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Bone & Joint Open
Vol. 5, Issue 8 | Pages 637 - 643
6 Aug 2024
Abelleyra Lastoria DA Casey L Beni R Papanastasiou AV Kamyab AA Devetzis K Scott CEH Hing CB

Aims. Our primary aim was to establish the proportion of female orthopaedic consultants who perform arthroplasty via cases submitted to the National Joint Registry (NJR), which covers England, Wales, Northern Ireland, the Isle of Man, and Guernsey. Secondary aims included comparing time since specialist registration, private practice participation, and number of hospitals worked in between male and female surgeons. Methods. Publicly available data from the NJR was extracted on the types of arthroplasty performed by each surgeon, and the number of procedures of each type undertaken. Each surgeon was cross-referenced with the General Medical Council (GMC) website, using GMC number to extract surgeon demographic data. These included sex, region of practice, and dates of full and specialist registration. Results. Of 2,895 surgeons contributing to the NJR in 2023, 102 (4%) were female. The highest proportions of female surgeons were among those who performed elbow (n = 25; 5%), shoulder (n = 24; 4%), and ankle (n = 8; 4%) arthroplasty. Hip (n = 66; 3%) and knee arthroplasty (n = 39; 2%) had the lowest female representation. Female surgeons had been practising for a median of 10.4 years since specialist registration compared to 13.7 years for males (p < 0.001). Northern Ireland was the region with the highest proportion of female arthroplasty surgeons (8%). A greater proportion of male surgeons worked in private practice (63% vs 24%; p < 0.001) and in multiple hospitals (74% vs 40%; p < 0.001). Conclusion. Only 4% of surgeons currently contributing cases to the NJR are female, with the highest proportion performing elbow arthroplasty (5%). Female orthopaedic surgeons in the NJR are earlier in their careers than male surgeons, and are less involved in private practice. There is a wide geographical variation in the proportion of female arthroplasty surgeons. Cite this article: Bone Jt Open 2024;5(8):637–643


The National Joint Registry (NJR) was set up by the Department of Health to collect information on all joint replacements. The NJR data is externally validated against nationally collated Hospital Episode Statistics (HES). Errors associated with the use of HES data have been widely documented. We sought to explore the accuracy of the NJR data, for a single surgeon, against a prospectively collected personal logbook. The NJR and logbook were compared over a 3-year period (01/07/2009 to 30/06/2012). Total procedure recorded in the personal logbook was 684 and in the NJR was 681. TKR in personal log book was 304 and in NJR 316, revision knee's in personal logbook 45 and in NJR 36, THR 274 in personal logbook and 271 in NJR, revision hip procedures in personal logbook 64 and 58 in NJR. Whilst the total number of procedures captured correlates closely (681 vs 684) there is more variation with the different individual procedures. This may be due to the addition of 11% of HES data used for this time period by the NJR as it is known to be inaccurate. This therefore demonstrates the importance of maintaining your own accurate records


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_11 | Pages 1 - 1
4 Jun 2024
Jennison T Goldberg A Sharpe I
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Introduction. Despite the increasing numbers of ankle replacements that are being performed there are still limited studies on the survival of ankle replacements and comparisons between different implants. The primary aim of this study is to link NJR data with NHS digital data to determine the true failure rates of ankle replacements. Secondary outcomes include analysis risk factors for failure, patient demographics and outcomes of individual prosthesis. Methods. A data linkage study combined National Joint Registry Data and NHS Digital data. The primary outcome of failure is defined as the removal or exchange of any components of the implanted device inserted during ankle replacement surgery. Life tables and Kaplan Meier survival charts demonstrated survivorship. Cox proportional hazards regression models with the Breslow method used for ties were fitted to compare failure rates. Results. 5,562 primary ankle replacement were recorded on the NJR. The 1-year survivorship was 98.8% (95% CI 98.4%–99.0%), 5-year survival in 2725 patients was 90.2% (95% CI 89.2%–91.1%), and 10-year survival in 199 patients was 86.2% (95% CI 84.6%–87.6%). When using a Cox regression model for all implants with over 100 implantations using the Infinity as the reference, only the Star (Hazard ratio 1.60 95% CI 0.87–2.96) and Inbone (HR 0.38 95% CI 0.05–2.84) did not produce significantly worse survivorship. Conclusion. Ankle replacements have increased in numbers over the past decade, and the currently used implants have lower failure rates than older prosthesis. It is expected that in the future the outcomes of ankle replacements will continue to improve


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_11 | Pages 38 - 38
7 Jun 2023
Ewels R Kassam A Evans J
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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


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_12 | Pages 2 - 2
1 Oct 2018
Dodd CAF Kennedy J Palan J Mellon SJ Pandit H Murray DW
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Introduction. The revision rate of unicompartmental knee replacement (UKR) in national joint registries is much higher than that of total knee replacements and that of UKR in cohort studies from multiple high-volume centres. The reasons for this are unclear but may be due to incorrect patient selection, inadequate surgical technique, and inappropriate indications for revision. Meniscal bearing UKR has well defined evidence based indications based on preoperative radiographs, the surgical technique can be assessed from post-operative radiographs and the reason for revision from pre-revision radiographs. However, for an accurate assessment aligned radiographs are required. The aim of the study was to determine why the revision rate of UKR in registries is so high by undertaking a radiographic review of revised UKR identified by the United Kingdom's (UK) National Joint Registry (NJR). Methods. A novel cross-sectional study was designed. Revised medial meniscal bearing UKR with primary operation registered with the NJR between 2006 and 2010 were identified. Participating centres from all over the country provided blinded pre-operative, post-operative, and pre-revision radiographs. Two observers reviewed the radiographs. Results. Radiographs were provided for 107 revised UKR from multiple centres. The recommended indications were not satisfied in 30%. The most common reason was the absence of bone-on-bone arthritis, and in 16 (19%) the medial joint space was normal or nearly normal. Post-operative films were mal-aligned in 50%. Significant surgical errors were seen in 50%, with most errors attributable to tibial component placement and orientation. No definite reason for revision was identified in 67%. Reasons for revision included disease progression (10%), tibial component loosening (7%), dislocation of the bearing (7%), infection (6%) femoral component loosening (3%), and peri-prosthetic fracture (2% - one femur, one tibia). Discussion and Conclusion. This study found that improper patient selection, inadequate surgical technique, inappropriate revisions and poorly taken radiographs all contributed to the high revision rate. There is a misconception that UKR should be used for early OA. Bone-on-bone arthritis is a requirement and was definitely not present in about 20%. There were many surgical errors, particularly related to the tibial cut: The new instrumentation should reduce this. There was a high prevalence of mal-aligned radiographs. Revisions should be avoided unless there is a definite problem, as the outcome of revision is usually poor in this situation. 80% of UKR revisions could potentially be avoided if surgeons adhered to the recommended indications for primary and revision surgery, and used the recommended surgical techniques. This study therefore suggests that if UKR was used appropriately the revision rate would be substantially lower and probably similar to that of TKR


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_12 | Pages 19 - 19
1 Jun 2017
Howard D Wall P Fernandez M Parsons H Howard P
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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


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_12 | Pages 75 - 75
23 Jun 2023
Blom A
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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


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIX | Pages 73 - 73
1 Jul 2012
Palmer A Dimbylow D Giritharan S Deo S
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Orthopaedic practice is increasingly guided by conclusions drawn from analysis of Joint Registry Data. Analysis of the England and Wales National Joint Registry (NJR) led Sibanda et al to conclude that UKR should be reserved for more elderly patients due to higher revision rates in younger patients. To determine our UKR revision rates at the Great Western Hospital we requested knee arthroplasty data from the NJR, Hospital Episode Statistics (HES) data submitted by our centre to the Primary Care Trust, and interrogated our internal theatre implant database. This revealed significant discrepancies between different data sources. We collected data from each source for 2005, 2006, and 2007. Operations were classified as TKR, UKR, Other or Unspecified. Results are illustrated in the attached table:. Key findings:. Our theatre implant database appears most accurate and includes a greater number of joint replacement operations than NJR or HES data and fewer ‘unspecified’ procedures. On average 15% NJR, 0% HES and 0.3% theatre data procedures were ‘unspecified’. NJR data comprises an average 17 fewer, and HES data an average 36 fewer procedures each year compared with our theatre data. Up to 80% UKRs performed are recorded as TKR in HES data. In summary there is significant inaccuracy in our NJR data which may affect the validity of conclusions drawn from NJR data analysis. HES data is even less accurate with implications for hospital funding. We strongly advise other centres to continue to maintain accurate implant data and to perform a similar audit to calculate error rates for NJR and HES data. Further analysis is required to identify at which stage of data collection inaccuracies occur so that solutions can be devised. We are currently analysing data from 2008 and 2009


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_6 | Pages 17 - 17
2 May 2024
Whitehouse M Patel R French J Beswick A Navvuga P Marques E Blom A Lenguerrand E
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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


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_10 | Pages 12 - 12
1 Aug 2021
Deere K Matharu G Ben-Shlomo Y Wilkinson J Blom A Sayers A Whitehouse M
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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


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_16 | Pages 61 - 61
19 Aug 2024
Whitehouse MR Patel R French J Beswick A Navvuga P Marques E Blom A Lenguerrand E
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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


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_6 | Pages 20 - 20
1 May 2019
Lamb J King S van Duren B West R Pandit H
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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


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_6 | Pages 41 - 41
1 May 2019
Afzal I Radha S Stafford G Smoljanović T Field R
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Patients need to know the benefits, risks and alternatives to any proposed treatment. Surgeons discussing the risk of a revision procedure becoming necessary, after a hip replacement can draw upon the orthopaedic literature and arthroplasty registries for long-term implant survival. However, early revision is required in a minority of cases. We have investigated the probability for revision hip replacement patients in terms of time-point and indication for revision. Of the 9,411 Primary Total Hip Replacements (THR), undertaken by 22 surgeons, over an eleven-year period, between January 2004 and March 2015, 1.70% (160) were subsequently reported to the National Joint Registry (NJR) as revised. Each revision case was reviewed under the supervision of senior hip specialist consultants. The modes of failure of were identified through clinical, laboratory and imaging (x-rays, CT, MRI and Isotope scans) studies. The revision rate for THRs was 0.58% in the first year. This was statistically higher than all subsequent years, P-Value <0.001. There was no statistical difference between any pair of subsequent years. Thereafter, the average revision rate was 0.30% per annum. The odds ratio for revision during the first post–operative year against the subsequent year average was 1.67. The indications for the early hip revisions in the first three years were infection, dislocation and peri-prosthetic fracture. The data from this study can help better inform patients of the revision rates after a primary THR and allow surgeons to develop implant surveillance strategies among high-risk patients


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_16 | Pages 39 - 39
17 Nov 2023
FARHAN-ALANIE M Gallacher D Kozdryk J Craig P Griffin J Mason J Wall P Wilkinson M Metcalfe A Foguet P
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Abstract. Introduction. Component mal-positioning in total hip replacement (THR) and total knee replacement (TKR) can increase the risk of revision for various reasons. Compared to conventional surgery, relatively improved accuracy of implant positioning can be achieved using computer assisted technologies including navigation, patient-specific jigs, and robotic systems. However, it is not known whether application of these technologies has improved prosthesis survival in the real-world. This study aimed to compare risk of revision for all-causes following primary THR and TKR, and revision for dislocation following primary THR performed using computer assisted technologies compared to conventional technique. Methods. We performed an observational study using National Joint Registry data. All adult patients undergoing primary THR and TKR for osteoarthritis between 01/04/2003 to 31/12/2020 were eligible. Patients who received metal-on-metal bearing THR were excluded. We generated propensity score weights, using Sturmer weight trimming, based on: age, gender, ASA grade, side, operation funding, year of surgery, approach, and fixation. Specific additional variables included position and bearing for THR and patellar resurfacing for TKR. For THR, effective sample sizes and duration of follow up for conventional versus computer-guided and robotic-assisted analyses were 9,379 and 10,600 procedures, and approximately 18 and 4 years, respectively. For TKR, effective sample sizes and durations of follow up for conventional versus computer-guided, patient-specific jigs, and robotic-assisted groups were 92,579 procedures over 18 years, 11,665 procedures over 8 years, and 644 procedures over 3 years, respectively. Outcomes were assessed using Kaplan-Meier analysis and expressed using hazard ratios (HR) and 95% confidence intervals (CI). Results. For THR, analysis comparing computer-guided versus conventional technique demonstrated HR of 0.771 (95%CI 0.573–1.036) p=0.085, and 0.594 (95%CI 0.297–1.190) p=0.142, for revision for all-causes and dislocation, respectively. When comparing robotic-assisted versus conventional technique, HR for revision for all-causes was 0.480 (95%CI 0.067 –3.452) p=0.466. For TKR, compared to conventional surgery, HR for all-cause revision for procedures performed using computer guidance and patient-specific jigs were 0.967 (95% CI 0.888–1.052) p=0.430, and 0.937 (95% CI 0.708–1.241) p=0.65, respectively. HR for analysis comparing robotic-assisted versus conventional technique was 2.0940 (0.2423, 18.0995) p = 0.50. Conclusions. This is the largest study investigating this topic utilising propensity score analysis methods. We did not find a statistically significant difference in revision for all-causes and dislocation although these analyses are underpowered to detect smaller differences in effect size between groups. Additional comparison for revision for dislocation between robotic-assisted versus conventionally performed THR was not performed as this is a subset of revision for all-causes and wide confidence intervals were already observed for that analysis. It is also important to mention this NJR analysis study is of an observational study design which has inherent limitations. Nonetheless, this is the most feasible study design to answer this research question requiring use of a large data set due to revision being a rare outcome. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_12 | Pages 26 - 26
1 Nov 2015
Skinner J Sabah S Henckel J Cook E Hothi H Hart A
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Introduction. The National Joint Registry (NJR) for England, Wales and Northern Ireland contributes important information on the performance of implants and surgeons. However, the quality of this data is not known. This study aimed to perform an independent validation of primary metal-on-metal hip procedures recorded on the NJR through linkage to the London Implant Retrieval Centre (LIRC). Patients/Materials & Methods. Primary, metal-on-metal hip arthroplasties performed between 1st April 2003 and 5th November 2013 were recruited from the NJR (n=67045). Retrieved, metal-on-metal components were recruited from the LIRC (n=782). Data linkage and validation checks were performed. Results. 476 procedures (60.9%) on the LIRC were successfully linked to the NJR. However, 306 procedures (39.1%) could not be linked. The outcome recorded by the NJR (as either revised, unrevised or death) for a primary procedure was incorrect in 79 linked cases (16.6%). The rate of registry-retrieval linkage and correct assignment of outcome code improved over time. The rates of error for component reference numbers on the NJR were: femoral head category number 14/229 (5.0%); femoral head batch number 13/232 (5.3%); acetabular component category number 2/293 (0.7%) and acetabular component batch number 24/347 (6.5%). Discussion. Registry-Retrieval linkage provided a novel means for data validation, particularly for component fields. This study suggests that NJR reports may underestimate revision rates for many types of metal-on-metal hip. This is topical given the increasing scope for NJR data. We recommend a system for continuous, independent evaluation of NJR data quality and validity


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_17 | Pages 6 - 6
1 Nov 2014
Rudge W Welck M Rudge B Goldberg A
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The National Joint Registry (NJR) was established in 2003, and was extended to include ankle arthroplasty on 1. st. April 2010, and shoulder and elbow arthroplasty in April 2012. The aim of this study was to evaluate the uptake of the NJR for ankle arthroplasty over its first 3 years. This is compared to the first 3 years of hip and knee data, and the first year of shoulder and elbow data. The methods of measuring compliance are also evaluated. NJR compliance is measured by comparing the number of procedures submitted to the NJR, against the number of levies raised through implant sales. This applies to all of the UK, and both independent and NHS providers. However, compliance can also be measured by comparing NJR submissions with data submitted to the Hospital Episode Statistics (HES) database. This only relates to NHS institutions in England. The NJR ankle data was compared to implant data, and adjusted to compare to HES data, to evaluate the different methods of measuring compliance. We also compared these figures with the first 3 years for hip and knee arthroplasties and the first year for shoulder and elbow arthroplasties. Results:. In 2011 there were 493 arthroplasties and the compliance was 64% against industry data. In 2012 there were 590 procedures with compliance improved to 77% against industry data. When adjusting NJR to compare with HES data, the compliance was 87% in 2012., with 507 ankle arthroplasties registered with the NJR and 582 on HES data. The reasons for this discrepancy are discussed. The specific difficulties of capturing ankle revisions are discussed, as some get revised to arthrodeses. The uptake is significantly higher than the first year for all other joints (shoulders 52%, hips 57%, knees 57%, and elbows 60%)


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


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_12 | Pages 84 - 84
23 Jun 2023
Devane P
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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. Unicompartmental knee replacement (UKR) offers advantages over total knee replacement but has higher revision rates particularly for aseptic loosening. Cementless UKR was introduced in an attempt to address this. We used National Joint Registry (NJR) data to compare the 10-year results of cemented and cementless mobile bearing UKR whilst matching for important patient, implant and surgical factors. We also explored the influence of caseload on outcome. Methods. We performed a retrospective observational study using NJR data on 30,814 cemented and 9,708 cementless mobile bearing UKR implanted between 2004 and 2016. Logistic regression was utilised to calculate propensity scores allowing for matching of cemented and cementless groups for various patient, implant and surgical confounders, including surgeon's caseload, using a one to one ratio. 14,814 UKRs (7407 cemented and 7407 cementless) were propensity score matched. Outcomes studied were revision, defined as removal, addition or exchange of a component, and reasons for revision. Implant survival was compared using Cox regression models and groups were stratified according to surgeon caseload. Results. Based on raw unmatched data the 10 year survival for cementless and cemented UKR were 89% (95% CI 88%–90%) and 93% (CI 90%–96%), with cementless having a lower revision rate (Hazard ratio (HR)=0.59 (CI 0.52–0.68, p<0.001). However, there were differences between the cohorts in many potential confounding factors particularly surgeons caseload: Surgeons using cementless had a higher caseloads than those using cemented and for both cohorts the revision rate decreased with increasing caseload. Following matching, all potential confounders were well balanced and the 10-year survival for cementless and cemented were 90% (CI 88%–92%) and 93% (95% CI 90–96%) with cementless having a lower revision rate (HR 0.76; CI 0.64–0.91; p=0.003). This was due to rate of revision for aseptic loosening more than halving (p<0.001) in the cementless (n=31, 0.4%) compared to cemented (n=74, 1.0%) and the rate of revision for pain decreasing (p=0.03) in the cementless (n=34, 0.5%) compared to the cemented (n=55, 0.7%). However, the rate of peri-prosthetic fracture increased significantly (p=0.01) in the cementless (n=19, 0.3%) compared to the cemented (n=7, 0.1%). Following matching the decrease in revision rate with the cementless was similar for low (<10 cases/year; HR 0.74), medium (10–30 cases/year; HR 0.79) and high (>10 cases/year; HR 0.79) caseload surgeons. The 10- year survival for cementless and cemented were for low caseload 87% & 82%, medium caseload 94% & 92% and high caseload 98% & 94% respectively. Conclusions. This is the first study to compare the 10-year survival of the cementless and cemented mobile bearing UKR. We have demonstrated that the cementless device has a 24% reduced risk of revision and that this was independent of surgeon caseload and other important patient, surgical and implant confounders. This improvement was due to the rate of revision for aseptic loosening and pain halving. However, there was a small increase in rate of periprosthetic fracture. The results of both cemented and cementless UKR improved with increasing surgeon caseload. Low volume surgeons have poor results with both cemented and cementless UKR so should consider either stopping doing UKR or doing more. Medium and high volume surgeons should consider using the cementless. High volume surgeons using the cementless had particularly good results with a 10-year survival of 98%. For figures, tables, or references, please contact authors directly


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIX | Pages 2 - 2
1 Jul 2012
Jones MA Newell C Howard PW
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Purpose. To establish the reliability of reporting and recording revision hip and knee arthroplasties by comparing data in the National Joint Registry (NJR), Hospital Episode Statistics (HES) and our local theatre records. Methods. The paper theatre registers for all orthopaedic theatres in the Royal Derby Hospitals NHS Trust were examined for details of revision hip and knee replacements carried out in 2007 and 2008. This was then cross-checked and merged with the local electronic theatre data to obtain a definitive local record of all revision hip and knee arthroplasties. Data for the same period was requested from the NJR and HES and these data were checked against our definitive local record for discrepancies. The HES codes used were the same codes used to compile the recent NJR annual reports. Results. The theatre registers and ORMIS identified 271 revision hip and knee arthroplasties in the study period. The NJR had corresponding data for 176 (65%) of these, and HES had 250 (92%). 10 cases (4%) were not recorded by either NJR or HES: 8 secondary resurfacings of patellae and 2 posterior lip augmentations in hips. Of those operations “missed” by HES, most had been assigned a correct “W” code, but had a “Y” or “Z” OPCS code not used in the NJR annual reports. Conclusion. When HES and the NJR data are combined, they are an accurate representation of real practice. More robust methods of reporting revision arthroplasty to the NJR are required. The OPCS codes used to indicate a revision need to be reviewed


Computer aided Total Hip Arthroplasty (THA) surgery is known to improve implantation precision, but clinical trials have failed to demonstrate an improvement in survivorship or patient reported outcome measures (PROMs). Our aim was to compare the risk of revision, PROMs and satisfaction rates between computer guided and THA implanted without computer guidance. We used the National Joint Registry dataset and linked PROMs data. Our sample included THAs implanted for osteoarthritis using cementless acetabular components from a single manufacturer (cementless and hybrid). An additional analysis was performed limiting the sample size to THAs using cementless stems (fully cementless). The primary endpoint was revision (of any component) for any reason. Kaplan Meier survivorship analysis and an adjusted Cox Proportional Hazards model were used. 41683 non computer guided, and 871 (2%) computer guided cases were included in our cementless and hybrid analysis. 943 revisions were recorded in the non-guided and 7 in the computer guided group (adjusted Log-rank test, p= 0.028). Cumulative revision rate at 10 years was 3.88% (95%CI: 3.59 – 4.18) and 1.06% (95%CI: 0.45 – 2.76) respectively. Cox Proportional Hazards adjusted HR: 0.45 (95%CI: 0.21 – 0.96, p=0.038). In the fully cementless group, cumulative revision rate at 10 years was 3.99% (95%CI: 3.62 – 4.38) and 1.20% (95%CI: 0.52 – 3.12) respectively. Cox Proportional Hazards adjusted HR: 0.47 (95%CI: 0.22 – 1.01, p=0.053). There was no statistically significant difference in the 6-month Oxford Hip Score, EQ-5D, EQ-VAS and success rates. Patient Satisfaction (single-item satisfaction outcome measure) was improved in the computer guided group but this finding was limited by a reduced number of responses. In this single manufacturer acetabular component analysis, the use of computer guided surgery was associated with a significant reduction in the early risk of revision. Causality cannot be inferred in view of the observational nature of the study, and further database and prospective studies are recommended to validate these findings


Total hip arthroplasty has been constantly evolving with technological improvements to achieve the best survival rates. Although the new implants are under closer surveillance through processes such as Beyond Compliance, orthopaedic surgeons generally tend to look out for the latest implants with good short-term results and hope for better long-term results for these. We questioned whether such an assumption or bias is valid.

We analysed the data of Kaplan-Meier estimates of cumulative revisions of primary hip replacement by fixation, stem/cup brand and bearing combinations from the NJR 19th Annual Report published in September 2022. We performed a univariate linear regression analysis to predict the 10- and 15-year revision rates for these different hip implant combinations from the 3- and 5-year revision rates.

Thirty-seven implant combinations had their 15-year revision rates reported and 67 had the 10-year revision rates. The correlation co-efficients were 0.43 and 0.58 for the 3-year and 5-year revision rates against 15-year revision rates. Only 17% of the variance in 15-year revision rates could be predicted by a linear regression model from the 3-year revision rate and 32% from the 5-year revision rate. Corresponding values for the 10-year revision rates were 46% and 67%.

95% prediction intervals for the 15-year revision rate were +/− 3.1% from the 3-year revision rate and +/− 2.8% from the 5-year revision rate. Corresponding values for the 10-year revision rates were +/− 1.3% and +/− 1%.

19 of 37 implant combinations showed 15-year revision rate of more than 4%. Average 3-year and 5-year revision rates for this cohort was 1.0% and 1.42% compared to 1.4% and 1.9% for the rest and the difference was statistically significant.

Although average early revision rates showed small but significant difference between the groups with lower and higher 15-year revision rates, the prediction intervals for 15-year revision rates for individual hips based on their 3-year and 5-year revision rates are very wide. Three- and 5-year revision rates for primary total hip replacements are poor predictors of 15-year revision rates.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_11 | Pages 3 - 3
1 Nov 2022
Mohan R Staunton D Carter J Highcock A
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Abstract

Background and study aim

The UK National Joint Registry(NJR) has not reported total knee replacement (TKR)survivorship based on design philosophy alone, unlike its international counterparts. We report outcomes of implant survivorship based on design philosophy using data from NJR's 2020 annual report.

Materials and methods

All TKR implants with an identifiable design philosophy from NJR data were included. Cumulative revision data for cruciate-retaining(CR), posterior stabilised(PS), mobile-bearing(MB) design philosophies was derived from merged NJR data. Cumulative revision data for individual brands of implants with the medial pivot(MP) philosophy were used to calculate overall survivorship for this design philosophy. The all-cause revision was used as the endpoint and calculated to 15 years follow-up with Kaplan-Meier curves.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_7 | Pages 2 - 2
1 Jul 2022
Mohan R Staunton DM Carter JR Highcock A
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Abstract

Introduction

The UK National Joint Registry(NJR) has not reported total knee replacement (TKR)survivorship based on design philosophy alone, unlike its international counterparts. We report outcomes of implant survivorship based on design philosophy using data from NJR's 2020 annual report.

Methodology

All TKR implants with an identifiable design philosophy from NJR data were included. Cumulative revision data for cruciate-retaining(CR), posterior stabilised(PS), mobile-bearing(MB) design philosophies was derived from merged NJR data. Cumulative revision data for individual brands of implants with the medial pivot(MP) philosophy were used to calculate overall survivorship for this design philosophy. The all-cause revision was used as the endpoint and calculated to 15 years follow-up with Kaplan-Meier curves.


The Bone & Joint Journal
Vol. 98-B, Issue 1 | Pages 33 - 39
1 Jan 2016
Sabah SA Henckel J Koutsouris S Rajani R Hothi H Skinner JA Hart AJ

Aims

The National Joint Registry for England, Wales and Northern Ireland (NJR) has extended its scope to report on hospital, surgeon and implant performance. Data linkage of the NJR to the London Implant Retrieval Centre (LIRC) has previously evaluated data quality for hip primary procedures, but did not assess revision records.

Methods

We analysed metal-on-metal hip revision procedures performed between 2003 and 2013. A total of 69 929 revision procedures from the NJR and 929 revised pairs of components from the LIRC were included.


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Whilst total hip replacement (THR) is generally safe and effective, pre-existing medical conditions, particularly those requiring inpatient admission, may increase the risk of post-operative mortality. Delaying elective surgery may reduce the risk, but it is unclear how long a delay is sufficient.

We analysed 958,145 primary THRs performed for solely osteoarthritis April 2003-December 2018, in the NJR linked to Hospital Episodes Statistics to identify inpatient admissions prior to elective THR for 17 conditions making up the Charlson index including myocardial infarction, congestive heart failure, cerebrovascular disease and diabetes. Crude analyses used Kaplan-Meier and adjusted analyses used Cox modelling. Patients were categorised for each co-morbidity into one of four groups: not recorded in previous five-years, recorded between five-years and six-months before THR, recorded six-months to three-months before THR, and recorded between three-months and day before surgery.

90-day mortality was 0.34% (95%CI: 0.33–0.35). In the 432 patients who had an acute MI in the three months before THR, this figure increased to 18.1% (95%CI 14.8, 22.0). Cox models observed 63 times increased hazard of death within 90-days if patients had an acute MI in the 3-months before their THR, compared to patients who had not had an MI in the five years before their THR (HR 63.6 (95%CI 50.8, 79.7)) This association reduced as the time between acute MI and THR increased. For congestive cardiac failure, the hazard in the same scenario was 18-times higher with a similar protective effect of delaying surgery.

Linked NJR and HES data demonstrate an association between inpatient admission for acute medical co-morbidities and death within 90-days of THR. This association is greatest in MI, congestive cardiac failure and cerebrovascular disease with smaller associations observed in several other conditions including diabetes. The hazard reduces when longer delays are seen between the admission for acute medical conditions and THR in all diagnoses. This information will help patients with previous medical admissions and surgeons to determine optimal timing for surgery.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_4 | Pages 72 - 72
1 Jan 2016
Timperley J Whitehouse S
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Mortality following hip arthroplasty is affected by a large number of confounding variables each of which must be considered to enable valid interpretation.

The aim of this study was to establish whether it is possible to determine a true cause-and-effect relationship between the risk of mortality and data that are routinely collected by the NJR and to establish the degree to which variation in the mortality rate could be explained by each variable.

Relevant variables available from the 2011 NJR data setwere included in a Cox model.

We carried out two analyses:

Firstly, we conducted an analysis of data collected from the NJR data set used in preparation of the NJR's 8th Annual Report (2011) looking for an association between the variables collected and the risk of mortality.

Secondly, as social deprivation is also known to influence mortalityrates but is not routinely collected as part of the NJR data set, a further analysis was performed which included social deprivation data derived from partial postcodes.

Mortality rates in hip arthroplasty patients were lower than in the age matched population across all hip types. Age at surgery, ASA grade, diagnosis, gender, provider type, hip type and lead surgeon grade all had a significant effect on mortality. Schemper's statistic showed that only 18.98% of the variation in mortality was explained by the variables available in the NJR data set.

It is inappropriate to use Registry data to study an outcome affected by a multitude of confounding variables when these cannot be adequately accounted for in the available data set.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 15 - 15
1 Jul 2020
Holleyman R Critchley R Jameson S Mason J Reed M Malviya A
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Prosthetic joint infections (PJI) are a devastating consequence in total hip arthroplasties (THA) with both significant morbidity and sometimes mortality, posing a significant health economic burden. Studies, both clinical and in-vitro have suggested possible reduction in PJI with the use of ceramic bearings.

We have investigated the relationship of ceramic-on-ceramic (CoC), ceramic-on-polyethylene (CoP) or metal-on-polyethylene (MoP) bearing surface in affecting outcome of revision surgery after primary THA using data collected from National Joint Registry for England and Wales, Northern Ireland and the Isle of Man between 2002 and 2016. We used a competing risk regression model to investigate predictors of each revision outcome, such as infection, dislocation, aseptic revision and all cause revisions. The results were adjusted for age, gender, ASA grade, BMI, indication for surgery, intraoperative complications and implant data.

We identified 456,457 THA (228,786 MoP, 128,403 CoC and 99,268 CoP). In a multivariable model, the adjusted risk of revision for PJI was lower with CoC (OR-0.748, p<0.001) and CoP (OR-0.775, p<0.001) when compared to MoP bearing. Additionally there was also a significant reduction in the risk of all cause revision for CoC (OR-0.918, p=0.002) and CoP (0.806, p<0.001), bearings as compared with MoP. The protective effect of ceramic bearing was predominantly seen after two years of implantation with a significant (p<0.0001) reduction of revision for PJI in both CoC (by 42.8%) and CoP (by 41.3%) group. Similarly significant effect was seen for aseptic revision beyond two years and overall all cause revision rate beyond two years reduced by 21.6% for CoC and 27.1% for CoP (p<0.001).

Within the limits of registry analysis, this study has demonstrated an association between the use of ceramic bearing and lower rates of revision for all cause revisions especially infection and aseptic loosening. This finding supports the use of ceramic bearings in THA.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_4 | Pages 25 - 25
1 Apr 2022
Evans J Salar O Whitehouse S Kassam A Howell J Wilson M Timperley J Sayers A Whitehouse M Wilton T Hubble M
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The Exeter V40 femoral stem is the most implanted stem in the NJR for primary 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, for example, patient anatomy requires a smaller stem with a 44mm offset. We aimed to investigate survival of this stem in comparison to others in the range when used in primary THAs recorded in the NJR.

Analyses were performed using a dataset based on that used for the 2020 NJR annual report. Our exposure was the stem; the outcome was all-cause construct revision. Crude analyses were performed using Kaplan-Meier and adjusted using Cox models. The 44/00/125 stem was directly compared to other stems in the Exeter range.

We analysed 330,732 primary THAs using the Exeter V40 stem comprising 34.5% of the 958,869 THAs with complete information from the start of the NJR to 31 December 2018. The 44/00/125 stem was implanted in 2,158 primary THAs with 67.5% in female patients and a mean age of 67.8. The 10-year revision estimate for the 44/00/125 stem was 4.9% (95%CI 3.6, 6.8) and in constructs using an Exeter V40 stem was 2.8% (95%CI 2.7, 2.8). Controlling for age, sex and ASA demonstrated an increased overall hazard of revision for constructs using the 44/00/125 stem compared to constructs using other Exeter V40 femoral stems (HR 1.8 (95%CI 1.4, 2.3)).

Although the revision estimate is within the NICE 10-year benchmark, survivorship of constructs using the 44/00/125 stem appears to be lower than the rest of the Exeter V40 range. Attempts to control for age, sex and ASA will not take into account confounding by indication i.e. patients with more complex anatomy who may have a higher risk of revision. Surgeons and patients should be reassured by this but should be aware of the observed increased revision estimate and use the stem according to its indications.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_11 | Pages 19 - 19
1 Jun 2016
Stirling E Gikas P Aston W Miles J Pollock R Carrington R Skinner J Briggs T
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Introduction

THR is one of the most frequently performed operations nationally. A large number of prostheses are available, and the procedure is therefore associated with variation in practice and outcomes. NICE guidelines aim to standardise best practice, and are informed by separate, independent bodies, such as the NJR and ODEP, which monitor data about the implants used and their performance. This study aims to determine whether clinical practice and component use has changed since the publication of NJR data.

Methods

NJR reports from 2006–2014 were analysed, with record made of the different prostheses used in THR, noting ODEP ratings of components used. Analysis was also performed by component type (i.e. cemented and cementless stems and cups), and combinations of components, according to their frequency of use in a given year. The Kruksal-Wallis test was used for statistical analysis.


Abstract

Introduction

The role of patellar resurfacing in total knee arthroplasty remains controversial. We questioned the effect of patellar resurfacing on the early and late revision rates after total knee arthroplasty.

Materials and Methods

We analysed the data of cumulative revisions of primary knee replacement from the NJR 19th Annual Report. NJR included secondary patellar resurfacing as a revision. We compared differences in the 3-year and 15-year revision rates between the patellar resurfacing and non-resurfacing for the different combinations of total knee replacements using a paired t-test. We performed subgroup analysis for the five combinations with the highest volumes.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_1 | Pages 76 - 76
1 Jan 2013
Baker P Jameson S Deehan D Gregg P Porter M Tucker K
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Background

Current analysis of unicondylar knee replacements (UKR) by national registries is based on the pooled results of medial and lateral implants. Using data from the National Joint Registry for England and Wales (NJR) we aimed to determine the proportion of lateral UKR implanted, their survival and reason for failure in comparison to medial UKR.

Methods

By combining information on the side of operation with component details held on the NJR we were able to determine implant laterality (medial vs. lateral) for 32,847 of the 35,624 (92%) UKR registered before December 2010. Kaplan Meier plots, Life tables and Cox' proportion hazards were used to compare the risk of failure for lateral and medial UKRs after adjustment for patient and implant covariates.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXXIX | Pages 167 - 167
1 Sep 2012
Bolland B Whitehouse S Howell J Hubble M Gie G Timperley A
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This study utilised NJR primary hip data from the 6th Annual Report to determine the rate and indication for revision between cemented, uncemented, hybrid and resurfacing prosthetic groups. Regression analysis was performed to identify the influence of gender and ASA grade on these revision rates. Validity of the data was interrogated by exploring for episodes of misclassification.

Results

We identified 2,264 misclassified episodes within the four groups (Misclassification rate 2.7% primary, 4.3% revision procedures). Analysis was performed using the “reclassified dataset”.

The Kaplan-Meier revision rates at 3 years were 0.9% (95%CI: 0.8%-1.0%) for cemented prostheses, 1.9% (95%CI: 1.8%-2.0%) for uncemented hips, 1.2% (95%CI: 1.0%-1.4%) for hybrids and 3.0%, (95%CI: 2.7%-3.3%) in the resurfacing group. The trends in revision rates were comparable to those published in the NJR (6th Edn.) with significant differences across all groups (p< 0.0001). Revision rates in the under 55 year age group showed an identical hierarchy with cemented and hybrid arthroplasty having the lowest revision rates.

Cox Regression analysis indicated that both the prosthesis group in isolation and the interaction between prosthesis group and ASA grade significantly influenced the rate of failure (p< 0.001).

Indications for revision showed significant differences in rates for, pain, aseptic loosening, dislocation and malalignment between prosthesis types (p< 0.001). The indications including Aseptic loosening, pain, malalignment and dislocation all demonstrated similar trends in revision rates between prosthetic groups with cemented hips having the lowest rates followed by ascending rates for hybrid, uncemented and resurfacing groups. The exception being dislocation with resurfacings having the lowest revision rates.

Discussion

This study provides important baseline revision rates by indication for each prosthetic group from which future comparisons can be made. Areas of misclassification within the NJR dataset have been reported back for future annual analysis.


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_10 | Pages 15 - 15
1 Aug 2021
Fowler T Blom A Reed M Aquilina A Sayers A Whitehouse M
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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.


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_1 | Pages 43 - 43
1 Jan 2018
Wilkinson J Hunt L Blom A
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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.


Our previous work presented at BHS revealed a reduced risk of revision for all reasons in THAs using lipped (asymmetric) liners. Some audience members felt that this finding may be due to unaccounted confounders and the hip surgery community remains sceptical.

A fully adjusted Cox model was built after exploratory Kaplan-Meier analyses. The following surgical approaches were included in the analysis: Posterior, Hardinge/anterolateral, Other. The variables included in the final Cox model included: Gender, liner asymmetry, age, head composition, stem fixation method, head diameter, indication for implantation and surgical approach. An additional analysis of the 3 most commonly used polyethylene liners with both a flat and asymmetric version was performed.

In the fully adjusted Cox model, the use of a flat liner was associated with increased risk of revision for instability (HR: 1.79, 95%CI: 1.52–2.10) and increased risk of revision for all reasons (HR 1.195, 95%CI: 1.104 – 1.293) when compared to THAs utilising flat liners. This finding was upheld in the product specific analysis.

When utilising flat liners, the Hardinge/anterolateral approach was associated with a reduced risk of revision for instability compared to the posterior approach (HR 0.56, 95%CI: 0.446 to 0.706). When an asymmetric liner was used, there was no significant difference in the risk of revision for instability between the Hardinge/anterolateral approach and the posterior approach (HR 0.838, 95%CI: 0.633 – 1.110).

The use of polyethylene-based bearings gives the surgeon the option to use asymmetric liners. The reduced risk of revision in THAs with asymmetric liners was seen in the analysis of the complete dataset and in the product specific analysis. Our results demonstrate that the posterior approach, when used with asymmetric XLPE liners, is not associated with a higher risk of revision for instability as historical data suggested.


Aim

To assess the effect of the bearing surface and head size on the survival of total hip replacements with modern bearing surface combinations.

Methods

We combined the NJR dataset with polyethylene manufacturing properties as supplied by the manufacturers to sub-divide polyethylene into conventional (PE) and highly crosslinked (XLPE). Cause specific and overall reasons for revisions were analysed using Kaplan-Meier and multi-variate Cox proportional hazard regression survival analyses. The bearing surface analysis was repeated in patients undergoing THR under the age of 55.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_1 | Pages 39 - 39
1 Jan 2013
Jameson S Baker P Charman S Deehan D Reed M Gregg P van der Meulen J
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Background

The most appropriate form of chemical thromboprophylaxis following knee replacement is a contentious issue. Most national guidelines recommend the use of low molecular weight Heparin (LMWH) whilst opposing the use of aspirin. We compared thromboembolic events, major haemorrhage and death after knee replacement in patients receiving either aspirin or LMWH.

Methods

Data from the National Joint Registry for England and Wales was linked to an administrative database of hospital admissions in the English National Health Service. A total of 156 798 patients undergoing knee replacement between April 2003 and September 2008 were included and followed up for 90 days. Multivariable risk modelling was used to estimate odds ratios adjusted for baseline risk factors (AOR). An AOR < 1 indicates that risk rates are lower with LMWH than with aspirin.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXI | Pages 118 - 118
1 May 2012
T P J R J M A P M H
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Background

A commonly held belief amongst surgeons and patients is that progression of disease (arthritis) to other compartments is a major cause of early failure of UKRs.

Methods

We analysed the NJR database records of 17,643 primary UKRs performed between April 2003 and April 2009. Where these had been revised the reason for revision was noted.


Aim

To assess the effect of different polyethylene modifications on Total Hip Replacement survival.

Methods

We combined the NJR dataset with polyethylene manufacturing properties as supplied by the manufacturers. Cause specific and overall reasons for revisions were analysed using Kaplan-Meier and multi-variate Cox proportional hazard regression survival analyses. Revision for aseptic loosening was the primary endpoint. Modification variables included resin type, radiation source, multiple cross-linking treatments, cross-linking dose, terminal sterilisation method, terminal sterilisation radiation dose, stabilisation treatment, total radiation dose, and packaging.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 579 - 579
1 Aug 2008
Baker PN Van Der Meulen J Lewsey J Gregg PJ
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Purpose: To examine how patients viewed the outcome of their joint replacement at least one year post surgery. Emphasis was placed on investigating the relative influence of ongoing pain and functional limitation on patient satisfaction.

Method: Questionnaire based assessment of the Oxford Knee Score (OKS), patient satisfaction, and need for reoperation in a group of 10,000 patients who had undergone primary unilateral knee replacement between April and December 2003. Questionnaires were linked to the NJR database to provide data on background demographics, clinical parameters and intraoperative surgical information for each patient.

Data was analysed to investigate the relationship between the OKS, satisfaction rate and the background factors. Multivariable logistic regression was performed to establish which factors influenced patient satisfaction.

Results: 87.4% patients returned questionnaires. Overall 81.8% indicated they were satisfied with their knee replacement, with 7.0% unsatisfied and 11.2% unsure. The mean OKS varied dependent upon patients’ satisfaction (satisfied=22.04 (S.D 7.87), unsatisfied=41.70 (S.D 8.32), unsure=35.17 (S.D 8.24)). These differences were statistically significant (p< 0.001).

Regression modelling showed that patients with higher scores relating to the pain and function elements of the OKS had lower levels of satisfaction (p< 0.001) and that ongoing pain was a stronger predictor of lower levels of satisfaction. Other predictors of lower levels of satisfaction included female gender (p< 0.05), a primary diagnosis of osteoarthritis (p=0.02) and unicondylar replacement (p=0.002). Differences in satisfaction rate were also observed dependent upon age and ASA grade

609 patients (7.4%) had undergone further surgery and 1476 patients (17.9%) indicated another procedure was planned. Both the OKS and satisfaction rates were significantly better in patients who had not suffered complications.

Conclusion: This study highlights a number of clinically important factors that influence patient satisfaction following knee replacement. This information could be used when planning surgery to counsel patients and help form realistic expectations of the anticipated postoperative result.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_1 | Pages 135 - 135
1 Jan 2013
Jameson S Kyle J Baker P Mason J Deehan D McMurtry I Reed M
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Introduction

National Institute for Health and Clinical Excellence (NICE) guidelines recommend the use of total hip replacement (THR) for displaced intracapsular fractured neck of femur (NOF) in cognitively intact patients who were independently mobile prior to the injury. The National Joint Registry for England and Wales (NJR) has collected data on THRs performed since 2003. This retrospective cohort study explores risk factors independently associated with implant failure and perioperative mortality.

Methods

NJR data recording a THR performed for acute fractured NOF between 2003 and 2010 were analysed. Cox proportional hazards models were used to analyse the extent to which risk of implant revision was related to specific covariates. Multivariable logistic regression was used to analyse factors affecting 90-day perioperative mortality. Significance was taken as p< 0.01.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_15 | Pages 24 - 24
1 Mar 2013
Brinkman J Bubra P Walker P Walsh W Bruce W
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In order to emulate normal knee kinematics more closely and thereby potentially improve wear characteristics and implant longevity the Medial Pivot type knee replacement geometry was designed. In the current study the clinical and radiographic results of 50 consecutive knee replacements using a Medial Pivot type knee replacement are reported; results are compared to the Australian Orthopaedic Associations National Joint Replacement Registry. The patients' data were crossed checked against the registry to see if they had been revised elsewhere. After a mean follow-up of 9.96 years results show that the Medial Pivot Knee replacement provides good pain relief and functional improvement according to KSS and Womac scores and on subjective patient questionnaires. There was one minor revision; insertion of a patella button at 6.64 years FU. There were no major revisions; all implants appeared to be well fixed on standard radiographic examination. While the revision rate for the Medial Pivot knee according to the Australia Joint Registry results is higher compared to all other types of knee replacements in the registry, and to what is reported in the literature on the medial pivot knee, it is not in the current series. Revision rate was similar to what is reported on in the literature, but after a longer follow-up period. However, long term follow-up is required to draw definitive conclusions on the longevity of this type of implant.


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.


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_1 | Pages 27 - 27
1 Jan 2013
Jameson S Baker P Mason J Deehan D Gregg P Porter M Reed M
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Introduction

Following in-depth analysis of the market leading brand combinations in which we identified implant influences on risk of revision, we compared revision in patients implanted with different categories of hip replacement in order to find implant with the lowest revision risk, once known flawed options were removed.

Methods

All patients with osteoarthritis who underwent a hip replacement (2003–2010) using an Exeter-Contemporary (cemented), Corail-Pinnacle (cementless), Exeter-Trident (Hybrid) or a Birmingham Hip resurfacing (BHR) were initially included within the analysis. Operations involving factors that were significant predictors of revision were excluded. Cox proportional hazard models were then used to assess the relative risk of revision for a category of implant (compared with cemented), after adjustment for patient covariates.


The Bone & Joint Journal
Vol. 105-B, Issue 3 | Pages 221 - 226
1 Mar 2023
Wilton T Skinner JA Haddad FS

Recent publications have drawn attention to the fact that some brands of joint replacement may contain variants which perform significantly worse (or better) than their ‘siblings’. As a result, the National Joint Registry has performed much more detailed analysis on the larger families of knee arthroplasties in order to identify exactly where these differences may be present and may hitherto have remained hidden. The analysis of the Nexgen knee arthroplasty brand identified that some posterior-stabilized combinations have particularly high revision rates for aseptic loosening of the tibia, and consequently a medical device recall has been issued for the Nexgen ‘option’ tibial component which was implicated. More elaborate signal detection is required in order to identify such variation in results in a routine fashion if patients are to be protected from such variation in outcomes between closely related implant types. Cite this article: Bone Joint J 2023;105-B(3):221–226


Bone & Joint 360
Vol. 13, Issue 3 | Pages 31 - 34
3 Jun 2024

The June 2024 Shoulder & Elbow Roundup. 360. looks at: Reverse versus anatomical total shoulder replacement for osteoarthritis? A UK national picture; Acute rehabilitation following traumatic anterior shoulder dislocation (ARTISAN): pragmatic, multicentre, randomized controlled trial; acid for rotator cuff repair: a systematic review and meta-analysis of randomized controlled trials; Metal or ceramic humeral head total shoulder arthroplasty: an analysis of data from the National Joint Registry; Platelet-rich plasma has better results for long-term functional improvement and pain relief for lateral epicondylitis: a systematic review and meta-analysis of randomized controlled trials; Quantitative fatty infiltration and 3D muscle volume after nonoperative treatment of symptomatic rotator cuff tears: a prospective MRI study of 79 patients; Locking plates for non-osteoporotic proximal humeral fractures in the long term; A systematic review of the treatment of primary acromioclavicular joint osteoarthritis


Bone & Joint 360
Vol. 12, Issue 6 | Pages 20 - 23
1 Dec 2023

The December 2023 Knee Roundup. 360. looks at: Obesity is associated with greater improvement in patient-reported outcomes following primary total knee arthroplasty; Does mild flexion of the femoral prosthesis in total knee arthroplasty result in better early postoperative outcomes?; Robotic or manual total knee arthroplasty: a randomized controlled trial; Patient-relevant outcomes following first revision total knee arthroplasty, by diagnosis: an analysis of implant survivorship, mortality, serious medical complications, and patient-reported outcome measures using the National Joint Registry data set; Sagittal alignment in total knee arthroplasty: are there any discrepancies between robotic-assisted and manual axis orientation?; Tourniquet use does not impact recovery trajectory in total knee arthroplasty; Impact of proximal tibial varus anatomy on survivorship after medial unicondylar knee arthroplasty; Bone cement directly to the implant in primary total knee arthroplasty?; Maintaining joint line obliquity optimizes outcomes in patients with constitutionally varus knees


The Bone & Joint Journal
Vol. 105-B, Issue 3 | Pages 301 - 306
1 Mar 2023
Jennison T Ukoumunne O Lamb S Sharpe I Goldberg AJ

Aims. Despite the increasing numbers of ankle arthroplasties, there are limited studies on their survival and comparisons between different implants. The primary aim of this study was to determine the failure rates of primary ankle arthroplasties commonly used in the UK. Methods. A data linkage study combined National Joint Registry (NJR) data and NHS Digital data. The primary outcome of failure was defined as the removal or exchange of any components of the implanted device. Life tables and Kaplan-Meier survival charts were used to illustrate survivorship. Cox proportional hazards regression models were fitted to compare failure rates between 1 April 2010 and 31 December 2018. Results. Overall, 5,562 primary ankle arthroplasties were recorded in the NJR. Linked data show a one-year survivorship of 98.8% (95% confidence interval (CI) 98.4% to 99.0%), five-year survival in 2,725 patients of 90.2% (95% CI 89.2% to 91.1%), and ten-year survival in 199 patients of 86.2% (95% CI 84.6% to 87.6%). The five-year survival for fixed-bearing implants was 94.3% (95% CI 91.3% to 96.3%) compared to 89.4% (95% CI 88.3% to 90.4%) for mobile-bearing implants. A Cox regression model for all implants with over 100 implantations using the implant with the best survivorship (Infinity) as the reference, only the STAR (hazard ratio (HR) 1.60 (95% CI 0.87 to 2.96)) and INBONE (HR 0.38 (95% CI 0.05 to 2.84)) did not demonstrate worse survival at three and five years. Conclusion. Ankle arthroplasties in the UK have a five-year survival rate of 90.2%, which is lower than recorded on the NJR, because we have shown that approximately one-third of ankle arthroplasty failures are not reported to the NJR. There are statistically significant differences in survival between different implants. Fixed-bearing implants appear to demonstrate higher survivorship than mobile-bearing implants. Cite this article: Bone Joint J 2023;105-B(3):301–306


Bone & Joint Research
Vol. 11, Issue 10 | Pages 690 - 699
4 Oct 2022
Lenguerrand E Whitehouse MR Kunutsor SK Beswick AD Baker RP Rolfson O Reed MR Blom AW

Aims. We compared the risks of re-revision and mortality between two-stage revision surgery and single-stage revision surgery among patients with infected primary knee arthroplasty. Methods. Patients with a periprosthetic joint infection (PJI) of their primary knee arthroplasty, initially revised with a single-stage or a two-stage procedure in England and Wales between 2003 and 2014, were identified from the National Joint Registry. We used Poisson regression with restricted cubic splines to compute hazard ratios (HR) at different postoperative periods. The total number of revisions and re-revisions undergone by patients was compared between the two strategies. Results. A total of 489 primary knee arthroplasties were revised with single-stage procedure (1,390 person-years) and 2,377 with two-stage procedure (8,349 person-years). The adjusted incidence rates of all-cause re-revision and for infection were comparable between these strategies (HR overall five years, 1.15 (95% confidence interval (CI) 0.87 to 1.52), p = 0.308; HR overall five years, 0.99 (95% CI 0.70 to 1.39), p = 0.949, respectively). Patients initially managed with single-stage revision received fewer revision procedures overall than after two-stage revision (1.2 vs 2.2, p < 0.001). Mortality was lower for single-stage revision between six and 18 months postoperative (HR at six months, 0.51 (95% CI 0.25 to 1.00), p = 0.049 HR at 18 months, 0.33 (95% CI 0.12 to 0.99), p = 0.048) and comparable at other timepoints. Conclusion. The risk of re-revision was similar between single- and two-stage revision for infected primary knee arthroplasty. Single-stage group required fewer revisions overall, with lower or comparable mortality at specific postoperative periods. The single-stage revision is a safe and effective strategy to treat infected knee arthroplasties. There is potential for increased use to reduce the burden of knee PJI for patients, and for the healthcare system. Cite this article: Bone Joint Res 2022;11(10):690–699