Hip bearing surfaces materials are typically broadly reported in national registry (metal-on-polyethylene, ceramic-on-ceramic etc). We investigated the revision rates of primary total hip replacement (THR) reported in the National Joint Registry (NJR) by detailed types of bearing surfaces used.

We analysed THR procedures across all orthopaedic units in England and Wales. Our analyses estimated all-cause and cause-specific revision rates. We identified primary THRs with heads and monobloc cups or modular acetabular component THRs with detailed head and shell/liner bearing material combinations. We used flexible parametric survival models to estimate adjusted hazard ratios (HR).

A total of 1,026,481 primary THRs performed between 2003–2019 were included in the primary analysis (Monobloc cups: n=378,979 and Modular cups: n=647,502) with 20,869 (2%) of these primary THRs subsequently undergoing a revision episode (Monobloc: n=7,381 and Modular: n=13,488).

Compared to implants with a cobalt chrome head and highly crosslinked polyethylene (HCLPE) cup, the overall risk of revision for monobloc acetabular implant was higher for patients with cobalt chrome or stainless steel head and non-HCLPE cup. The risk of revision was lower for patients with a delta ceramic head and HCLPE cup implant, at any post-operative period.

Compared to patients with a cobalt chrome head and HCLPE liner primary THR, the overall risk of revision for modular acetabular implant varied non-constantly. THRs with a delta ceramic or oxidised zirconium head and HCLPE liner had a lower risk of revision throughout the entire post-operative period.

The overall and indication-specific risk of prosthesis revision, at different time points following the initial implantation, is reduced for implants with a delta ceramic or oxidised zirconium head and a HCLPE liner/cup in reference to THRs with a cobalt chrome head and HCLPE liner/cup.

Hip prosthetic joint infection (PJI) is a debilitating complication following joint replacement surgery, with significant impact on patients and healthcare systems. The INFection ORthopaedic Management: Evidence into Practice (INFORM:EP) study, builds upon the 6-year INFORM programme by developing evidence-based guidelines for the identification and management of hip PJI.

A panel of 21 expert stakeholders collaborated to develop best practice guidelines based on evidence from INFORM \[1\]. An expert consensus process was used to refine guidelines using RAND/UCLA criteria. The guidelines were then implemented over a 12-month period through a Learning Collaborative of 24 healthcare professionals from 12 orthopaedic centres in England. Qualitative interviews were conducted with 17 members of the collaborative and findings used to inform the development of an implementation support toolkit. Patient and public involvement contextualised the implementation of the guidelines. The study is registered with the ISCRTN (34710385).

The INFORM guidelines, structured around the stages of PJI management, were largely supported by surgeons, although barriers included limited awareness among non-surgical team members, lack of job planning for multidisciplinary teams, and challenges in ensuring timely referrals from primary care. Psychological support for patients was identified as a critical gap. Advanced Nurse Practitioners and multidisciplinary team (MDT) coordinators were seen as potential bridges to address these knowledge gaps. The guidelines were also viewed as a useful tool for service development.

This study presents the first evidence-based guidelines for hip PJI management, offering a comprehensive approach to prevention, treatment, and postoperative care. Effective implementation is crucial, involving wider dissemination amongst primary and community care, as well as non-specialist treatment centres. Further resources are needed to ensure job planning for MDTs and psychological support for patients. Overall, this study lays the foundation for improved PJI management, benefiting patients and healthcare systems.

Implants in total hip replacement (THR) are associated with different clinical and cost-effectiveness profiles,. We estimate the costs and outcomes for NHS patients in the year after THR associated with implant bearing materials using linked routinely collected data.

We linked NJR primary elective THR patients for osteoarthritis to HES and National PROMs. We estimated health care costs, health-related quality of life indices, and revision risks, in the year after primary and revision THRs overall. We used generalised linear models adjusting for patient and hospital characteristics and estimated 10-year cumulative probability of revision. We imputed utilities using chained equations for half the sample with missing PROMS.

We linked 577,973 elective primary THRs and 11,812 subsequent revisions. One year after primary THR, patients with the cemented THRs using cobalt chrome or stainless steel head with HCLPE liner/cup cost the NHS, on average, £13,101 (95%CI £13,080,£13,122), had an average quality-of-life score of 0.788 (95%CI 0.787,0.788), and a 10-year revision probability of 1.9% (95%CI 1.6,2.3). Compared to the reference, patients receiving a cemented THR with delta ceramic head and HCLPE liner/cup, hybrid THR with delta ceramic head and HCLPE liner/cup, and hybrid THR with alumina head and HCLPE liner/cup had lower 1-year costs (-£572 \[95% CI -£775,-£385\], -£346 \[-£501,-£192\], -£371 \[-£574,-£168\] respectively), better quality of life (0.007 \[95% CI 0.003,0.011\], 0.013 \[0.010,0.016\], 0.009 \[0.005,0.013\] respectively), and lower 10-year revision probabilities (1.4% \[1.03,2.0\], 1.5 \[1.3,1.7\], 1.6%\[1.2,2.1\] respectively).

Implant bearing materials are associated with varying mean costs and health outcomes after primary THR. Ours is the first study to derive costs and health outcomes from large, linked databases using multiple imputation methods to deal with bias. Our findings are useful for commissioning and procurement decisions and to inform a subsequent cost-effectiveness model with more granular detail on THR implant types.

There is paucity of reliable data examining the treatment pathway for hip replacements over the life of the patient in terms of risk of revision and re-revisions.

We did a retrospective observational registry-based study of the National Joint Registry, using data on hip replacements from all participating hospitals in England and Wales, UK. We included data on all first revisions, with an identifiable primary procedure, with osteoarthritis as the sole indication for the original primary procedure. Kaplan-Meier estimates were used to determine the cumulative probability of revision and subsequent re-revision after primary hip replacement. Analyses were stratified by age and gender, and the influence of time from first to second revision on the risk of further revision was explored.

Between 2003, and 2019, there were 29 010 revision hip replacements with a linked primary episode. Revision rates of revision hip replacements were higher in patients younger than 55 years than in older age groups. After revision of primary total hip replacement, 21·3% (95% CI 18·6–24·4) of first revisions were revised again within 15 years, 22·3% (20·3–24·4) of second revisions were revised again within 7 years, and 22·3% (18·3–27·0) of third revisions were revised again within 3 years. After revision of hip resurfacing, 23·7% (95% CI 19·6–28·5) of these revisions were revised again within 15 years, 21·0% (17·0–25·8) of second revisions were revised again within 7 years, and 19·3% (11·9–30·4) of third revisions were revised again within 3 years. A shorter time between revision episodes was associated with earlier subsequent revision.

Younger patients are at an increased risk of multiple revisions. Patients who undergo a revision have a steadily increasing risk of further revision the more procedures they undergo, and each subsequent revision lasts for approximately half the time of the previous one.

A recent French report suggested that cobalt metal ions released from total hip replacements (THRs) were associated with an increased risk of dilated cardiomyopathy and heart failure. If the association is causal the consequences would be significant given the millions of Orthopaedic procedures in which cobalt-chrome is used annually. We examined whether cobalt-chrome containing THRs were associated with an increased risk of all-cause mortality, heart failure, cancer, and neurodegenerative disorders.

Data from the National Joint Registry was linked to NHS English hospital inpatient episodes for 375,067 primary THRs with up to 14·5 years follow-up. Implants were grouped as either containing cobalt-chrome or not containing cobalt-chrome. The association between implant construct and the risk of all-cause mortality and incident heart failure, cancer, and neurodegenerative disorders was examined.

There were 132,119 individuals (35·2%) with an implant containing cobalt-chrome. There were 48,106 deaths, 27,406 heart outcomes, 35,823 cancers, and 22,097 neurodegenerative disorders. There was no evidence of an association that patients with cobalt-chrome implants had higher rates of any of the outcomes. For all-cause mortality there was a very small survival advantage for patients having a cobalt-chrome implant (restricted mean survival time 13·8=days, 95% CI=6·8-20·9).

Cobalt-chrome containing THRs did not have an increased risk of all-cause mortality, heart failure, cancer, and neurodegenerative disorders into the second decade post-implantation. Our findings will reassure clinicians and patients that primary THR is not associated with systemic implant effects.

Total hip replacement (THR) for end-stage osteoarthritis is a commonly performed cost-effective procedure, which provides patients with significant clinical improvement. Estimating the future demand for joint replacement is important to identify the healthcare resources needed. We estimated the number of primary THRs that will need to be performed up to the year 2060.

We used data from The National Joint Registry for England, Wales, Northern Ireland and the Isle of Man on the current volume of primary THR (n=94,936) performed in 2018. We projected future numbers of THR using a static estimated rate from 2018 applied to population growth forecast data from the UK Office for National Statistics up to 2060.

By 2060, primary THR volume would increase from 2018 levels by an estimated 37.7% (n=130,766). For both males and females demand for surgery was also higher for patients aged 70 and over, with older patients having the biggest relative increase in volume over time: 70–79 years (144.6% males, 141.2% females); 80–89 years (212.4% males, 185.6% females); 90 years and older (448.0% males, 298.2% females).

By 2060 demand for THR is estimated to increase by almost 40%. Demand will be greatest in older patients (70 years+), which will have significant implications for the health service that requires forward planning given morbidity and resource use is higher in this population. There is a backlog of current demand with cancellation of elective surgery due to seasonal flu pressures in 2017 and now Covid-19 in 2020. Orthopaedics already has the largest waiting list of any speciality. These issues will negatively impact the health services ability to deliver timely joint replacement to many patients for a number of years and require urgent planning.

Total hip replacements (THRs) are performed by surgeons at various stages in their training, with varying levels of senior supervision. There is a balance between protecting training opportunities for the next generation of surgeons, while limiting the exposure of patients to unnecessary risk during the training process. The aim of this study was to examine the association between surgeon grade, the senior supervision of trainees, and the risk of revision following THR.

We included 603 474 primary THRs recorded in the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man (NJR) between 2003 and 2016 for an indication of osteoarthritis. Exposures were the grade of the surgeon (consultant or trainee), and whether trainees were supervised by a scrubbed consultant or not. Outcomes were all-cause revision, the indication for revision, and the temporal variation in risk of revision (all up to 10 years). Net failure was calculated using Kaplan-Meier analysis and adjusted analyses used Cox regression and flexible parametric survival analysis (adjusted for patient, operative, and unit level factors).

There was no association between surgeon grade and all-cause revision up to 10 years (crude hazard ratio (HR) 0·999, 95% confidence interval (CI) 0.936–1.065; p=0.966); a finding which persisted with adjusted analysis. Adjusted analysis demonstrated an association between trainees operating without supervision by a scrubbed consultant and an increase in all-cause revision (HR 1.100, 95% CI 1.002–1.207; p=0.045). There was an association between the trainee-performed THRs and revision due to instability (crude HR 1.143, 95% CI, 1.007–1.298; p=0.039). However, this was not observed in fully adjusted models, or when trainees were supervised by a scrubbed consultant.

Within the current training system in the United Kingdom, trainees achieve comparable outcomes to consultant surgeons when supervised by a scrubbed consultant. Revision rates are higher when trainees are not supervised by a scrubbed consultant but remain within internationally recognised acceptable limits.

Considerable debate exists regarding which agent(s) should be preferred for venous thromboembolism (VTE) chemical prophylaxis following joint replacement. We assessed the practice of surgeons regarding VTE chemical prophylaxis for primary THR and TKR, pre and post issuing of updated NICE guidance in 2018.

A survey, circulated through the British Hip Society and regional trainee networks/collaboratives, was completed by 306 UK surgeons at 187 units. VTE chemical prophylaxis prescribing patterns for surgeons carrying out primary THR (n=258) and TKR (n=253) in low-risk patients were assessed post publication of 2018 NICE recommendations. Prescribing patterns before and after the NICE publication were subsequently explored. Questions were also asked about surgeon equipoise for participation in future RCTs.

Following the new guidance, 34% (n=87) used low-molecular weight heparin (LMWH) alone, 33% (n=85) aspirin (commonly preceded by LMWH), and 31% (n=81) direct oral anticoagulants (DOACs: with/without preceding LMWH) for THR. For TKR, 42% (n=105) used aspirin (usually monotherapy), 31% (n=78) LMWH alone, and 27% (n=68) DOAC (with/without preceding LMWH). NICE guidance changed the practice of 34% of hip and 41% of knee surgeons, with significantly increased use of aspirin preceded by LMWH for THR (before=25% vs. after=73%;p<0.001), and aspirin for TKR (before=18% vs. after=84%;p<0.001). Significantly more regimens were NICE guidance compliant after the 2018 update for THR (before=85.7% vs. after=92.6%;p=0.011) and TKR (before=87.0% vs. after=98.8%;p<0.001). Support from surgeons for future RCTs was dependent on the clinical question, ranging from 48% participation in trials (effectiveness of aspirin vs. a DOAC) to 79% (effectiveness of 14 days LMWH vs. 28 days LMWH).

Over one-third of surveyed surgeons changed their VTE chemical prophylaxis in response to 2018 NICE recommendations, with more THR and TKR surgeons now compliant with latest NICE guidance. The major change in practice was an increased use of aspirin for VTE chemical prophylaxis. Furthermore, there is an appetite amongst UK surgeons for participating in future RCTs, with a trial comparing standard versus extended duration LMWH likely feasible in current practice.

Aims

To develop and externally validate a parsimonious statistical prediction model of 90-day mortality after elective total hip arthroplasty (THA), and to provide a web calculator for clinical usage.

Total hip replacements (THRs) provide pain relief and improved function to thousands of patients suffering from end-stage osteoarthritis, every year. Over 800 different THR constructs were implanted in the UK in 2017. To ensure reliable implants are used, a NICE revision benchmark of 5% after 10 years exists. Given the 10-year cumulative mortality of patients under 55 years of age receiving THRs is only 5% and that a recent study suggests 25-year THR survival of 58%, we aim to produce revision estimates out to 30 years that may guide future long-term benchmarks.

The local database of the Princess Elizabeth Orthopaedic Centre (PEOC), Exeter, holds data on over 20,000 patients with nearly 30-years follow-up with contemporary prostheses. A previous study suggests that the results of this centre are generalisable if comparisons restricted to the same prostheses. Via flexible parametric survival analysis, we created an algorithm using this database, for revision of any part of the construct for any reason, controlling for age and gender. This algorithm was applied to 664,761 patients in the NJR who have undergone THR, producing a revision prediction for patients with the same prostheses as those used at this centre.

Using our algorithm, the 10-year predicted revision rate of THRs in the NJR was 2.2% (95% CI 1.8, 2.7) based on a 68-year-old female patient; well below the current NICE benchmark. Our predictions were validated by comparison to the maximum observed survival in the NJR (14.2 years) using restricted mean survival time (P=0.32). Our predicted cumulative revision estimate after 30 years is 6.5% (95% CI 4.5, 9.4). The low observed and predicted revision rate with the prosthesis combinations studied, suggest current benchmarks may be lowered and new ones introduced at 15 and 20 years to encourage the use of prostheses with high survival.

Over 800 total hip replacement (THR) constructs were implanted in the UK in 2017. To ensure reliable implants are used, a NICE revision benchmark of 5% after 10 years exists. Surgeons are guided in choice by organisations such as the Orthopaedic Data Evaluation Panel (ODEP). Currently, ODEP publishes ratings for stem and cup separately and not for constructs. We used NJR data to investigate whether revision estimates of an individual stem (with all cups) is an accurate indicator of survival of all constructs using that stem.

The dataset comprised 234,289 THRs using the most frequently implanted stem between 2004 and 2017. Crude ten-year revision estimates were calculated using Kaplan-Meier for all THRs and for the five most implanted constructs. Adjusted comparisons between individual constructs and the overall stem revision estimate were made using flexible parametric survival analysis.

The 10-year crude, revision estimate for all THRs was 2.3% (95% CI 2.2, 2.4). Only four of the most frequently used constructs had long enough follow-up to analyse. 10-year estimates for these constructs ranged from 1.8% (95% CI 1.5, 2.1) to 3.7% (95% CI 3.2, 4.1), a log-rank test revealed strong evidence against the null hypothesis that revision estimates were the same for all constructs (p<0.001). Adjusted for age, sex and ASA, three of the four constructs showed a difference in 10-year revision estimates compared to this stem with all cups (P=0.03, P<0.001, P<0.001).

This study suggests 10-year revision estimates for all THRs using the most implanted stem in the NJR are not representative of all constructs involving that stem in crude or adjusted analyses. Current benchmarking systems report survival for the stem in combination with all cups and not for constructs. We suggest that benchmarking ratings basing on revision estimates for THR constructs would provide more accurate information, enabling informed construct decisions.

Aims

The aim of this study was to conduct evidence synthesis on the available published literature of the impact of the training status of the operating surgeon (trainee vs. consultant) on the survival and revision rate of primary hip and knee replacements.

Background

Total hip replacement (THR) is clinically and cost-effective. The surgical approach influences outcomes, however there is little generalisable and robust evidence to guide practice. We assessed the effect of surgical approach on THR outcomes.

Introduction

Analysis of registry data shows that few units achieve results better than 99·98% control limits. Implant selection is considered a predictor of outcome variation in joint replacement. We analysed the outcomes of a unit with statistically “better than expected” results and compared to all other units within the National Joint Registry for England, Wales, Northern Ireland and Isle of Man (NJR). We sought to determine whether improved implant survival following primary total hip replacement (THR) is a centre effect or mediated by implant selection.

Introduction

Total hip arthroplasty (THA) is indicated in independently mobile patients sustaining displaced intracapsular hip fractures. Studies presently suggest that the anterolateral approach is preferable to the posterior approach due to a perceived reduced risk of reoperations and dislocations. However, these observations come from small studies with short follow-up. We assessed whether surgical approach in THA performed for hip fractures effects outcomes.

Introduction

The development of an algorithm that provides accurate individualised estimates of revision risk could help patients make informed surgical treatment choices. This requires building a survival model based on fixed and modifiable risk factors that predict outcome at the individual level. Here we compare different survival models for predicting prosthesis survivorship after hip replacement for osteoarthritis using data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man (NJR).

Osteoarthritis of the hip is common and the mainstay of surgical treatment for end-stage disease is total hip replacement. There are few RCTs comparing long-term outcomes between prostheses; therefore, surgeons and patients are reliant on single-centre case-series and recently, analysis of joint registries, when making evidence-based implant choices.

We conducted a systematic review, conforming to PRISMA, of Medline and Embase in September 2017. Single-centre case-series and papers analysing registries were included. Series looking at disease-specific cohorts (other than OA), under 15 years follow-up or lacking survival analyses were excluded. Resurfacings, revisions and complex-primaries were also excluded. 2750 abstracts were screened, resulting in 299 full-text articles. Following full review 124 articles were excluded and 21 series added from references, resulting in 150 analyses of individual prostheses/constructs and 12 papers from registries. We also analysed annual reports of registries.

Registry data indicated cemented prostheses tended to better outcomes at late follow-ups, whereas case-series showed cementless prostheses tended to have better survival past 15 years with revision for any reason (of stem, cup or either component) as the end-point.

The discrepancy between results from registry data and single-centre case series is stark, and whilst the reasons for these differences may be multifactorial, single-centre case-series included in this review often lacked sufficient power to provide precise estimates of survival. This is contrasted to data from registries, which tended to have far greater numbers from multiple centres, allowing results to be generalised to the population.

The difference between these two modes of analysis suggests bias exists in selection and outcomes from single-centre series. The varied quality of reporting in case-series make it difficult for a reader to adequately assess bias, and accurately inform contemporary decision making.

Surgeons and patients should be cautious when interpreting single-centre case series and systems relying on data generated from them.

With the increasing demand for hip and knee replacement and move towards seven-day services, we examined whether this planned, elective surgery performed at the weekend is associated with a different 30-day mortality versus that performed between Monday and Friday.

The study dataset comprised 118,096 joint replacement episodes performed at the weekend and 1,233,882 episodes done on a weekday. We used a Kaplan-Meier framework to examine the 30-day cumulative mortality rate for all elective hip and knee replacements performed in England and Wales and recorded in the NJR between 1st April 2003 and 31st December 2014, with Cox proportional-hazards regression models to assess for time-dependent variation and adjust for identified risk factors for mortality.

For hip replacement the cumulative 30-day mortality was 0.15% (95%CI: 0.12–0.19) for patients operated on at the weekend versus 0.20% (0.19–0.21) for patients undergoing surgery during the normal working week. For knee replacement the cumulative 30-day mortality was 0.14% (0.11–0.17) for patients operated on at the weekend versus 0.18% (0.17–0.19) for patients undergoing surgery during the normal working week. The lower mortality associated with weekend operating was most apparent in the later years of the audit (2009 to 2014) and remained after adjustment for any differences in patient age, gender, American Society of Anaesthesiologist grade, surgeon seniority, surgical and anaesthetic practices, and thrombo-prophylaxis choice in weekend versus weekday operated patients.

Routine hip and knee replacements performed at the weekend in England and Wales and are not associated with an increased risk of post-operative mortality.

With the increasing demand for hip and knee replacement, and the increasing pressure to move towards routine seven-day services within the National Health Service, the trend towards weekend operating is set to increase. We aimed to determine whether planned, elective total hip and total knee replacement performed at the weekend is associated with a different 30-day mortality versus those performed between Monday and Friday.

We used National Joint Registry of England, Wales, Northern Ireland and Isle of Man (NJR) linked to Office for National Statistics (ONS) data. The study dataset comprised 118,096 joint replacement episodes performed at the weekend and 1,233,882 episodes done on a weekday. The main outcome measure was 30-day all-causes mortality. We applied a survivorship analysis using a Kaplan-Meier framework to examine the 30-day cumulative mortality rate for all elective hip and knee replacements performed in England and Wales between 1st April 2003 and 31st December 2014, with Cox proportional-hazards regression models to assess for time-dependent variation and adjust for identified risk factors for mortality.

For hip replacement the cumulative 30-day mortality was 0.15% (95%CI: 0.12–0.19) for patients operated on at the weekend versus 0.20% (0.19–0.21) for patients undergoing surgery during the normal working week. For knee replacement the cumulative 30-day mortality was 0.14% (0.11–0.17) for patients operated on at the weekend versus 0.18% (0.17–0.19) for patients undergoing surgery during the normal working week. The lower mortality associated with weekend operating was most apparent in the later years of the audit (2009 to 2014) and remained after adjustment for any differences in patient age, gender, American Society of Anaesthesiologist grade, surgeon seniority, surgical and anaesthetic practices, and thrombo-prophylaxis choice in weekend versus weekday operated patients.

Hip and knee replacements are routinely performed on Saturdays, and to a lesser extent on Sundays, in England and Wales and are not associated with an increased risk of post-operative mortality.