CT measures of femoral and tibial version and rotational position of femoral and tibial components of knee replacements: limitations in reliability and suitability for routine clinical practice.

OBJECTIVES: Rotational malalignment of knee replacements as measured on CT is understood to be associated with poor outcomes. The aim of this study is to measure the inter-rater and intra-rater reliability of measures of femoral and tibial version in the native arthritic knee and postoperative TKR component position using CT. METHODS: Eighty patients underwent CT of the knee before and after total knee replacement. Preoperative femoral and tibial version and component rotation were independently measured by two musculoskeletal radiologists. RESULTS: Mean differences between and within raters were small (< 1.6°). Maximum 95% limits of agreement for inter-rater and intra-rater comparisons were 8.1° and 7.6° for preoperative femoral version, 9.0° and 7.9° for postoperative femoral rotation, 26.0° and 20.5° for preoperative tibial version, and 24.9° and 23.6° for postoperative tibial rotation respectively. Postoperative ICCs varied from 0.68 to 0.81 (lower 95% CI:0.55-0.72) for both intra- and inter-rater comparisons. Preoperative ICCs were lower: 0.55-0.75 (lower 95% CI:0.40-0.65). CONCLUSION: The lower 95% confidence level for ICC of version and rotational measurements using the Berger protocol of TKRs on CT are all less than 0.73 and that the normal range of differences between observers is up to 9° for the femoral component and 26° for the tibial component. This suggests that CT measurements derived from the Berger protocol may not be consistent enough for clinical practice. KEY POINTS: • CT is commonly used to measure the rotational profile of knee replacements in symptomatic patients using the Berger protocol. • The limits of agreement for both femoral and tibial component rotation are wide even for experienced observers. • CT measurements of the rotation of knee arthroplasty are not reliable enough for routine clinical use.

The use of the independent sector in providing NHS services during the Covid-19 outbreak; two hospitals experience.

This paper reviews the activity undertaken between a teaching hospital and its adjacent Independent Hospital and its implementation under the Independent Sector Provider Contract between NHSE and the Independent Sector. RESULTS: From the instigation of the NHSE contract with the Independent Sector up until 28th June 2020 The Norfolk and Norwich University NHS Trust (NNUH) delivered 9016 episodes of care including 576 surgical episodes at its nearby Independent Hospital. During the time that a seven day household isolation period was required, no patients from the 31 tested postoperatively were recorded as testing positive for Covid-19. In the month after moving to a mandatory 14 day period of household isolation, 29 patients had their surgery postponed as they were unable to comply with the required period of isolation. CONCLUSION: Working cooperatively with the independent sector can deliver significant additional capacity for the NHS. Fourteen days household isolation may impact on a patient's decision to have surgery, despite, in some cases, that surgery being time-sensitive. The recommendation from NICE reducing the length of isolation largely reversed this impact.

Primary care referral for knee MRI in the United Kingdom: Association with demography and subsequent surgical intervention.

BACKGROUND: Since 2008 primary care physicians (GPs) in our region have been allowed open access to knee MRI scans. There are questions about whether this changes referral practice and if it is an effective use of resources. PURPOSE: To describe the change in demographics of patients referred for knee MRI following implementation of a new referral pathway. STUDY TYPE: Retrospective observational study. POPULATION: All primary care referrals between 2008 and 2015 for knee MRI from a population of 900,000. FIELD STRENGTH/SEQUENCE: Not applicable. ASSESSMENT: Demographic profile and number of knee MRI referrals and subsequent arthroscopies. STATISTICAL TESTS: Comparisons between urban and rural populations used the t-test. Test for normality used Shapiro-Wilks. Comparison between abnormal MRI proportions used a chi-squared test. RESULTS: There were 23,928 knee MRI referrals (10,695 from GPs) between 2000 and 2015. MRI knee referrals rose from 210 in 2008 to 2379 in 2015. The average age of the patient decreased from 46.8 (SD = 14.9) in 2008 to 41.3 (SD = 14.7) in 2015. Conversion to arthroscopy declined from 15.4% to 10.2%, but there was no significant change in abnormal scan proportion. Conversion rates showed no significant difference between rural (9.6%) and urban populations (10.5%). Referral rates were significantly higher in low socioeconomic status areas (47.3% vs. 34.6%). The median referral rate per 1000 patients was 13.8 (interquartile range = 8.4). Referral rates varied widely between practices. DATA CONCLUSION: Despite a large rise in knee MRI referrals from primary care, there has been no substantial change in the age profile, suggesting that there has been no increase in inappropriate referral of elderly patients in whom MRI is unlikely to influence management. A modest decrease in the conversion rate to arthroscopy may be reasonably offset against a decrease in secondary care referrals. Socioeconomic status of the target population must be considered when planning primary care knee MRI services. LEVEL OF EVIDENCE: 4 Technical Efficacy Stage: 6 J. Magn. Reson. Imaging 2019.

Development of an occupational advice intervention for patients undergoing lower limb arthroplasty (the OPAL study).

BACKGROUND: There are an increasing number of patients of working age undergoing hip and knee replacements. Currently there is variation in the advice and support given about sickness absence, recovery to usual activities and return to work after these procedures. Earlier, sustainable, return to work improves the health of patients and benefits their employers and society. An intervention that encourages and supports early recovery to usual activities, including work, has the potential to reduce the health and socioeconomic burden of hip and knee replacements. METHODS/DESIGN: A two-phase research programme delivered over 27 months will be used to develop and subsequently test the feasibility of an occupational advice intervention to facilitate return to work and usual activities in patients undergoing lower limb arthroplasty. The 2 phases will incorporate a six-stage intervention mapping process: Phase 1: Intervention mapping stages 1-3: 1 Needs assessment (including rapid evidence synthesis, prospective cohort analysis and structured stakeholder interviews) 2 Identification of intended outcomes and performance objectives 3 Selection of theory-based methods and practical strategies Phase 2: Intervention mapping stages 4-6: 4 Development of components and materials for the occupational advice intervention using a modified Delphi process 5 Adoption and implementation of the intervention 6 Evaluation and feasibility testing The study will be undertaken in four National Health Service (NHS) hospitals in the United Kingdom and two Higher Education Institutions. DISCUSSION: OPAL (Occupational advice for Patients undergoing Arthroplasty of the Lower limb) aims to develop an occupational advice intervention to support early recovery to usual activities including work, which is tailored to the requirements of patients undergoing hip and knee replacements. The developed intervention will then be assessed with a specific focus on evaluating its feasibility as a potential trial intervention to improve speed of recovery to usual activities including work. TRIAL REGISTRATION: The study was registered retrospectively with the International Standard Randomised Controlled Trials Number (ISRCTN): 27426982 (Date 20/12/2016) and the International prospective register of systematic reviews (PROSPERO): CRD42016045235 (Date 04/08/2016).

The trochlear isometric point is different in patients with recurrent patellar instability compared to controls: a radiographical study.

PURPOSE: The purpose of the study was to investigate the theoretical isometric point based of the curve of the femoral groove and relating it to the origin of the MPFL femoral tunnel on lateral radiograph by comparing a patellar instability cohort with a control cohort. METHODS: From a Patellar Instability database the radiographs of 40 consecutive patients were analysed to define Schöttle's point, and the arc of the circle of the trochlear groove. A comparison population of 20 radiographs from comparable patients with tibiofemoral joint disorders was used as a control. The distance from Schöttle's point to the most anterior part of the groove (extension) was also compared to the distance to the distal end of the roof of the notch (flexion). RESULTS: The trochlea was circular in the controls but not the Patellofemoral Instability cohort where trochlear dysplasia is usually present. The difference between the extension and flexion length was a mean of - 2.0 ± 0.5 mm in the controls and + 6.0 ± 0.5 mm in the patellofemoral cohort. In neither cohort did the centre of the circle correspond to Schöttle's point. The extension distance correlated with the boss height. CONCLUSIONS: The dysplastic trochlea is not circular and the centre of the best matched circle was different to the control trochleae which were circular. The circle centres did not correlate with Schöttle's point for either cohort, and was more proximal in the Patellofemoral Instability cohort. CLINICAL RELEVANCE: For the MPFL to have equal tension throughout flexion within the groove, the length should not change. In normal knees the MPFL does not behave isometrically. The change in length, as measured from Schöttle's point to the trochlea, was greater for patellofemoral instability patients explaining why an isolated MPFL reconstruction in the presence of severe trochlear dysplasia risks poor outcomes. Level of evidence III.

The inferomedial patellar protuberance and medial patellar ossicle in patellar instability.

PURPOSE: The purpose of the study was to define the frequency of an inferomedial patellar protuberance in patients presenting to a specialist Patella Clinic and to characterise the clinical and radiological features as well the association between the inferomedial patellar protuberance and the medial patellar ossicle. METHODS: A cohort of 163 patients (166 knees) was reviewed from a prospectively collected clinical database and radiological imaging. This included a record of patellar tracking. RESULTS: An inferomedial patellar protuberance was found in 62 (37 %) knees. A medial patellar ossicle was noted in 56 (34 %) knees. In all, an inferomedial patellar protuberance or medial patellar ossicle or both was found in 90 (54 %) knees. The association between inferomedial patellar protuberance and significant trochlear dysplasia was highly significant (p = 0.01), but not for the medial patellar ossicle (n.s.). The presence of an inferomedial patellar protuberance was significantly less likely in patients with hypermobility syndrome (p = 0.001); however, there was no significant association between hypermobility syndrome and medial patellar ossicle (n.s.), or the presence of either or both an inferomedial patellar protuberance and medial patellar ossicle (n.s.). All patients with a clunk at 20°-30° flexion had significant trochlear dysplasia and an inferomedial patellar protuberance. CONCLUSION: Radiological changes consistent with an inferomedial patellar protuberance were found in about one-third of patients presenting to a specialist Patella Clinic. Patellar maltracking and a clunk at 20°-30° flexion are associated with significant trochlear dysplasia plus an inferomedial patellar protuberance. If undertaking an operative correction, both deformities should be considered in order to avoid joint incongruity. LEVEL OF EVIDENCE: III.

Medial compartment knee osteoarthritis: age-stratified cost-effectiveness of total knee arthroplasty, unicompartmental knee arthroplasty, and high tibial osteotomy.

PURPOSE: To compare the age-based cost-effectiveness of total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), and high tibial osteotomy (HTO) for the treatment of medial compartment knee osteoarthritis (MCOA). METHODS: A Markov model was used to simulate theoretical cohorts of patients 40, 50, 60, and 70 years of age undergoing primary TKA, UKA, or HTO. Costs and outcomes associated with initial and subsequent interventions were estimated by following these virtual cohorts over a 10-year period. Revision and mortality rates, costs, and functional outcome data were estimated from a systematic review of the literature. Probabilistic analysis was conducted to accommodate these parameters' inherent uncertainty, and both discrete and probabilistic sensitivity analyses were utilized to assess the robustness of the model's outputs to changes in key variables. RESULTS: HTO was most likely to be cost-effective in cohorts under 60, and UKA most likely in those 60 and over. Probabilistic results did not indicate one intervention to be significantly more cost-effective than another. The model was exquisitely sensitive to changes in utility (functional outcome), somewhat sensitive to changes in cost, and least sensitive to changes in 10-year revision risk. CONCLUSIONS: HTO may be the most cost-effective option when treating MCOA in younger patients, while UKA may be preferred in older patients. Functional utility is the primary driver of the cost-effectiveness of these interventions. For the clinician, this study supports HTO as a competitive treatment option in young patient populations. It also validates each one of the three interventions considered as potentially optimal, depending heavily on patient preferences and functional utility derived over time.

Surgical fixation methods for tibial plateau fractures.

BACKGROUND: Fractures of the tibial plateau, which are intra-articular injuries of the knee joint, are often difficult to treat and have a high complication rate, including early-onset osteoarthritis. Surgical fixation is usually used for more complex tibial plateau fractures. Additionally, bone void fillers are often used to address bone defects caused by the injury. Currently there is no consensus on either the best method of fixation or bone void filler. OBJECTIVES: To assess the effects (benefits and harms) of different surgical interventions, and the use of bone void fillers, for treating tibial plateau fractures. SEARCH METHODS: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (12 September 2014), the Cochrane Central Register of Controlled Trials (2014 Issue 8), MEDLINE (1946 to September Week 1 2014), EMBASE (1974 to 2014 Week 36), trial registries (4 July 2014), conference proceedings and grey literature (4 July 2014). SELECTION CRITERIA: We included randomised and quasi-randomised controlled clinical trials comparing surgical interventions for treating tibial plateau fractures and the different types of filler for filling bone defects. DATA COLLECTION AND ANALYSIS: Two review authors independently screened search results, selected studies, extracted data and assessed risk of bias. We calculated risk ratios (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, with 95% confidence intervals (CIs). Only very limited pooling, using the fixed-effect model, was possible. Our primary outcomes were quality of life measures, patient-reported outcome measures of lower limb function and serious adverse events. MAIN RESULTS: We included six trials in the review, with a total of 429 adult participants, the majority of whom were male (63%). Three trials evaluated different types of fixation and three analysed different types of bone graft substitutes. All six trials were small and at substantial risk of bias. We judged the quality of most of the available evidence to be very low, meaning that we are very uncertain about these results.One trial compared the use of a circular fixator combined with insertion of percutaneous screws (hybrid fixation) versus standard open reduction and internal fixation (ORIF) in people with open or closed Schatzker types V or VI tibial plateau fractures. Results (66 participants) for quality of life scores using the 36-item Short Form Health Survey (SF-36)), Hospital for Special Surgery (HSS) scores and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function scores tended to favour hybrid fixation, but a benefit of ORIF could not be ruled out. Participants in the hybrid fixation group had a lower risk for an unplanned reoperation (351 per 1000 people compared with 450 in the ORIF group; 95% CI 197 fewer to 144 more) and were more likely to have returned to their pre-injury activity level (303 per 1000 people, compared with 121 in the ORIF group; 95% CI 15 fewer to 748 more). Results of the two groups were comparable for the WOMAC pain subscale and stiffness scores, but mean knee range of motion values were higher in the hybrid group.Another trial compared the use of a minimally invasive plate (LISS system) versus double-plating ORIF in 84 people who had open or closed bicondylar tibial plateau fractures. Nearly twice as many participants (22 versus 12) in the ORIF group had a bone graft. Quality of life, pain, knee range of motion and return to pre-injury activity were not reported. The trial provided no evidence of differences in HSS knee scores, complications or reoperation entailing implant removal or revision fixation. A quasi-randomised trial comparing arthroscopically-assisted percutaneous reduction and internal fixation versus standard ORIF reported results at 14 months in 58 people with closed Schatzker types II or III tibial plateau fracture. Quality of life, pain and return to pre-injury activity were not reported. There was very low quality evidence of higher HSS knee scores and higher knee range of motion values in the arthroscopically assisted group. No reoperations were reported.Three trials compared different types of bone substitute versus autologous bone graft (autograft) for managing bone defects. Quality of life, pain and return to pre-injury activity were not reported. Only one trial (25 participants) reported on lower limb function, finding good or excellent results in both groups for walking, climbing stairs, squatting and jumping at 12 months. The incidences of individual complications were similar between groups in all three trials. One trial found no cases of inflammatory response in the 20 participants receiving bone substitute, and two found no complications associated with the donor site in the autograft group (58 participants). However, all 38 participants in the autologous iliac bone graft group of one trial reported prolonged pain from the harvest site. Two trials reported similar range of motion results in the two groups, whereas the third trial favoured the bone substitute group. AUTHORS' CONCLUSIONS: Currently, there is insufficient evidence to ascertain the best method of fixation or the best method of addressing bone defects during surgery. However, the evidence does not contradict approaches aiming to limit soft-tissue dissection and damage or to avoid autograft donor site complications through using bone substitutes. Further well-designed, larger randomised trials are warranted.

Impact factors of orthopaedic journals between 2000 and 2010: trends and comparisons with other surgical specialties.

PURPOSE: The impact factors (IF) of orthopaedic journals is an important component in determining the future of orthopaedic research funding. We aim to characterise the trend in journal IF over the last decade and draw comparisons with other surgical specialties. METHODS: We conducted an analysis of impact factors from Journal Citation Reports between 2000 and 2010. RESULTS: Between 2000 and 2010 the number of orthopaedic journals increased from 24 to 41, more than any other surgical specialty and the mean IF increased from 0.842 to 1.400. Journals printed in the English language had a significantly higher IF in the year 2010 (1.64 vs. 0.33, p = 0.01) than those printed in other languages. English language journals published in the US had significantly higher mean 2010 IF (1.932 vs. 1.243, p = 0.025) than those published in Europe, and this had changed compared with 2000 mean IF (0.978 Vs. 0.704, p = 0.360). Orthopaedics was ranked sixth out of 11 surgical subspecialties in 2000 but dropped to seventh out of 11 in 2010. CONCLUSIONS: The quality of orthopaedic journals has significantly increased over the last decade and this has been accompanied by a rise in mean IF. It is important that orthopaedics continues to improve the quality of research, which may help orthopaedic researchers secure funding in the future.

Comparison of the Journey II bicruciate stabilised (JII-BCS) and GENESIS II total knee arthroplasty for functional ability and motor impairment: the CAPAbility, blinded, randomised controlled trial.

OBJECTIVES: To determine if a newer design of total knee replacement (TKR) (Journey II BCS) produces superior patient-reported outcomes scores and biomechanical outcomes than the older, more established design (Genesis II). SETTING: Patients were recruited from an NHS University Hospital between July 2018 and October 2019 with surgery at two sites. Biomechanical and functional capacity measurements were at a University Movement and Exercise Laboratory. PARTICIPANTS: 80 participants undergoing single-stage TKR. INTERVENTIONS: Patients were randomised to receive either the Journey II BCS (JII-BCS) or Genesis II TKR. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome was the Oxford Knee Score (OKS), at 6 months. Secondary outcomes were: OKS Activity and Participation Questionnaire, EQ-5D-5L and UCLA Activity scores, Timed Up and Go Test, 6 min walk test, lower limb kinematics and lower limb muscle activity during walking and balance. RESULTS: This study found no difference in the OKS between groups. The OKS scores for the JII-BCS and Genesis II groups were mean (SD) 42.97 (5.21) and 43.13 (5.20) respectively, adjusted effect size 0.35 (-2.01,2.71) p=0.771In secondary outcome measures, the Genesis II group demonstrated a significantly greater walking range-of-movement (50.62 (7.33) vs 46.07 (7.71) degrees, adjusted effect size, 3.14 (0.61,5.68) p=0.02) and higher peak knee flexion angular velocity during walking (mean (SD) 307.69 (38.96) vs 330.38 (41.40) degrees/second, adjusted effect size was 21.75 (4.54,38.96), p=0.01) and better postural control (smaller resultant centre of path length) during quiet standing than the JII-BCS group (mean (SD) 158.14 (65.40) vs 235.48 (176.94) mm, adjusted effect size, 59.91 (-105.98, -13.85) p=0.01.). CONCLUSIONS: In this study population, the findings do not support the hypothesis that the Journey II BCS produces a better outcome than the Genesis II for the primary outcome of the OKS at 6 months after surgery. TRIAL REGISTRATION NUMBER: ISRCTN32315753.

YBX1-interacting small RNAs and RUNX2 can be blocked in primary bone cancer using CADD522.

Primary bone cancer (PBC) comprises several subtypes each underpinned by distinctive genetic drivers. This driver diversity produces novel morphological features and clinical behaviour that serendipitously makes PBC an excellent metastasis model. Here, we report that some transfer RNA-derived small RNAs termed tRNA fragments (tRFs) perform as a constitutive tumour suppressor mechanism by blunting a potential pro-metastatic protein-RNA interaction. This mechanism is reduced in PBC progression with a gradual loss of tRNAGlyTCC cleavage into 5' end tRF-GlyTCC when comparing low-grade, intermediate-grade and high-grade patient tumours. We detected recurrent activation of miR-140 leading to upregulated RUNX2 expression in high-grade patient tumours. Both tRF-GlyTCC and RUNX2 share a sequence motif in their 3' ends that matches the YBX1 recognition site known to stabilise pro-metastatic mRNAs. Investigating some aspects of this interaction network, gain- and loss-of-function experiments using small RNA mimics and antisense LNAs, respectively, showed that ectopic tRF-GlyTCC reduced RUNX2 expression and dispersed 3D micromass architecture in vitro. iCLIP sequencing revealed YBX1 physical binding to the 3' UTR of RUNX2. The interaction between YBX1, tRF-GlyTCC and RUNX2 led to the development of the RUNX2 inhibitor CADD522 as a PBC treatment. CADD522 assessment in vitro revealed significant effects on PBC cell behaviour. In xenograft mouse models, CADD522 as a single agent without surgery significantly reduced tumour volume, increased overall and metastasis-free survival and reduced cancer-induced bone disease. Our results provide insight into PBC molecular abnormalities that have led to the identification of new targets and a new therapeutic.

Genome-Scale Metabolic Modelling Approach to Understand the Metabolism of the Opportunistic Human Pathogen Staphylococcus epidermidis RP62A.

Staphylococcus epidermidis is a common commensal of collagen-rich regions of the body, such as the skin, but also represents a threat to patients with medical implants (joints and heart), and to preterm babies. Far less studied than Staphylococcus aureus, the mechanisms behind this increasingly recognised pathogenicity are yet to be fully understood. Improving our knowledge of the metabolic processes that allow S. epidermidis to colonise different body sites is key to defining its pathogenic potential. Thus, we have constructed a fully curated, genome-scale metabolic model for S. epidermidis RP62A, and investigated its metabolic properties with a focus on substrate auxotrophies and its utilisation for energy and biomass production. Our results show that, although glucose is available in the medium, only a small portion of it enters the glycolytic pathways, whils most is utilised for the production of biofilm, storage and the structural components of biomass. Amino acids, proline, valine, alanine, glutamate and arginine, are preferred sources of energy and biomass production. In contrast to previous studies, we have shown that this strain has no real substrate auxotrophies, although removal of proline from the media has the highest impact on the model and the experimental growth characteristics. Further study is needed to determine the significance of proline, an abundant amino acid in collagen, in S. epidermidis colonisation.

Preoperative and perioperative risk factors, and risk score development for prosthetic joint infection due to Staphylococcus aureus: a multinational matched case-control study.

OBJECTIVES: We aim to identify the preoperative and perioperative risk factors associated with post-surgical Staphylococcus aureus prosthetic joint infections (PJI) and to develop and validate risk-scoring systems, to allow a better identification of high-risk patients for more efficient targeted interventions. METHODS: We performed a multicenter matched case-control study of patients who underwent a primary hip and knee arthroplasty from 2014 to 2016. Two multivariable models by logistic regression were performed, one for the preoperative and one for perioperative variables; predictive scores also were developed and validated in an external cohort. RESULTS: In total, 130 cases and 386 controls were included. The variables independently associated with S. aureus-PJI in the preoperative period were (adjusted OR; 95% CI): body mass index >30 kg/m2 (3.0; 1.9 to 4.8), resident in a long-term care facility (2.8; 1.05 to 7.5), fracture as reason for arthroplasty (2.7; 1.4 to 5.03), skin disorders (2.5; 0.9 to 7.04), previous surgery in the index joint (2.4; 1.3 to 4.4), male sex (1.9; 1.2 to 2.9) and American Society of Anesthesiologists index score 3 to 4 (1.8; 1.2 to 2.9). The area under the receiver operating characteristic curve was 0.73 (95% CI 0.68 to 0.78). In perioperative model, the risk factors were the previous ones plus surgical antibiotic prophylaxis administered out of the first 60 minutes before incision (5.9; 2.1 to 16.2), wound drainage for >72 hours after arthroplasty (4.5; 1.9 to 19.4) and use of metal bearing material versus ceramic (1.9; 1.1 to 3.3). The area under the receiver operating characteristic curve was 0.78 (95% CI 0.72 to 0.83). The predictive scores developed were validated in the external cohort. DISCUSSION: Predictive scores for S. aureus-PJI were developed and validated; this information would be useful for implementation of specific preventive measures.

Rates and Predictors of Treatment Failure in Staphylococcus aureus Prosthetic Joint Infections According to Different Management Strategies: A Multinational Cohort Study-The ARTHR-IS Study Group.

INTRODUCTION: Guidelines have improved the management of prosthetic joint infections (PJI). However, it is necessary to reassess the incidence and risk factors for treatment failure (TF) of Staphylococcus aureus PJI (SA-PJI) including functional loss, which has so far been neglected as an outcome. METHODS: A retrospective cohort study of SA-PJI was performed in 19 European hospitals between 2014 and 2016. The outcome variable was TF, including related mortality, clinical failure and functional loss both after the initial surgical procedure and after all procedures at 18 months. Predictors of TF were identified by logistic regression. Landmark analysis was used to avoid immortal time bias with rifampicin when debridement, antibiotics and implant retention (DAIR) was performed. RESULTS: One hundred twenty cases of SA-PJI were included. TF rates after the first and all surgical procedures performed were 32.8% and 24.2%, respectively. After all procedures, functional loss was 6.0% for DAIR and 17.2% for prosthesis removal. Variables independently associated with TF for the first procedure were Charlson ≥ 2, haemoglobin < 10 g/dL, bacteraemia, polymicrobial infection and additional debridement(s). For DAIR, TF was also associated with a body mass index (BMI) > 30 kg/m2 and delay of DAIR, while rifampicin use was protective. For all procedures, the variables associated with TF were haemoglobin < 10 g/dL, hip fracture and additional joint surgery not related to persistent infection. CONCLUSIONS: TF remains common in SA-PJI. Functional loss accounted for a substantial proportion of treatment failures, particularly after prosthesis removal. Use of rifampicin after DAIR was associated with a protective effect. Among the risk factors identified, anaemia and obesity have not frequently been reported in previous studies. TRIAL REGISTRATION: This study is registered at clinicaltrials.gov, registration no. NCT03826108.

Staphylococcus aureus is one of the most virulent bacteria and frequently causes prosthetic joint infections.Knowledge of the treatment of this type of infection has advanced in recent years, and treatment guidelines have led to improved management. Typically, the successful treatment of these infections has been determined by clinical cure, that is, the symptoms of infection have disappeared, but has not taken into account loss of function (such as significant difficulties walking), which is critical for the patient's quality of life. Our aim in this study was to evaluate the success of current management strategies for S. aureus prosthetic joint infection, including recovery of functionality, and the factors that predict why some of these infections are not cured, to identify areas for improvement.In a multinational cohort of 128 patients with S. aureus prosthetic joint infection, rates of treatment failure were found to be high, with significant rates of loss of function, especially when the prosthesis needed to be removed. Loss of function was less frequent when the infection was initially treated with surgical cleaning without removal of the prosthesis, even when this procedure failed at first. We found that anaemia and obesity were associated with lower treatment success, and that the probability of treatment success increased when surgical cleaning without prosthesis removal was performed early, and when the antibiotic rifampicin was used in combination with another antibiotic.

Increased 30-day mortality rate in patients admitted with hip fractures during the COVID-19 pandemic in the UK.

INTRODUCTION: Hip fractures are the most common traumatic injury in the UK's elderly population. Patients are often extremely frail with multiple comorbidities and so are at high risk of death should they contract COVID-19. This study aims to quantify the effects of COVID-19 on patients presenting with hip fractures to the Norfolk and Norwich University Hospital (NNUH). METHODS: This is a single centre, prospective, observational cohort study of patients over the age of sixty admitted with a hip fracture to NNUH between March 24th and April 22nd, 2020 and comparing them retrospectively with controls in April 2019. Patients were followed up for 30 days; data collected includes demographics, COVID-19 PCR results, date/cause of death and other prognostic indicators. RESULTS: 66 consecutive patients managed for hip fractures were included in the study. 30-day mortality increased from 8.5% in April 2019 to 18.2% in April 2020. The 30-day mortality rate was 80% for those patients who test positive for COVID-19 as an inpatient, and was 13.8% for patients COVID-19 negative and for those who were untested. Those admitted from a healthcare institution were more likely to test positive for COVID-19 and had a higher 30-day mortality (p = 0.04 & p = 0.006, respectively). Suspected COVID-19-positive patients at time of admission had a delayed time to theatre, 46.7 h versus 27.1 h (p = 0.007), however this had no significant effect on mortality (p = 0.7). CONCLUSIONS: The combination of fragility hip fracture and COVID-19 is associated with poor outcomes. COVID-19 has also indirectly increased mortality in this patient group.

Improved cerebrovascular reactivity following low flow EC/IC bypass in patients with occlusive carotid disease.

Patients with major cerebral artery occlusive disease can suffer cerebral hypoperfusion and be at an increased risk of future strokes. EC/IC bypass has been shown to reduce this risk. Patients with cerebral hypoperfusion, and who are at risk of haemodynamic ischaemia, can be identified by the use of xenon computerised tomography (XeCT) to demonstrate severe impairment of the cerebrovascular reserve (CVR). We report our series on the effect of low flow EC/IC bypass on CVR in patients with symptomatic cerebral haemodynamic ischaemia. Thirteen patients with clinical and radiological features of cerebral hypoperfusion were assessed with acetazolamide activated XeCT. Pre- and postoperative regional cerebral blood flow (rCBF) and CVR were assessed. The change in CVR from pre- to post surgery was calculated (%CVR). Values were compared using ANOVA and Student's paired t-test. Unless otherwise stated, values are given as mean +/- standard error of the mean. Statistical significance was taken at p < 0.05. Pre-operative symptomatic hemisphere CBF was 38 +/- 2 mls/100g/min compared to 40 +/- 3.2 mls/100 g/min in the asymptomatic hemisphere, with the greatest difference observed in the MCA territory (38.6 +/- 2 cf 45.4 +/- 3.2 mls/100g/min). Baseline CBF was not significantly improved post EC/IC bypass. However CVR was significantly improved in the symptomatic hemisphere post-operatively (p = 0.015), with the greatest increase (28%) seen in the MCA territory (p = 0.0105). First, 85% of patients had either an improvement in symptoms or no further symptoms. There was a 93% graft patency and no operative mortality. Low flow EC/IC bypass can improve CVR in patients with symptomatic cerebral ischaemia in the presence of occlusive carotid disease. However, therapy must be individualised, with careful patient selection and minimal surgical morbidity.

Impaction bone grafting in revision hip surgery: past, present and future.

Joint replacement surgery can have excellent clinical results. However, as the number of patients undergoing surgery increases, the number of failed joint replacements is set to rise. One of the greatest challenges for the revision surgeon is the restoration of bone stock. This article focuses upon revision hip surgery, with particular reference to the scope of the problem; historical and current solutions to bone loss in the femur and acetabulum; the clinical results following revision surgery; and the basic science behind impaction bone grafting, before ending with possible future directions for improving the restoration of bone stock.

CAPAbility: comparison of the JOURNEY II Bi-Cruciate Stabilised and GENESIS II total knee arthroplasty in performance and functional ability: protocol of a randomised controlled trial.

BACKGROUND: Osteoarthritis of the knee is a common condition that is expected to rise in the next two decades leading to an associated increase in total knee replacement (TKR) surgery. Although there is little debate regarding the safety and efficacy of modern TKR, up to 20% of patients report poor functional outcomes following surgery. This study will investigate the functional outcome of two TKRs; the JOURNEY II Bi-Cruciate Stabilised knee arthroplasty, a newer knee prosthesis designed to provide guided motion and improve knee kinematics by more closely approximating a normal knee, and the GENESIS II, a proven existing design. AIM: To compare the change in Patient-reported Outcome Measures (PROMs) scores of the JOURNEY II BCS and the GENESIS II from pre-operation to 6 months post operation. METHODS: CAPAbility is a pragmatic, blinded, two-arm parallel, randomised controlled trial recruiting patients with primary osteoarthritis due to have unilateral TKR surgery across two UK hospitals. Eligible participants (n = 80) will be randomly allocated to receive either the JOURNEY II or the GENESIS II BCS knee prosthesis. Baseline measures will be taken prior to surgery. Patients will be followed at 1 week, 6 to 8 weeks and 6 months post-operatively. The primary outcome is the Oxford Knee Score (OKS) at 6 months post-operatively. Secondary outcomes include: other PROMs, biomechanical, radiological (computerised tomography, (CT)), clinical efficacy and safety outcomes. An embedded qualitative study will also investigate patients' perspectives via interview pre and post surgery on variables known to affect the outcome of TKR surgery. A sub-sample (n = 30) will have additional in-depth interviews to explore the themes identified. The surgeons' perspectives on the operation will be investigated by a group interview after all participants have undergone surgery. DISCUSSION: This trial will evaluate two generations of TKR using PROMS, kinematic and radiological analyses and qualitative outcomes from the patient perspective. TRIAL REGISTRATION: International Standard Randomised Controlled Trials Number Registration, ID: ISRCTN32315753. Registered on 12 December 2017.

Preliminary evaluation of a rapid lateral flow calprotectin test for the diagnosis of prosthetic joint infection.

AIMS: This pilot study tested the performance of a rapid assay for diagnosing prosthetic joint infection (PJI), which measures synovial fluid calprotectin from total hip and knee revision patients. METHODS: A convenience series of 69 synovial fluid samples from revision patients at the Norfolk and Norwich University Hospital were collected intraoperatively (52 hips, 17 knees) and frozen. Synovial fluid calprotectin was measured retrospectively using a new commercially available lateral flow assay for PJI diagnosis (Lyfstone AS) and compared to International Consensus Meeting (ICM) 2018 criteria and clinical case review (ICM-CR) gold standards. RESULTS: According to ICM, 24 patients were defined as PJI positive and the remaining 45 were negative. The overall accuracy of the lateral flow test compared to ICM was 75.36% (52/69, 95% CI 63.51% to 84.95%), sensitivity and specificity were 75.00% (18/24, 95% CI 53.29% to 90.23%) and 75.56% (34/45, 95% CI 60.46% to 87.12%), respectively, positive predictive value (PPV) was 62.07% (18/29, 95% CI 48.23% to 74.19%) and negative predictive value (NPV) was 85.00% (34/40, 95% CI 73.54% to 92.04%), and area under the receiver operating characteristic (ROC) curve (AUC) was 0.78 (95% CI 0.66 to 0.87). Patient data from discordant cases were reviewed by the clinical team to develop the ICM-CR gold standard. The lateral flow test performance improved significantly when compared to ICM-CR, with accuracy increasing to 82.61% (57/69, 95% CI 71.59% to 90.68%), sensitivity increasing to 94.74% (18/19, 95% CI 73.97% to 99.87%), NPV increasing to 97.50% (39/40, 95% CI 85.20% to 99.62%), and AUC increasing to 0.91 (95% CI 0.81 to 0.96). Test performance was better in knees (100.00% accurate (17/17, 95% CI 80.49% to 100.00%)) compared to hips (76.92% accurate (40/52, 95% CI 63.16% to 87.47%)). CONCLUSION: This study demonstrates that the calprotectin lateral flow assay could be an effective diagnostic test for PJI, however additional prospective studies testing fresh samples are required.Cite this article: Bone Joint Res. 2020;9(5):202-210.

Occupational advice to help people return to work following lower limb arthroplasty: the OPAL intervention mapping study.

BACKGROUND: Hip and knee replacements are regularly carried out for patients who work. There is little evidence about these patients' needs and the factors influencing their return to work. There is a paucity of guidance to help patients return to work after surgery and a need for structured occupational advice to enable them to return to work safely and effectively. OBJECTIVES: To develop an occupational advice intervention to support early recovery to usual activities including work that is tailored to the requirements of patients undergoing hip or knee replacements. To test the acceptability, practicality and feasibility of this intervention within current care frameworks. DESIGN: An intervention mapping approach was used to develop the intervention. The research methods employed were rapid evidence synthesis, qualitative interviews with patients and stakeholders, a prospective cohort study, a survey of clinical practice and a modified Delphi consensus process. The developed intervention was implemented and assessed during the final feasibility stage of the intervention mapping process. SETTING: Orthopaedic departments in NHS secondary care. PARTICIPANTS: Patients who were in work and intending to return to work following primary elective hip or knee replacement surgery, health-care professionals and employers. INTERVENTIONS: Occupational advice intervention. MAIN OUTCOME MEASURES: Development of an occupational advice intervention, fidelity of the developed intervention when delivered in a clinical setting, patient and clinician perspectives of the intervention and preliminary assessments of intervention effectiveness and cost. RESULTS: A cohort study (154 patients), 110 stakeholder interviews, a survey of practice (152 respondents) and evidence synthesis provided the necessary information to develop the intervention. The intervention included information resources, a personalised return-to-work plan and co-ordination from the health-care team to support the delivery of 13 patient and 20 staff performance objectives. To support delivery, a range of tools (e.g. occupational checklists, patient workbooks and employer information), roles (e.g. return-to-work co-ordinator) and training resources were created. Feasibility was assessed for 21 of the 26 patients recruited from three NHS trusts. Adherence to the defined performance objectives was 75% for patient performance objectives and 74% for staff performance objectives. The intervention was generally well received, although the short time frame available for implementation and concurrent research evaluation led to some confusion among patients and those delivering the intervention regarding its purpose and the roles and responsibilities of key staff. LIMITATIONS: Implementation and uptake of the intervention was not standardised and was limited by the study time frame. Evaluation of the intervention involved a small number of patients, which limited the ability to assess it. CONCLUSIONS: The developed occupational advice intervention supports best practice. Evaluation demonstrated good rates of adherence against defined performance objectives. However, a number of operational and implementation issues require further attention. FUTURE WORK: The intervention warrants a randomised controlled trial to assess its clinical effectiveness and cost-effectiveness to improve rates and timing of sustained return to work after surgery. This research should include the development of a robust implementation strategy to ensure that adoption is sustained. STUDY REGISTRATION: Current Controlled Trials ISRCTN27426982 and PROSPERO CRD42016045235. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 45. See the NIHR Journals Library website for further project information.

Hip and knee replacements are regularly carried out for patients who work. There is a lack of evidence about these patients' needs and how they return to work. Guidance to enable return to work after surgery is limited. There is, therefore, a need for structured occupational advice to help these patients. The aim of this project was to develop a multidisciplinary occupational advice intervention for this patient population and assess if it could be delivered. The study also aimed to make recommendations about its further assessment in a clinical trial. The study combined different methods of research (quantitative and qualitative) to identify the population likely to benefit, their current care, and the outcomes important to patients and health-care professionals. All of the information gathered was mapped through a framework (intervention mapping), which included a consensus process with stakeholders to develop the intervention. The intervention delivery was assessed for a small number of patients across orthopaedic departments, employer organisations and primary care networks. The study involved 154 patients, 110 stakeholders (general practitioners, surgeons, employers and health professionals/nurses) and a survey of current care (152 respondents) to develop the intervention. The intervention included information resources, a personalised return-to-work plan and co-ordination from the health-care team to support the delivery of 33 patient and staff performance objectives. To support delivery, a range of tools (e.g. occupational checklists, patient workbooks and employer information), roles (e.g. return-to-work co-ordinator) and training resources were created. The intervention was assessed in 26 patients and staff, and showed high rates of adherence to the defined performance objectives. The overall results demonstrated that the occupational advice intervention developed for hip and knee replacement patients is deliverable. The intervention warrants further research to assess its clinical effectiveness and cost-effectiveness as a tool to improve rates and timing of sustained return to work after surgery.