At the end of 2018, the NZ Joint Registry introduced a “Surgeon Outlier” policy, whereby each year, if an individual surgeons’ lower 95% confidence interval of their revision rate, measured in revision/100 component years(r/ocys), was above the NZ mean (0.71 r/ocys), that surgeon was required to audit their results with a nominated peer. This study investigates whether outlier surgeons also have high early (1 month and 1 year) revision rates. In 2018, 236 surgeons performed 9,186 total hip arthroplasties in NZ. At the end of 2018, 11 surgeons received notification they were outliers. Results from all surgeons for years 2016, 2017 and 2018 were combined to form the first (pre-notification) time interval, and results from years 2019, 2020 and 2021 were combined to form the second time interval (post-notification). Outlier surgeons performed 2001 total hip replacements in the first time interval and 1947 hips in the second. Early revision rates (1 month and 1 year) of both outlier and nonoutlier surgeons for both time intervals were analysed. Non-outlier surgeons had a consistent mean early revision rate of 0.75% at one month and 1.6% at one year for both time intervals. The 11 outlier surgeons had a higher earlier revision rate of 1.35% at one month and 2.45% at one year for the pre-notification time interval. These values reduced for the post-notification time interval to a revision rate of 1.23% for one month and 2.36% for one year. Poor joint registry results of individual surgeons are often attributed to a poor choice of prosthesis. This study shows early revision rates of outlier surgeons, where prosthesis selection has minimal influence, are also high. A slight improvement in early revision rates of outlier surgeons since introduction of the policy shows it is working

Introduction. The American Joint Replacement Registry (AJRR) was created to capture total hip (THA) and total knee arthroplasty (TKA) procedural data in order to conduct implant-specific survivorship analyses, produce risk-adjusted patient outcome data, and provide hospitals and surgeons with quality benchmarks. The purpose of this study is to compare early reports from the AJRR to other national registries to identify similarities and differences in surgeon practice and potential topics for future analysis. Methods. Hip arthroplasty data were extracted from the annual reports from the AJRR and other national registries including: the Australian registry; the New Zealand registry; the United Kingdom, Wales, and Isle of Man registry; the Norwegian registry; and the Swedish registry from 2014 to 2016. Data regarding femoral and acetabular fixation, bearing surface type, femoral head size, the use of dual mobility articulation bearings, hip resurfacing utilization, and THA revision burden were evaluated. Revision burden is defined as the ratio of implant revisions to the total number of arthroplasties performed in a given time period. Registry characteristics and patient demographic data were recorded across all registries. The results were compared between the various registries and reported using descriptive statistics. Results. In 2016, the AJRR captured data from approximately 28% of all arthroplasty procedures performed in the United States, compared to 95–98% amongst the other registries that were evaluated. Total hip arthroplasty patients in the AJRR were similar to the other registries, with a mean age of 66.6 years for primary THA compared to a range of 67.0–69.0 years amongst the other registries. The operative diagnoses varied for primary THA between the registries. Osteoarthritis was the most common diagnosis but it represented 93% of patients in the UK and Wales registry,. 79% in the AJRR and 76.5% in the Norwegian registry. THA practices in the AJRR revealed much higher usage of cementless femoral and acetabular components (93%). In comparison, the other registries reported variable rates of usage of cementless femoral and acetabular fixation including: Australian registry (63.4%); United Kingdom and Wales (38.5%); New Zealand registry (39.1%) and the Swedish registry (21.8%). In the AJRR ceramic heads (52.8%) and 36mm heads (60.2%) were most frequently used; in all other registries metal heads (52.7–69.4%) and 32mm heads (37.0–72.7%) were the most popular. Dual mobility articulations were infrequently reported by the other registries but accounted for 8% of primary THAs and 28% of revision THAs in the AJRR. In 2016 the THA revision burden was 8.6% in the AJRR compared to 8.2 – 13.8% in the other registries. Conclusion. The present study offers an early comparison of data reported by the AJRR and other national registries and identifies several differences in THA practice patterns between the United States and other countries. As the AJRR continues to grow, future studies should focus on understanding why international differences in total joint arthroplasty practice trends exist and differences in outcomes associated with these practices

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

Electronic Health Records (EHRs) have benefits for hospitals and uptake in the UK is increasing. The National Joint Registry (NJR) monitors implant and surgeon performance and relies on accuracy of data. NJR data are used for identification of potential outliers for both mortality and revision; analyses are adjusted for age, sex, and American Society of Anaesthesiologists score (ASA) and cases with some indications are excluded from analyses. In October 2020, the Royal Devon University Hospitals NHS Foundation Trust “went live” on an EHR, almost eradicating paper from the Trust. This included stopping use of paper NJR forms by creating a bespoke electronic template. We sought to identify discrepancies between operation notes and data input to the NJR in variables that may influence potential outlier analyses. Data input to the NJR from 15/10/2020 to 18/10/2022 for hip procedures were provided by NEC Software Solutions. NJR data were compared to those recorded on operation notes. There were 1067 hip procedures recorded in the NJR (946 primary THRs). Of the primary THRs, discrepancies in indication between NJR and operation note were identified in 139 (15%) cases. Common discrepancies included cases being recorded as osteoarthritis where the true indication was acute trauma (n=63), avascular necrosis (n=14), metastatic cancer/malignancy (n=6) and 21 cases with no recorded indication. We identified 88 cases where the ASA recorded in the NJR differed from the anaesthetic chart. Other inaccuracies were identified including 23 cases missing type of procedure (e.g., primary or revision) and one where revision surgery had been recorded as primary. We identified at least 83 cases that should have been excluded from NJR mortality analyses but were not. Given the low incidence of mortality following primary THR, these cases (with increased risk of death) have the potential to incorrectly identify the hospital as a potential outlier. Discrepancies in ASA may also impact on both revision and mortality outlier calculations. We urge caution to hospitals in the implementation of EHRs and advise regular audit of data sent to the NJR

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

Aims. The Exeter V40 femoral stem is the most implanted stem in the National Joint Registry (NJR) for primary total hip arthroplasty (THA). In 2004, the 44/00/125 stem was released for use in ‘cement-in-cement’ revision cases. It has, however, been used ‘off-label’ as a primary stem when patient anatomy requires a smaller stem with a 44 mm offset. We aimed to investigate survival of this implant in comparison to others in the range when used in primary THAs recorded in the NJR. Methods. We analyzed 328,737 primary THAs using the Exeter V40 stem, comprising 34.3% of the 958,869 from the start of the NJR to December 2018. Our exposure was the stem, and the outcome was all-cause construct revision. We stratified analyses into four groups: constructs using the 44/00/125 stem, those using the 44/0/150 stem, those including a 35.5/125 stem, and constructs using any other Exeter V40 stem. Results. In all 328,737 THAs using an Exeter V40 stem, the revision estimate was 2.8% (95% confidence interval (CI) 2.7 to 2.8). The 44/00/125 stem was implanted in 2,158 primary THAs, and the ten-year revision estimate was 4.9% (95% CI 3.6 to 6.8). Controlling for age, sex, year of operation, indication, and American Society of Anesthesiologists grade demonstrated an increased overall hazard of revision for constructs using the 44/00/125 stem compared to constructs using other Exeter V40 femoral stems (hazard ratio 1.8 (95% CI 1.4 to 2.3)). Conclusion. Although the revision estimate is within the National Institute for Health and Care Excellence ten-year benchmark, survivorship of constructs using the 44/00/125 stem appears to be lower than the rest of the range. Adjusted analyses will not take into account ‘confounding by indication’, e.g. patients with complex anatomy who may have a higher risk of revision. Surgeons and patients should be reassured but be aware of the observed increased revision estimate, and only use this stem when other implants are not suitable. Cite this article: Bone Joint J 2023;105-B(5):504–510

Aims. Periprosthetic femoral fractures (PPF) are a serious complication of total hip arthroplasty (THA) and are becoming an increasingly common indication for revision arthroplasty with the ageing population. This study aimed to identify potential risk factors for PPF based on an analysis of registry data. Methods. Cases recorded with PPF as the primary indication for revision arthroplasty in the German Arthroplasty Registry (Endoprothesenregister Deutschland (EPRD)), as well as those classified as having a PPF according to the International Classification of Diseases (ICD) codes in patients’ insurance records were identified from the complete datasets of 249,639 registered primary hip arthroplasties in the EPRD and included in the analysis. Results. The incidence of PPFs was higher (24.6%; 1,483) than reported in EPRD annual reports listing PPF as the main reason for revision (10.9%; 654). The majority of fractures occurred intraoperatively and were directly related to the implantation process. Patients who were elderly, female, or had comorbidities were at higher risk of PPFs (p < 0.001). German hospitals with a surgical volume of < 300 primary procedures per year had a higher rate of PPFs (p < 0.001). The use of cemented and collared prostheses had a lower fracture risk PPF compared to uncemented and collarless components, respectively (both p < 0.001). Collared prostheses reduced the risk of PPF irrespective of the fixation method and hospital’s surgical volume. Conclusion. The high proportion of intraoperative fractures emphasises the need to improve surgeon training and surgical technique. Registry data should be interpreted with caution because of potential differences in coding standards between institutions. Cite this article: Bone Joint J 2021;103-B(4):650–658

We investigated the revision rates of primary total hip replacement (THR) reported in the National Joint Registry (NJR) by 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 head and shell/liner 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 are included in the primary analysis (Monobloc: n=378,979 and Modular: 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 all-cause 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 all-cause 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 all-cause and indication-specific risk of prosthesis revision, at different time points following the initial implantation, is lower for implants with a delta ceramic or oxidised zirconium head and a HCLPE liner/cup than commonly used alternatives such as cobalt chrome heads and HCLPE liner/cup

FAI may cause pain or functional impairment for an individual, as well as potentially resulting in arthritis and degeneration of the hip joint. Results from recent randomised control trials demonstrate the superiority of surgery over physiotherapy in patients with FAI. However, there is paucity of evidence regarding which factors influence outcomes for FAI surgery, most notably on patient reported outcomes measures (PROMs). Our study looks to explore factors influencing the outcomes for patients undergoing surgery for FAI utilising data from the Non-Arthroplasty Hip Registry. This study is a retrospective analysis of data collected prospectively via the NAHR database. Patients meeting the inclusion criteria, who underwent surgery between January 2011 and September 2019 were identified and included in the study. Follow-up data was captured in September 2020 to allow a minimum of 12 months follow-up. Patients consenting to data collection received questionnaires to determine EQ-5D Index and iHOT-12 scores preoperatively and at 6 months, 1, 2- and 5-year follow-up. Changes in outcome scores were analysed for all patients and sub-analysis was performed looking at the influence of; FAI morphological subtype, age, and sex, on outcome scores. Our cohort included 4,963 patients who underwent arthroscopic treatment for FAI. There was significant improvement from pre-operative PROMs when compared with those at 6 and 12 months. Pre-operatively, and at 12-month follow-up, iHOT-12 scores were significantly better for the cam / mixed groups compared to the pincer group (p<0.01). In multivariable regression analysis, pincer pathology and a high-grade chondral lesion were associated significantly poorer iHOT-12 improvement at 6 and 12 months (p<0.05). Age (<40 vs >40) demonstrated no statistical significance when considering 12 months outcome scores. This study demonstrates that hip arthroscopy is an effective treatment for patients with symptomatic FAI and shows statistically significant improvements at 12 months. The findings of this study are relevant to orthopaedic surgeons who manage young adults with hip pathology. This will help them to; predict which patients may benefit from operative intervention, and better inform patients, when undertaking shared decision making

Background. The purpose of this study was to report functional outcome scores following arthroscopic acetabular chondral procedures using the U.K. Non-Arthroplasty Hip Registry (NAHR). Methods. Data on adult patients who underwent hip arthroscopy between January 2012 and December 2018 was extracted from the NAHR. Patients who underwent femoral sided chondral procedures were excluded. Patients who underwent osteophyte excision or a concurrent extra-articular procedure were also excluded. Cases were then classified according to the acetabular chondral procedure performed – ‘chondroplasty’, ‘microfracture’ or ‘none’ (no chondral procedure recorded). Outcomes comprised EuroQol-5 Dimensions (EQ-5D) index and the International Hip Outcome Tool 12 (iHOT-12), preoperatively and at 6 and 12 months. Results. A total of 4,978 arthroscopies were identified (chondroplasty 26.4%, microfracture 5.4%, none 68.2%). Patients who underwent microfracture were significantly older (37.9y vs 37.3y) and of higher BMI (26.4 vs 25.8 kg/m2) than patients who underwent chondroplasty. Pre-operative, 6 and 12-month follow-up were available for 77%, 42% and 38% of cases respectively. This registry study found significant clinical improvement in all groups based on arthroscopic chondral procedure following hip arthroscopy. Patients who have microfracture seem to take longer to improve and have lower peak scores as compared with chondroplasty. All groups saw significant (p <0.0001) EQ-5D and iHOT-12 gain compared to pre-operative baseline scores at 6 months which was maintained at 12 months (12 month iHOT-12 gain: chondroplasty = +27.6 (95%CI 25.0 to 30.2), microfracture = +22.6 (95%CI 17.6 to 27.6), none = +25.4 (23.8 to 27.0)). There were no statistically significant between group differences in iHOT-12 gain. Comparing <40y vs >40y age groups, all saw significant improvements in baseline scores maintained up to 12 months however patients over 40y were slower to improve, particularly in microfracture with significantly poorer iHOT-12 gain at 6 months in comparison to patients under 40y but significance was lost by 12 months. Conclusion. Whilst patient selection is crucial (and we acknowledge selection bias as a key limitation), all three chondral procedures were effective at improving patient outcomes for both younger and older patients

Aims. To investigate the effect of polyethylene manufacturing characteristics and irradiation dose on the survival of cemented and reverse hybrid total hip arthroplasties (THAs). Methods. In this registry study, data from the National Joint Registry of England, Wales, Northern Ireland and the Isle of Man (NJR) were linked with manufacturing data supplied by manufacturers. The primary endpoint was revision of any component. Cox proportional hazard regression was a primary analytic approach adjusting for competing risk of death, patient characteristics, head composition, and stem fixation. Results. A total of 290,770 primary THAs were successfully linked with manufacturing characteristics. Overall 4,708 revisions were analyzed, 1,260 of which were due to aseptic loosening. Total radiation dose was identified as a risk factor and included in the Cox model. For statistical modelling of aseptic loosening, THAs were grouped into three categories: G1 (no radiation); G2 ( > 0 to < 5 Mrad); and G3 ( ≥ 5 Mrad). G1 had the worst survivorship. The Cox regression hazard ratio for revision due to aseptic loosening for G2 was 0.7 (95% confidence interval (CI) 0.58 to 0.83), and for G3 0.4 (95% CI 0.30 to 0.53). Male sex and uncemented stem fixation were associated with higher risk of revision and ceramic heads with lower risk. Conclusion. Polyethylene irradiation was associated with reduced risk of revision for aseptic loosening. Radiation doses of ≥ 5 Mrad were associated with a further reduction in risk. Cite this article: Bone Joint Res 2020;9(9):563–571

Objectives. The aim of this study was to use registry data to report and compare early patient outcomes following arthroscopic repair or debridement of the acetabular labrum. Methods. Data on adult patients who underwent arthroscopic labral debridement or repair between January 2012 and March 2019 was extracted from the UK Non-Arthroplasty Hip Registry dataset. Patients who underwent microfracture, osteophyte excision or a concurrent extra-articular procedure were excluded. Outcomes comprised EuroQol-5 Dimensions (EQ-5D) index and the International Hip Outcome Tool 12 (iHOT-12), preoperatively and at 6 and 12 months. Results. A total of 3,553 arthroscopies comprising 1,986 labral debridement (56%) and 1,567 labral repairs (44%) were identified. Both groups saw significant (p <0.0001) EQ-5D and iHOT-12 gain compared to pre-operative baseline scores at 6 months (iHOT-12: repair = +27.4 (95%CI 25.2 to 29.5), debridement = +24.8 (95%CI 22.7 to 26.9)) which was maintained at 12 months (repair = +28.3 (95%CI 26.0 to 30.6), debridement = +24.3 (95%CI 22.0 to 26.5)) with improvement being significantly greater in the repair group by 12 months (p = 0.016) including after modelling for patient and surgical factors. Overall, 64% of cases achieved the minimum clinically important difference (MCID) and 47% achieved substantial clinical benefit (SCB: repair = 51%, debridement = 43%, p = 0.005) at 12 months. Significant functional improvement was seen for both genders and in younger and older (>40 years) cohorts. Conclusion. Both labral repair and debridement techniques were successful in significantly improving 12-month outcomes following hip arthroscopy regardless of age or gender. Labral repair was associated with superior outcomes in comparison to debridement. Whilst patient selection is crucial, our findings support the repair of an injured labrum where possible. A multi-centre randomised controlled trial would be the most appropriate next step to overcome bias inherent in the existing literature

Aims. The primary aim of this paper was to outline the processes involved in building the Partners Arthroplasty Registry (PAR), established in April 2016 to capture baseline and outcome data for patients undergoing arthroplasty in a regional healthcare system. A secondary aim was to determine the quality of PAR’s data. A tertiary aim was to report preliminary findings from the registry and contributions to quality improvement initiatives and research up to March 2019. Methods. Structured Query Language was used to obtain data relating to patients who underwent total hip or knee arthroplasty (THA and TKA) from the hospital network’s electronic medical record (EMR) system to be included in the PAR. Data were stored in a secure database and visualized in dashboards. Quality assurance of PAR data was performed by review of the medical records. Capture rate was determined by comparing two months of PAR data with operating room schedules. Linear and binary logistic regression models were constructed to determine if length of stay (LOS), discharge to a care home, and readmission rates improved between 2016 and 2019. Results. The PAR captured 16,163 THAs and TKAs between April 2016 and March 2019, performed in seven hospitals by 110 surgeons. Manual comparison to operating schedules showed a 100% capture rate. Review of the records was performed for 2,603 random operations; 2,298 (88.3%) had complete and accurate data. The PAR provided the data for three abstracts presented at international conferences and has led to preoperative mental health treatment as a quality improvement initiative in the participating institutions. For primary THA and TKA surgeries, the LOS decreased significantly (p < 0.001) and the rate of home discharge increased significantly (p < 0.001) between 2016 and 2019. Readmission rates did not correlated with the date of surgery (p = 0.953). Conclusion. The PAR has high rates of coverage (the number of patients treated within the Partners healthcare network) and data completion and can be used for both research purposes and quality improvement. The same method of creating a registry that was used in the PAR can be applied to hospitals using similar EMR systems. Cite this article: Bone Joint J 2020;102-B(7 Supple B):90–98

Ceramic on ceramic (CoC) bearings in total hip arthroplasty (THA) are commonly used but concerns exist regarding ceramic fracture. This study aims to report the risk of revision for fracture of modern CoC bearings and identify factors that might influence this risk, using data from the National Joint Registry. We analysed data on 111,681 primary CoC THA's and 182 linked revisions for bearing fracture recorded in the National Joint Registry of England, Wales, Northern Ireland and the Isle of Man (NJR). We used implant codes to identify ceramic bearing composition and generated Kaplan-Meier estimates for implant survivorship. Logistic regression analyses were performed for implant size and patient specific variables to determine any associated risks for revision. 99.8% of bearings were CeramTec Biolox® products. Revisions for fracture were linked to 7 of 79,442 (0.009%) Biolox® Delta heads, 38 of 31,982 (0.119%) Biolox® Forte heads, 101 of 80,170 (0.126%) Biolox® Delta liners and 35 of 31,258 (0.112%) Biolox® Forte liners. Regression analysis of implant size revealed smaller heads had significantly higher odds of fracture (χ2=68.0, p<0.0001). The highest fracture risk were observed in the 28mm Biolox® Forte subgroup (0.382%). There were no fractures in the 40mm head group for either ceramic type. Liner thickness was not predictive of fracture (p=0.67). BMI was independently associated with revision for both head fractures (OR 1.09 per unit increase, p=0.031) and liner fractures (OR 1.06 per unit increase, p=0.006). We report the largest registry study of CoC bearing fractures to date. Modern CoC bearing fractures are rare events. Fourth generation ceramic heads are around 10 times less likely to fracture than third generation heads, but liner fracture risk remains similar between these generations

Background. Method of fixation in THA is a contentious issue, with proponents of either technique citing improved implant survival and outcomes. Current comparisons rely on insufficiently powered studies with short-term follow up or larger poorly controlled registry studies. Patient factors are considered a key variable contributing to the risk of implant failure. One way to overcome this confounder is to compare the survival of cementless and cemented THAs patients who have undergone bilateral THAs with cemented hip on one side and cementless hip on the other. We compared stem survival of patients who have bilateral THA with one cemented stem in one hip and a cementless stem in the contralateral hip in the National Joint Registry. Methods. UK National Joint Registry is the largest registry of its kind in the world. This study included 2934 patients with 5868 THAs who underwent bilateral THAs s between 2003 and 2016. These patients had undergone bilateral sequential THAs within 3 years of each other: cemented THA on one side and cementless on the other, Patients had identical pre-operative American Society of Anaesthesiologists group for both THAs and same indication for surgery. Implant survival was compared using Cox regression with an endpoint of stem revision. Results. Ten-year all-cause survival of cementless stems was lower than for cemented stems (p<0.001), as was survival to aseptic loosening revision (p<0.001). Similar trends were seen across all age groups including young and old patients. There was a non-significant trend towards superiority of cemented stems in survival until periprosthetic fracture, dislocation and infection. Conclusion. Comparison of cementless with cemented stems within patients is a novel method to compare the outcomes of orthopaedic implants. Survival was better for cemented stems including for younger patients and aseptic loosening

Background. This study aimed to investigate the effect of body mass index (BMI) on functional outcome following hip preservation surgery using the U.K. Non-Arthroplasty Hip Registry (NAHR). Methods. Data on adult patients who underwent hip arthroscopy or periacetabular osteotomy (PAO) between January 2012 and December 2018 was extracted from the UK Non-Arthroplasty Hip Registry dataset allowing a minimum of 12 months follow-up. Data is collected via an online clinician and patient portal. Outcomes comprised EuroQol-5 Dimensions (EQ-5D) index and the International Hip Outcome Tool 12 (iHOT-12), preoperatively and at 6 and 12 months. Results. A total of 6,666 patients were identified with BMI data available in 52%, comprising 3,220 arthroscopies and 277 PAO. Patients were divided into WHO groups: <25kg/m. 2. (n=1,745 (49.8%)), 25–30kg/m. 2. (n=1,199 (34.2%)), and ≥30kg/m. 2. (n=562 (16.0%)). Patients with higher BMI tended to be older. Pre-operative, 6 and 12-month follow-up were available for 91%, 49% and 45% of cases respectively. Higher BMI was associated with significantly poorer baseline, 6- and 12-month outcomes (12-month mean iHOT-12 score: <25kg/m. 2. = 62.3 (95%CI 60.4 to 64.3), 25–30kg/m. 2. = 57.3 (95%CI 55.0 to 59.7), ≥30kg/m. 2. = 54.7 (95%CI 51.1 to 58.2)). However, all groups saw similar and statistically significant improvement in pre- vs post-op scores (mean 12-month iHOT-12 gain: <25kg/m. 2. = +27.1 (95%CI 25.1 to 29.0), 25–30kg/m. 2. = +26.5 (95%CI 24.0 to 29.0), ≥30kg/m. 2. = +26.8 (95%CI 23.2 to 30.4), between-group p = 0.9). EQ-5D outcomes followed the same trend. Modelling for age, sex and procedure we found no significant difference in 12-month iHOT-12 gain between BMI groups. Conclusion. Whilst obese patients started from, and achieved lower post-operative raw functional scores, all BMI groups saw similar and significant degrees of improvement in functional outcome post-operatively. Obesity should not be considered a contraindication to hip preservation surgery

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

Current advice regarding implant choice is based on estimates of cost-benefit derived from implant survival to an endpoint of revision. Current estimates do not account for many implant failures which are treated with non-revision surgery and may not be accurate. The aim of this study was to estimate survival of major stem implant design groups to an endpoint of reoperation. Primary total hip replacement and linked revision form the National Joint Registry (NJR) and Hospital Episode Statistics (HES) data linked by unique identifier were used. Survival of femoral implant groups (cemented stainless steel polished taper [PTSS], cemented cobalt chrome polished taper [PTCC], cemented composite beam [CB], collarless cementless [NCOL] and collared cementless [COL]) was estimated using Kaplan-Meier method. 809,832 patients with valid NJR and HES data from England, were included. Cumulative failure at ten years for PTSS increased overall from 2.9% (95%CI 2.8–2.9) to 3.6% (95%CI 3.6–3.7) after inclusion of reoperations. Cumulative failure at ten years for PTSS increased from 2.5% (95%CI 2.5–2.6) to 3.3% (95%CI 3.2–3.4), for PTCC increased from 3.8% (95%CI 3.5–4.0) to 5.4% (95%CI 5.1–5.6), for CB increased from 3.1% (95%CI 2.9–3.3) to 4.1% (95%CI 3.8–4.3), for NCOL increased from 3.4% (95%CI 3.3–3.5) to 3.9% (95%CI 3.8–4.0), and for COL increased from 2.5% (95%CI 2.4–2.6) to 3.1% (95%CI 2.9–3.2), after inclusion of reoperations. Re-operation for internal fixation is as significant life event for the patient as revision. When a more inclusive metric is used, the patient and clinician's perspective on what constitutes a GIRFT implant may not be the same. Further work is required to update implant selection guidance in view of the change in implant performance

Aims. Natural Language Processing (NLP) offers an automated method to extract data from unstructured free text fields for arthroplasty registry participation. Our objective was to investigate how accurately NLP can be used to extract structured clinical data from unstructured clinical notes when compared with manual data extraction. Methods. A group of 1,000 randomly selected clinical and hospital notes from eight different surgeons were collected for patients undergoing primary arthroplasty between 2012 and 2018. In all, 19 preoperative, 17 operative, and two postoperative variables of interest were manually extracted from these notes. A NLP algorithm was created to automatically extract these variables from a training sample of these notes, and the algorithm was tested on a random test sample of notes. Performance of the NLP algorithm was measured in Statistical Analysis System (SAS) by calculating the accuracy of the variables collected, the ability of the algorithm to collect the correct information when it was indeed in the note (sensitivity), and the ability of the algorithm to not collect a certain data element when it was not in the note (specificity). Results. The NLP algorithm performed well at extracting variables from unstructured data in our random test dataset (accuracy = 96.3%, sensitivity = 95.2%, and specificity = 97.4%). It performed better at extracting data that were in a structured, templated format such as range of movement (ROM) (accuracy = 98%) and implant brand (accuracy = 98%) than data that were entered with variation depending on the author of the note such as the presence of deep-vein thrombosis (DVT) (accuracy = 90%). Conclusion. The NLP algorithm used in this study was able to identify a subset of variables from randomly selected unstructured notes in arthroplasty with an accuracy above 90%. For some variables, such as objective exam data, the accuracy was very high. Our findings suggest that automated algorithms using NLP can help orthopaedic practices retrospectively collect information for registries and quality improvement (QI) efforts. Cite this article: Bone Joint J 2020;102-B(7 Supple B):99–104

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