Dislocation is still one of the more common reasons for revision of THR.Registry and large institutional data has demonstrated the effectiveness of Dual Mobility articulations in reducing revision for dislocation after THR. There is little data about whether the use of dual mobility is associated with a comprised clinical functional outcome. This study aimed to ascertain whether the use of Dual Mobility articulations (DM cups) comes within a compromise to the functional of the THR procedure as measured by the Hip disability and Osteoarthritis Outcome Score (HOOS). Utilising a retrospective design, patients were grouped into those with DM cups with 12 PROMs (Cohort 1) or a large data base of all THR procedures also with a complete set of 12 month PROMs (Cohort 2). The 2 groups were matched for age and gender through propensity score matching. The comparison focused on five domains of the HOOS: Pain, Symptoms, Activities of Daily Living (ADL), Sports and Recreation, and Quality of Life (QOL) at 6- and 12-months post-operation. 12 month PROM data suggested a convergence in scores for several domains, no uniform superiority of one articulation type over the other was found across all domains. These results suggest that both DM cup and standard articulations can effectively improve patient-reported outcomes in THR surgeries, but there are variations in recovery within each cohort that are potentially influenced by factors beyond the articulation type. This study contributes to the ongoing dialogue on optimising prosthetic selection to enhance recovery trajectories and quality of life for THR patients, emphasising the critical role of evidence-based decision-making in orthopaedic surgery

Aims

The Patient-Reported Outcomes Measurement Information System (PROMIS) has demonstrated faster administration, lower burden of data capture and reduced floor and ceiling effects compared to traditional Patient Reported Outcomes Measurements (PROMs). We investigated the suitability of PROMIS Mobility score in assessing physical function in the sequelae of childhood hip disease.

Aims. To compare the functional outcome, health-related quality of life (HRQoL), and satisfaction of patients who underwent primary total hip arthroplasty (THA) and a single debridement, antibiotics and implant retention (DAIR) procedure for deep infection, using either the transgluteal or the posterior surgical approach for both procedures. Methods. The study was registered at clinicaltrials.gov (ID: NCT03161990) on 15 May 2017. Patients treated with a single DAIR procedure for deep infection through the same operative approach as their primary THA (either the transgluteal or the posterior approach) were identified in the Norwegian Arthroplasty Register and given a questionnaire. Median follow-up after DAIR by questionnaire was 5.5 years in the transgluteal group (n = 87) and 2.5 years in the posterior approach group (n = 102). Results. Patients in the posterior approach group were less likely to limp after the DAIR procedure (17% vs 36% limped all the time; p = 0.005), had a higher mean Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) function score (80 vs 71; p = 0.013), and were more likely to achieve a patient acceptable symptom state for the WOMAC function score (76% vs 55%; p = 0.002). In a multivariable analysis, the point estimate for the increase in WOMAC function score using the posterior approach was 10.2 (95% CI 3.1 to 17.2; p = 0.005), which is above the minimal clinically important improvement. The patients in the posterior approach group also reported better mean HRQoL scores and were more likely to be satisfied with their hip arthroplasty (77% vs 55%; p = 0.001). Conclusion. In patients treated with a single, successful DAIR procedure for deep infection of a primary THA, the use of the posterior approach in both primary surgery and DAIR was associated with less limping, better functional outcome, better HRQoL, and higher patient satisfaction compared with cases where both were performed using the transgluteal approach. The observed differences in functional outcome and patient satisfaction were clinically relevant. Cite this article: Bone Joint J 2020;102-B(12):1662–1669

Aims. Complex total hip arthroplasty (THA) with subtrochanteric shortening osteotomy is necessary in conditions other than developmental dysplasia of the hip (DDH) and septic arthritis sequelae with significant proximal femur migration. Our aim was to evaluate the hip centre restoration with THAs in these hips. Methods. In all, 27 THAs in 25 patients requiring THA with femoral shortening between 2012 and 2019 were assessed. Bilateral shortening was required in two patients. Subtrochanteric shortening was required in 14 out of 27 hips (51.9%) with aetiology other than DDH or septic arthritis. Vertical centre of rotation (VCOR), horizontal centre of rotation, offset, and functional outcome was calculated. The mean followup was 24.4 months (5 to 92 months). Results. The mean VCOR was 17.43 mm (9.5 to 27 mm) and horizontal centre of rotation (HCOR) was 24.79 mm (17.2 to 37.6 mm). Dislocation at three months following acetabulum reconstruction required femoral shortening for offset correction and hip centre restoration in one hip. Mean horizontal offset was 39.72 (32.7 to 48.2 mm) compared to 42.89 (26.7 to 50.6 mm) on the normal side. Mean Harris Hip Score (HHS) of 22.64 (14 to 35) improved to 79.43 (68 to 92). Mean pre-operative shortening was 3.95 cm (2 to 8 cm). Residual limb length discrepancy was 1.5 cm (0 to 2 cm). Sciatic neuropraxia in two patients recovered by six months, and femoral neuropraxia in one hip recovered by 12 months. Mean Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was 13.92 (9 to 19). Mean 12-item short form survey (SF-12) physical scores of 50.6 and mental of 60.12 were obtained. Conclusion. THA with subtrochanteric shortening is valuable in complex hips with high dislocation. The restoration of the hip centre of rotation and offset is important in these hips. Level of evidence IV. Femoral shortening useful in conditions other than DDH and septic sequelae. Restoration of hip centre combined with offset to be planned and ensured

Aims

The primary aim of our study was to assess the influence of age on hip-specific outcome following total hip arthroplasty (THA). Secondary aims were to assess health-related quality of life (HRQoL) and level of activity according to age.

Aims. Advocates of debridement, antibiotics and implant retention (DAIR) in hip periprosthetic joint infection (PJI) argue that a procedure not disturbing a sound prosthesis-bone interface is likely to lead to better survival and functional outcome compared with revision. This case-control study aims were to compare outcome of DAIRs for infected primary total hip arthroplasty (THA) with outcomes following primary THA and two-stage revision of infected primary THAs. Patients and Methods. We retrospectively reviewed all DAIRs, performed for confirmed infected primary hip arthropasty (n = 82) at out institution, between 1997 and 2013. Data recorded included full patient information and type of surgery. Outcome measures included complications, mortality, implant survivorship and functional outcome. Outcome was compared with two control groups matched for gender and age; a cohort of primary THAs (n = 120) and a cohort of two-stage revisions for infection (n = 66). Results. Mean age at DAIR was 69 years (33 to 87) and mean follow-up was eight years (2 to 17; standard deviation (. sd). 5). A total of 52 (63%) of DAIRs were for early PJI (less than six weeks). Greater success in the eradication of infection with DAIR was identified with early PJI, comprising an interval less than a week between onset of symptoms and exchange of modular components with the DAIR procedure. Eradication of infection, complications and re-operation rates were similar in the DAIR and two-stage revision groups. For hips with successful eradication of infection with DAIR, the five-year survival (98%; 95% confidence interval (CI) 94 to 100) was similar to the primary THA group (98%; 95% CI 95 to 100) (n = 43; p = 0.3). The DAIR group had inferior mean Oxford Hip Scores (OHS) (38; 12 to 48) compared with the primary THA group (42; 15 to 48) (p = 0.02) but a significantly better mean OHS compared with the two-stage revision group (31; 0 to 48) (p = 0.008). Patients who required only one DAIR for eradication of infection had a similar mean OHS (41; 20 to 48) to the primary THA group (p = 0.2). Conclusion. The DAIR procedure is associated with a similar complication rate and ability to eradicate infection as two-stage revision. This study emphasises the need for exchange of modular components for improved chances of eradication of infection. This is the first study showing that DAIR is better than a two-stage revision regarding functional outcome. Cite this article: Bone Joint J 2017;99-B:614–22

We have evaluated the quality of life and functional outcome after unilateral primary total hip replacement (THR). Between 5 January 1998 and 31 July 2000, we recruited a consecutive series of 627 patients undergoing this procedure and investigated them prospectively. Each was assessed before operation and reviewed after six months, 18 months, three years and five years. The Short Form-36 Health Survey (SF-36) and Harris Hip scores were evaluated at each appointment. All dimensions of the SF-36 except for mental health and general health perception, improved significantly after operation and this was maintained throughout the follow-up. The greatest improvement was seen at the six-month assessment. On average, women reported lower SF-36 scores pre-operatively, but the gender difference did not continue post-operatively. The Harris Hip scores improved significantly after operation, reaching a plateau after 18 months. The improved quality of life was sustained five years after THR

Aims

Improvements in functional results and long-term survival are variable following conversion of hip fusion to total hip arthroplasty (THA) and complications are high. The aim of the study was to analyze the clinical and functional results in patients who underwent conversion of hip fusion to THA using a consistent technique and uncemented implants.

Introduction. Joint preserving procedures have gained popularity in an attempt to delay arthroplasty in young, dysplastic hips. Excellent results can be achieved with peri-acetabular osteotomy (PAO) in congruent non-arthritic hips. The role of salvage procedures such as the Shelf acetabuloplasty remains undefined. This study aims to determine the long-term survival and functional outcome following Shelf acetabuloplasty and to identify factors that influence outcome. Patients/Materials & Methods. This is a retrospective, consecutive, multi-surgeon, case series from a UK referral centre. 125 Shelf procedures were performed between 1987–2013 on 117 patients for symptomatic hip dysplasia. Mean age was 33 years (15–53). Mean follow-up was 10 years (1–27). Radiographic parameters measured included pre-operative arthritis, acetabular-index, centre-edge-angle, joint congruency, subluxation and femoral sphericity. Oxford Hip and UCLA scores were collected at follow-up. Failure was defined as conversion to arthroplasty or OHS<20. Results. The acetabular index and centre-edge angles have been improved from 23° (SD:9) and 12° (SD:8) pre-operatively to 10° (SD:9) and 45° (SD:11) post-operatively. By follow-up, 63 hips (50%) had converted to arthroplasty. The mean OHS and UCLA scores were 33 (SD:12) and 6 (SD:3), respectively. Survival rates were 82% at 5 years, 60% at 10 years and 43% at 15 years. The only factor influencing 10-yr survival was minimal pre-op arthritis (65% Vs 40%, p=0.02). Optimal functional outcome was seen when post-operative centre-edge angle was between 20–40° (p=0.01). Discussion. This largest long-term series of Shelf acetabuloplasties reported to-date emphasises the value of this procedure in patients that pose treatment dilemmas as they are symptomatic, too young for arthroplasty but have features that make them unsuitable for PAO. Never-the-less, in 60% of cases a Shelf acetabuloplasty will delay arthroplasty for 10 years. If performed in patients with minimal arthritis and congruent joint 10-year survival is 85%. Conclusion. Shelf acetabuloplasty is a simple, reliable procedure with good mid- to long-term results

Introduction. Total Hip Replacement (THR) is an effective treatment for end stage degenerative disease of the hip and offers patients the prospect of long term pain relief, improved joint function and quality of life. Enhanced Recovery Programmes (ERP) aim to standardise routine perioperative care, reduce hospital length of stay (LOS) and promote rapid recovery after elective surgery. The aim of this study was to determine whether the implementation of an ERP could successfully reduce the length of hospital stay associated with primary THR and whether this could be achieved without compromising the expected functional outcome or risking an increased dislocation rate. Patients/Materials & Methods. Prospectively collected data on 1161 patients (611 managed with traditional rehabilitation and 550 with ERP) undergoing primary unilateral THR between 2005 and 2013 was retrospectively reviewed. Univariable statistical analysis was undertaken to identify factors that appeared to predict length of stay and a multiple linear regression model was then constructed to determine the significance and strength of effect of the individual predictors. Results. Median LOS was 5 days for those managed in the traditional method and 3 days for those managed with ERP (p<0.001). Multivariate regression models demonstrate that this effect on LOS is independent of and stronger than other factors affecting LOS and we did not observe increased rates of dislocation (1.03% versus 0.73%, p=0.75) or mortality (1.5% versus 0.6%, p=0.14) at one year postoperative in patients managed with ERP. Both groups demonstrated significant improvement in mean Harris Hip Score (+42.8 versus +41.5) at twelve to eighteen months postoperative and there was no significant difference in the magnitude of improvement between groups (p=0.09). Discussion. This is the first study to demonstrate the independent effect of ERP on LOS through multiple regression analysis and to directly compare functional outcomes of patients managed with ERP with the accepted gold standard (traditional rehabilitation) and these findings will be of use to surgeons counselling patients peiroperatively and healthcare planners. Conclusion. Implementation of ERP can reduce the hospital LOS for primary THR without adverse effects on dislocation rates and functional outcomes at 12 to 18 months postoperative

Aims. The primary aim of this study was to investigate the effect of an enhanced recovery program (ERP) on the short-term functional outcome after total hip arthroplasty (THA). Secondary outcomes included its effect on rates of dislocation and mortality. . Patients and Methods. Data were gathered on 1161 patients undergoing primary THA which included 611 patients treated with traditional rehabilitation and 550 treated with an ERP. . Results. The ERP was shown to be a significant independent factor which shortened length of stay (LOS) by a mean of 1.5 days (95% confidence interval (CI) 1.3 to 1.8, p < 0.001) after adjusting for confounding variables. The rates of dislocation (traditional 1.03% vs ERP 0.91%, p = 0.84) and mortality (1.5% vs 0.6%, p = 0.14) one year post-operatively were not significantly different. Both groups showed significant improvement in Harris Hip Score (42.8 vs 41.5) at 12 to 18 months post-operatively and there was no significant difference in the magnitude of improvement on univariate (p = 0.09) and multivariate analysis (p = 0.35). There was no significant difference in any of the eight domain scores of the Short-Form - 36 general health surveys post-operatively (p > 0.38). . Conclusion . We conclude that an ERP after THA shortens LOS by a mean of 1.5 days and does not increase the rate of complications post-operatively. It gives equivalent functional outcomes to a traditional rehabilitation pathway. Take home message: ERP reduces LOS after THA in comparison to traditional rehabilitation, without adversely affecting functional outcomes, dislocation rates or mortality. Cite this article: Bone Joint J 2016;98-B:475–82

Background. Hip arthroscopy is a rapidly growing, evolving area within arthroscopic Orthopaedic Surgery, with annual rates increasing as much as 25-fold each year. Despite improvements in equipment and training, it remains a challenging procedure. Rates of revision surgery have been reported as 6.3% to 16.9%. Objectives. The primary objective was to determine the success of joint preservation after hip arthroscopy. The secondary objective was to determine whether patient characteristics or PROM functional score trends could predict revision hip arthroscopy or Total Hip Arthroplasty (THA). Study Design & Methods. We reviewed 1363 hip arthroscopies performed from January 2010 to December 2016 by a single high-volume surgeon at a single institution. Data was prospectively collected and retrospectively reviewed with a minimum 2-year follow-up. Functional outcomes were assessed with the International Hip Outcome Tool (IHOT-33). Hip arthroscopy failures were defined as Total Hip Arthroplasty or revision hip arthroscopy after index hip arthroscopy. Results. There were751 females and 612 males with an average age of 34.63 years (19 – 58 years). There were 199 cases (14.6%) of labrum repairs only, 286 (20.9%) cam and labrum repairs, 319 (23.4%) cam and pincer surgeries and 193 (14.1%) cam only surgeries. All pre-operative IHOT-33 patient-reported outcomes scores (27.42 ± 6.2) improved significantly at the 6 week-, 3 month- and 6-month follow-up visits (p<0.05). The best improvements were seen in symptoms and functional improvements (IHOT-SFL) (p<0.05) while the poorest amelioration of job-related concerns (IHOT-JRC) existed at all time points (p<0.05). There were 223 failures, 131 patients (9.61%) underwent revision hip arthroscopy and 92 required THA (6.75%) at 18.45 months ± 7.34 months. The 2-year survival rate was 89.2%. The THA conversion rate was 8.4% for patients > 50 years old and 3.72% for patients < 50 years old. Age (>50 years) and female sex were associated with increased risk of conversion to THA (p<0.05) while young (<25 years old) and female patients were most likely to undergo hip revision arthroscopy. Surgery involving repair of the labrum only are more likely to result in revision arthroscopy surgery and THA (70.7% at 10.6 years). CAM & pincer surgery have best longevity (90.9% at 10.6 years). Conclusions. Joint preservation and no subsequent surgery at 10.6 years is 83.64%. This study showed that predictors of revision hip arthroscopy or THA included poor pre-morbid functional score, female gender, age > 45, sudden functional score decrease at 3 months follow-up and cases in which only the labrum is surgically repaired

Aims. Using data from the Hip Fracture Evaluation with Alternatives of Total Hip Arthroplasty versus Hemiarthroplasty (HEALTH) trial, we sought to determine if a difference in functional outcomes exists between monopolar and bipolar hemiarthroplasty (HA). Methods. This study is a secondary analysis of patients aged 50 years or older with a displaced femoral neck fracture who were enrolled in the HEALTH trial and underwent monopolar and bipolar HA. Scores from the Western Ontario and McMaster University Arthritis Index (WOMAC) and 12-Item Short Form Health Survey (SF-12) Physical Component Summary (PCS) and (MCS) were compared between the two HA groups using a propensity score-weighted analysis. Results. Of 746 HAs performed in the HEALTH trial, 404 were bipolar prostheses and 342 were unipolar. After propensity score weighting, adequate balance between the bipolar and unipolar groups was obtained as shown by standardized mean differences less than 0.1 for each covariable. A total of 24 months after HA, the total WOMAC score and its subcomponents showed no statistically significant difference between the unipolar and bipolar groups. Similarly, no statistically significant difference was found in the PCS and MCS scores of the SF-12 questionnaire. In participants aged 70 years and younger, no difference was found in any of the functional outcomes. Conclusion. From the results of this study, the use of bipolar HA over unipolar design does not provide superior functional outcomes at 24 months postoperatively. The theoretical advantage of reduced acetabular wear with bipolar designs does not appear to influence functional outcomes in the first two years postoperatively. Cite this article: Bone Jt Open 2023;4(5):370–377

Aims. Custom-made partial pelvis replacements (PPRs) are increasingly used in the reconstruction of large acetabular defects and have mainly been designed using a triflange approach, requiring extensive soft-tissue dissection. The monoflange design, where primary intramedullary fixation within the ilium combined with a monoflange for rotational stability, was anticipated to overcome this obstacle. The aim of this study was to evaluate the design with regard to functional outcome, complications, and acetabular reconstruction. Methods. Between 2014 and 2023, 79 patients with a mean follow-up of 33 months (SD 22; 9 to 103) were included. Functional outcome was measured using the Harris Hip Score and EuroQol five-dimension questionnaire (EQ-5D). PPR revisions were defined as an endpoint, and subgroups were analyzed to determine risk factors. Results. Implantation was possible in all cases with a 2D centre of rotation deviation of 10 mm (SD 5.8; 1 to 29). PPR revision was necessary in eight (10%) patients. HHS increased significantly from 33 to 72 postoperatively, with a mean increase of 39 points (p < 0.001). Postoperative EQ-5D score was 0.7 (SD 0.3; -0.3 to 1). Risk factor analysis showed significant revision rates for septic indications (p ≤ 0.001) as well as femoral defect size (p = 0.001). Conclusion. Since large acetabular defects are being treated surgically more often, custom-made PPR should be integrated as an option in treatment algorithms. Monoflange PPR, with primary iliac fixation, offers a viable treatment option for Paprosky III defects with promising functional results, while requiring less soft-tissue exposure and allowing immediate full weightbearing. Cite this article: Bone Jt Open 2024;5(8):688–696

Aims. The aim of this study was to explore the functional results in a fitter subgroup of participants in the Hip Fracture Evaluation with Alternatives of Total Hip Arthroplasty versus Hemiarthroplasty (HEALTH) trial to determine whether there was an advantage of total hip arthroplasty (THA) versus hemiarthroplasty (HA) in this population. Methods. We performed a post hoc exploratory analysis of a fitter cohort of patients from the HEALTH trial. Participants were aged over 50 years and had sustained a low-energy displaced femoral neck fracture (FNF). The fittest participant cohort was defined as participants aged 70 years or younger, classified as American Society of Anesthesiologists grade I or II, independent walkers prior to fracture, and living at home prior to fracture. Multilevel models were used to estimate the effect of THA versus HA on functional outcomes. In addition, a sensitivity analysis of the definition of the fittest participant cohort was performed. Results. There were 143 patients included in the fittest cohort. Mean age was 66 years (SD 4.5) and 103 were female (72%). No clinically relevant differences were found between the treatment groups in the primary and sensitivity analyses. Conclusion. This analysis found no differences in functional outcomes between HA and THA within two years of displaced low-energy FNF in a subgroup analysis of the fittest HEALTH patients. These findings suggest that very few patients above 50 years of age benefit in a clinically meaningful way from a THA versus a HA early after injury. Cite this article: Bone Jt Open 2022;3(8):611–617

Studies have shown that 10–30% patients do not achieve optimal function outcomes after total hip replacement (THR). High quality randomised controlled trials (RCTs) evaluating the clinical and cost-effectiveness of techniques to improve functional outcomes after THR are lacking. We performed this study to evaluate the feasibility of a RCT comparing patient-reported functional outcomes after hybrid or fully cemented THR (ISRCTN11097021). Patients were recruited from two centres and randomised to receive either a fully cemented or hybrid THR. Data collection included Patient Reported Outcome Measures (PROMs), non-serious adverse events of special interest (AESI), serious adverse device effects (SADE) and NHS resource use. Qualitative interviews were undertaken to understand a) patient experiences of study processes and their reasons for taking part or not, and b) to understand surgeons’ perceptions of the study, factors affecting willingness to participate, and barriers to implementation of the future RCT findings. The target of 40 patients were successfully recruited for the feasibility RCT; the ratio of successful recruitment to eligible patients was 0.61 across both sites. Treatment crossovers occurred in four patients, all related to bone quality. Four patients were withdrawn due to not undergoing surgery within the study window because of the pandemic. Follow-up was 100% and PROMs were completed by all patients at all time points. The feasibility of conducting a within-trial cost-utility analysis was demonstrated. Interviews were conducted with 27 patients and 16 surgeons. Patients and surgeons generally found the study procedures acceptable and workable. Some declined participation because they did not want treatment allocated at random, or because blinding was off-putting. Surgeons’ perceptions of equipoise varied, and implementation of findings from the future RCT would need to recognise the ‘craft’ nature of surgery and the issue of training. We conclude that a full RCT with economic analysis will be both feasible and practicable, although mechanisms to safely implement potential changes to practice because of RCT findings may need consideration by the wider arthroplasty community

The significance of periprosthetic fractures about a total hip arthroplasty (THA) is becoming increasingly important. Recent studies have demonstrated post-operative periprosthetic fracture rates are higher amongst cemented polished taper slip (PTS) stem designs compared to collared cementless (CC) designs. However, in the National Joint Registry, the rate of intra-operative periprosthetic femoral fractures (IOPFF) with cementless implant systems remains higher (0.87% vs 0.42%. p <0.001) potentially leading to more post-operative complications. This study identifies the incidence of IOPFF, the fracture subtype and compares functional outcomes and revision rates of CC femoral implants with an IOPFF to CC stems and PTS stems without a fracture. 5376 consecutive CC stem THA, carried out through a posterior approach were reviewed for IOPFF. Each fracture was subdivided into calcar fracture, greater trochanter (GT) fracture or shaft fracture. 1:1:1 matched analysis was carried out to compare Oxford scores at one year. Matching criteria included; sex (exact), age (± 1 year), American Society of Anaesthesiologists (ASA) grade (exact), and date of surgery (± 6 months). Electronic records were used to review revision rates. Following review of the CC stems, 44 (0.8%) were identified as having an IOPFF. Of these 30 (0.6%) were calcar fractures, 11 (0.2%) GT fractures and 3 (0.06%) were shaft fractures. There were no shaft penetrations. Overall, no significant difference in Oxford scores at one year were observed when comparing the CC IOPFF, CC non-IOPFF and PTS groups. There were no CC stems revised for any reason with either a calcar fracture or trochanteric fracture within the period of 8 years follow-up. IOPFF do occur more frequently in cementless systems than cemented. The majority are calcar and GT fractures. These fractures, when identified and managed intra-operatively, do not have worse functional outcomes or revision rates compared to matched non-IOPFF cases

Aims. The Birmingham Hip Resurfacing (BHR) arthroplasty has been used as a surgical treatment of coxarthrosis since 1997. We present 20-year results of 234 consecutive BHRs performed in our unit. Methods. Between 1999 and 2001, there were 217 patients: 142 males (65.4%), mean age 52 years (18 to 68) who had 234 implants (17 bilateral). They had patient-reported outcome measures collected, imaging (radiograph and ultrasound), and serum metal ion assessment. Survivorship analysis was performed using Kaplan-Meier estimates. Revision for any cause was considered as an endpoint for the analysis. Results. Mean follow-up was 20.9 years (19.3 to 22.4). Registry data revealed that 19 hips (8.1%) had been revised and 26 patients (12%) had died from causes unrelated to the BHR. Among the remaining 189 hips, 61% were available for clinical follow-up at 20 years (n = 115) and 70% of patients had biochemical follow-up (n = 132). The cumulative implant survival rate at 20 years for male patients was 96.5% (95% confidence interval (CI) 93.5 to 99.6), and for female patients 87% (95% CI 79.7 to 94.9). The difference was statistically significant (p = 0.029). The mean Oxford Hip Score, Hip disability and Osteoarthritis Outcome Score, and Forgotten Joint Score were 45 (29 to 48), 89 (43 to 100), and 84 (19 to 100), respectively. The mean scores for each of the five domains of the EuroQol five-dimension three-level questionnaire were 1.2, 1.0, 1.2, 1.3, and 1.1, and mean overall score 82.6 (50 to 100). Ultrasound showed no pseudotumour. Mean cobalt and chromium levels were 32.1 nmol/l (1 to 374) and 45.5 nmol/l (9 to 408), respectively. Conclusion. This study shows that BHRs provide excellent survivorship and functional outcomes in young male patients. At 20 years, soft-tissue imaging and serum metal ion studies suggest that a metal-on-metal resurfacing implant can be well tolerated in a group of young patients. Cite this article: Bone Joint J 2023;105-B(9):946–952

Aims. Achieving accurate implant positioning and restoring native hip biomechanics are key surgeon-controlled technical objectives in total hip arthroplasty (THA). The primary objective of this study was to compare the reproducibility of the planned preoperative centre of hip rotation (COR) in patients undergoing robotic arm-assisted THA versus conventional THA. Methods. This prospective randomized controlled trial (RCT) included 60 patients with symptomatic hip osteoarthritis undergoing conventional THA (CO THA) versus robotic arm-assisted THA (RO THA). Patients in both arms underwent pre- and postoperative CT scans, and a patient-specific plan was created using the robotic software. The COR, combined offset, acetabular orientation, and leg length discrepancy were measured on the pre- and postoperative CT scanogram at six weeks following surgery. Results. There were no significant differences for any of the baseline characteristics including spinopelvic mobility. The absolute error for achieving the planned horizontal COR was median 1.4 mm (interquartile range (IQR) 0.87 to 3.42) in RO THA versus 4.3 mm (IQR 3 to 6.8; p < 0.001); vertical COR mean 0.91 mm (SD 0.73) in RO THA versus 2.3 mm (SD 1.3; p < 0.001); and combined offset median 2 mm (IQR 0.97 to 5.45) in RO THA versus 3.9 mm (IQR 2 to 7.9; p = 0.019). Improved accuracy was observed with RO THA in achieving the desired acetabular component positioning (root mean square error for anteversion and inclination was 2.6 and 1.3 vs 8.9 and 5.3, repectively) and leg length (mean 0.6 mm vs 1.4 mm; p < 0.001). Patient-reported outcome measures were comparable between the two groups at baseline and one year. Participants in the RO THA group needed fewer physiotherapy sessions postoperatively (median six (IQR 4.5 to 8) vs eight (IQR 6 to 11; p = 0.005). Conclusion. This RCT suggested that robotic-arm assistance in THA was associated with improved accuracy in restoring the native COR, better preservation of the combined offset, leg length correction, and superior accuracy in achieving the desired acetabular component positioning. Further evaluation through long-term and registry data is necessary to assess whether these findings translate into improved implant survival and functional outcomes. Cite this article: Bone Joint J 2024;106-B(4):324–335

Aims. Large acetabular bone defects encountered in revision total hip arthroplasty (THA) are challenging to restore. Metal constructs for structural support are combined with bone graft materials for restoration. Autograft is restricted due to limited volume, and allogenic grafts have downsides including cost, availability, and operative processing. Bone graft substitutes (BGS) are an attractive alternative if they can demonstrate positive remodelling. One potential product is a biphasic injectable mixture (Cerament) that combines a fast-resorbing material (calcium sulphate) with the highly osteoconductive material hydroxyapatite. This study reviews the application of this biomaterial in large acetabular defects. Methods. We performed a retrospective review at a single institution of patients undergoing revision THA by a single surgeon. We identified 49 consecutive patients with large acetabular defects where the biphasic BGS was applied, with no other products added to the BGS. After placement of metallic acetabular implants, the BGS was injected into the remaining bone defects surrounding the new implants. Patients were followed and monitored for functional outcome scores, implant fixation, radiological graft site remodelling, and revision failures. Results. Mean follow-up was 39.5 months (36 to 71), with a significant improvement in post-revision function compared to preoperative function. Graft site remodelling was rated radiologically as moderate in 31 hips (63%) and strong in 12 hips (24%). There were no cases of complete graft site dissolution. No acetabular loosening was identified. None of the patients developed clinically significant heterotopic ossification. There were twelve reoperations: six patients developed post-revision infections, three experienced dislocations, two sustained periprosthetic femur fractures, and one subject had femoral component aseptic loosening. Conclusion. Our series reports bone defect restoration with the sole use of a biphasic injectable BGS in the periacetabular region. We did not observe significant graft dissolution. We emphasize that successful graft site remodelling requires meticulous recipient site preparation. Cite this article: Bone Jt Open 2022;3(12):991–997