National Joint Registry Research Articles

First-time revision knee arthroplasty using a hinged prosthesis : temporal trends, indications, and risk factors associated with re-revision using data from the National Joint Registry for 3,855 patients.

The aim of this study was to identify variables associated with time to revision, demographic details associated with revision indication, and type of prosthesis employed, and to describe the survival of hinge knee arthroplasty (HKA) when used for first-time knee revision surgery and factors that were associated with re-revision. Patient demographic details, BMI, American Society of Anesthesiologists (ASA) grade, indication for revision, surgical approach, surgeon grade, implant type (fixed and rotating), time of revision from primary implantation, and re-revision if undertaken were obtained from the National Joint Registry data for England, Wales, Northern Ireland, and the Isle of Man over an 18-year period (2003 to 2021). There were 3,855 patient episodes analyzed with a median age of 73 years (interquartile range (IQR) 66 to 80), and the majority were female (n = 2,480, 64.3%). The median time to revision from primary knee arthroplasty was 1,219 days (IQR 579 to 2,422). Younger age (p < 0.001), decreasing ASA grade (p < 0.001), and indications for revision of sepsis (p < 0.001), unexplained pain (p < 0.001), non-polyethylene wear (p < 0.001), and malalignment (p < 0.001) were all associated with an earlier time to revision from primary implantation. The median follow-up was 4.56 years (range 0.00 to 17.52), during which there were 410 re-revisions. The overall unadjusted probability of re-revision for all revision HKAs at one, five, and ten years after surgery were 2.7% (95% confidence interval (CI) 2.2 to 3.3), 10.7% (95% CI 9.6 to 11.9), and 16.2% (95% CI 14.5 to 17.9), respectively. Male sex (p < 0.001), younger age (p < 0.001), revision for septic indications (p < 0.001) or implant fracture (p = 0.010), a fixed hinge (p < 0.001), or surgery performed by a non-consultant grade (p = 0.023) were independently associated with an increased risk of re-revision. There were several factors associated with time to first revision. The re-revision rate was 16.2% at ten years; however, the risk factors associated with an increased risk of re-revision could be used to counsel patients regarding their outcome.Cite this article: Bone Joint J2023;105-B(1):47-55.

Apparent trends in the use of femoral megaprostheses: an analysis from the National Joint Registry

BackgroundMegaprosthetic replacement (MPR) of the femur is typically reserved for salvage or oncological reconstruction. Presently little is known about the provision of femoral MPRs performed nationally, the trends in indications for their use, and their outcomes beyond published unit-level data. Although the National Joint Registry (NJR) collects data as part of a mandatory arthroplasty audit process, MPR data entry on this platform is thought to be inconsistent. The aim of this study is to determine current trends for femoral MPR procedures as submitted to the NJR.MethodsData for all procedures submitted to the NJR using the following implants were extracted: METS (Stanmore/Stryker), MUTARS (Implantcast), Segmental (Zimmer), GMRS (Stryker) and MEGA C (LINK). Pseudoanonymized data were analyzed through the NJR’s research Data Access Portal and are reported using descriptive statistics.ResultsA total of 1781 procedures were identified. Submitted cases increased for primary and revision hip and knee categories over the study period, although they plateaued in recent years. MPR implants were most commonly used in revision hip arthroplasty procedures. MPR use for the management of peri-prosthetic fractures has increased and now represents the most commonly reported indication for MPR use in both hip and knee revision categories. Few centers submitted large MPR case volumes (which were noted to be lower than published unit case series, indicating NJR under-reporting), and the vast majority of centers submitting MPR cases did so in low volume.ConclusionsDue to the limitations identified, reported case volumes must be interpreted with caution. An MPR-specific NJR data entry form has been developed to allow more accurate and tailored reporting of MPR procedures, to support specialist service provision, and to provide meaningful data for future research.

International Registries: U.K. National Joint Registry, Nordic Registries, and Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR).

National-level joint arthroplasty registries were among the first large orthopaedic surgery databases and represent some of the longest-running and most influential big databases in our profession. Nordic registries were among the first registries and were followed by excellent registries in the United Kingdom and Australia. In this article, we describe each of these registries and highlight the data elements collected, the data points that can be obtained by linking the national arthroplasty registries to other national registries or databases, the completeness of data, and the strengths and weaknesses of each database. Each of these registries publishes an annual report that is available online, and each also can do more detailed analysis of certain aspects of its data for special studies.When evaluating and interpreting data from national joint registries, the user should be aware that, despite the power of huge numbers, there remain numerous limitations to the observational data. Strong selection biases exist with regard to which patients are chosen for which procedure. Surgeons of different skill levels may use one technique or implant differentially compared with another. The end points that registries collect differ widely: for example, some report only hip dislocations leading to revision rather than all dislocations. Registries in countries in which there are long wait times for revision surgery may report artificially low revision rates compared with countries in which revision surgery is more easily accessible. Despite these limitations, registries have the merit of reporting the actual results of huge numbers of surgical procedures performed across the spectrum of hospitals, surgeons, and patients, making the data extremely powerful for identifying trends, identifying early signs of problems related to certain implants or implant classes, and identifying associations between variables that can be further studied to determine if the effect is causal.

State-Based and National U.S. Registries: The Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI), California Joint Replacement Registry (CJRR), and American Joint Replacement Registry (AJRR).

The concept of a total joint registry as a tool to gather and compare longitudinal clinical outcome data emerged in the early 1970s; although initially begun as a single-institution effort, it soon spread to the development of large nationwide registries, first in Scandinavia and subsequently around the world. These national registries established the value of population-wide results, large cohorts, and the importance of ongoing implant surveillance efforts, as detailed elsewhere in this series. In the United States, concerted efforts to establish a national total joint registry for the hip and knee began in earnest in the early 2000s and culminated with the incorporation of the American Joint Replacement Registry (AJRR) in 2009. Parallel efforts soon followed to establish state-based total joint registries, either as stand-alone entities or in affiliation with the AJRR. Some of these state-based efforts succeeded, and some did not.In the first section of this article, Brian Hallstrom, MD, details the highly successful Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI). This state-based effort was made possible by a unique partnership between a single dominant statewide private payer and the Michigan orthopaedic surgery community; it has already successfully advanced the quality of care for patients in Michigan, and efforts are ongoing.The second section, by James I. Huddelston, MD, details a different path to the establishment of a focused state-based registry. The California Joint Replacement Registry (CJRR) was the result of a partnership with representatives of the statewide business community and resulted in a pioneering effort to successfully collect and publicly report patient-reported outcome measures as part of the registry data set. Further discussed are the establishment, development, and status of the AJRR and its current place among the family of American Academy of Orthopaedic Surgeons (AAOS) registries, which were inspired by the AJRR and span a range of orthopaedic specialties.

Mortality and re-revision following single-stage and two-stage revision surgery for the management of infected primary knee arthroplasty in England and Wales : evidence from the National Joint Registry.

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. 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. 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. 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 Res2022;11(10):690-699.

A Cohort Study of Risk Factors for Failure of Total Ankle Replacements: A Data Linkage Study using the National Joint Registry and NHS Digital

Category: Ankle Arthritis Introduction/Purpose: Despite the increasing numbers of ankle replacements that are being performed there are still limited studies on the survival of ankle replacements and which factors influence survivorship 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 and to determine the risk factors for failure of total ankle replacements 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 between 1st April 2010 and 31st December 2018. The unadjusted 1-year survivorship of ankle replacements was 98.8% (95% CI 98.4%-99.0the 5-year survival in 2725 patients was 90.2% (95% CI 89.2%-91.1) and the 10-year survival in 199 patients was 86.2% (95% CI 84.6%-87.6%). In univariate cox regression models age, BMI, ASA, Charlson co-morbidity score, indication for surgery were significantly associated with an increased risk of failure. In multivariate cox regression models only age (HR 0.956, 95% CI 0.942-0.970), BMI (HR 1.032, 95% CI 1.006-1.059) and indication (HR 0.880, 95% CI 0.799-0.968) were associated with an increased risk of failure. Conclusion: Ankle replacements have been demonstrated to have higher failure rates in younger patients, those with an increased BMI, and those with osteoarthritis. These findings should be taken into account when deciding which patients should undergo an ankle replacement and in counselling them on the likely survivorship of their ankle replacement

Outcome of Conversion to Fusion for a Failed Ankle Replacement: A Data Linkage Study using the National Joint Registry and NHS Digital

Category: Ankle Arthritis Introduction/Purpose: There are limited studies on the outcomes of conversion to fusion following a failed ankle replacement. The primary aim of this NJR data linkage study is to determine the outcomes of conversion to fusion following a failed ankle replacement. Methods: A data linkage study combined National Joint Registry Data and NHS Digital data. The primary outcome of failure is defined as a further fusion procedure or amputation. 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: 131 patients underwent conversion to fusion. The mean time from primary replacement was 33.8 months (range 1-100). The mean age was 63.3 (range 33-85), there were 73 males (55.7%). The mean BMI was 30.7 (SD 5.3) mean ASA was 2.0 and the mean Charlson co-morbidity score was 2.5. The most commonly revised implant was the Mobility in 45.0%, Zenith in 16.8% and Box in 11.5%.105 (80.2%) were as a single stage and 26 (19.8%) as a 2 stage procedure. The 1 year survivorship was 96.0% (95% CI 90.6%-98.3%), 2 year survivorship was 83.8% (95% CI 75.4%-89.5%) and 5 year survivorship was 72.4% (95% CI 62.0%-80.4%) A Cox regression model adjusting for individual factors did not find any risk factor significantly increased the risk of failure. Conclusion: Conversion to fusion following a failed ankle replacement has high rates of further surgery. Further prospective studies are required to determine risk factors for failure to improve outcomes for these patients.

No exponential rise in revision knee replacement surgery over the past 15 years: an analysis from the National Joint Registry

To investigate trends in the incidence rate and the main indication for revision knee replacement (rKR) over the past 15 years in the UK. Repeated national cross-sectional study from 2006 to 2020 using data from the National Joint Registry (NJR). Crude incidence rates were calculated using population statistics from the Office for National Statistics. Annual total counts of rKR increased from 2,743 procedures in 2006 to 6,819 procedures in 2019 (149% increase). The incidence rate of rKR increased from 6.3 per 100,000 adults in 2006 (95% CI 6.1 to 6.5) to 14 per 100,000 adults in 2019 (95% CI 14 to 14) (122% increase). Annual increases in the incidence rate of rKR became smaller over the study period. There was a 43.6% reduction in total rKR procedures in 2020 (during the Covid-19 pandemic) compared to 2019. Aseptic loosening was the most frequent indication for rKR overall (20.7% procedures). rKR for aseptic loosening peaked in 2012 and subsequently decreased. rKR for infection increased incrementally over the study period to become the most frequent indication in 2019 (2.7 per 100,000 adults [95% CI 2.6 to 2.9]). Infection accounted for 17.1% first linked rKR, 36.5% second linked rKR and 49.4% third or more linked rKR from 2014 to 2019. Recent trends suggest slowing of the rate of increase in the incidence of rKR. Infection is now the most common indication for rKR, following recent decreases in rKR for aseptic loosening. Infection was prevalent in re-revision KR procedures.

Implementing large-scale data quality validation in a national arthroplasty registry to improve compliance : the National Joint Registry data quality audit programme.

Data of high quality are critical for the meaningful interpretation of registry information. The National Joint Registry (NJR) was established in 2002 as the result of an unexpectedly high failure rate of a cemented total hip arthroplasty. The NJR began data collection in 2003. In this study we report on the outcomes following the establishment of a formal data quality (DQ) audit process within the NJR, within which each patient episode entry is validated against the hospital unit’s Patient Administration System and vice-versa. This process enables bidirectional validation of every NJR entry and retrospective correction of any errors in the dataset. In 2014/15 baseline average compliance was 92.6% and this increased year-on-year with repeated audit cycles to 96.0% in 2018/19, with 76.4% of units achieving > 95% compliance. Following the closure of the audit cycle, an overall compliance rate of 97.9% was achieved for the 2018/19 period. An automated system was initiated in 2018 to reduce administrative burden and to integrate the DQ process into standard workflows. Our processes and quality improvement results demonstrate that DQ may be implemented successfully at national level, while minimizing the burden on hospitals.Cite this article: Bone Jt Open 2022;3(9):716–725.

Temporal trends in comorbidity in adult elective hip and knee arthroplasty patients in England : a national population-based cohort study from the National Joint Registry.

Our main aim was to describe the trend in the comorbidities of patients undergoing elective total hip arthroplasties (THAs) and knee arthroplasties (KAs) between 1 January 2005 and 31 December 2018 in England. We combined data from the National Joint Registry (NJR) on primary elective hip and knee arthroplasties performed between 2005 and 2018 with pre-existing conditions recorded at the time of their primary operation from Hospital Episodes Statistics. We described the temporal trend in the number of comorbidities identified using the Charlson Comorbidity Index, and how this varied by age, sex, American Society of Anesthesiologists (ASA) grade, index of multiple deprivation, and type of KA. We included 696,504 and 833,745 elective primary THAs and KAs respectively, performed for any indication. Between 2005 and 2018, the proportion of elective THA and KA patients with one or more comorbidity at the time of their operation increased substantially (THA: 20% to 38%, KA: 22% to 41%). This was driven by increases in four conditions: chronic obstructive pulmonary disease (COPD) (2018: ~17%), diabetes without complications (2018: THA 10%, KA 14%), myocardial infarction (2018: 4%), and renal disease (2018: ~8%). Notably, renal disease prevalence increased from < 1% in 2005 to ~8% in 2018. Between 2005 and 2018 there were significant changes in the number of comorbidities recorded in patients having elective primary THAs and KAs. Renal disease is now one of the most prevalent comorbidities in this patient population. Future research should explore whether this comorbidity trend has increased the burden on other medical specialities to optimize these patients before surgery and to provide additional postoperative care.Cite this article: Bone Joint J2022;104-B(9):1052-1059.

324 Total Knee Arthroplasty in Haemophilia Patients: A Systematic Review and Meta-Analysis of Long-Term Survivorship, Functional Outcomes and Complications

Abstract Aim End-stage arthropathy is a well-known complication of haemophilia, with recurrent haemarthroses leading to joint destruction, deformity, pain, and stiffness. In the knee, this is often treated with total knee arthroplasty (TKA), which can be more challenging in patients with haemophilia (PwH) and associated with poorer outcomes. We conducted a systematic literature review and meta-analysis to determine implant survivorship, functional outcomes, and complication rates. Method A systematic review was conducted using MEDLINE, EMBASE, and PubMed for studies reporting TKA outcomes with Kaplan-Meier survivorship in PwH (PROSPERO registered). Meta-analysis was performed for survivorship and outcomes, and the results were compared to outcomes from the National Joint Registry (NJR). Results 19 studies, totalling 1187 TKAs (average age 39 years) were reviewed. In PwH, implant survivorship at 5, 10, and 15 years was 94%, 86%, and 76% respectively, whereas NJR reported survivorship for males &amp;lt;55 years was 94%, 90%, and 86%. Survivorship generally improved over the time period studied (1973–2017) but was inversely correlated with HIV infection (common in PwH). Range of motion improved by 10–20° post-operatively, and there were large improvements in Patient Reported Outcome Measures (PROMS). The prosthetic joint infection rate (PJI) was 6% compared to 0.5–1% in non-PwH, but the reporting of other complications, especially haematological, was inconsistent. Conclusions TKA in PwH has similar 5-year survivorship to non-PwH, but a six-fold higher infection rate. There were marked improvements in range of motion and PROMS, but complications were poorly reported. There remains a need for larger, long-term studies with standardised reporting.

830 Audit of Readmissions Within 30 Days of Total Knee Replacement (TKR)

Abstract Background Total knee replacement (TKR) is a very successful operation but like all surgery carries risks. Patients can be readmitted, but not all necessarily linked to post-operative complications. National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man: 17th annual report, 2020, Prosthetic infection after total knee replacement is (TKR) of average 0.92%. Aim To identify causes of readmission after TKR &amp; their frequency, within 30 days of surgery. Method Data spanning 2 years (Apr 2018- Apr 2020) were analysed. Patients’ details were retrieved for those with at least one readmission within 30 days of TKR and details include: Results Conclusion

Never events in orthopaedics: A nationwide data analysis and guidance on preventative measures.

Never Events (NE) are serious clinical incidents that are wholly preventable if appropriate institutional safeguards are in place and followed. They are often used as a surrogate of the quality of healthcare delivered by an institution. Most NEs are surgical and orthopaedic surgery is one of the most involved specialties. The aim of this study was to identify common NE themes associated with orthopaedics within the National Health Service (NHS) of England. We conducted an observational study analysing the annual NE data published by the NHS England from 2012 to 2020 to collate all orthopaedic surgery-related NE and construct relevant recurring themes. We identified 460 orthopaedic NE out of a total of 3247 (14.16%) reported NE to NHS England. There were 206 Wrong implants/prostheses under 8 different themes. Wrong hip and knee prosthesis were the commonest "wrong implants" (n = 94; 45.63% and n = 91; 44.17% respectively). There were 197 "wrong-site surgery" incidents in 22 different themes. The commonest of these was the laterality problems accounting for 64 (32.48%) incidents followed by 63 (31.97%) incidents of wrong spinal level interventions. There were 18 (9.13%) incidents of intervention on the wrong patients and 17 (8.62%) wrong incisions. Retained pieces of instruments were the commonest retained foreign body with 15 (26.13%) incidents. The next categories were retained drill parts and retained instruments with 13 (22.80%) incidents each. We identified 47 different themes of NE specific to orthopaedic surgery. Awareness of these themes would help in their prevention. Site marking can be challenging in the presence of cast and on operating on the digits and spine. Addition of a real-time intra-operative implant scan to the National Joint Registry can avoid wrong implant selection while fiducial markers, intraoperative imaging, O-arm navigation, and second time-out could help prevent wrong level spinal surgery.

What Is the Outcome of the First Revision Procedure of Primary THA for Osteoarthritis? A Study From the Australian Orthopaedic Association National Joint Replacement Registry.

Joint arthroplasty registries traditionally report survivorship outcomes mainly on primary joint arthroplasty. The outcome of first revision procedures is less commonly reported, because large numbers of primary procedures are required to analyze a sufficient number of first revision procedures. Additionally, adequate linkage of primary procedures to revisions and mortality is required. When undertaking revision hip surgery, it is important for surgeons to understand the outcomes of these procedures to better inform patients. Using data from a large national joint registry, we asked: (1) What is the overall rate of revision of the first aseptic revision procedure for a primary THA? (2) Does the rate of revision of the first revision vary by the diagnosis for the first revision? (3) What is the mortality after the first revision, and does it vary by the reason for first revision? The Australian Orthopaedic Association National Joint Replacement Registry longitudinally maintains data on all primary and revision joint arthroplasties, with nearly 100% capture. The analyses for this study were performed on primary THA procedures in patients with a diagnosis of osteoarthritis up to December 31, 2020, who had undergone subsequent revision. We excluded all primary THAs involving metal-on-metal and ceramic-on-metal bearing surfaces and prostheses with exchangeable necks because these designs may have particular issues associated with revisions, such as extensive soft tissue destruction, that are not seen with conventional bearings, making a comparative analysis of the first revision involving these bearing surfaces more complicated. Metal-on-metal bearing surfaces have not been used in Australia since 2017. We identified 17,046 first revision procedures from the above study population and after exclusions, included 13,713 first revision procedures in the analyses. The mean age at the first revision was 71 ± 11 years, and 55% (7496 of 13,713) of the patients were women. The median (IQR) time from the primary procedure to the first revision was 3 years (0.3 to 7.3), ranging from 0.8 years for the diagnosis of dislocation and instability to 10 years for osteolysis. There was some variation depending on the reason for the first revision. For example, patients undergoing revision for fracture were slightly older (mean age 76 ± 11 years) and patients undergoing revision for dislocation were more likely to be women (61% [2213 of 3620]). The registry has endeavored to standardize the sequence of revisions and uses a numerical approach to describe revision procedures. The first revision is the revision of a primary procedure, the second revision is the revision of the first revision, and so on. We therefore described the outcome of the first revision as the cumulative percent second revision. The outcome measure was the cumulative percent revision, which was defined using Kaplan-Meier estimates of survivorship to describe the time to the second revision. Hazard ratios from Cox proportional hazards models, adjusting for age and gender, were performed to compare the revision rates among groups. When possible, the cumulative percent second revision at the longest follow-up timepoint was determined with the available data, and when there were insufficient numbers, we used appropriate earlier time periods. The cumulative percent second revision at 18 years was 26% (95% confidence interval [CI] 24% to 28%). When comparing the outcome of the first revision by reason, prosthesis dislocation or instability had the highest rate of second revision compared with the other reasons for first revision. Dual-mobility prostheses had a lower rate of second revision for dislocation or instability than head sizes 32 mm or smaller and when compared to constrained prostheses after 3 months. There was no difference between dual-mobility prostheses and head sizes larger than 32 mm. There were no differences in the rate of second revision when first revisions for loosening, periprosthetic fracture, and osteolysis were compared. If cemented femoral fixation was performed at the time of the first revision, there was a higher cumulative percent second revision for loosening than cementless fixation from 6 months to 6 years, and after this time, there was no difference. The overall mortality after a first revision of primary conventional THA was 1% at 30 days, 2% at 90 days, 5% at 1 year, and 40% at 10 years. A first revision for periprosthetic fracture had the highest mortality at all timepoints compared with other reasons for the first revision. Larger head sizes and dual-mobility cups may help reduce further revisions for dislocation, and the use of cementless stems for a first revision for loosening seems advantageous. Surgeons may counsel patients about the higher risk of death after first revision procedures, particularly if the first revision is performed for periprosthetic fracture.Level of Evidence Level III, therapeutic study.

What’s New in Hip Replacement

What’s New in Hip Replacement

The Influence of Surgeon Caseload and Usage on the Long-Term Outcomes of Mobile-Bearing Unicompartmental Knee Arthroplasty: An Analysis of Data From the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man

BackgroundUnicompartmental knee arthroplasty (UKA) revision rates are variable and known to be influenced by a surgeon’s caseload (number of UKAs performed annually) and usage (UKA as a proportion of overall knee arthroplasty practice). It is not known which is more important. We explored the influence of caseload and usage on cemented and cementless UKA. MethodsA total of 34,277 medial Oxford UKAs (23,707 cemented and 10,570 cementless) from the National Joint Registry were analyzed. UKAs were subdivided by the following: (1) surgeon caseload, into low (<10 UKAs/y) and high (≥10 UKAs/y) categories; and (2) usage, into low (<20%) and high (≥20%) categories. The 10-year revision rates were compared. ResultsThe 10-year survival of the low-caseload/low-usage cemented and cementless UKA was 82.8% (CI 81.6-83.9) and 86.2% (CI 72.1-93.4), respectively. The 10-year survival of the high-caseload/high-usage cemented and cementless UKA was 90.0% (CI 89.2-90.6) and 93.3% (CI 91.3-94.8), respectively. For cemented UKA, the high-caseload/high-usage group had lower revision rates (hazard ratio [HR] 0.57, CI 0.52-0.63, P < .001) compared to the low-caseload/low-usage group. The high-caseload/low-usage (HR 0.74, CI 0.66-0.83, P < .001) and the low-caseload/high-usage (HR 0.86, CI 0.74-0.99, P = .04) groups also had lower revision rates than the low-caseload/low-usage group. ConclusionMobile-bearing UKA revision rates improve with both increasing surgeon UKA caseload and usage. Surgeons using cemented UKA who have usage ≥20% and caseload ≥10/year had a 10-year survival of 90%. Higher survivorship was associated with higher caseload, higher usage, and cementless fixation. Levels of evidenceIII.

The Effect of Age on the Relative Outcomes of Cemented and Cementless Mobile-Bearing Unicompartmental Knee Arthroplasty, Based on Data From National Databases

BackgroundUnicompartmental knee arthroplasty (UKA) is an effective treatment for medial compartment arthritis. A challenge is that patients requiring knee arthroplasty are becoming younger. It is currently unknown what the relative performances of cemented and cementless UKAs are, in different age groups. MethodsA total of 12,882 cemented and cementless UKAs from the National Joint Registry and Hospital Episodes Statistics databases were matched on patient and surgical factors. Patients were stratified into 3 groups: (1) <60 years; (2) 60-69 years; and (3) ≥70 years. Revision and reoperation rates were compared using Cox regression analyses. ResultsThe 10-year implant survival for the matched cemented and cementless UKAs for (1) <60 years were 81.4% (CI 73.6-87.0) and 86.7% (CI 80.7-90.9) (hazard ratio [HR] 0.73, CI 0.56-0.94, P = .02); (2) for 60-69 years were 91.8% (CI 88.9-94.0) and 94.5% (CI 92.9-95.7) (HR 0.90, CI 0.67-1.22, P = .51); and (3) ≥70 years were 93.5% (CI 91.1-95.3) and 94.2% (CI 92.0-95.8) (HR 1.0, CI 0.71-1.40, P = .99). The same trend was observed for reoperations. In the <60 years and 60-69 years groups there were significantly fewer revisions for aseptic loosening in the cementless group (0.5% versus 1.6% [P < .001] and 0.4% versus 1.3% [P = .002], respectively). ConclusionYounger ages were associated with higher revision rates in both cemented and cementless UKA groups. Cementless fixation has reduced long-term revision rates compared to cemented fixation in the <60 years group with aseptic loosening rates 3 times lower. Level of evidenceIII.

How long do revised and multiply revised hip replacements last? A retrospective observational study of the National Joint Registry.

Hip replacements are common and effective operations but patients that undergo this intervention are at risk of the replacements failing, requiring costly and often complex revision surgery with poorer outcomes than primary surgery. 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 aim to provide detailed information on the longevity of hip revision surgery. 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 April 1, 2003, and Dec 31, 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. Although hip replacements are effective for improving pain and function and usually last a remarkably long time, if they are revised, successive revisions are progressively and markedly less successful. NIHR Biomedical Research Centre at the University Hospitals Bristol and Weston NHS Foundation Trust and the University of Bristol, Healthcare Quality Improvement Partnership; and the National Joint Registry.

The Association Between Preoperative Patient-Reported Health Status and Postoperative Survey Completion Following Arthroplasty: Registry-Based Cohort Study.

BackgroundPatient-reported outcome measures (PROMs) are commonly used to report outcomes after hip and knee arthroplasty, but response rates are rarely complete. Given that preoperative health status (as measured by PROMs) is a strong predictor of outcomes (using the same measures) and that these outcomes may influence the response rate, it is possible that postoperative response rates (the proportion of patients providing preoperative PROMs who also provide postoperative PROMs) may be influenced by preoperative health status.ObjectiveThis study aims to test the association between preoperative PROMs and postoperative response status following hip and knee arthroplasty.MethodsData from the PROMs program of the Australian national joint registry were used. The preoperative PROMs were the Oxford Hip Score or Oxford Knee Score, The EQ-5D Utility Index, and the EQ visual analog scale (VAS) for overall health. Logistic regression, adjusting for age, sex, BMI, and the American Society of Anesthesiologists (ASA) Physical Status Classification System, was used to test the association between each preoperative PROM and response status for the 6-month postsurgery survey.ResultsData from 9499 and 16,539 patients undergoing elective total hip arthroplasty (THA) and total knee arthroplasty (TKA) for osteoarthritis, respectively, were included in the analysis. Adjusting for age, sex, BMI, and ASA, there was no significant difference in response status at the postoperative follow-up based on the preoperative Oxford Hip or Knee Scores (odds ratio [OR] 1.00, 95% CI 0.99-1.01 for both; P=.70 for THA and P=.85 for TKA). Healthier patients (based on the EQ VAS scores) preoperatively were more likely to respond postoperatively, but this difference was negligible (OR 1.00, 95% CI 1.00-1.01 for THA and TKA; P=.004 for THA and P<.001 for TKA). The preoperative EQ Utility Index was not associated with the postoperative response rate for THA (OR 1.14, 95% CI 0.96-1.36; P=.13) or TKA patients (OR 1.05, 95% CI 0.91-1.22; P=.49).ConclusionsThe likelihood of responding to a postoperative PROMs survey for patients undergoing hip or knee arthroplasty was not associated with clinically important differences in preoperative patient-reported joint pain, function, or health-related quality of life. This suggests that the assessment of postoperative outcomes in hip and knee arthroplasty is not biased by differences in preoperative health measures between responders and nonresponders.

What effect have NHS commissioners' policies for body mass index had on access to knee replacement surgery in England?: An interrupted time series analysis from the National Joint Registry.

To assess the impact of local commissioners' policies for body mass index on access to knee replacement surgery in England. A Natural Experimental Study using interrupted time series and difference-in-differences analysis. We used National Joint Registry for England data linked to the 2015 Index of Multiple Deprivation for 481,555 patients who had primary knee replacement surgery in England between January 2009 and December 2019. Clinical Commissioning Group policies introduced before June 2018 to alter access to knee replacement for patients who were overweight or obese were considered the intervention. The main outcome measures were rate per 100,000 of primary knee replacement surgery and patient demographics (body mass index, Index of Multiple Deprivation, independently-funded surgery) over time. Rates of surgery had a sustained fall after the introduction of a policy (trend change of -0.98 operations per 100,000 population aged 40+, 95% confidence interval -1.22 to -0.74, P<0.001), whereas rates increased in localities with no policy introduction. At three years after introduction, there were 10.5 per 100,000 population fewer operations per quarter aged 40+ compared to the counterfactual, representing a fall of 14.1% from the rate expected had there been no change in trend. There was no dose response effect with policy severity. Rates of surgery fell in all patient groups, including non-obese patients following policy introduction. The proportion of independently-funded operations increased after policy introduction, as did the measure of socioeconomic deprivation of patients. Body mass index policy introduction was associated with decreases in the rates of knee replacement surgery across localities that introduced policies. This affected all patient groups, not just obese patients at whom the policies were targeted. Changes in patient demographics seen after policy introduction suggest these policies may increase health inequalities and further qualitative research is needed to understand their implementation and impact.