Aims Since April 2009, patients undergoing NHS-funded primary elective total knee or hip arthroplasties (TKAs or THAs) should be invited to complete patient-reported outcome measures (PROMs). The aim of this study was to use National Joint Registry (NJR) data to identify patient and demographic differences between those with complete versus those with missing PROMs. Methods Patients undergoing publicly funded elective primary TKA or THA between April 2009 and December 2018 recorded in the NJR were eligible. NJR data were linked to the English Hospital Episode Statistics (HES), and PROMs data. Oxford Knee/Hip scores (OKS/OHS) were eligible for inclusion if recorded up to 18 weeks preoperatively (Q1) and between six and 12 months postoperatively (Q2). Proportions were used to describe the completeness of PROMs data. The following variables were assessed to determine associations with completeness of PROMs data: age, sex, American Society of Anesthesiologists (ASA) grade, BMI, socioeconomic deprivation, baseline (Q1) OKS/OHS, and hospital. Results Of 570,449 eligible TKAs and 507,962 eligible THAs, complete pre- and postoperative PROMs were available for 229,794 TKAs (40.3%) and 210,929 THAs (41.5%). There were no differences in the patient and demographic factors between those with and without complete PROMs. Patients with complete PROMs had higher preoperative PROMs (less pain and functional limitations) than those with preoperative but no postoperative PROMs (TKA: median OKS = 19 vs 15; THA: median OHS = 17 vs 14). For Q2 PROMs, the median hospital-level completeness was 71% OKS (IQR 60 to 76) and 72% OHS (IQR 62 to 77), with little variation between high and low volume hospitals. In contrast, Q1 completeness varied between hospitals (69% in high-volume hospitals vs 57% in low-volume hospitals). Conclusion Although up to 60% of patients did not have complete pre- and postoperative PROMs, the patient and demographic factors, and the rates of revision and mortality, were similar to those with complete PROMs. PROMs which are collected may therefore probably be generalizable to wider groups of patients who undergo TKA and THA. Cite this article: Bone Joint J 2026;108-B(6):773–780.

BACKGROUND:Reducing health inequalities is of national importance. Total hip replacement (THR) is a commonly used elective surgical procedure. Few studies have examined area-level inequalities for a wide range of outcomes following THR. The aim of this study is to compare area-level socioeconomic differences in outcomes following primary THR surgery for osteoarthritis in England. METHODS AND FINDINGS:This is a population-based prospective cohort study of the National Joint Registry (NJR). Data from the NJR were linked to national mortality, Hospital Episode Statistics and Patient Reported Outcome Measures (PROMs) databases for England from 2007 to 2017 with follow-up to 2023 for outcomes, for patients aged 50 years and over with osteoarthritis. Outcomes of 90-day mortality; 5-year revision rate; 6-month health complications; 1-year rehospitalisation and reoperation for orthopaedic indications; and patient-reported Oxford Hip Score (OHS), post-THR surgery were examined by area-level Index of Multiple Deprivation quintiles. Modified Poisson regression was adjusted for patient age, sex, body mass index, pre-operative physical state and comorbidity. Among 448,184 patients with primary THR, mean age was 70 years (standard deviation: 9 years) and 61% were women. Patients from the most deprived group were more likely to die within 90 days of the operation compared to the least deprived group (adjusted rate ratio, RR: 1.25 (95% confidence interval (CI) [1.07, 1.46]); adjusted risk difference, RD: 9 (95% CI [2, 16]) per 10,000. Similarly, those from the most deprived group were more likely to experience complications (RR: 1.26 (95% CI [1.21, 1.32]); RD: 1.14% (95% CI [0.92, 1.36])); be rehospitalised (RR: 1.16 (95% CI [1.14, 1.19]; RD: 2.78% (95% CI [2.39, 3.17])) or reoperated (RR: 1.23 (95% CI [1.13, 1.33]); RD: 0.31% (95% CI [0.19, 0.44])) and report poorer OHS (adjusted score: -2.97 (95% CI [-3.10, -2.84]) N = 200,522). There was no variation by deprivation level for THR revision rates at 5 years (RR: 1.02 (95% CI [0.94, 1.10]); RD: 0.02% (95% CI [-0.10, 0.15])). The main study limitations are the lack of complete PROMs data, and the exclusion of self-funded patients or those with private insurance for THR procedures in independent hospitals. CONCLUSIONS:Inequalities in several outcomes after THR are present in England by area-level deprivation. These findings are useful to inform shared decision-making for patients deciding whether to undergo hip replacement and to benchmark the effectiveness of policies which aim to reduce health inequalities following THR.

Aims:Bone cement continues to be part of the fixation strategy for a large proportion of all total hip arthroplasties (THAs) in the UK and other countries. The aim of this study was to investigate the association between specific commercially available bone cement formulations and the risk of revision surgery after primary elective THA. Methods:This was a population-based cohort study using data from the National Joint Registry from 1 April 2003 to 31 December 2024. All consenting patients having a cemented, hybrid, or reverse hybrid primary THA for osteoarthritis were included. Multilevel over-dispersed piecewise Poisson models were used to compare the rate of revision surgery by cement type adjusted for implant type, age, sex, and American Society of Anesthesiologists grade. Results:A total of 515,433 procedures were included, mean patient age was 71.31 years (SD 9.5), and 63% (n = 324,962) were female. In total, 21 different cement types were used. Compared to Heraeus Medical Palacos R+G high-viscosity (68.2% of all procedures), we did not observe a different incidence rate ratio for most cement types commonly used in contemporaneous practice. However, DePuy CMW3 medium viscosity with gentamicin (incidence rate ratio (IRR) 2.21 (95% CI 1.75 to 2.75)), DePuy CMW1 high viscosity with gentamicin (IRR 1.27 (95% CI 1.08 to 1.49)), Schering-Plough HMP low viscosity with gentamicin (IRR 1.78 (95% CI 1.06 to 2.96)), Biomet Optipac Refobacin R medium viscosity with gentamicin (IRR 1.36 (95% CI 1.07 to 1.72)), and Stryker Simplex medium viscosity (IRR 1.24 (95% CI 1.04 to 1.47)) were associated with a significantly increased rate of revision surgery. Conclusion:Most cement types in contemporaneous practice have similar incidence rate ratios of revision to the reference cement (Heraeus Medical Palacos R+G high viscosity), but five cement types were associated with a significantly higher rate of revision. Vigilance is required as new cements are introduced into the market.

Aims:Since April 2009, patients undergoing NHS-funded primary elective total knee or hip arthroplasties (TKAs or THAs) should be invited to complete patient-reported outcome measures (PROMs). The aim of this study was to use National Joint Registry (NJR) data to identify patient and demographic differences between those with complete versus those with missing PROMs. Methods:Patients undergoing publicly funded elective primary TKA or THA between April 2009 and December 2018 recorded in the NJR were eligible. NJR data were linked to the English Hospital Episode Statistics (HES), and PROMs data. Oxford Knee/Hip scores (OKS/OHS) were eligible for inclusion if recorded up to 18 weeks preoperatively (Q1) and between six and 12 months postoperatively (Q2). Proportions were used to describe the completeness of PROMs data. The following variables were assessed to determine associations with completeness of PROMs data: age, sex, American Society of Anesthesiologists (ASA) grade, BMI, socioeconomic deprivation, baseline (Q1) OKS/OHS, and hospital. Results:Of 570,449 eligible TKAs and 507,962 eligible THAs, complete pre- and postoperative PROMs were available for 229,794 TKAs (40.3%) and 210,929 THAs (41.5%). There were no differences in the patient and demographic factors between those with and without complete PROMs. Patients with complete PROMs had higher preoperative PROMs (less pain and functional limitations) than those with preoperative but no postoperative PROMs (TKA: median OKS = 19 vs 15; THA: median OHS = 17 vs 14). For Q2 PROMs, the median hospital-level completeness was 71% OKS (IQR 60 to 76) and 72% OHS (IQR 62 to 77), with little variation between high and low volume hospitals. In contrast, Q1 completeness varied between hospitals (69% in high-volume hospitals vs 57% in low-volume hospitals). Conclusion:Although up to 60% of patients did not have complete pre- and postoperative PROMs, the patient and demographic factors, and the rates of revision and mortality, were similar to those with complete PROMs. PROMs which are collected may therefore probably be generalizable to wider groups of patients who undergo TKA and THA.

BACKGROUND:Implant revision is an operation with exchange of implants, and is used as a standard outcome after total hip replacement (THR), but may not fully represent the patient experience after a THR. Major reoperation (hereafter referred to as 'reoperation') without revision of implants can also lead to increased patient morbidity and mortality, and most commonly occurs when the femur fractures around an implant (postoperative periprosthetic femoral fractures; POPFF) and is treated with fixation and the implant is left in place. Reliance on revision metrics that do not capture these reoperations has led to large-scale underreporting of reoperations in THR, and is likely to have affected implant performance estimates, which have guided national policy and implant selection. It is important to include these additional reoperations when estimating treatment success to guide innovation and clinical practice. We aimed to estimate the incidence of reoperation following primary THR. METHODS AND FINDINGS:We performed a large national cohort study on a mandatory, prospective database, the National Joint Registry, linked to Hospital Episode Statistics. All linkable primary THRs using recently available implants, with highest safety ratings between 01/01/2010 and 31/12/2020, were included. Major reoperation was defined as the first revision for any cause or fixation of POPFF and was identified using a combination of procedural and diagnosis codes. We identified 372,967 THRs representing 2,127,464 prostheses years at risk with a median follow-up time of 5.39 years (range 0 to 12.1 years). A total of 8,043 reoperations were identified that had been surgically treated by revision for any cause or fixation of POPFF. The incidence of reoperation was 3.78% (95% confidence interval [CI 3.70%, 3.86%]) per 1,000 prostheses years in comparison to 3.00% (95% CI [2.93%, 3.07%]) per 1,000 prostheses years when using conventional revision only outcomes. Cumulative incidence of major reoperation at 10 years was 3.1% (95% CI [3.0%, 3.1%]). Cumulative reoperation estimates were stratified by age and sex. In men aged 68 years and older, collared cementless stems performed better than cemented stems and in women aged 75 years and older, the relationship was reversed. Residual differences in patient characteristics may affect the accuracy of the estimates. CONCLUSIONS:Treatment failure after THR has been underrepresented by revision-only estimates. Major reoperation rates in older men were lowest with cementless collared stems, and in older women, reoperation rates were lowest with cemented polished taper stems made of stainless steel. These results prompt a review of the current implant guidance for hip replacements in older patients. LEVEL OF EVIDENCE:III (Retrospective cohort study).

Major reoperation (hereafter referred to as ‘reoperation’) without revision of implants can leads to significant patient morbidity and mortality, and most commonly occurs when the femur fractures around an implant (postoperative periprosthetic femoral fractures; POPFF) and is treated with fixation and the implant is left in place. Reliance on revision metrics that do not capture these reoperation s has led to large-scale under reporting of failures in THR, and is likely to have affected implant performance estimates, which have guided national policy and implant selection. We aimed to estimate the incidence of reoperation following primary. We analysed a mandatory, prospective database, the National Joint Registry (NJR), linked to Hospital Episode Statistics (HES). All linkable primary THRs using recently available implants, with highest safety rating between 01/01/2010 to 31/12/2020 were included. Reoperation was defined as the first revision for any cause or fixation of POPFF and was identified using a combination of procedural and diagnosis codes. We identified 452,901 THRs representing 2,558,325 prosthesis years at risk. A total of 9,407 reoperations were identified that had been surgically treated by revision for any cause or fixation of POPFF. The incidence of reoperation was 3.68 (95% CI 3.60, 3.75) per 1000 prostheses years in comparison to 3.03 (95% CI 2.96 to 3.10%) per 1000 prostheses years when using conventional revision only outcomes. Cumulative incidence of major reoperation at ten years was 3.0% (95% CI 2.9 to 3.0%). In older men collared cementless stems performed better than cemented stems and in older women the trend was reversed. Rates in older men were lowest with cementless collared stems, and in older women reoperation rates were lowest with cemented polished taper stems made of stainless steel. These results prompt a review of the current implant guidance for hip replacements in older patients.

BACKGROUND:Length of stay (LOS) after hip and knee replacement has decreased steadily in the modern era with enhanced recovery protocols, enabling healthcare systems to address rising surgical demand in an ageing, comorbid population. This study examines trends in LOS, patient characteristics, and their associations for NHS-funded procedures in England, covering a period that includes the COVID-19 pandemic. METHODS:Data from the National Joint Registry and Hospital Episode Statistics were linked to identify patients who underwent primary total hip replacement (THR) and total or unicompartmental (partial) knee replacement (TKR/UKR) in England between January 2010 and March 2022. LOS was analysed using flexible parametric models to estimate median values over time, with subsequent adjustment to examine associations between changing patient characteristics. Trends in 30-day readmission rates were also analysed. RESULTS:From 2010 to 2022, median LOS decreased from 4.26 days (95% CI 4.22 to 4.30) to 2.75 days (95% CI 2.74 to 2.77) for THR, from 4.35 days (95% CI 4.32 to 4.39) to 2.91 days (95% CI 2.90 to 2.92) for TKR, and from 3.2 days (95% CI 3.16 to 3.25) to 1.91 days (95% CI 1.89 to 1.95) for UKR. Variability also decreased. There were no increases in crude 30-day readmission rates. Trends in patient demographics showed increasing comorbidity, obesity, male sex, affluence, and use of the independent sector, all of which were associated with LOS and had the overall effect of slightly attenuating its reduction. Significant changes in patient characteristics occurred around the time of the COVID-19 pandemic but have since resumed previous trends. CONCLUSIONS:Patients in England now typically stay fewer than three days for total hip or knee replacement and under two days for partial knee replacement. Despite demographic trends towards characteristics associated with longer LOS, reductions have occurred independently of these changes, suggesting potential for further shortening. However, as these diverging trends continue, ensuring equitable access to surgery will be increasingly important.

BACKGROUND:Total knee replacements (TKRs) are performed by surgeons at different stages in training with varying levels of supervision, but we do not know if this is a safe practice or whether trainees achieve equivalent outcomes to consultant-performed TKR. This study aimed to investigate the association between surgeon grade, the supervision of trainees, and the risk of revision following TKR. Revision is defined by the National Joint Registry (NJR) for England and Wales as any procedure to add, remove, or modify one or more components of an implant construct for any reason. METHODS AND FINDINGS:We conducted an observational study using prospectively collected data from the NJR. We included 953,081 cases in 788,288 adult patients who underwent primary TKR for osteoarthritis (OA), recorded in the NJR between 2003 and 2019. Exposures were surgeon grade (consultant or trainee) and the level of scrubbed consultant supervision of trainees. The primary outcome was all-cause revision, and the secondary outcome was the number of procedures revised for the following indications: aseptic loosening/lysis, infection, progression of OA, unexplained pain, and instability. Flexible parametric survival models (FPM) were incrementally adjusted in the following manner. Model 1 was unadjusted. Model 2 was adjusted for patient-level factors (age, sex, American Society of Anaesthesiologists [ASA] grade, and index of multiple deprivation [IMD] decile). Model 3 was further adjusted for operation-level factors (anaesthetic, approach, fixation, constraint and whether or not the patella was resurfaced). Model 4 was further adjusted for healthcare setting factors (funding source, and year of operation). Trainees performed 96,544 (10.1%) TKRs and were directly supervised by a scrubbed consultant in 63.2% of trainee-performed cases. Trainees achieved comparable outcomes to consultants in terms of the unadjusted cumulative probability of all-cause revision (e.g., 15 years of follow-up: consultant % Failure 4.79 (95% CI [4.67, 4.92]) versus trainee (overall) % Failure 4.75 (95% CI [4.43, 5.10]). Adjusted FPM analysis indicated evidence of an association between trainee-performed TKR and a small increased risk of early all-cause revision up to, but not exceeding, 4 years follow-up (1 year: HR 1.12 (95% CI [1.05, 1.19]), 4 years: HR 1.00 (95% CI [0.95, 1.06]), 16 years: HR 0.89 (95% CI [0.81, 0.98])). This association was not explained by the level of supervision. Further analysis suggested that this association may be attributable to revisions for aseptic loosening/lysis, infection, and progression of OA (i.e., subsequent patellar resurfacing). Limitations of this study relate to its observational design and include: the potential for non-random allocation of cases by consultants to trainees; residual confounding; and the use of the binary variable 'surgeon grade', which does not capture variations in the level of experience between trainees. CONCLUSIONS:Trainees in England and Wales achieve safe and acceptable all-cause TKR implant survival, with comparable outcomes to consultants. However, adjusted analyses suggest an association between trainee-performed TKR and a small increase in the risk of early all-cause revision. This association may be attributable to factors including aseptic loosening, infection, and progression of OA. Current training practices for TKR in England and Wales are safe in terms of equivalence of all-cause implant survival to consultant-performed TKR, but we have identified areas for potential improvement in trainee outcomes.

In response to rising demand, disruptions from the COVID-19 pandemic, and the need for improved cost-effectiveness, the way hip and knee replacements are being delivered is rapidly changing. Increasingly, they are being performed as day case procedures without an overnight stay in hospital. This study assessed the safety of this for a national cohort of NHS-funded procedures in England. Data from the National Joint Registry, Hospital Episode Statistics, and Civil Registration of Deaths databases were linked to identify patients who underwent total hip replacement (THR) and total or unicompartmental knee replacement (TKR/UKR) in England between 2010 and 2022. Outcomes including 30-day readmissions, 90-day serious adverse events, and 1-year reoperations were compared between day case and one-day stay inpatients using adjusted flexible parametric survival models. The study included 7485 day case and 60,747 one-day stay inpatient procedures. Day case surgery was associated with a higher risk of 30-day readmission for THR (adjusted relative risk (RR) 1.28, 95

Objective To determine the importance of comorbidity measures when predicting mortality and revision surgery after elective primary shoulder replacement surgery.Design Population based cohort study.Setting Linked data from the National Joint Registry and NHS Hospital Episode Statistics were used to identify all elective primary shoulder replacements in England, 6 January 2012 to 30 March 2022.Participants 37 176 consenting patients, aged 18-100 years, who had elective primary shoulder replacement surgery.Main outcome measures Risk of mortality at 90 and 365 days, and risk of long term revision surgery after the primary surgery. Results 37 176 primary shoulder replacement procedures were included; 102 patients died within 90 days and 445 within 365 days of the primary surgery. 1219 patients had revision surgery over a maximum follow-up period of >10 years. The addition of comorbidity measures derived from Hospital Episode Statistics (Charlson comorbidity index with summary hospital mortality index weights, Elixhauser comorbidity index, and hospital frailty risk score) to simpler models resulted in little improvement in predictive performance. Optimism adjusted performance (C index) of the models that included age, sex, American Society of Anesthesiologists (ASA) grade, and main surgical indication was 0.76 (95% confidence interval (CI) 0.72 to 0.81) for 90 day mortality, 0.74 (0.71 to 0.76) for 365 day mortality, and 0.64 (0.63 to 0.66) for revision surgery. The best performing models that included a comorbidity measure had an optimism adjusted C index of 0.77 (95% CI 0.73 to 0.81) for 90 day mortality, 0.76 (0.74 to 0.78) for 365 day mortality, and 0.65 (0.63 to 0.66) for revision surgery. Heterogeneity in model performance across regions of England was low, and decision curve analysis showed minimal improvement in net benefit when including comorbidity measures.Conclusions In this study, patient comorbidity scores added little improvement to simpler models that included age, sex, ASA grade, and main surgical indication for predicting mortality and revision surgery after elective primary shoulder replacement surgery. This improvement needs to be balanced against the additional challenges of routine data linkage to obtain these scores.

INTRODUCTION:Understanding the prognostic factors associated with the failure of total elbow replacement (TER) is crucial for informing patients about risks and enabling shared decision-making regarding TER as a definitive management option. This protocol outlines the planned analysis of National Joint Registry (NJR) data to investigate prognostic factors for TER failure. METHODS AND ANALYSIS:The primary analysis will use the NJR elbow dataset, including all eligible patients who underwent TER surgery between April 2012 and December 2023. To incorporate ethnicity and comorbidities as potential prognostic factors, the NJR will be linked to the National Health Service (NHS) England Hospital Episode Statistics-Admitted Patient Care (HES-APC) data for a secondary analysis. The analysis will adhere to the REporting recommendations for tumour MARKer prognostic studies guidelines. The primary outcome under investigation is TER failure, defined as requiring revision surgery. Initially, the overall prognosis of TER will be examined using unadjusted net implant failure via the Kaplan-Meier method. The list of potential prognostic factors to be investigated in this study has been informed by a systematic review on this topic, input from patient and public involvement and engagement (PPIE) groups and a survey shared with healthcare professionals providing TER services. The relationship between each potential prognostic factor and failure will be assessed using univariable regression methods. Based on the findings from our systematic review, the univariable association will also be adjusted for age, sex and indication for TER surgery using multivariable regression methods. The extent of missing data will be reported, and the reasons for missing data will be explored. A very high degree of data completeness is expected, and a complete case analysis will be performed as the primary analysis. Multiple imputations will be considered as a sensitivity analysis. ETHICS AND DISSEMINATION:The NJR research committee approved this analysis, and the NHS Health Research Authority tool guidance dictates that the secondary use of such data for research does not require approval from a research ethics committee. The results from this analysis will be published in a peer-reviewed journal and presented at scientific conferences. TRIAL REGISTRATION NUMBER:NCT06760585.

Hip and knee replacements are increasingly being performed as day-case procedures without an overnight stay in hospital. The aim of this study was to describe trends surrounding this practice for a national cohort of patients in England. The National Joint Registry and Hospital Episode Statistics were linked to identify patients who underwent NHS-funded total hip replacement (THR) and total or unicompartmental knee replacement (TKR/UKR) in England between January 2010 and March 2022. Trends in day-case surgery were described as counts and proportions of all inpatient procedures at national, regional, and local levels. Day-case patient and surgical characteristics were described and compared over time and by volume, using linear regression models, in relation to trends in inpatient procedures. A total of 1,455,842 procedures were included, of which 7,485 were day-cases: 2,420 THRs, 2,509 TKRs, and 2,556 UKRs. The rate of day-case surgery increased over time, with 52.9% of recorded day-case procedures occuring from 2019 onwards. Between 2016 and 2022, the proportion of procedures done as a day-case increased from 0.3% to 1.05% for THR, from 0.38% to 1.05% for TKR, and from 1.98% to 9.3% for UKR. Most of the increase in day-case activity occurred in NHS units. There was significant regional and local variation, with a small number of units accounting for most day-case procedures. Patients who underwent THR or TKR as a day-case were significantly younger and healthier than those who underwent these procedures as an inpatient, with a trend towards increasing selectivity over time. However, by contrast, higher-volume day-case units became slightly less selective for certain characteristics as volume increased. Although the number of major joint replacements being undertaken as a day-case has increased rapidly in England, particularly since the COVID-19 pandemic, this remains a small proportion of procedures compared with the rates in other contemporary healthcare settings. Cite this article: Bone Joint J 2025;107-B(10):1064–1075.

BackgroundThere is growing evidence that access to joint replacement surgery is being restricted based on body mass index (BMI) despite any formal recommendations. Our aim was to investigate the association between BMI and patient outcomes after elective primary shoulder replacement surgery to inform future commissioning and national guidance.Methods and findingsIn this population-based cohort study, patients aged 18-100 years having elective primary shoulder replacement surgery were identified using linked national joint registry and hospital data from public and private hospitals in the United Kingdom (2018-22) and Denmark (2006-21). The main outcome measure was mortality within 365 days of surgery. Secondary outcome measures included mortality within 90 days, serious adverse events within 90 days, and revision surgery within 4.5 years of surgery. The association between BMI and patient outcomes was assessed using flexible parametric survival models and logistic regression models, adjusting for age, sex, deprivation, main surgical indication and American Society of Anaesthesiologists (ASA) score. 15,320 and 5,446 shoulder replacement procedures from within the United Kingdom and Denmark, respectively, met the inclusion criteria. In the United Kingdom, the average age was 72.2 years, 68.3% were female and the average BMI was 29.4 kg/m2. In Denmark, the average age was 70.5 years, 65.3% were female and the average BMI was 28.0 kg/m2. There was a decreased risk of 365-day mortality in obese (BMI 40 kg/m2) patients (hazard ratio (HR) 0.40 [95%CI 0.21, 0.73]) and an increased risk in underweight (BMI < 18.5 kg/m2) patients (HR 1.18 [95%CI 1.06, 1.32]), compared to patients with BMI 21.75 kg/m2. Underweight patients had an increased risk of 90-day mortality (HR 1.69 [95%CI 1.14, 2.52]), 90-day serious adverse events (odds ratio 1.36 [95%CI 1.05, 1.77]) and revision surgery (HR 1.70 [95%CI 1.25, 2.33]). Increasing BMI was not associated with a significantly increased risk of any secondary outcome. The main limitation of this study was the high proportion of missing BMI data and the small case numbers for the underweight study population (n = 131[UK], 70[Denmark]).ConclusionsIncreasing BMI was associated with lower 365-day mortality, and no poorer outcomes after elective primary shoulder replacement surgery. This surgery is safe and effective in obese patients and access to shoulder replacements should not be restricted based on BMI alone. Clinicians and hospitals should be aware that underweight patients appear more at risk of mortality, serious adverse events and revision surgery after shoulder replacement.

Aims:Hip and knee replacements are increasingly being performed as day-case procedures without an overnight stay in hospital. The aim of this study was to describe trends surrounding this practice for a national cohort of patients in England. Methods:The National Joint Registry and Hospital Episode Statistics were linked to identify patients who underwent NHS-funded total hip replacement (THR) and total or unicompartmental knee replacement (TKR/UKR) in England between January 2010 and March 2022. Trends in day-case surgery were described as counts and proportions of all inpatient procedures at national, regional, and local levels. Day-case patient and surgical characteristics were described and compared over time and by volume, using linear regression models, in relation to trends in inpatient procedures. Results:A total of 1,455,842 procedures were included, of which 7,485 were day-cases: 2,420 THRs, 2,509 TKRs, and 2,556 UKRs. The rate of day-case surgery increased over time, with 52.9% of recorded day-case procedures occuring from 2019 onwards. Between 2016 and 2022, the proportion of procedures done as a day-case increased from 0.3% to 1.05% for THR, from 0.38% to 1.05% for TKR, and from 1.98% to 9.3% for UKR. Most of the increase in day-case activity occurred in NHS units. There was significant regional and local variation, with a small number of units accounting for most day-case procedures. Patients who underwent THR or TKR as a day-case were significantly younger and healthier than those who underwent these procedures as an inpatient, with a trend towards increasing selectivity over time. However, by contrast, higher-volume day-case units became slightly less selective for certain characteristics as volume increased. Conclusion:Although the number of major joint replacements being undertaken as a day-case has increased rapidly in England, particularly since the COVID-19 pandemic, this remains a small proportion of procedures compared with the rates in other contemporary healthcare settings.

OBJECTIVES To answer a national research priority by comparing the risk -benefit and costs associated with reverse total shoulder replacement (RTSR) and anatomical total shoulder replacement (TSR) in patients having elective primary shoulder replacement for osteoarthritis. DESIGN Population based cohort study using data from the National Joint Registry and Hospital Episode Statistics for England. SETTING Public hospitals and publicly funded procedures at private hospitals in England, 2012-20. PARTICIPANTS Adults aged 60 years or older who underwent RTSR or TSR for osteoarthritis with intact rotator cuff tendons. Patients were identified from the National Joint Registry and linked to NHS Hospital Episode Statistics and civil registration mortality data. Propensity score matching and inverse probability of treatment weighting were used to balance the study groups. MAIN OUTCOME MEASURES The main outcome measure was revision surgery. Secondary outcome measures included serious adverse events within 90 days, reoperations within 12 months, prolonged hospital stay (more than three nights), change in Oxford Shoulder Score (preoperative to six month postoperative), and lifetime costs to the healthcare service. RESULTS The propensity score matched population comprised 7124 RTSR or TSR procedures (126 were revised), and the inverse probability of treatment weighted population comprised 12 968 procedures (294 were revised) with a maximum follow-up of 8.75 years. RTSR had a reduced hazard ratio of revision in the first three years (hazard ratio local minimum 0.33, 95% confidence interval 0.18 to 0.59) with no clinically important difference in revision -free restricted mean survival time, and a reduced relative risk of reoperations at 12 months (odds ratio 0.45, 95% confidence interval 0.25 to 0.83) with an absolute risk difference of -0.51% (95% confidence interval -0.89 to -0.13). Serious adverse events and prolonged hospital stay risks, change in Oxford Shoulder Score, and modelled mean lifetime costs were similar. Outcomes remained consistent after weighting. CONCLUSIONS This study's findings provide reassurance that RTSR is an acceptable alternative to TSR for patients aged 60 years or older with osteoarthritis and intact rotator cuff tendons. Despite a significant difference in the risk profiles of revision surgery over time, no statistically significant and clinically important differences between RTSR and TSR were found in terms of long term revision surgery, serious adverse events, reoperations, prolonged hospital stay, or lifetime healthcare costs.

Aims:The COVID-19 pandemic has disrupted the provision of arthroplasty services in England, Wales, and Northern Ireland. This study aimed to quantify the backlog, analyze national trends, and predict time to recovery. Methods:We performed an analysis of the mandatory prospective national registry of all independent and publicly funded hip, knee, shoulder, elbow, and ankle replacements in England, Wales, and Northern Ireland between January 2019 and December 2022 inclusive, totalling 729,642 operations. The deficit was calculated per year compared to a continuation of 2019 volume. Total deficit of cases between 2020 to 2022 was expressed as a percentage of 2019 volume. Sub-analyses were performed based on procedure type, country, and unit sector. Results:Between January 2020 and December 2022, there was a deficit of 158,994 joint replacements. This is equivalent to over two-thirds of a year of normal expected operating activity (71.6%). There were 104,724 (-47.1%) fewer performed in 2020, 41,928 (-18.9%) fewer performed in 2021, and 12,342 (-5.6%) fewer performed in 2022, respectively, than in 2019. Independent-sector procedures increased to make it the predominant arthroplasty provider (53% in 2022). NHS activity was 73.2% of 2019 levels, while independent activity increased to 126.8%. Wales (-136.3%) and Northern Ireland (-121.3%) recorded deficits of more than a year's worth of procedures, substantially more than England (-66.7%). It would take until 2031 to eliminate this deficit with an immediate expansion of capacity over 2019 levels by 10%. Conclusion:The arthroplasty deficit following the COVID-19 pandemic is now equivalent to over two-thirds of a year of normal operating activity, and continues to increase. Patients awaiting different types of arthroplasty, in each country, have been affected disproportionately. A rapid and significant expansion in services is required to address the deficit, and will still take many years to rectify.

BACKGROUND AND PURPOSE:National joint replacement registries were developed for prospective monitoring of outcomes and post-market surveillance of implants. Increasingly registry data informs practice. However, analysis of a registry can only be as good as the data it captures on the population of interest. We aimed to analyze completeness of reporting of hip and knee replacement procedures for all national registries worldwide. METHODS:We analyzed annual reports and data provided following written requests to all active national hip and knee replacement registries. Coverage was defined as the proportion of hospitals in the country that participate in the registry. Procedure completeness was defined as the proportion of procedures successfully captured by the registry. RESULTS:14 national registries were included, spanning years 2004 to 2022. Coverage was complete in 10. Median procedure completeness for primary hip and knee replacement across all years was 96.5% (interquartile range [IQR] 94.0-97.7%). Median procedure completeness for revisions was 88.5% (IQR 81.0-92.5%). The terminology used and method of calculation of completeness estimates in the registries were variable. CONCLUSION:National hip and knee replacement registry data generally reflects excellent coverage (full in 10 of 14 registries) and completeness (primary procedures 96.5% and revisions 88.5%) over the last 2 decades.

Total hip replacement (THR) is commonly performed to treat hip fractures. Dual -mobility constructs (DMCs) are increasingly used for this indication. The aim of this study was to use evidence synthesis techniques to estimate net all -cause construct survival for THR with DMC performed for hip fracture. Additionally, we aimed to investigate and describe differences in all -cause construct survival (if present) between THRs performed with DMC (DMC-THR) or with a conventional bearing construct following hip fracture. We performed a systematic review and meta -analysis of published studies (including joint registries), including DMC-THR for hip fracture which provided Kaplan -Meier (KM) survival estimates. The primary outcome was all -cause construct survival over time. The study was prospectively registered on PROSPERO (CRD42020173117). A total of 557 papers and 17 registry reports were identified. Six studies (four registry reports, one matchedpair cohort study utilising joint registry data, and one single -institution case series) met the inclusion criteria, including 17,370 DMC THRs and 167,377 conventional THRs. Five-year KM survival estimates (95% confidence intervals) were similar at 95.4% (94.9 to 95.8%) for DMC-THR and 96.2% (96.0 to 96.4%) for conventional THR. The relative risk of revision for DMC-THR at five years was 1.21 (1.05 to 1.41). These results suggest that DMC-THR has a lower all -cause survival than conventional THR following hip fracture. This analysis does not support the routine use of DMC-THR over conventional bearing THR.

Aims:The aim of this audit was to assess and improve the completeness and accuracy of the National Joint Registry (NJR) dataset for arthroplasty of the elbow. Methods:It was performed in two phases. In Phase 1, the completeness was assessed by comparing the NJR elbow dataset with the NHS England Hospital Episode Statistics (HES) data between April 2012 and April 2020. In order to assess the accuracy of the data, the components of each arthroplasty recorded in the NJR were compared to the type of arthroplasty which was recorded. In Phase 2, a national collaborative audit was undertaken to evaluate the reasons for unmatched data, add missing arthroplasties, and evaluate the reasons for the recording of inaccurate arthroplasties and correct them. Results:Phase 1 identified 5,539 arthroplasties in HES which did not match an arthroplasty on the NJR, and 448 inaccurate arthroplasties from 254 hospitals. Most mismatched procedures (3,960 procedures; 71%) were radial head arthroplasties (RHAs). In Phase 2, 142 NHS hospitals with 3,640 (66%) mismatched and 314 (69%) inaccurate arthroplasties volunteered to assess their records. A large proportion of the unmatched data (3,000 arthroplasties; 82%) were confirmed as being missing from the NJR. The overall rate of completeness of the NJR elbow dataset improved from 63% to 83% following phase 2, and the completeness of total elbow arthroplasty data improved to 93%. Missing RHAs had the biggest impact on the overall completeness, but through the audit the number of RHAs in the NJR nearly doubled and completeness increased from 35% to 70%. The accuracy of data was 94% and improved to 98% after correcting 212 of the 448 inaccurately recorded arthroplasties. Conclusion:The rate of completeness of the NJR total elbow arthroplasty dataset is currently 93% and the accuracy is 98%. This audit identified challenges of data capture with regard to RHAs. Collaboration with a trauma and orthopaedic trainees through the British Orthopaedic Trainee Association improved the completeness and accuracy of the NJR elbow dataset, which will improve the validity of the reports and of the associated research.