpose of this review. Summary of the review. Arthroscopy, osteotomy and arthroplasty are three major techniques for knee osteoarthritis. Arthroscopy is more and more common as it is diagnostically and therapeutically useful, especially for patients with painful osteoarthritis with mechanical symptoms. Recently, arthroscopic techniques to treat subchondral bone marrow lesions associated with knee osteoarthritis have been developed. Osteotomy is a technique that preserves the natural biomechanics of the joint and reestablishes joint alignment. Its accuracy has been improved with the advancement of computer-assisted surgery. Arthroplasty includes Unicompartmental knee arthroplasty (UKA) and Total knee arthroplasty (TKA). In UKA, patient selection is a key factor for good outcomes, which can be enhanced with newer implant designs and robotic technology. TKA is the mainstay technique for end-stage osteoarthritis. Minimally invasive TKA was developed to overcome major limitations of conventional technique. Considerable number of new technologies have been introduced for patients requiring TKA, such as gender-specific knee implants, computer-assisted navigation, robotic-assisted surgery and patient-specific cutting guides. Conclusion. As advances in surgical techniques and tools continue and numerous options are available, appropriate patient selection and understanding indications to each options are critical to success

Background. The indication of unicompartmental knee arthroplasty (UKA) for end-stage osteoarthritis (OA) remains controversial. This study aimed to investigate patient reported outcomes (PROs) of UKA in patients with severe varus deformity of the knee and compare the results with those of total knee arthroplasty (TKA) at mid-term follow up. Methods. A total of 96 TKAs of 69 patients and 61 UKAs of 50 patients were included. All patients presented with severe knee OA with hip-knee-ankle angle (HKA) ranged from −25 degree to −10 degree, preoperatively. Mean HKAs in TKA group and UKA group were −14.95º and −13.38º, respectively. PROs were assessed using Knee Society Score (KSS 2011), PainDETECT score (PD), and Pain Catastrophizing Scale (PCS) at a mean follow up of 58.65 months for TKA and 58.05 months for UKA. Kaplan-Meier survival analysis was performed to assess implant survival. Complication rate was also assessed. All data were compared between TKA group and UKA group. Results. Mean postoperative knee flexion angle was 124.38 º for TKA group and 133.69 º for UKA group, indicating that knee flexion angle of UKA was significantly greater than that of TKA (p=0.000). There were no statistically differences in KSS and their items, PD, and PCS. Regarding mid-term survivorship, TKA (96.0%) was less than UKA (96.8%), but there was no statistically significance. Major complications of the knee occurred in 4cases (4.0%) for TKA and 7 cases (11.1%) for UKA but there was also no statistically significance. Complications of UKA included 3 cases of OA progression in the lateral compartment. Discussion. Although greater flexion angle was observed in UKA group, there was no significant differences in PROs between the two groups. The survival rate are practically considered worse in TKA and the complication rate are practically considered worse in UKA, but there are no statistically significance. Further assessment should be needed after increasing the number of subjects and follow-up period

A prospective randomized trial on 128 patients with end-stage osteoarthritis was conducted to assess the accuracy of patient-specific guides. In cohort A (n = 64), patient- specific guides from four different manufacturers (Subgroup A1 Signature ®, A2 Trumatch ®, A3 Visionaire ® and A4 PSI ®) were used to guide the bone cuts. Surgical navigation was used as an intraoperative control for outliers. In cohort B (n = 64), conventional instrumentation was used. All patients of cohorts A and B underwent a postoperative full-leg standing X-ray and CT scan for measuring overall coronal alignment of the limb and three-planar alignment of the femoral and the tibial component. Three-planar alignment was the primary endpoint. Deviation of more than three degrees from the target in any plane, as measured with surgical navigation or radiologic imaging, was defined as an outlier. In 14 patients (22%) of cohort A, the use of the patient-specific guide was abandoned because of outliers in more than one plane. In 18 patients (28%), a correction of the position indicated by the guide, was made in at least one plane. A change in cranial-caudal position was most common. Cohort A and B showed a similar percentage of outliers in long-leg coronal alignment (24.6%, 28.1%, p = 0.69), femoral coronal alignment (6.6%, 14.1%, p = 0.24) and femoral axial alignment (23%, 17.2%, p = 0.50). Cohort A had more outliers in coronal tibial alignment (14.6%) and sagittal tibial alignment (21.3%) than cohort B (3.1%, p = 0.03 and 3.1%, p = 0.002, respectively). These data indicate that patient specific guides do not improve accuracy in total knee arthroplasty

We performed a systematic review and meta-analysis of modern total ankle replacements (TARs) to determine the survivorship, outcome, complications, radiological findings and range of movement, in patients with end-stage osteoarthritis (OA) of the ankle who undergo this procedure. We used the methodology of the Cochrane Collaboration, which uses risk of bias profiling to assess the quality of papers in favour of a domain-based approach. Continuous outcome scores were pooled across studies using the generic inverse variance method and the random-effects model was used to incorporate clinical and methodological heterogeneity. We included 58 papers (7942 TARs) with an interobserver reliability (Kappa) for selection, performance, attrition, detection and reporting bias of between 0.83 and 0.98. The overall survivorship was 89% at ten years with an annual failure rate of 1.2% (95% confidence interval (CI) 0.7 to 1.6). The mean American Orthopaedic Foot and Ankle Society score changed from 40 (95% CI 36 to 43) pre-operatively to 80 (95% CI 76 to 84) at a mean follow-up of 8.2 years (7 to 10) (p < 0.01). Radiolucencies were identified in up to 23% of TARs after a mean of 4.4 years (2.3 to 9.6). The mean total range of movement improved from 23° (95% CI 19 to 26) to 34° (95% CI 26 to 41) (p = 0.01). Our study demonstrates that TAR has a positive impact on patients’ lives, with benefits lasting ten years, as judged by improvement in pain and function, as well as improved gait and increased range of movement. However, the quality of evidence is weak and fraught with biases and high quality randomised controlled trials are required to compare TAR with other forms of treatment such as fusion. Cite this article: Bone Joint J 2013;95-B:1500–7

Total hip arthroplasty (THA) is one of the preferable solutions for regaining ambulatory activity for patients with end-stage osteoarthritis, and the procedure is well developed technically and large numbers of patients benefit from THA worldwide. However, despite the improvements in implant designs and surgical techniques, revision rates remain high, and the number of revisions is expected to increase in the future as a result of the increase in the volume of primary THA and the increase in the proportion of younger, more active patients who are likely to survive longer than their prosthetic implants. In revision THA, associated loss of bone stock in the acetabulum presents one of the major challenges. The aim of the present study was to analyze the clinical and radiographic outcomes and Kaplan-Meier survivorship of patients underwent revision surgeries of the acetabular cup sustaining aseptic loosening. We reviewed consecutive 101 patients (120 hips; 10 men 11 hips; 91 women 109 hips; age at surgery, 66 years, range, 45–85) who underwent acetabular component revision surgery, at a follow-up period of 14.6 years (range, 10–30). For the evaluation of the state of the acebtabulum, acetabular bony defects were classified according to the classification of the AAOS based on the intraoperative findings as follows; type I [segmental deficiencies] in 24 hips, type II [cavity deficiency] in 48 hips, type III [combined deficiency] in 46, and type IV [pelvic discontinuity] in 2. Basically, we used the implant for acetabular revision surgery that cement or cementless cups were for the AAOS type I acetabular defects, cementless cup, or cemented cup with reinforcement device were for type II, cemented cup with reinforcement device were for type III. Follow-up examination revealed that Harris Hip score improved from 42.5±7.8 points before surgery to 76±16.2 points (p<0.05). The survival rates of the acetabular revision surgery with cemented cups, cementless cups, and cemented cups with reinforcement devices were 65.1%, 72.8%, and 79.8%, respectively, however, there was no significant differences between the groups. There were nine cases, which failed in the early stage in the groups of cementless cups and cemented cups with reinforcement devices, because of the instability of the cementless cups or breakage of reinforcement plates caused by inadequate bone grafting. We conclude that the usage of the cementless cups for type I and II acetabular bony defects, and the cemented cups with reinforcement devices for type III bony defects will demonstrate durable long-term fixation in case of adequate contact between acetabular components and host-bone with restoration of bone stock by impaction bone grafting

Introduction. Total knee arthroplasty (TKA) is an excellent treatment for end-stage osteoarthritis of the knee. In Asian countries, the number of TKA performed has rapidly increased, and is expected to continue so with its 4.4 billion population and increasing life expectancy. Asians' knees are known to be kinematically different to Caucasians after TKA. Controversy exists as to whether multi-radius (MR) or the newer single-radius (SR) TKA has superior outcome. Studies regarding this have been largely based on Caucasian data with few small sample Asian data. Methods. This is a retrospective analysis of prospectively collected institutional registry data between 2004 and 2015. Outcomes of 133 single-radius (SR) (Scorpio NRG, Stryker) and 363 multi-radius (MR) (Nexgen LPS, Zimmer) primary TKA for primary osteoarthritis were compared. All TKA was performed or directly supervised by the senior author. Range of motion (ROM), Oxford Knee Score (OKS), SF-36 physical component score (SF36-PCS), SF-36 mental component score (SF36-MCS), Knee Society Function Score (KS-FS) and Knee Score (KS-KS) were recorded preoperatively and at 2 years post-operation. Results. The mean age in both groups were similar at 66 ± 8 years (p=0.66). Both groups were in majority female (71% and 70% females in SR and MR respectively, p=0.10) and ethnic Chinese (79% and 84% in SR and MR respectively, p=0.53). The preoperative ROM and outcome scores in both groups were similar. MR-TKA achieved significantly greater improvement over 2 years in terms of ROM (7.5º ± 18.2º vs. 3.5º ± 19.3º, p=0.04), KS-KS (49.0 ± 20.9 vs. 42.7 ± 21.1, p=0.01), OKS (17.4 ± 18.4, p=0.03), and SF36-PCS (17.1 ± 12.5, p=0.02). At 2-years follow up, MR-TKA group fared slightly better for SF36-PCS (48 ± 10 vs. 46 ± 10, p=0.032), but the absolute difference was only 2 points. There were no significant differences between SR-TKA and MR-TKA for ROM (115º ± 16º vs. 117º ± 16º, p=0.218), KS-KS (81 ± 16 vs. 85 ± 12, p=0.795), KS-FS (74 ± 21 vs. 75 ± 20, p=0.627), OKS (20 ± 7 vs. 18 ± 6, p=0.099), and SF36-MCS (56 ± 10 vs. 55 ± 10, p=0.324). There were larger proportions of MR-TKA patients who achieved the minimum clinically important difference (MCID) for OKS (95% vs. 82%, p<0.001) and SF36-PCS (67% vs. 55%, p=0.011) at 2-years follow-up. Logistic regression, controlling for all preoperative variables, showed SR-TKA is less likely to achieve MCID for OKS with an odds ratio of 0.275 (95% confidence interval: 0.114 – 0.663, p=0.004), and SF36-PCS with an odds ration of 0.547 (0.316 – 0.946, p=0.031). Discussion and conclusion. SR-TKA and MR-TKA produced similar outcomes, in concordance with current literature. However, SR-TKA has lower odds of achieving MCID in OKS and SF36-PCS, possibly due to its smaller improvement in flexion over 2 years. This subtle difference has a greater impact in the context of Asian patients due to the cultural practice of kneeling and/or squating

The number of hip arthroplasty procedures has steadily increased in the United States over the last decade [Wolford, et. al, 2015]. This trend will continue as this treatment is the most effective approach in relieving pain, improving mobility, reducing fall risk and improving the quality of life in patients with end-stage osteoarthritis. The effectiveness of recovery can be impacted by factors such as access to postoperative physical therapy regimens. During the recovery period, it is important for therapists to be guided in their therapeutic decision making by accurate data concerning the patient's performance on a variety of measures. This project is designed to map the gait recovery curves of individuals who have undergone unilateral hip arthroplasty. To date, eight individuals (4 females, mean age 64.9, SD 11.1) have participated in the study. Five of the patients were treated by traditional press-fit Accolade II implants (Stryker, Mahwah, NJ USA) through a direct anterior approach THA and the other three has been treated by using DAA THA and using neck preserving Minihip. TM. short stem implant (Corin Ltd., Cirencester, UK). Each participant walked on an instrumented treadmill as a self-selected speed for three minutes pre-surgery. Post-surgery data collections occurred at three and six weeks, and three and six months and employed the same treadmill speed as used prior to surgery. Bilateral lower limb kinematic data was collected with a 12 camera motion capture system Vicon® (Oxford Metrics, Oxford, UK) using reflective markers attached to the hip, knee, ankle, heel and toe. Force plates embedded in the treadmill provided kinetic data that aided in the detection of heel strike and toe off. The temporal features associated with gait, including stride, stance time and double support time were obtained for both the surgical and non-surgical limbs and were used to assess changes in performance during the recovery period. The stance and double support data were also converted to a percentage of stance values which provide additional insights into gait control strategies. Repeated measure MANOVAs were used to evaluate any potential differences in the variables either between limbs or over time. Results from the statistical testing revealed that there were no significant differences between the two limbs for either stride or stance time. This was expected since global asymmetrical gait would have led to the participants veer off of the treadmill. There was a main effect of ‘Time’ for both stride and stance times. Post hoc testing indicated that the 6-month post-surgery measures were significantly reduced when compared to the Pre-surgery and 3-week post-surgery measures. Similarly, there were no significant differences in double support times between the two legs but there was a main effect for time. Post hoc testing revealed that the 6-month post-surgery double support time was significantly less than the Pre-surgery and 3-week post-surgery measures. These significant changes clearly indicate that surgery is effective in improving gait parameters. Moreover, clinicians may want to consider assessing double support time as this measure is a particularly robust indicator of the effectiveness of unilateral hip arthroplasty

Hip arthroplasty is commonly used as the final treatment approach for patients experiencing end-stage osteoarthritis. The number of these patients needing this treatment is expected to grow significantly by year 2030 to more than 572000 patients [Kurtz et al., 2007]. One of the important outcomes of hip arthroplasty is to improve patients' functions postoperatively. The evaluation of walking can provide a wealth of information regarding the efficiency of this treatment in improving a patient's mobility. Assessing the kinematic features of gait collected with a motion capture system combined with the aid of a motor-driven treadmill provides the advantage of enabling the evaluator to collect precise information about a large number of strides in a short period of time. Body segment kinematics (i.e. joint motion) are most often represented in the form of time series data with the abscissa (X axis) representing time and the ordinate (y axis) representing the motion of a particular joint. Although a great deal of information can be gained from the analyses of time series data, non-linear analyses tools can provide an additional and important dimension to a clinician's assessment of gait recovery. In this study eight patients (4 females, mean age 64.9, SD 11.1) have currently been assessed after unilateral hip arthroplasty. All surgeries were conducted by direct anterior approach by using two different approaches; three of the patients were treated by bone preservation technique and received Minihip short stem implant (Corin Ltd., Cirencester, UK) and five were treated by using a press fit stem implant Accolade II (Stryker, Mahwah, NJ USA). Patients performed a single three-minute trial of walking on a motor-driven treadmill at a self-selected pace. Using a 12 camera system, bilateral lower limb joint motion was collected prior to the surgery, at three and six weeks and at three and 6 months after the surgery. Depending upon the patient's preferred walking pace; between 40 and 45 strides were collected during each trial. Kinematic data obtained from force plates embedded in the treadmill were used to identify the heel strike and toe off events for each stride. After time normalizing the each of the joint angles (i.e. hip, knee, ankle) for each stride to 100 data points the data were then amplitude normalized to the initial point of the pre-surgery data. The non-linear tools of angle-angle and phase plane were used to explore relationships that are not readily apparent with linear wave form analyses. Angle-angle diagrams between a variety of joints angles both within a single limb or bilaterally enabled us to explore segmental coordination patterns and how they changed over the six months after surgery. Phase plane analyses included comparing joint motion relative to the velocity of that motion. This technique provided insights into the nature of the control of the joint. The additional information that results from the use of non-linear analyses provides an additional dimension of that can aide the clinician in understanding the recovery curve. This additional insight can be used to guide therapeutic decision making

INTRODUCTION. Total knee arthroplasty (TKA) is an effective technique to treat end-stage osteoarthritis of the knee. One important goal of the procedure is to restore physiological knee kinematics. However, fluoroscopy studies have consistently shown abnormal knee kinematics after TKA, which may lead to suboptimal clinical outcomes. Posterior slope of the tibial component may significantly impact the knee kinematics after TKA. There is currently no consensus about the most appropriate slope. The goal of the present study was to analyze the impact of different prosthetic slopes on the kinematics of a PCL-preserving TKA. The tested hypothesis was that the knee kinematics will be different for all tested tibial slopes. MATERIAL. PCL-retaining TKAs (Optetrak Logic CR, Exactech, Gainesville, FL) were performed by fellowship trained orthopedic surgeons on six fresh frozen cadaver with healthy knees and intact PCL. The TKA was implanted using a computer-assisted surgical navigation system (ExactechGPS®, Blue-Ortho, Grenoble, FR). The implanted tibial baseplate was specially designed (figure 1) to allow modifying the posterior slope without repeatedly removing/assembling the tibial insert with varying posterior slopes, avoiding potential damages to the soft-tissue envelope. METHODS. Knee kinematics was evaluated by performing a passive range of motion (ROM) from full extension to at least 100 degrees of flexion. Passive ROM was repeated three times at each of the 4 posterior slopes selected: 10°, 7°, 4°, and 1° using the adjustable tibial component (figure 1). Respective 3D positioning of femur and tibia implants was recorded by the navigation system. Hip-knee-ankle (HKA) angle, femoro-tibial antero-posterior (AP) translation and internal-external (I/E) rotation were plotted according to the knee flexion angle. RESULTS. HKA angle (figure 2B): all 4 different tibial slopes induced a physiologic motion curve, and the kinematic differences between 10°, 7°, 4°, and 1° of posterior slope with the native knee were small. All slopes induced a varus angle beyond 60° of flexion, most likely was due to the external rotation of the femoral component. Femoro-tibial AP translation (figure 2C): all 4 different tibial slopes induced a physiologic motion curve and all slopes induced a large posterior translation before 80° of flexion, which was proportional to the slope. I/E rotation (figure 2A): all slopes induced an excessive internal rotation before 60° of flexion. DISCUSSION. A change in the tibial slope may impact significantly the TKA kinematics. Slopes of 1° and 4° seemed to be the better compromise with the specific implant used. Navigation systems are able to assess the knee kinematics after TKA. The test protocol has been assessed for reproducibility in a separate study with satisfactory results. Changing the tibial slope significantly impacted the TKA kinematics. With the specific implant used, rotational and coronal kinematics was only marginally impacted by the change in tibial slope. AP kinematics was significantly impacted by the change in tibial slope. These changes may be related to a change in the PCL strain. Slopes of 1° and 4° induced the more physiologic compromise

Introduction. A total knee replacement is a proven cost-effective treatment for end-stage osteoarthritis, with a positive effect on pain and function. However, only 80% of the patients are satisfied after surgery. It is known that high preoperative expectations and residual postoperative pain are important determinants of satisfaction, but also malalignment, poor function and disturbed kinematics can be a cause. The purpose of this study was to investigate the correlation between the preoperative function and the postoperative patient reported outcomes PROMs) as well as the influence of the postoperative functional rehabilitation on the PROMs. Methods. 57 patients (mean 62,9j ± 10,6j), who suffer from knee osteoarthritis and who were scheduled for a total knee replacement at our centre, participated in this study. The range of motion of the knee, the muscle strength of the M. Quadriceps and the M. Hamstrings and the functional parameters (‘stair climbing test’ (SCT), ‘Sit to stand’ (STS) and ‘6 minutes walking test’ (6MWT)) were measured the night before surgery, ±6 months and ±1 year after surgery. This happened respectively with the use of a goniometer, HHD 2, stopwatch and the ‘DynaPort Hybrid’. Correlations between pre- and postoperative values were investigated. Secondly, a prediction was made about the influence of the preoperative parameters on on the subjective questionnaires (KOOS, OXFORD and KSS) as well as a linear and logistic regression. Results. 6 Months after surgery, an improvement of all parameters for ROM, muscle strength and functional status was found. With a significant difference for the active and passive ROM toward knee flexion (p=0.007;p=0.008), asymmetry in active and passive ROM toward flexion between the healthy leg and the leg with the TKA (p=0.001;p=0.001), Quadriceps- and Hamstrings strength (p=0.001;p<0.001), time of the STS test (p=0.012), time sit-stand (p=0.002), time stand-sit (p=0.001;p<0.001), all parameters for the 6MWT and the time of the SCT (p=0.001). Regarding the prediction model, the 6month PROMs can be predicted by some parameters for the 6MWT (distance (p=0.001), gait steps (p=0.002) and step time TKA (p=0.007)). These parameters are predictors for the score on the subscales ‘symptoms’ and ‘pain’ of the KOOS questionnaire. 1 Year after surgery, there is an improvement of all parameters, except for the active and passive ROM toward knee extension. However, these differences are not significant. The 1 year PROMs can only be predicted by the muscle strength (Quadriceps- and Hamstrings strength (p=0.026; p=0.039) and the asymmetry in Quadriceps strength between the healthy leg and the leg with the TKA (p=0.031)). The score on the subscale ‘pain’ can be predicted based on the parameters mentioned above. Conclusion. Patient satisfaction after TKA is a multivariate model. Regarding the functional outcome, we could find that there is a correlation between the muscle force, walking distance and the PROMs. More research is currently being done to create a better prediction model and investigate the correlations more thoroughly

Hip resurfacing arthroplasty is emerging as an increasingly popular, conservative option for the treatment of end-stage osteoarthritis in the young and active patient. Despite the encouraging clinical results of hip resurfacing, aseptic loosening and femoral neck fracture remains concerns for the success of this procedure. This study used finite element analysis (FEA) to analyse the stresses within proximal femoral bone resulting from implantation with a conservative hip prosthesis. FEA is a computational method used to analyse the performance of real-world structures through the development of simplified computational models using essential features. The aim of this study was to examine the correlation between the orientation of the femoral component of a hip resurfacing prosthesis (using the Birmingham Hip Resurfacing as a model) and outcomes during both walking and stair climbing. The outcomes of interest were stresses in the femoral neck predisposing to fracture, and bone remodelling within the proximal femur. Multiple three-dimensional finite element models of a resurfaced femur were generated, with stem-shaft angles representing anatomic (135°), valgus (145°), and varus (125°) angulations. Applied loading conditions included normal walking and stair climbing. Bone remodelling was assessed in both the medial and lateral cortices. Analyses revealed that amongst all orientations, valgus positioning produced the most physiological stress patterns within these regions, thereby encouraging bone growth. Stress concentration was observed in cortical and cancellous bone regions adjacent to the rim of the prosthesis. As one would expect, stair climbing produced consistently higher stress than walking. The highest stress values occurred in the varus-orientated femur during both walking and stair climbing, whilst anatomic angulation resulted in the lowest stress values of all implanted femurs in comparison to the intact femur. This study has shown through the use of FEA that optimising the stem-shaft angle towards a valgus orientation is recommended when implanting a hip resurfacing arthroplasty. This positioning produces physiological stress patterns within the proximal femur that are conducive to bone growth, thus reducing the risk of femoral neck fracture associated with conservative hip arthroplasty

Introduction: Arthrodesis has been recommended for the treatment of end-stage osteoarthritis of the ankle joint, especially as the results of prosthetic ankle replacement are not comparable with those achieved with total hip or knee replacement. In vitro studies revealed that ankle arthrodesis restricts kinematics more than total ankle replacement in terms of range of motion as well as movment transfer. However, little is known about in vivo gait patterns in patients with arthrodesis of the ankle joint. Aim of this retropective study was to determine plantar pressure distribution in patients who underwent ankle arthrodesis with a standardized screw fixation technique in a single surgeon population. Methods: 21 patients (7 male/14 female) who underwent isolated unilateral ankle arthrodesis with 3 crossed 7,3 mm AO screws (Synthes Gmbh, Austria) in a standardized technique by a single surgeon between October 2000 and January 2008 have been included in this study. At a mean follow-up of 25 months (range 12 – 75) pedobarograhy (Novel GmbH., Munich), clinical evaluation using the AOFAS hindfoot score and weight-bearing x-rays of the foot were performed. Results: Pedobarographic assessment revealed no statistically significant difference between the operated foot and the contralateral foot eighter in terms of peak pressure, maximum force, contact area and contact time or the gait line parameters velocity of center of pressure, lateral-medial force indices or lateral-medial area indices. The average AOFAS score was 80,5 (range 46 – 92) and mean tibioplantar angle determined on the lateral standing radiograph was 91° (82° – 100°). Non-union didn’t occur in any patient. Discussion: The results of the present study indicate that ankle arthrodesis restores plantar pressure distribution patterns to those of healthy feet. Therefore, the functional outcome of ankle arthrodesis seems to be good as long as the fusion is in fixed in an appropriate position

Total knee replacement (TKR) has become the standard procedure in management of degenerative joint disease with its success depending mainly on two factors: three dimensional alignment and soft tissue balancing. The aim of this work was to develop and validate an algorithm to indicate appropriate medial soft tissue release during TKR for varus knees using initial kinematics quantified via navigation techniques. Kinematic data was collected intra-operatively for 46 patients with primary end-stage osteoarthritis undergoing TKR surgery using a CT-free navigation system. All patients had preoperative varus knees and medial release was made using the surgeon’s experience. From this data an algorithm was developed to define the medial release based on the pre-operative mechanical femoral-tibial angle with valgus stress;. No release (tibial cut only) when valgus stress > −2/3°. Moderate release (medial aspect of tibia +/− semimembranosous tendon) when valgus stress > −5° and < −2°. Extensive release (proximal) when valgus stress < −5°. If there was a fixed flexion deformity > 5° then a posterior release was performed. This algorithm was validated on a further set of 35 patients where it was used to determine the medial release based only on the kinematic data. The post-operative varus and valgus stress angles for the two groups were compared and showed good outcomes in terms of distribution and outliers. The results showed that the algorithm was a suitable tool to indicate the type of release required based on intra-operatively measured pre-implant valgus stress and extension deficit angles. It reduced the percentage of releases made and the results were more appropriate than the decisions made by an experienced surgeon

The aim of this study was to investigate the pre-operative factors predicting the knee range of motion during stair ascending and descending a year after total knee arthroplasty. The pre-operative and one year post-operative results of fifty six patients with osteoarthritis were analysed. Range of knee motion during stair ascent and descent was recorded using electrogoniometry. Pre-operative measures were grouped in three different domains; the Demographic Domain with age and Body Mass Index (BMI), the Body Function Domain with knee range of motion in long sitting (ROMsit), Knee extensor moment, Pain on a Visual Analogue Scale and the stiffness component of the Western Ontario McMaster University Osteoarthritis Index (WOMAC) and thirdly the Psychosocial Domain with the Tampa scale for ‘fear of movement’ (TSK) and the sense of helplessness due to pain. Hierarchical Multiple Regression was used to analyse the relative importance of measures grouped into the three domain blocks on range of motion of the operated knee during stair ascent and descent. Model 1 contained domain block 1, model 2 included domain blocks 1 and 2 and model 3 included domain blocks 1,2 and 3. Learned helplessness was a significant predicting factor for stair descent (beta; −0.538, p=0.025) while for stair ascent, age (beta 0.375, p=0.005) and ROMsit (beta 0.365, p=0.021) were significant predicting variables. These results show that postoperative stair ascent and descent are predicted by different pre-operative factors. For stair ascent the demographic factors age and function factor ROM are important, while for stair descent, only the addition of the psychosocial factors in model 3 resulted in a significant change. These results indicate that treatment of patients with end-stage osteoarthritis should not only be aimed at improving range of motion of the knee but should also take into account psychosocial variables such as a sense of helplessness due to pain

End-stage osteoarthritis is characterised by pain and reduced physical function, for which total knee arthroplasty (TKA) is recognised to be a highly effective treatment. Most implants are multi radius in design, though modern kinematic theory suggests a single flexion/extension axis is located in the femur. A recently launched TKA implant (Triathlon, Stryker US), is based on this theory, adopting a single radius of curvature femoral component. It is hypothesised that this design allows better function, and specifically, that it results in enhanced efficiency of the quadriceps group through a longer patello-femoral moment arm. Change in power output was compared between single and multi radius implants as part of a larger ongoing randomised controlled trial to benchmark the new implant. Power output was assessed using a Leg Extensor Power Rig, well validated for use with this population, pre-operatively and at 6, 26 and 52 weeks post-operatively in 101 Triathlon and 82 Kinemax implants. All patients were diagnosed with osteoarthritis, and drawn from a single centre. Output was reported as maximal wattage (W) generated in a single leg extension, and expressed as a proportion of the contralateral limb power output to act as an internal control. The results are shown in the table below. Two-way repeated measures ANOVA demonstrated a significant effect of TKA on the quadriceps power output, F = 249.09, p = <0.001 and also a significant interaction of the implant group on the output F = 11.33, p = 0.001. Independent samples t-tests of between group differences at the four assessment periods highlighted greater improvement in the single radius TKA group at all post-operative assessments (p <0.03), see table. The theoretical enhanced quadriceps efficiency conferred by single radius design was found in this study. Power output was significantly greater at all post-operative assessments in the single radius compared to the multi radius group. This difference was particularly relevant at early 6 week and 1 year assessment. Lower limb power output is known to link positively to functional ability. The results support the hypothesis that TKAs with a single radius design have enhanced recovery and better function

Introduction. Total Knee Arthroplasty (TKA) is an established procedure for relieving patients of pain and functional degradation associated with end-stage osteoarthritis of the knee. Historically, alignment of components in TKA has focused on a ‘reconstructive’ approach neutral to the mechanical axes of the femur and tibia coupled with ligament balancing to achieve a balanced state. More recently, Howell et al. have proposed an alternate approach to TKA alignment, called kinematic alignment. (Howell, 2012) This approach seeks to position the implants to reproduce underlying, pre-disease state femoral condylar and tibial plateau morphology, and in doing is ‘restorative’ of the patients underlying knee kinematic behaviour rather than ‘reconstructive’. While some promising early clinical results have been reported at the RCT level (Dosset, 2014), in vivo comparisons of the kinematic outcome achieved at patient specific levels with the two alignment techniques remain an impossibility. The aim of this research is to develop and report preliminary findings of a means of simulating both alignment techniques on a number of patients. Method. In 20 TKR subjects, 3D geometry of the patient was reconstructed from preoperative CT scans, which were then used to define a patient specific soft tissue attachment model. The knees were then modelled passing through a 0 to 140 degree flexion cycle post TKR under each alignment technique. A multi-radius CR knee design has been used to model the TKA under each alignment paradigm. Kinematic measurements of femoral rollback, internal to external rotation, coronal plane joint torque, patella shear force and varus-valgus angulation are reported at 5, 30, 60, 90 and 120 degrees of flexion. Student's paired 2 sample t-tests are used to determine significant differences in means of the kinematic variables. Results. The mean femoral component alignment to the femoral mechanical axis was 3.3° ± 2.2° valgus and 2.3° ± 1.6° internal to the surgical transepicondylar axis in the kinematically aligned models. The mean tibial component alignment to the tibial mechanical axis was 3.5° ± 2.4° varus and 7.6° ± 6.5° internal to Insall's tibial anterior-posterior axis. The mechanically aligned model sims were all neutral to both axes. As a result of the relative match in femoral valgus & tibial varus component angulation, mean long leg varus at 5° degrees through 60° is not significantly different from the mechanically aligned knees, though with much higher variance in the kinematically aligned group. Statistically significant differences were observed at 90 and 120 degrees, where the long leg angle is dictated by posterior condylar contact on the femur rather than distal. Other statistically significant differences in mean results were observed, notably for coronal plain joint torque (at 5° and 30°, mechanical alignment higher). Discussion. Kinematic aligned TKR is conceptually a very different operation to mechanically aligned TKR, targeting different biomechanical goals. While evidence exists for improved clinical results in patients at a broad level, simulation tools at a patient specific level are a platform that, with development, could distinguish between patients benefiting most from a restorative or a reconstructive approach to their surgery

Introduction: Posttraumatic osteoarthritis of the ankle joint usually occurs secondary to an intraarticular fracture of the weight bearing ankle joint. The question whether also recurrent ankle sprain and /or chronic instability alone can cause this entity, is, however, still a question to debate. The aim of this retrospective study was, therefore, to analyse the history and findings of a consecutive series of patients that were treated for post-traumatic end-stage osteoarthrosis of the ankle. Methods: The complete database (including physical exam, standard radiographs, patient questionnaire and AOFAS hindfoot score) of all patients was analysed. Results: Out of 268 patients (females, 135 patients; males, 133) 221 (82.5%) had had a fracture (Fx) and 47 (17.5%) suffered from chronic ankle instability with recurrent sprains (but did not have a fracture). The latter group could be subdivided into 29 (10.8%) patients with recurrent sprains (RS) and 10 (6.7%) patients with only a single sprain (SS). The mean (range) delay between primary trauma and surgical treatment for endstage osteoarthritis was 21.1 (1–58) months for Fx, 37.07 (1–61) months for RS and 22.5 (5–48) months for SS. Conclusion: Obviously, not only fractures, but also severe sprains and /or chronic instability play an important role as a cause of end stage osteaorthrosis of the ankle joint. The obtained results suggest that a single severe sprain (dislocation) can cause similar articular damages to an intraarticular fracture, as the time to develop osteoarthrosis does not differ. This is in contrast to the current opinion that ankle sprain, in most instances, does not result in symptomatic articular degeneration

We wanted to assess the possible correlation between the intra-operative kinematics of the knee and the clinical results after total knee replacement (TKR). 187 cases of TKR implanted with help of a navigation system for end-stage osteoarthritis have been prospectively analyzed. There were 127 women and 60 men, with a mean age of 71 years. Indication for TKR was osteoarthritis in 161 cases and inflammatory arthritis in 26 cases. A floating platform, PCL preserving, cemented TKR was implanted in all cases. A non-image based navigation system was used in all cases to help for accuracy of bone resections and ligamentous balancing. The standard navigation system was modified to allow recording the three-dimensional tibio-femoral movement during passive knee flexion during the surgical procedure. Two sets of records have been performed: before any intra-articular procedure and after final implantation. Only antero-posterior femoral translation (in mm) and internal-external femoral rotation (in degrees) have been recorded. Kinematic data have been analyzed in a quantitative manner (total amount of displacement) and in a qualitative manner (restoration of the physiological posterior femoral translation and femoral external rotation during knee flexion). Clinical and functional results have been analysed according to the Knee Society scoring system with a minimal follow-up of one year. Statistical links between kinematic data and Knee Society scores have been analysed with an ANOVA test and a Spearman correlation test at a 0.05 level of significance. 101 knees had a posterior femoral translation during flexion before and after TKR. 18 knees had a paradoxical anterior femoral translation during flexion before and after TKR. 51 knees had the pre-TKR paradoxical anterior femoral translation corrected to posterior femoral translation after TKR. 14 knees had the pre-TKR posterior femoral translation modified to a paradoxical anterior femoral translation after TKR. 91 knees had a femoral external rotation during flexion before and after TKR. 34 knees had a paradoxical femoral internal rotation during flexion before and after TKR. 50 knees had the pre-TKR paradoxical femoral internal rotation corrected to a femoral external rotation after TKR. Nine knees had the pre-TKR femoral external rotation modified to a paradoxical femoral internal rotation after TKR. There was a moderate statistical link between the reconstruction of a physiological kinematics after TKR and the Knee Society scores, with higher scores in the group of physiological kinematics after reconstruction. There was no correlation between the quantitative data and the Knee Society scores. To record the knee kinematics during TKR is feasible. This information might help the surgeon choosing the optimal reconstruction compromise. However, it is not well defined how to influence final kinematics during knee replacement. The exact influence of the quality of the kinematic reconstruction measured during surgery on the clinical and functional results has to be investigated more extensively

INTRODUCTION. We wanted to assess the possible correlation between the intra-operative kinematics of the knee and the clinical results after total knee replacement (TKR). MATERIAL. 187 cases of TKR implanted with help of a navigation system for end-stage osteoarthritis have been prospectively analyzed. There were 127 women and 60 men, with a mean age of 71.4 years. Indication for TKR was osteoarthritis in 161 cases and inflammatory arthritis in 26 cases. METHODS. A floating platform, PCL preserving, cemented TKR was implanted in all cases. A non-image based navigation system was used in all cases to help for accuracy of bone resections and ligamentous balancing. The standard navigation system was modified to allow recording the three-dimensional tibio-femoral movement during passive knee flexion during the surgical procedure. Two sets of records have been performed: before any intra-articular procedure and after final implantation. Only antero-posterior femoral translation (in mm) and internal-external femoral rotation (in degrees) have been recorded. Kinematic data have been analyzed in a quantitative manner (total amount of displacement) and in a qualitative manner (restoration of the physiological posterior femoral translation and femoral external rotation during knee flexion). Clinical and functional results have been analyzed according to the Knee Society scoring system with a minimal follow-up of one year. Statistical links between kinematic data and Knee Society scores have been analyzed with an ANOVA test and a Spearman correlation test at a 0.05 level of significance. RESULTS. 101 knees had a posterior femoral translation during flexion before and after TKR. 18 knees had a paradoxical anterior femoral translation during flexion before and after TKR. 51 knees had the pre-TKR paradoxical anterior femoral translation corrected to posterior femoral translation after TKR. 14 knees had the pre-TKR posterior femoral translation modified to a paradoxical anterior femoral translation after TKR. 91 knees had a femoral external rotation during flexion before and after TKR. 34 knees had a paradoxical femoral internal rotation during flexion before and after TKR. 50 knees had the pre-TKR paradoxical femoral internal rotation corrected to a femoral external rotation after TKR. 9 knees had the pre-TKR femoral external rotation modified to a paradoxical femoral internal rotation after TKR. There was a moderate statistical link between the reconstruction of a physiological kinematics after TKR and the Knee Society scores, with higher scores in the group of physiological kinematics after reconstruction. There was no correlation between the quantitative data and the Knee Society scores. DISCUSSION. To record the knee kinematics during TKR is feasible. This information might help the surgeon choosing the optimal reconstruction compromise. However, it is not well defined how to influence final kinematics during knee replacement. The exact influence of the quality of the kinematic reconstruction measured during surgery on the clinical and functional results has to be investigated more extensively. SUMMARY. There is a statistical relationship between the intra-operative knee kinematics and the clinical and functional results

Young, active patients with end-stage medial osteoarthritis (OA) secondary to anterior cruciate ligament (ACL) deficiency present a treatment challenge for surgeons. Current surgical treatment options include high tibial osteotomy (HTO) with or without ACL reconstruction, unicompartmental knee arthroplasty (UKA) with ACL reconstruction, and total knee arthroplasty (TKA). A recent systematic review reported a much higher rate of complications in HTO combined with ACL reconstruction than with UKA-ACL (21.1% vs 2.8%), while survivorship between the two procedures was similar. UKA offers several advantages over TKA, namely faster recovery, lower blood loss, lower rate of postoperative complications, better range of motion, and better knee kinematics. However, UKA has classically been contraindicated in the presence of ACL deficiency due to reported concerns over increased incidence aseptic loosening tibia. However, as a majority of patients presenting with this pathology are young and active, concerns about implant longevity with TKRA and loss of bone stock have arisen. As a result, several authors have described combining ACL reconstruction with medial UKA to decrease the tibiofemoral translation-related stress on the tibial component, thereby decreasing aseptic loosening-related failures. The purpose of this study was to compare the functional outcomes and survivorship of combined medial UKA and ACL reconstruction (UKA-ACL) with those of a matched TKA cohort. We hypothesized that UKA-ACL patients would have better functional outcomes than TKA patients while maintaining similar survivorship. Material and Methods. We conducted a case-control study establishing UKA-ACL as the study group and TKA as the control group by a single senior surgeon between October 2005 and January 2015. We excluded patients who were over the age of 55 at the time of surgery and those who had less than two-year follow-up. A total of 21 patients (23 knees) were ultimately included in each group. Propensity matching was for age-, sex-, and body mass index (BMI)-matched control group of TKA cases. Surgical technique. UKA-ACL. This patient's had an arthroscopy to allow for tunnel preparation in the standard fashion and then the graft was passed and fixed on the femoral side. An MIS medial incision was then made to allow for insertion of the Oxford mobile-bearing unicompartmental prosthesis (Zimmer Biomet, Warsaw, IN). Primary choice of ACL graft was autogenous ipsilateral semitendinosus and gracilis tendons, which was available I and 6 of the cases were revision from previous Gore-Tex synthetic ligament reconstruction. Results. Preoperatively, baseline questionnaires demonstrated that the TKA group had scored significantly lower on the symptom subscore of the KOOS. There was no difference between the groups in the rest of the KOOS subscores, (the UCLA, and the Tegner. All scores (UCLA, and Tegner – TBC post stats) improved significantly after surgery in both groups. Improvement in each subscore of the KOOS surpassed the minimal clinically important difference in both the UKA-ACL and TKA groups. At latest follow-up, there was no significant difference between the groups on the KOOS, UCLA or Tegner, showing that our UKA-ACL patients fared as our TKA patients. This confirms that UKA-ACL is an important tool in dealing with young patients with end-stage medial OA and ACL deficiency and offers an option that leads to less bone loss and potentially easier future revision. For any figures or tables, please contact authors directly

Aims

Shoulder arthroplasty is effective in the management of end-stage glenohumeral joint arthritis. However, it is major surgery and patients must balance multiple factors when considering the procedure. An understanding of patients’ decision-making processes may facilitate greater support of those considering shoulder arthroplasty and inform the outcomes of future research.

Aims

The extended wait that most patients are now experiencing for hip and knee arthroplasty has raised questions about whether reliance on waiting time as the primary driver for prioritization is ethical, and if other additional factors should be included in determining surgical priority. Our Prioritization of THose aWaiting hip and knee ArthroplastY (PATHWAY) project will explore which perioperative factors are important to consider when prioritizing those on the waiting list for hip and knee arthroplasty, and how these factors should be weighted. The final product will include a weighted benefit score that can be used to aid in surgical prioritization for those awaiting elective primary hip and knee arthroplasty.

The Cementless Oxford Unicompartmental Knee Replacement (OUKR) was developed to address problems related to cementation, and has been demonstrated in a randomised study to have similar clinical outcomes with fewer radiolucencies than observed with the cemented device. However, before its widespread use it is necessary to clarify contraindications and assess the complications. This requires a larger study than any previously published. We present a prospective multicentre series of 1000 cementless OUKRs in 881 patients at a minimum follow-up of one year. All patients had radiological assessment aligned to the bone–implant interfaces and clinical scores. Analysis was performed at a mean of 38.2 months (19 to 88) following surgery. A total of 17 patients died (comprising 19 knees (1.9%)), none as a result of surgery; there were no tibial or femoral loosenings. A total of 19 knees (1.9%) had significant implant-related complications or required revision. Implant survival at six years was 97.2%, and there was a partial radiolucency at the bone–implant interface in 72 knees (8.9%), with no complete radiolucencies. There was no significant increase in complication rate compared with cemented fixation (p = 0.87), and no specific contraindications to cementless fixation were identified. Cementless OUKR appears to be safe and reproducible in patients with end-stage anteromedial osteoarthritis of the knee, with radiological evidence of improved fixation compared with previous reports using cemented fixation. Cite this article: Bone Joint J 2013;95-B:181–7

The October 2023 Research Roundup³⁶⁰ looks at: Gut microbiota in high-risk individuals for rheumatoid arthritis associated with disturbed metabolome and initiates arthritis by triggering mucosal immunity imbalance; International Consensus on Anaemia Management in Surgical Patients (ICCAMS); Sleep disturbance trends in the short-term postoperative period for patients undergoing total joint replacement; Achilles tendon tissue turnover before and immediately after an acute rupture; Quadriceps or hip exercises for patellofemoral pain? A randomized controlled equivalence trial; Total-body MRI for screening in patients with multiple osteochondromas.

Aims

The use of cementless total knee arthroplasty (TKA) components has increased during the past decade. The initial design of cementless metal-backed patellar components had shown high failure rates due to many factors. The aim of this study was to evaluate the clinical results of a second-generation cementless, metal-backed patellar component of a modern design.

The August 2024 Knee Roundup³⁶⁰ looks at: Calcification’s role in knee osteoarthritis: implications for surgical decision-making; Lower complication rates and shorter lengths of hospital stay with technology-assisted total knee arthroplasty; Revision surgery: the hidden burden on surgeons; Are preoperative weight loss interventions worthwhile?; Total knee arthroplasty with or without prior bariatric surgery: a systematic review and meta-analysis; Aspirin triumphs in knee arthroplasty: a decade of evidence; Efficacy of DAIR in unicompartmental knee arthroplasty: a glimpse from Oxford.

Aims

The aim of this study was to compare the migration of the femoral component, five years postoperatively, between patients with a highly cross-linked polyethylene (HXLPE) insert and those with a conventional polyethylene (PE) insert in an uncemented Triathlon fixed insert cruciate-retaining total knee arthroplasty (TKA). Secondary aims included clinical outcomes and patient-reported outcome measures (PROMs). We have previously reported the migration and outcome of the tibial components in these patients.

Aims

The aim of this study was to investigate whether anterior pelvic plane-pelvic tilt (APP-PT) is associated with distinct hip pathomorphologies. We asked: is there a difference in APP-PT between young symptomatic patients being evaluated for joint preservation surgery and an asymptomatic control group? Does APP-PT vary among distinct acetabular and femoral pathomorphologies? And does APP-PT differ in symptomatic hips based on demographic factors?

Aims

The COVID-19 pandemic has caused unprecedented disruption to elective orthopaedic services. The primary objective of this study was to examine changes in functional scores in patients awaiting total hip arthroplasty (THA), total knee arthroplasty (TKA), and unicompartmental knee arthroplasty (UKA). Secondary objectives were to investigate differences between these groups and identify those in a health state ‘worse than death’ (WTD).

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The primary objective of this study was to compare the five-year tibial component migration and wear between highly crosslinked polyethylene (HXLPE) inserts and conventional polyethylene (PE) inserts of the uncemented Triathlon fixed insert cruciate-retaining total knee arthroplasty (TKA). Secondary objectives included clinical outcomes and patient-reported outcome measures (PROMs).

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Tenosynovial giant cell tumour (TGCT) is a rare benign tumour of the musculoskeletal system. Surgical management is fraught with challenges due to high recurrence rates. The aim of this study was to describe surgical treatment and evaluate surgical outcomes of TGCT at an Australian tertiary referral centre for musculoskeletal tumours and to identify factors affecting recurrence rates.

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The aim of this meta-analysis was to determine the pooled incidence of postoperative urinary retention (POUR) following total hip and knee arthroplasty (total joint replacement (TJR)) and to evaluate the risk factors and complications associated with POUR.

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The mean age of patients undergoing total knee arthroplasty (TKA) has reduced with time. Younger patients have increased expectations following TKA. Aseptic loosening of the tibial component is the most common cause of failure of TKA in the UK. Interest in cementless TKA has re-emerged due to its encouraging results in the younger patient population. We review a large series of tantalum trabecular metal cementless implants in patients who are at the highest risk of revision surgery.

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Although the Fitmore Hip Stem has been on the market for almost 15 years, it is still not well documented in randomized controlled trials. This study compares the Fitmore stem with the CementLeSs (CLS) in several different clinical and radiological aspects. The hypothesis is that there will be no difference in outcome between stems.

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The aim of this study was to describe the pattern of revision indications for unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) and any change to this pattern for UKA patients over the last 20 years, and to investigate potential associations to changes in surgical practice over time.

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We aim to evaluate the usefulness of postoperative blood tests by investigating the incidence of abnormal results following total joint replacement (TJR), as well as identifying preoperative risk factors for abnormal blood test results postoperatively, especially pertaining to anaemia and acute kidney injury (AKI).

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Metal and ceramic humeral head bearing surfaces are available choices in anatomical shoulder arthroplasties. Wear studies have shown superior performance of ceramic heads, however comparison of clinical outcomes according to bearing surface in total shoulder arthroplasty (TSA) and hemiarthroplasty (HA) is limited. This study aimed to compare the rates of revision and reoperation following metal and ceramic humeral head TSA and HA using data from the National Joint Registry (NJR), which collects data from England, Wales, Northern Ireland, Isle of Man and the States of Guernsey.

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Total knee arthroplasty (TKA) with a highly congruent condylar-stabilized (CS) articulation may be advantageous due to increased stability versus cruciate-retaining (CR) designs, while mitigating the limitations of a posterior-stabilized construct. The aim was to assess ten-year implant survival and functional outcomes of a cemented single-radius TKA with a CS insert, performed without posterior cruciate ligament sacrifice.

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This study examined whether systemic administration of melatonin would have different effects on osseointegration in ovariectomized (OVX) rats, depending on whether this was administered during the day or night.

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The primary aim was to assess whether robotic total knee arthroplasty (rTKA) had a greater early knee-specific outcome when compared to manual TKA (mTKA). Secondary aims were to assess whether rTKA was associated with improved expectation fulfilment, health-related quality of life (HRQoL), and patient satisfaction when compared to mTKA.

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Multiple secondary surgical procedures of the shoulder, such as soft-tissue releases, tendon transfers, and osteotomies, are described in brachial plexus birth palsy (BPBP) patients. The long-term functional outcomes of these procedures described in the literature are inconclusive. We aimed to analyze the literature looking for a consensus on treatment options.

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Unicompartmental knee arthroplasty (UKA) has a higher risk of revision than total knee arthroplasty (TKA), particularly for younger patients. The outcome of knee arthroplasty is typically defined as implant survival or revision incidence after a defined number of years. This can be difficult for patients to conceptualize. We aimed to calculate the ‘lifetime risk’ of revision for UKA as a more meaningful estimate of risk projection over a patient’s remaining lifetime, and to compare this to TKA.

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The purpose of this study is to determine an individual’s age-specific prevalence of total knee arthroplasty (TKA) after cruciate ligament surgery, and to identify clinical and genetic risk factors associated with undergoing TKA.

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The diagnosis of joint infections is an inexact science using combinations of blood inflammatory markers and microscopy, culture, and sensitivity of synovial fluid (SF). There is potential for small molecule metabolites in infected SF to act as infection markers that could improve accuracy and speed of detection. The objective of this study was to use nuclear magnetic resonance (NMR) spectroscopy to identify small molecule differences between infected and noninfected human SF.

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Stemless humeral implants have been developed to overcome stem-related complications in total shoulder arthroplasty (TSA). However, stemless implant designs may hypothetically result in less stable initial fixation, potentially affecting long-term survival. The aim of this study is to investigate early fixation and migration patterns of the stemless humeral component of the Simpliciti Shoulder System and to evaluate clinical outcomes.

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The goal of the current systematic review was to assess the impact of implant placement accuracy on outcomes following total knee arthroplasty (TKA).

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Social determinants of health (SDOHs) may contribute to the total cost of care (TCOC) for patients undergoing total knee arthroplasty (TKA). The aim of this study was to investigate the association between demographic data, health status, and SDOHs on 30-day length of stay (LOS) and TCOC after this procedure.

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Higher osteoblastic bone activity is expected in aseptic loosening and painful unicompartmental knee arthroplasty (UKA). However, insights into normal bone activity patterns after medial UKAs are lacking. The aim of this study was to identify the evolution in bone activity pattern in well-functioning medial mobile-bearing UKAs.

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Short, bone-conserving femoral components are increasingly used in total hip arthroplasty (THA). They are expected to allow tissue-conserving implantation and to render future revision surgery more straightforward but the long-term data on such components is limited. One such component is the global tissue-sparing (GTS) stem. Following the model for stepwise introduction of new orthopaedic implants, we evaluated early implant fixation and clinical outcome of this novel short-stem THA and compared it to that of a component with established good long-term clinical outcome.

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Unicompartmental knee arthroplasty (UKA) and bicompartmental knee arthroplasty (BCA) have been associated with improved functional outcomes compared to total knee arthroplasty (TKA) in suitable patients, although the reason is poorly understood. The aim of this study was to measure how the different arthroplasties affect knee extensor function.

Cementless knee arthroplasty has seen a recent resurgence in popularity due to conceptual advantages, including improved osseointegration providing biological fixation, increased surgical efficiency, and reduced systemic complications associated with cement impaction and wear from cement debris. Increasingly younger and higher demand patients are requiring knee arthroplasty, and as such, there is optimism cementless fixation may improve implant survivorship and functional outcomes.

Compared to cemented implants, the National Joint Registry (NJR) currently reports higher revision rates in cementless total knee arthroplasty (TKA), but lower in unicompartmental knee arthroplasty (UKA). However, recent studies are beginning to show excellent outcomes with cementless implants, particularly with UKA which has shown superior performance to cemented varieties. Cementless TKA has yet to show long-term benefit, and currently performs equivalently to cemented in short- to medium-term cohort studies. However, with novel concepts including 3D-printed coatings, robotic-assisted surgery, radiostereometric analysis, and kinematic or functional knee alignment principles, it is hoped they may help improve the outcomes of cementless TKA in the long-term. In addition, though cementless implant costs remain higher due to novel implant coatings, it is speculated cost-effectiveness can be achieved through greater surgical efficiency and potential reduction in revision costs. There is paucity of level one data on long-term outcomes between fixation methods and the cost-effectiveness of modern cementless knee arthroplasty.

This review explores recent literature on cementless knee arthroplasty, with regards to clinical outcomes, implant survivorship, complications, and cost-effectiveness; providing a concise update to assist clinicians on implant choice.

Cite this article: Bone Jt Open 2021;2(1):48–57.

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Patients with a deformity of the hindfoot present a particular challenge when performing total knee arthroplasty (TKA). The literature contains little information about the relationship between TKA and hindfoot alignment. This systematic review aimed to determine from both clinical and radiological studies whether TKA would alter a preoperative hindfoot deformity and whether the outcome of TKA is affected by the presence of a postoperative hindfoot deformity.

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In previous studies, we identified multiple factors influencing the survivorship of hip resurfacing arthroplasties (HRAs), such as initial anatomical conditions and surgical technique. In addition, the University of California, Los Angeles (UCLA) activity score presents a ceiling effect, so a better quantification of activity is important to determine which activities may be advisable or detrimental to the recovered patient. We aimed to determine the effect of specific groups of sporting activities on the survivorship free of aseptic failure of a large series of HRA.

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The aims of this study were to determine the change in the sagittal alignment of the pelvis and the associated impact on acetabular component position at one-year follow-up after total hip arthroplasty (THA).

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Total knee arthroplasty is an established treatment for knee osteoarthritis with excellent long-term results, but there remains controversy about the role of uncemented prostheses. We present the long-term results of a randomized trial comparing an uncemented tantalum metal tibial component with a conventional cemented component of the same implant design.

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For cementless implants, stability is initially attained by an interference fit into the bone and osteo-integration may be encouraged by coating the implant with bioactive substances. Blood based autologous glue provides an easy, cost-effective way of obtaining high concentrations of growth factors for tissue healing and regeneration with the intention of spraying it onto the implant surface during surgery. The aim of this study was to incorporate nucleated cells from autologous bone marrow (BM) aspirate into gels made from the patient’s own blood, and to investigate the effects of incorporating three different concentrations of platelet rich plasma (PRP) on the proliferation and viability of the cells in the gel.

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Enhanced perioperative protocols have significantly improved patient recovery following primary total knee arthroplasty (TKA). Little has been investigated the effectiveness of these protocols for revision TKA (RTKA). We report on a matched group of aseptic revision and primary TKA patients treated with an identical pain and rehabilitation programmes.

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The aim of this study was to examine whether hips with unilateral osteoarthritis (OA) secondary to developmental dysplasia of the hip (DDH) have significant asymmetry in femoral length, and to determine potential related factors.

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Second-generation metal-on-metal (MoM) articulations in total hip arthroplasty (THA) were introduced in order to reduce wear-related complications. The current study reports on the serum cobalt levels and the clinical outcome at a minimum of 20 years following THA with a MoM (Metasul) or a ceramic-on-polyethylene (CoP) bearing.