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

This was a retrospective study of registry data from a National Orthopaedic Hospital for all THRs with 10-year follow-up data. Inclusion criteria were all THRs with a minimum of 10-year follow-up data. All metal-on-metal (MoM) THRs and MoM resurfacings were excluded from the analysis due to the high rate of revision associated with these bearings. Univariate and multivariate analyses controlling for confounding variables were performed to compare outcomes. A total of 1,697 THRs were performed in 1,553 patients. The four significant predictors for revision were fixation type (p<0.01), surface bearing type (p<0.01), age (P<0.05) and head size (p<0.05). Gender, BMI and approach had no effect on revision rates. The lowest 10-year all-cause revision rates were seen in cemented THRs at 1.7%. Ceramic-on-poly bearings had the lowest revision rate at only 1.2%. Metal-on-poly bearings had a 1.7% revision rate. Ceramic on ceramic bearings had a 7.1% revision rate with 1 revision for squeak and 1 revision for ceramic head fracture. The causes for revision in order of decreasing frequency were as follows: Infection (n=13, 0.7%), dislocation (n=7, 0.4%), periprosthetic fracture (n=3, 0.2%) and aseptic loosening (n=2, 0.1%). There were 2 re-revisions at 10 years in total. The smaller 22.225mm head sizes had a significantly lower revision rate than other head sizes (p<0.05). Ceramic-on-poly bearings, cemented fixation and smaller head sizes perform better in the experience of this registry. However, with multivariate analysis, these differences were shown to be insignificant

Abstract. INTRODUCTION. In the NHS the structure of a “regular healthcare team” is no longer the case. The NHS is facing a workforce crisis where cross-covering of ward-based health professionals is at an all-time high, this includes nurses, doctors, therapists, pharmacists and clerks. Comprehensive post-operative care documentation is essential to maintain patient safety, reduce information clarification requests, delays in rehabilitation, treatment, and investigations. The value of complete surgical registry data is emerging, and in the UK this has recently become mandated, but the completeness of post-operative care documentation is not held to the same importance, and at present there is no published standard. This project summarises a 4-stage approach, including 6 audit cycles, >400 reviewed operation notes, over a 5 year period. OBJECTIVE. To deliver a sustainable change in post operative care documentation practices through quality improvement frameworks. METHODS. Stage 1: Characterise the problem and increase engagement through: SMART aims, process mapping, hybrid action-effect and driver diagram and stakeholder analysis. Multi disciplinary stakeholders were involved in achieving a consensus of evidence-based auditable criteria. Stage 2: Baseline audit to assess current practice. Stage 3: Intervention planning by stakeholders. Stage 4: Longitudinal monitoring through run charts and iterative refinement. RESULTS. Stage 1: Process mapping identified numerous downstream effects of the absence of critical information from operation notes, and the action-effect diagram highlighted the multiple unnecessary mitigating actions performed by ward staff. An MDT consensus was achieved on 15 essential criteria for complete documentation, including important negative fields. Interest-influence matrix identified stakeholder groups with high influence but low interest who needed engagement to deliver change. Stage 2: Baseline audit demonstrated unexpectedly poor documentation: >75% compliance in 4 criteria, and <50% compliance in 10 criteria, which elevated the interest of key stakeholders. Stage 3: A post-operative care template based on the 15 criteria was embedded within the existing IT software. It allowed use of existing operative templates, with a non-overwriting suffix requiring only two mouse clicks. Stage 4: Re-audit at 3 and 12 months showed improved and sustained compliance. At 24 months compliance had declined. Questionnaire of template usage identified problems of criteria response options, and lack of awareness of template by newly appointed staff. Template update improved compliance over the next 6 months (>75% compliance in 11 criteria). Finally, a further reaudit conducted 12 months after the template update (5 years post baseline audit) showed a sustained improvement in compliance (>75% compliance in 13 criteria). CONCLUSIONS. Simple innovation through quality improvement frameworks has changed documentation practices by 1) achieving a consensus from stakeholders, 2) a “shock and awe” moment to highlight existing poor documentation and increase engagement 3) implementing change which fit easily into existing systems, 4) respecting autonomy rather than enforcing change and 5) longitudinal monitoring using run charts and an iterative process to ensure the template remains fit for purpose. This model has now successfully been translated to other subspecialities within the orthopaedic department. 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

Abstract. Purpose. Clinical registries are an important aspect of orthopaedic research in assessing the outcomes of surgical intervention and track medical devices. This study aimed to explore the research methodology available to account for patients lost to follow-up (LTFU) specifically in studies related to arthroscopic intervention and whether the rates of patient LTFU are within the acceptable margins for survey studies. Methods. A scoping review, where a literature search for studies from nine arthroscopy registries, was performed on EMBASE, MEDLINE, and the annual reports of each registry. Inclusion criteria included studies with information on patient-reported outcome measures and being based on nine national registries identified. Exclusion criteria included review articles, conference abstracts, studies not based on registry data, and studies from regional, claims-based, or multi-centre registries. Studies were then divided into categories based on method of LTFU analysis used. Results. Thirty-six articles were identified for the final analysis. Categories for LTFU analysis included dropout analyses (n=10), referencing validation studies (n=12), contacting non-responders (n=4), and sensitivity analyses (n=1). Referencing validation studies was the most common method (n=12). Majority (n=35) of the studies exceeded the recommended maximum rates for LTFU. Conclusions. Most arthroscopy studies have rates of LTFU higher than traditionally acceptable. Therefore, any conclusions drawn from these research papers may not be sufficiently valid or free from non-response bias

Abstract. Objectives. Patella resurfacing in primary total knee arthroplasty (TKA) remains a contentious issue. Australian rates of patellar resurfacing are 66.6%, significantly higher compared to UK rates of 8–15% and Swedish rates of 2%. Resurfacing has gained popularity in Australia since registry data has shown decreased revision rates with no increase in patellar component related complications. We present for discussion an analysis of 113,694 total knee arthroplasties using commonly implanted prostheses in the UK. Methods. We included all TKA's since the Australian register's conception on 01/09/1999 for a primary diagnosis of osteoarthritis involving the use of either the Triathlon or Duracon implant with and without patellar components. The primary outcome of the study was time to revision for Triathlon's resurfaced and non-resurfaced prosthesis compared to the Duracon's equivalent data. We also analysed the reasons for revision between the 4 groups, type of revision and complication rates. We then compared minimally stabilised and posterior stabilised prostheses. Results. The cumulative revision rate for Triathlon prostheses with resurfacing after 12 years was 3.2% (95% CI, 2.9% to 3.6%) compared to 5.6% (95% CI, 5.0% to 6.2%) without resurfacing. Duracon's equivalent data was 6.3% with resurfacing and 5.9% without resurfacing. Triathlon prosthesis with resurfacing have much lower rates of revision due to loosening, patellofemoral pain, patellar erosion compared to unresurfaced Triathlon prostheses. Conclusion. Triathlon with re-surfacing has lower revision rates regardless of age or BMI. Previous concerns regarding patellofemoral loosening, tibial wear, maltracking relate to Duracon only, indicating the importance of implant specific studies. 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

Objectives. The Attune total knee arthroplasty (TKA) has been used in over 600 000 patients worldwide. Registry data show good clinical outcome; however, concerns over the cement-tibial interface have been reported. We used retrieval analysis to give further insight into this controversial topic. Methods. We examined 12 titanium (Ti) PFC Sigma implants, eight cobalt-chromium (CoCr) PFC Sigma implants, eight cobalt-chromium PFC Sigma rotating platform (RP) implants, and 11 Attune implants. We used a peer-reviewed digital imaging method to quantify the amount of cement attached to the backside of each tibial tray. We then measured: 1) the size of tibial tray thickness, tray projections, peripheral lips, and undercuts; and 2) surface roughness (Ra) on the backside and keel of the trays. Statistical analyses were performed to investigate differences between the two designs. Results. There was no evidence of cement attachment on any of the 11 Attune trays examined. There were significant differences between Ti and CoCr PFC Sigma implants and Attune designs (p < 0.05); however, there was no significant difference between CoCr PFC Sigma RP and Attune designs (p > 0.05). There were significant differences in the design features between the investigated designs (p < 0.05). Conclusion. The majority of the earliest PFC Sigma designs showed evidence of cement, while all of the retrieved Attune trays and the majority of the RP PFC trays in this study had no cement attached. This may be attributable to the design differences of these implants, in particular in relation to the cement pockets. Our results may help explain a controversial aspect related to cement attachment in a recently introduced TKA design. Cite this article: A. Cerquiglini, J. Henckel, H. Hothi, P. Allen, J. Lewis, A. Eskelinen, J. Skinner, M. T. Hirschmann, A. J. Hart. Analysis of the Attune tibial tray backside: A comparative retrieval study. Bone Joint Res 2019;8:136–145. DOI: 10.1302/2046-3758.83.BJJ-2018-0102.R2

Background. Since it's establishment in 2007, the National Hip Fracture Database [NHFD] has been the key driving force in improving care for hip fracture patients across the UK. It has facilitated the setting of standards to which all musculoskeletal units are held, and guides service development to optimise outcomes in this group of patients. As with any audit, the ability to draw conclusions and make recommendations for changes in practise relies on the accuracy of data collection. This project aimed to scrutinise the data submitted to the NHFD from a Major Trauma Centre [MTC], focusing on procedure coding, and discuss the implications of any inaccuracies. Method. The authors performed a retrospective analysis of all procedure coding data entered into the NHFD from July 2009 to July 2014 at Cambridge University Hospitals NHS Foundation Trust. We examined 1978 cases for discrepancies, comparing procedure codes entered into the NHFD with post-procedure imaging and operative notes. Results. The procedure coding data submitted to the NHFD was highly inaccurate, with incorrect procedure codes in 24% of the 1978 cases reviewed. In particular, coding of cemented total arthroplasty and cemented bipolar hemiarthroplasty, with coding errors in registry data of 42% and 39% respectively. Of the 67 THRs performed only 52% were correctly coded for, and only 626 of the 915 hemiarthroplasties (68%). 16% of cannulated hip screws actually underwent primary arthroplasty. Conclusions. This study highlights the inaccuracy of coding data entered into the NHFD from a Major Trauma Centre, with data on arthroplasty being particularly inadequate. The unreliability of procedure data leaves us unable to evaluate surgical treatment strategies using the NHFD. This has worrying implications for standard setting, service development and, consequently, patient care. Level of evidence. 2c

Background. Over 96% of primary total hip replacements (THR) recorded in the National Joint Registry (NJR) are performed through a posterior or lateral surgical approach. There is no high quality evidence available to support the use of one approach over the other in primary THR and even less evidence when the outcome of revision THR is considered. Methods. Questionnaires were sent to 267 patients who had revision hip replacements between January 2006 and March 2010 for aseptic loosening. They rated their pain from 0–10, and used the Self-Administered Patient Satisfaction Scale (SAPS), Oxford Hip Score (OHS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and Short form-12 (SF-12). Results. We performed 275 revision total hip replacements for aseptic loosening on patients in whom the primary operation details were available. Their mean age was 69 years (SD12) with 43% male and 57% right-sided procedures. 205 patients responded to our questionnaires (209/275 hips, 76%). Unfortunately 19 patients had died, 4 had dementia and 13 declined to participate. We were unable to contact a further 33.Grouping by approach, 20% (43/209) had primary and revision lateral approaches, 20% (43/209) had primary lateral and revision posterior and 60% (123/209) had both primary and revision via posterior approaches. The WOMAC and OHS were significantly better in patients who had a posterior approach for both primary and revision surgery, compared to those that did not (OHS p=0.028, WOMAC p=0.026). We found no significant differences in pain, satisfaction or health-related quality of life between the groups. Conclusions. Registry data may help further explore the relationship between surgical approach and outcome in revision hip surgery. A randomised controlled trial of the posterior versus lateral approach for revision surgery would provide a definitive answer. Level of Evidence. 2b - retrospective cohort study. Disclosures. No financial disclosures or conflicts of interests from any authors

Summary Statement. For RA patients undergoing TKR, the gain in function at 6 months following surgery is less than that experienced by OA patients; for THR, however, gains are similar in OA and RA patients. Introduction. Total joint replacement (TJR) is commonly used in rheumatoid arthritis (RA) patients and yet little information is available to quantify their functional gain following surgery and how it differs from what the osteoarthritis (OA) population experiences. Therefore, we examined 6-month functional outcomes of TJR in a population-based observational cohort of RA and OA patients who underwent total hip (THR) or knee (TKR) replacement. Methods. Patients undergoing primary TKR from 7/1/11 through 12/3/12 were identified from the FORCE-TJR national research consortium which enrolls patients from 111 surgeons across 27 states in the US. The registry gathers data from patients, surgeons and hospitals on patient demographics, underlying type of arthritis, operative joint severity based on the estimated Western Ontario and McMaster Universities Arthritis Index (WOMAC) using the Hip and Knee Disability and Osteoarthritis Outcome Scores, function based on the Short Form 36 Physical Component Score (PCS), and mental health using the SF-36 Mental Component Score (MCS). Descriptive statistics were performed. Results. There were 95 RA and 991 OA patients who underwent primary TKR, and 59 RA and 740 OA patients who underwent primary THR. Among TKR patients, RA patients are more likely to be women (68% vs. 61%), nonwhite (17% vs. 9%), unmarried (59% vs. 70%) with an annual income of ≤$45,000 (57% vs. 39%) as well as lower baseline emotional health (48 vs. 52) and functioning (31 vs 33). Among THR patients, RA patients are more likely to be nonwhite (18% vs. 8%), unmarried (66% vs. 69%) with an annual income of ≤$45,000 (54% vs. 34%) as well as lower baseline emotional health (46 vs. 51) and functioning (30 vs 32). RA patients undergoing TKR have less functional gain 6 months post-surgery (6.6 vs. 9.7; p=0.002) as compared to OA patients. In contrast, RA patients who undergo THR have similar functional gain (11.6 vs. 13.8; p=0.13) as compared to OA patients. Discussion/Conclusion. RA patients have less functional improvement as compared to those with OA when undergoing TKR but similar gains when undergoing THR

A total of 20 pairs of fresh-frozen cadaver femurs were assigned to four alignment groups consisting of relative varus (10° and 20°) and relative valgus (10° and 20°), 75 composite femurs of two neck geometries were also used. In both the cadaver and the composite femurs, placing the component in 20° of valgus resulted in a significant increase in load to failure. Placing the component in 10° of valgus had no appreciable effect on increasing the load to failure except in the composite femurs with varus native femoral necks. Specimens in 10° of varus were significantly weaker than the neutrally-aligned specimens.

The results suggest that retention of the intact proximal femoral strength occurs at an implant angulation of ≥ 142°. However, the benefit of extreme valgus alignment may be outweighed in clinical practice by the risk of superior femoral neck notching, which was avoided in this study.