Summary Statement. This study provides preliminary evidence that people with knee osteoarthritis have greater asymmetry in joint loading than healthy controls. Altered loading of the contralateral limb may signify increased risk of injury to other lower limb joints in knee osteoarthritis. Introduction. Compensatory overloading of other lower limb joints is a potential reason for the non-random evolution of osteoarthritis (OA). In individuals with knee OA altered joint loading exists of the contralateral cognate joints. However, previous studies have neglected the temporal features of asymmetry in joint loading. The study aimed to identify the amount and temporal features of asymmetry in lower limb joint loading in advanced knee OA. Patients and Methods. Participants (n=15) were awaiting primary unilateral total knee replacement for OA (age 67.0 SD 8.9 years, height 1.66 SD 0.13 m, mass 84.2 SD 15.8 kg, BMI 30.7 SD 6.2 kg/m. 2. , median KL grade 4). Data were compared to asymptomatic age and sex matched controls. Kinematic and kinetic data during walking was acquired with 12 cameras (VICON MX-F20) and two Kistler force platforms at 100 Hz and 400 Hz respectively. Data were analysed in Visual3D (C-Motion Inc., USA). Asymmetry was computed in MatLab using a recently published symmetry index (SI) and symmetry function (SF). Variables (computed using inverse dynamics) were the peak external moments (%BW∗Height) of the hip, knee and ankle. Differences between means of the SI variables in the OA and control groups were compared using Student's t-tests. Discrete variables were also compared between limbs (paired t-test) or between the affected limb and matched control limb. Effect sizes (Cohen's d) for the differences were also computed. Results. A significant between group difference (OA and control) for SI was observed for the transverse plane ankle joint moment (16.1 SD 8.0 vs. 10.4 SD 4.8 d = 0.8 p = 0.049). A large effect size for the sagittal plane knee joint moment (22.9 SD 12.1 vs. 12.7 SD 5.1 d = 1.1 p = 0.178) and a medium effect size for the transverse plane hip joint moment (26.4 SD 15.9 vs. 16.6 SD 9.0 d = 0.7 p = 0.098) were observed. The unaffected limb (OA group) had higher peak hip flexion (5.76 SD 1.49 vs.5.32 SD 1.51 p = 0.041) and internal rotation moments (−0.67 SD 0.34 vs. −0.41 SD 0.18 d = 0.004) and a lower ankle inversion moment (0.16 SD 0.14 vs. 0.34 SD 0.24 d = 0.9 p = 0.030) compared to the affected limb. Only the difference in the first peak knee adduction moment for the affected and matched control limb was statistically significant (−2.65 SD 1.38 vs. −2.16 SD 1.16 d = 0.7 p = 0.031). Discussion and Conclusion. This study provides preliminary evidence of more asymmetry in joint moments of the lower limb in people with knee OA compared to controls. Further investigation with a larger sample is required to verify these findings. Altered loading of the contralateral cognate joints may signify increased risk of injury at the hip and ankle and highlights the need for monitoring of other lower limb joints in knee OA

Background. Deciding how to allocate scarce surgical resources is a worldwide issue. These decisions are difficult when considering procedures aimed primarily at improving functional quality of life, such as lower extremity joint replacement (LEJR) surgery, and procedures perceived as life preserving which also have impacts on physical function, such as coronary artery bypass graft (CABG) surgery. Comparing functional outcomes of these two procedures may provide further evidence to guide resource allocation decisions. Methods. We compared patient-reported functional outcomes following CABG and LEJR surgery using standardised, validated outcome metrics. A retrospective review of prospectively collected pre- and post-operative health related quality of life (SF-36) measures were conducted from 105 patients undergoing elective CABG and 105 elective LEJR surgery patients. Patients were matched based on gender and age. Results. Pre-operatively, CABG patients reported statistically superior (p< 0.05) Physical Functioning, Bodily Pain, and Physical Component summary SF-36 scores compared to LEJR patients. However, their pre-operative General Health scores were lower. Surgery resulted in improvements in SF-36 scores for all patients, with statistically significant improvements in Bodily Pain and Physical Component scores occurring in both groups. Interestingly, improvements in 8 out of 10 SF-36 index scores were greater in the LEJR group, with the exception of Vitality and the Mental Component Summary. The pre-operative pattern of statistically better Physical Functioning in the CABG group, and superior General Health scores in the LEJR group remained following surgery. Conclusion. It appears that, despite being matched for age and gender, significant pre-operative general health differences exist between CABG and LEJR patients that persist post-operatively. While surgery results in significant improvements for both groups, CABG patients enjoy greater improvement in General Health scores while LEJR patients benefit from greater improvements in Bodily Pain scores. Further research is underway, examining how these differences reflect disease-specific scores and health care resource utilisation

Introduction: Infection after hip or knee replacement occurs with low frequency but shares high morbidity. Aim of this study was an evaluation of incidence and risk factors related to post operative infection after joint lower limb joint replacement in an orthopaedics unit. Material and methods: This is a monocentric, retrospective, case control study over the years 2000 to 2002. All first intention Total Hip and Knee Replacement and revision cases for mechanical reasons that became infected were identified. Demographic, surgical and medical variables, potentially associated to prosthetic infection were compared for these patients to a control group of non ifected patients over the same time, matched for sex, age and surgery type. Results: Ten patients, all male, contracted post operative joint infection, out of 630 Total Hip or Knee Arthroplasties. This represented 1.2% after hip replacement and 3.1% after knee replacement. Bacteriological datas showed a majority of Staphylococal infection (5 aureus, 1 epidermidis), 2 among these being resistant to meticillin, but also evidence of ENT commensals (2 Streptococci milleri, 1 Actinomyces) and one epidermal commensal (Propionobacterium acnes). Univariate analysis: datas associated with increased risk of infection were diabetes melitus (OR 9.3; CI 95% 1.4–63), operating time exceeding 120 minutes (OR15.5 ; CI 95% 1,73–139,66), superficial wound infection (odds ratio 29; CI95% 2,77–303,32), coinfection outside the operation site (urinary tract , dental infection) (OR: 9,3 ; CI 95% 1,33–63,2). In our study an MNIS score higher than 1, autologous transfusion, locore-gional anaesthesia with or without the use of a catheter, antibioprophylaxis that did not comply with national recommendations could not be drawn as a risk factor. Discussion: Incidence of infection and risk factors related to infection in our study were found similar tothe results of published datas. The small number of events (10 cases) did not allow us to realize multivariate analysis and could explain that some known risk factors such as non recommended antibioprophylaxis, could not be elicitated. However these results suggested the need to reevaluate the system of prevention of infection in our centre such as protocolization of antibioprophylaxis and screening for and treatement of perioperative coinfection

Purpose: Deciding how to allocate scarce surgical resources is a worldwide issue. These decisions can be especially difficult when considering procedures aimed primarily at improving functional quality of life, such as lower extremity joint replacement (LEJR) surgery, and those procedures that can be perceived primarily as life preserving but should also have an impact on physical function, such as coronary artery bypass graft (CABG) surgery. A comparison of the functional outcomes of these two different procedures may provide further evidence to guide resource allocation decisions. The purpose of this study is to compare patient-reported functional outcomes following CABG and LEJR surgery using standardized, validated outcome metrics. Method: A retrospective review of prospectively collected pre and post-operative health related quality of life (SF-36) measures from patients undergoing elective CABG and elective LEJR surgery in an academic surgical center. The sample included 112 CABG patients who were matched with LEJR patients based on gender and age. Results: The mean age in the CABG group was 63 years, in the LEJR group 64 years. Seventy eight percent (78%) of the patients were male. Pre-operatively, CABG patients reported statistically higher (p< 0.05) Physical Functioning, less Bodily Pain, and superior Physical Component summary SF-36 scores compared to the LEJR group. However, their pre-operative General Health scores were statistically lower. Surgery resulted in a general improvement in all SF-36 scales and summary scores for all patients, with statistically significant improvements in Bodily Pain and General Health Scores occurring in both groups. Interestingly, the improvement in Bodily Pain score was greater for the LEJR group than the CABG group, whereas the improvement in General Health Score was greater in the CABG group. However the pre-operative pattern of statistically better Physical Functioning, Bodily Pain and Physical Component summary SF-36 scores in the CABG group, and superior General Health scores in the LEJR group remained following surgery. Conclusion: It appears that, despite being matched for age and gender, significant pre-operative general health differences exist between CABG and LEJR patients that persist post-operatively. While surgery does result in significant improvements for both groups, CABG patients enjoy greater improvement in General Health scores while LEJR patients benefit from greater improvements in Bodily Pain scores. Further research is currently underway to examine how these differences are reflected in disease-specific scores and in health care resource utilization

Aims

Complex joint fractures of the lower extremity are often accompanied by soft-tissue swelling and are associated with prolonged hospitalization and soft-tissue complications. The aim of the study was to evaluate the effect of vascular impulse technology (VIT) on soft-tissue conditioning in comparison with conventional elevation.

We investigated the role of Plasma Viscosity (PV), C-reactive protein (CRP) and Frozen Section (FS) in diagnosing prosthetic joint infection. We compared these results with microbiological diagnosis of infection of the tissue samples (three or more samples grown same organisms in culture).

53 patients, average age 67 years (37 – 89) underwent joint revision surgery. 34 patients had hip and 19 patients had knee joint revision arthroplasty, this includes single and multiple stage revision surgeries and excision arthroplasty. Nine (17%) patients had microbiologically proven joint infection. PV had sensitivity of 100%, specificity of 43% and negative predictive value of 100%. CRP had sensitivity of 89 %, specificity of 75% and negative predictive value of 97%. FS (presence of infection being more than 5 neutrophils/hpf) had sensitivity of 56% and specificity of 84%.

We recommend PV and CRP to be used in the investigation of prosthetic joint infection. If both CRP and PV are normal the chance of infection is very low (negative predictive value of 100%). In our series an elevated PV and CRP represented a 50% chance of having a joint infection. The role of frozen section does not appear to be beneficial in the diagnosis of joint

Introduction: Joint replacement has a low mortality rate, few adverse occurrences, excellent survivorship and is considered a cost-effective intervention to reduce disability in the community. However, the assessment of complications and survivorship fail to measure the success of joint replacement in achieving pain relief and restoration of functional ability. The aim of this large cross-sectional postal survey was to provide information on the prevalence of pain, disability, poor quality of life and patient dissatisfaction at 1–3 years after a range of lower limb orthopaedic surgeries in the UK.

Patient and Methods: A questionnaire was posted to all 3,125 consecutive alive patients who underwent a primary THR, hip resurfacing, TKR, UKR or patellar resurfacing at the Avon Orthopaedic Centre between January 2004 – April 2006. The questionnaire included the WOMAC, HOOS/KOOS quality of life scale and a validated satisfaction scale. All questionnaires are scored on a 0–100 scale (worst-best) and a poor outcome was defined as a score of ≤ 50 on the outcome measure.

Results: Completed questionnaires were received from 2,085 patients (response rate of 67%). Patients had a mean age of 67 years and 42% were male. The mean length of follow-up was 28 months (range 14–44 months). 911 patients had a THR, 157 patients had a hip resurfacing, 866 patients had a TKR, 100 patients had a UKR and 51 patients had a patellar resurfacing.

Pain: the prevalence of poor outcomes were 6% of patients with a THR, 4% with a hip resurfacing, 12% with a TKR, 9% with a UKR and 31% with a patellar resurfacing.

Conclusion: This survey has provided descriptive data on the prevalence of patient-reported levels of pain, disability, poor joint-related quality of life and dissatisfaction after lower limb arthroplasty. It is important that patient-reported outcomes after joint replacement are rigorously assessed in order to provide information on which patients do poorly after surgery, with the aim of targeting these patients with an intervention to improve their outcome.

North Bristol Trust Small Grants Scheme provided funding for the consumables for this study.

We aim to determine the differences in lower limb joint kinematics during the golf swing of patients who had undergone Total Knee Arthroplasty (TKA) and a control group of native knee golfers. A case-control study was undertaken with ten golfers who had undergone TKA (cruciate retaining single radius implant) and five age and matched golfers with native knees. Each golfer performed five swings with a driver whilst being recorded at 200Hz by a ten-camera motion capture system. Knee and hip three-dimensional joint angles (JA) and joint angular velocities (JAV) were calculated and statistically compared between the groups at six swing events. The only significant differences in knee joint kinematics between TKA and control groups was a lower external rotation JA in the left knee during the backswing (p=0.010). There was no significant difference in knee JAV between the groups. Both hips demonstrated significantly (p=0.023 for left and p=0.037 for right) lower flexion in the TKA group during the takeaway swing event, and there was lower internal rotation in the backswing and greater external rotation in the downswing of the right hip. There was also slower left hip extension JAV in the downswing. Normal knee kinematics were observed during the golf swing following TKA, with the exception of reduced external rotation in the left knee during the back swing and the right during the down swing. The differences demonstrated in the hip motion indicate that they may make compensatory movements to adjust to the reduced external rotation demonstrated in the knee

Introduction. Sheffield Children's Hospital specialises in limb lengthening for children. Soft tissue contracture and loss of range of motion at the knee and ankle are common complications. This review aims to look at therapeutic techniques used by the therapy team to manage these issues. Materials & Methods. A retrospective case review of therapy notes was performed of femoral and tibial lengthening's over the last 3 years. Included were children having long bone lengthening with an iIntramedullary nail, circular frame or mono-lateral rail. Patients excluded were any external fixators crossing the knee/ankle joints. Results. 20 tibial and 25 femoral lengthening's met the inclusion criteria. Pathologies included, complex fractures, limb deficiency, post septic necrosis and other congenital conditions leading to growth disturbance. All patients had issues with loss of motion at some point during the lengthening process. The knee and foot/ankle were equally affected. Numerous risk factors were identified across the cohort. Treatment provided included splinting, serial casting, bolt on shoes, exercise therapy, electrical muscle stimulation and passive stretching. Conclusions. Loss of motion in lower limb joints was common. Patients at higher risk were those with abnormal anatomy, larger target lengthening's, poor compliance or lack of access to local services. Therapy played a significant role in managing joint motion during treatment. However, limitations were noted. No one treatment option gave preferential outcomes, selection of treatment needed to be patient specific. Future research should look at guidelines to aid timely input and avoid secondary complications

Medial knee OA effects approximately 4.1 million people in England. Non-surgical strategies to lower knee joint loading is commonly researched in the knee OA literature as a method to alleviate pain and discomfort. Medial knee OA is much more prevalent than lateral knee OA due to the weight bearing line passing medial to the knee causing an external knee adduction moment (KAM). Numerous potential gait retraining strategies have been proposed to reduce either the first and/or the second peak KAM, including: toe-in gait, toe-out gait, lateral trunk lean and medial thrust gait. Gait retraining has been researched with little regard to the biomechanical consequences at the hip and ankle joints. This systematic review aimed to establish whether gait retraining can reduce medial knee loading as assessed by first and second peak KAMs, establish what are the biomechanical effects a reduced KAM has on other lower limb joint biomechanics and outline patient/participant reported outcomes on how easy the gait retraining style was to implement. The protocol for this systematic review was registered with PROSPERO on the 23rd January 2018 (registration ID: CRD42018085738). 13 databases were searched by one author (J.B.B). Additionally, PROSPERO was searched for ongoing or recently completed systematic reviews. Risk of bias was assessed using the Downs and Black quality index. Search: Group one consisted of keywords “walk” OR “gait”. Keywords “knee” OR “adduction moment” built up the second group. Group three consisted “osteoarthriti” OR “arthriti” OR “osteo arthriti”, OR “OA”. Group four included “hip” OR “ankle”. the searched results of each group were combined with conjunction “AND” in all fields. Out of the eight different gait retraining strategies identified, trunk lean reduced first peak KAM the most, which was evaluated in 3 studies, reducing first peak KAM by 20%-65%. There was a lack of collective pelvic, hip and/or ankle joint biomechanical variables reported across all 11 studies. Of eight gait retraining styles identified, the strategy that reduced first peak KAM the most was an increased lateral trunk lean, which was evaluated in 3 different studies. This is the first systematic review that has highlighted that there is limited evidence of the biomechanical consequences of a reduced knee joint load has on the pelvic, hip and/or ankle joints when undertaking gait retraining protocols. Future studies assessing gait retraining strategies should provide biomechanical outputs for other lower limb joints other than the knee joint, as well as providing participant perceptions on the level of difficulty the gait style is to perform

Power production in the terminal stance phase is essential for propelling the body forward during walking and is generated primarily by ankle plantarflexion. Osteoarthritis (OA) of the ankle restricts joint range of motion and is expected to reduce power production at that ankle. This loss of power may be compensated for by unaffected joints on both the ipsilateral and contralateral limbs resulting in overloading of the asymptomatic joints. Total ankle arthroplasty (TAA) has been shown to reduce pain and has the potential to restore range of motion and therefore increase ankle joint power, which could reduce overloading of the unaffected joints and increase walking speed. The purpose of this study was to test the hypothesis that ankle OA causes a loss of power in the affected ankle, compensatory power changes in unaffected lower limb joints, and that TAA will increase ankle power in the repaired ankle and reduce compensatory changes in other joints. One hundred and eighty-three patients (86 men, 97 women with average ages 64.1 and 62.4 years respectively) requiring surgical intervention for ankle OA were prospectively enrolled. Implant selection of either a fixed (INBONE or Salto Talaris) or mobile (STAR) bearing implant was based on surgeon preference. Three-dimensional kinematics and kinetics were collected prior to surgery and one year post-operatively during self-selected speed level walking using an eight-camera motion capture system and a series of force platforms. Subject walking speed and lower extremity joint power during the last third of stance at the ankle, knee, and hip were calculated bilaterally and compared before and after surgical intervention across the entire group and by implant type (fixed vs. mobile), and gender using a series of ANOVAs (JMP SAS, Cary, NC), with statistical significance defined as p < 0 .05. There were no gender differences in age, walking speed, or joint power. All patients increased walking as a result of surgery (0.87 m/s±0.26 prior to surgery and 1.13 m/s±0.24 after surgery, p < 0 .001) and increased total limb power. Normalized to total power (which accounts for changes in speed and distribution of power production across joints), prior to surgery the affected ankle contributed 19%±10% of total power while the unaffected ankle contributed 42%±12% (P < 0 .001). After surgery, the affected ankle increased to 25%±9% of total power and the unaffected ankle decreased to 38%±9% of total (P < 0.001). Other joints showed no significant power changes following surgery. Fixed bearing implants provide greater surgical ankle power improvement (61% versus 29% increase, p < 0 .002). Much of that change was due to the fact that those that received fixed-bearing implants had significantly lower walking speed and power before surgery. Ankle OA reduced ankle power production, which was partially compensated for by the unaffected ankle. TAA increases walking speed and power at the affected ankle while lowering power production on the unaffected side. The modifications in power production could lead to increased physical activity and reduced overloading of asymptomatic joints

Abstract. OBJECTIVES. Application of deep learning approaches to marker trajectories and ground reaction forces (mocap data), is often hampered by small datasets. Enlarging dataset size is possible using some simple numerical approaches, although these may not be suited to preserving the physiological relevance of mocap data. We propose augmenting mocap data using a deep learning architecture called “generative adversarial networks” (GANs). We demonstrate appropriate use of GANs can capture variations of walking patterns due to subject- and task-specific conditions (mass, leg length, age, gender and walking speed), which significantly affect walking kinematics and kinetics, resulting in augmented datasets amenable to deep learning analysis approaches. METHODS. A publicly available (. https://www.nature.com/articles/s41597-019-0124-4. ) gait dataset (733 trials, 21 women and 25 men, 37.2 ± 13.0 years, 1.74 ± 0.09 m, 72.0 ± 11.4 kg, walking speeds ranging from 0.18 m/s to 2.04 m/s) was used as the experimental dataset. The GAN comprised three neural networks: an encoder, a decoder, and a discriminator. The encoder compressed experimental data into a fixed-length vector, while the decoder transformed the encoder's output vector and a condition vector (containing information about the subject and trial) into mocap data. The discriminator distinguished between the encoded experimental data from randomly sampled vectors of the same size. By training these networks jointly using the experimental dataset, the generator (decoder) could generate synthetic data respecting specified conditions from randomly sampled vectors. Synthetic mocap data and lower limb joint angles were generated and compared to the experimental data, by identifying the statistically significant differences across the gait cycle for a randomly selected subset of the experimental data from 5 female subjects (73 trials, aged 26–40, weighing 57–74 kg, with leg lengths between 868–931 mm, and walking speeds ranging from 0.81–1.68 m/s). By conducting these comparisons for this subset, we aimed to assess the synthetic data generated using multiple conditions. RESULTS. We visually inspected the synthetic trials to ensure that they appeared realistic. The statistical comparison revealed that, on average, only 2.5% of the gait cycle showed significantly differences in the joint angles of the two data groups. Additionally, the synthetic ground reaction forces deviated from the experimental data distribution for an average of 2.9% of the gait cycle. CONCLUSIONS. We introduced a novel approach for generating synthetic mocap data of human walking based on the conditions that influence walking patterns. The synthetic data closely followed the trends observed in the experimental data, also in the literature, suggesting that our approach can augment mocap datasets considering multiple conditions, an approach unfeasible in previous work. Creation of large, augmented datasets allows the application of other deep learning approaches, with the potential to generate realistic mocap data from limited and non-lab-based data. Our method could also enhance data sharing since synthetic data does not raise ethical concerns. You can generate and download virtual gait data using our GAN approach from . https://thisgaitdoesnotexist.streamlit.app/. . Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction. Bundled Payments (BP) were a revolutionary new experiment for CMS that tested whether risk sharing for an episode of care would improve quality and reduce costs. The initial success of BP accelerated their growth as evidence by the launch of both mandatory and commercial bundles. Success in BP is dependent on the target price and the opportunity to reduce avoidable costs during the episode of care. There is concern that the aggressive target pricing methodology in the new model (BPCI-Advanced) penalizes high performing groups that already achieved low episode costs through prior experience and investment in BP. We hypothesize that this methodology incorporates unsustainable downward trends on target prices to a point beyond reasonableness for efficient groups to reduce additional costs and will lead to a large percentage of groups opting out of BPCI-A in favor of a return to fee for service (FFS) reimbursement. Methods. Using CMS data, we compared the target price factors for hospitals that participated in both BPCI classic (2013 –2018) and BPCI Advanced (beginning 10/2018), referred to as “legacy hospitals”, with hospitals that only participated in BPCI Advanced (beginning 10/2018). With the rebasing of BPCI-A target prices in Jan 2020 and the opportunity for participants to drop out of individual episode types or the program all together, we compared the retention of episode types that hospitals initially enrolled at the onset of BPCI-A with the current enrollment in 2020. Locally, we analyzed the BPCI-A target price factors across hospitals for a large orthopaedic practice that participated in BPCI Classic and the impact it had on the financial incentive/disincentive to remain in the lower extremity joint replacement episode type in 2020. Results. At its peak in July 2015, 423 acute care hospitals participated in one or more episode type in BPCI Classic. At its peak in March 2019, 715 acute care hospitals participated in one or more episode types in BPCI-Advanced. 130 (18%) of the hospitals in BPCI Advanced were also legacy participants in BPCI Classic, enrolling in 414 of the same episode types during both programs. In 2020, 251 (61%) of the episode types that hospitals were in enrolled in for both BPCI Classic and BPCI Advanced were dropped, suggesting prior experience in BPCI influences a participant's opportunity for success in BPCI Advanced. Furthermore, an analysis of the target price factors for episode types enrolled in by legacy hospitals during both programs suggests that prior participation in BPCI Classic is correlated with more aggressive target prices. A comparison of target price factors of similar hospitals reveals that legacy BPCI Classic hospitals that participated in lower extremity joint replacement (LEJR) BPCI Advanced received a larger negative adjustment on the target price (0.11 lower on average as a product of the Peer Adjusted Trend factor and ACH Efficiency factor) than non-legacy hospitals that participated in BPCI Advanced. Furthermore, analysis of the hospital targets for a large, high-performing legacy Physician Group Practice in BPCI Classic for LEJR revealed even greater negative adjustment on the target price than non-legacy participants. Comparing participants of similar peer groups on the Peer Adjusted Trend and ACH Efficiency factors suggests that CMS expects costs to decline more for legacy hospitals that have achieved efficiency than hospitals with no prior BP experience and higher baseline spend. Conclusions. BPCI Advanced provides little to no opportunity for a reduction in cost for already efficient TJA providers, as evident by the 55% dropout rate for BPCI-A participants in LEJR between model years 1 and 3. Efficient TJA providers in BPCI Advanced are challenged by the program's utilization of a peer adjusted trend factor and efficiency factor that presumes their costs will decline at the same aggressive rate or more than nonefficient TJA providers. It remains to be seen if reverting to Medicare fee for service will support the same level of care coordination, cost and quality achieved in historical TJA bundled payment programs

Aims

This study investigated the effects of transcatheter arterial embolization (TAE) on pain, function, and quality of life in people with early-stage symptomatic knee osteoarthritis (OA) compared to a sham procedure.

Thromboembolic disease (TED) remains as a major concern for orthopaedic surgeons and is a well-known complication of lower extremity joint replacement procedures. While there is voluminous literature on the topic, it is difficult for the average orthopaedic surgeon to keep up with all the advancements in this area as well as the newer pharmacological options for prophylaxis. To address this, the American Academy of Orthopaedic Surgeons (AAOS) has developed a clinical practice guideline (CPG) in this area to provide treatment recommendations based on the best available evidence. Historically, guidelines for TED prophylaxis have been based largely on randomised controlled trials whose outcome measure was venographically documented deep vein thrombosis (DVT). However, many venographically documented DVTs, particularly those distal to the popliteal vein, are of no clinical consequence. Therefore, in the AAOS CPG the systematic review of the literature was focused on those outcomes that have the most clinical relevance: all-cause mortality, symptomatic or fatal pulmonary embolism (PE), proximal DVT, major bleeding and symptomatic DVT rates. Using these as the clinically important endpoints, it is evident that the extant literature is insufficient to provide definitive guidance in this area and to make specific recommendations about optimal pharmacological prophylaxis. Nonetheless, one strong recommendation has emerged from this systematic review: the guideline recommended against routine post-operative duplex ultrasonography screening of patients who undergo elective hip or knee arthroplasty. Only one risk factor – previous history of TED – had evidence demonstrating a higher risk beyond the risk from elective hip or knee arthroplasty itself (weak recommendation). There was not sufficient evidence that other potential risk factors increase the risk of TED, likely because of the relatively high background risk of elective hip or knee arthroplasty. In addition, there is very little evidence defining populations at increased risk for bleeding and bleeding-associated complications associated with pharmacological prophylaxis. However, the panel did come to a consensus that patients with known bleeding disorders or active liver disease are at an increased risk for post-operative bleeding. In these circumstances, it is recommended that mechanical compressive devices be the primary modality of prophylaxis as pharmacologic prophylaxis may increase the risk of bleeding. There was a moderate strength recommendation for the superiority of neuraxial anesthesia to limit blood loss even though there is no demonstrable effect on the incidence of TED. Finally, there was a moderate grade recommendation that pharmacologic agents (including aspirin) and/or mechanical compression devices be utilised for the prevention of VTE in patients that are undergoing elective hip or knee arthroplasty who are not at elevated risk beyond that of the surgery itself for VTE or bleeding. Clearly there is great need for better evidence with appropriately powered studies that examine the most clinically relevant outcomes in TED prophylaxis

The flat foot is a frequent deformity in children and results in various levels of functional alterations. A diagnosis based on foot morphology is not sufficient to define the therapeutic approach. In fact, the degree of severity of the deformity and the effects of treatments require careful functional assessment. In case of functional flatfoot, subtalar arthroereisis is the surgical treatment of choice. The aim of this study is to evaluate and compare the functional outcomes of two different bioabsorbable implants designed for subtalar arthroereisis in childhood severe flat foot by means of thorough gait analysis. Ten children (11.3 ± 1.6 yrs, 19.7 ± 2.8 BMI) were operated for flat foot correction [1,2] in both feet, one with the calcaneo-stop method, i.e. a screw implanted into the calcaneus, the other with an endoprosthesis implanted into the sinus-tarsi. Gait analysis was performed pre- and 24 month post-operatively using a 8-camera motion system (Vicon, UK) and a surface EMG system (Cometa, Italy) to detect muscular activation of the main lower limb muscles. A combination of established protocols, for lower limb [3] and multi-segment foot [4] kinematic analysis, was used to calculate joint rotations and moments during three level walking trials for each patient. At the foot, the tibio-talar, Chopart, Lisfranc, 1. st. metatarso-phalangeal joints were tracked in three-dimensions, together with the medial longitudinal arch. Significant differences in standard X-ray measurements were observed between pre- and post-op, but not between the two treatment groups. Analysis of the kinematic variables revealed functional improvements after surgery. In particular, a reduction of eversion between the shank and calcaneus (about 15° on average) and a reduction of inversion between metatarsus and calcaneus (about 18° on average) were detected between pre- and post-operatively after both treatments. Activation of the main plantar/dorsiflexor muscles was similar at both pre- and post-op assessments with both implants. The combined lower limb and multi-segment foot kinematic analyses were found adequate to provide accurate functional assessment of the feet and of the lower limbs. Both surgical treatments restored nearly normal kinematics of the foot and of the lower limb joints, associated also to a physiologic muscular activation

Aims

Body exhaust suits or surgical helmet systems (colloquially, ‘space suits’) are frequently used in many forms of arthroplasty, with the aim of providing personal protection to surgeons and, perhaps, reducing periprosthetic joint infections, although this has not consistently been borne out in systematic reviews and registry studies. To date, no large-scale study has investigated whether this is applicable to shoulder arthroplasty. We used the New Zealand Joint Registry to assess whether the use of surgical helmet systems was associated with lower all-cause revision or revision for deep infection in primary shoulder arthroplasties.

Objectives. The Oxford Hip and Knee Scores (OHS, OKS) have been demonstrated to vary according to age and gender, making it difficult to compare results in cohorts with different demographics. The aim of this paper was to calculate reference values for different patient groups and highlight the concept of normative reference data to contextualise an individual’s outcome. Methods. We accessed prospectively collected OHS and OKS data for patients undergoing lower limb joint arthroplasty at a single orthopaedic teaching hospital during a five-year period. T-scores were calculated based on the OHS and OKS distributions. . Results. Data were obtained from 3203 total hip arthroplasty (THA) patients and 2742 total knee arthroplasty (TKA) patients. The mean age of the patient was 68.0 years (. sd. 11.3, 58.4% women) in the THA group and in 70.2 (. sd. 9.4; 57.5% women) in the TKA group. T-scores were calculated for age and gender subgroups by operation. Different T-score thresholds are seen at different time points pre and post surgery. Values are further stratified by operation (THA/TKA) age and gender. Conclusions. Normative data interpretation requires a fundamental shift in the thinking as to the use of the Oxford Scores. Instead of reporting actual score points, the patient is rated by their relative position within the group of all patients undergoing the same procedure. It is proposed that this form of transformation is beneficial (a) for more appropriately comparing different patient cohorts and (b) informing an individual patient how they are progressing compared with others of their age and gender. Cite this article: Bone Joint Res 2015;4:137–144

Many studies describe the use of the Ilizarov ring fixator for lower limb lengthening and for the management of the 3-dimensional lower limb deformities in achondroplasia, and most confirm the efficacy of this technique. However, long term follow up of these achondroplastic patients is lacking. Most studies have focused on magnitude of lengthening, treatment time required and complications, but no study has analyzed the long term postoperative condition of these patients using an objective, functional method such as gait analysis. Nineteen (19) achondroplastic patients, 12 males and 7 females, aged 19–38 years (mean 27.3 y) who have undergone tibia and femur lengthening, using the Ilizarov method, at the age of 9–19 years (mean 12.6 y), were evaluated 5–19 years (mean 10.1 y) after their last surgery, using 3-dimensional gait analysis. Nineteen (19) normal, height-matched subjects were used as controls. The VICON Nexus 8 Camera System was used to accurately measure spatiotemporal characteristics (walking velocity, stride length, step length, cadence) and kinematics (range of motion) of lower limb joints. Statistical comparison of deformity parameters between achondroplastic patients and normal population was done using the student t- test. A level of p<0.05 was considered statistically significant. Walking velocity, step length and stride length were statistically significantly decreased (p<0.05) in achondroplastic patients compared to normal population values. The achondroplastic group presented with excessive anterior pelvic tilt (mean 21.9. o. ± 7.3), excessive pelvic rotation (range 28.7. o. ±7.8), decreased hip extension (mean 1.8. o. ±10.1) and decreased plantar flexion (mean 17.1. o. ±5.1) when compared to normal controls. There was no statistically significant difference in the knee kinematics between the operated achondroplastic patients and normal controls. The achondroplastic patients present decreased values in their spatiotemporal characteristics compared to the normal subjects because, despite the height gain, their lower limbs remain shorter. Their excessive anterior pelvic tilt is attributed to their lordosis. Their excessive forward pelvic rotation is an attempt to increase stride and step length. The decreased hip extension is due to their anterior pelvic tilt. The correction of these patients genu varum restored knee kinematics to normal. In order to address the hip and pelvis deformities a proximal femoral osteotomy should be considered. The Ilizarov method provides functional height gain and substantially corrects the three-dimensional lower limb deformities of achondroplastic patients especially around the knee joint but more planning needs to be implemented when the system is applied to correct the disease specific deformities of the hip and pelvis. Gait analysis is an objective tool that can be used to address these design issues

The purpose of this study was to compare lower limb joint mechanics in patients who underwent a total knee arthroplasty (TKA) with either a posterior stabilised (PS) or with a medial pivot (MP) implant to healthy controls (CTRL) during stair ascent and descent tasks. Six PS (age: 67.2±1.5 years, BMI: 31.0±3.2 kg/m2) and 11 MP (age: 62.3±6.0 years, BMI: 29.7±3.9 kg/m2) TKA patients matched to 10 healthy CTRL participants (age: 65.6±5.5 years, BMI: 27.2±5.0 kg/m2) were included in the study. TKA patients went through 3D motion analysis after unilateral TKA with either a MP (11.7±3.4 months post-surgery) or PS (10.1±3.4 months post-surgery) implant performed using either a subvastus or medial parapatellar approach. Kinematic and kinetic data was collected using a 10-camera Vicon and two portable Kistler force plates placed on the first and second stair of a three-step staircase. Nonparametric Kruskal Wallace ANOVA tests were used and Wilcoxon rank sum tests were used to identify where significant (p < 0.05) differences occurred. When comparing both stair tasks, stair ascent showed a larger number of significant differences in kinematic and kinetic variables than stair descent. Peak knee extension was significantly (p < 0.05) greater in both TKA groups compared to the CTRL during stair descent, whereas only the PS group had significantly (p = 0.02) greater knee extension angle than the CTRL during stair ascent. The PS group had a significantly (p = 0.01) lower peak knee extension moment than the CTRL group during both tasks and compared to the MP group during stairs ascent. During stair ascent, the MP group had significantly (p = 0.02) larger peak hip extension moments than both PS and CTRL group. Greater knee extension angles in TKA groups at foot strike during stair tasks support the notion that TKA groups exhibit stiff knee during stance to reduce or avoid shear displacement on the operated knee. This could also result from many years of muscle adaptation waiting to receive a knee replacement. Reduced peak knee extension moment in the PS group during stairs tasks showed a quadriceps deficiency that could increase the risk of revision or of other joint replacement on the contralateral side or ipsilateral hip. MP group reproduced similar joint loading patterns as the CTRLs which may reduce their risk of revision. In conclusion, TKA patients continue to exhibit discrepancies from healthy knee mechanics during stair ascent and descent. Further research examining muscle function especially during stair ascent is warranted