Aims. The primary aim of this trial was to compare the subsidence of two similar hydroxyapatite-coated titanium femoral components from different manufacturers. Secondary aims were to compare rotational migration (anteversion/retroversion and varus/valgus tilt) and patient-reported outcome measures between both femoral components. Methods. Patients were randomized to receive one of the two femoral components (Avenir or Corail) during their primary total hip arthroplasty between August 2018 and September 2020. Radiostereometric analysis examinations at six, 12, and 24 months were used to assess the migration of each implanted femoral component compared to a baseline assessment. Patient-reported outcome measures were also recorded for these same timepoints. Overall, 50 patients were enrolled (62% male (n = 31), with a mean age of 65.7 years (SD 7.3), and mean BMI of 30.2 kg/m. 2. (SD 5.2)). Results. The two-year subsidence was similar for Avenir (-0.018 mm (95% confidence interval (CI) -0.053 to 0.018) and Corail (0.000 mm (95% CI -0.027 to 0.026; p = 0.428). Both anteversion/retroversion (Avenir 0.139° (95% CI -0.204 to 0.481°); Corail -0.196° (95% CI -0.445 to 0.053°; p = 0.110) and varus/valgus tilt (Avenir -0.024° (95% CI -0.077 to 0.028); Corail -0.049° (95% CI -0.098 to 0.000°; p = 0.473) were not statistically significantly different. After two years, patients reported similar improvements in EuroQol five-dimension five-level health questionnaire (Avenir 0.22 (SD 0.2); Corail 0.22 (SD 0.18); p = 0.965) and other outcomes scores. Patient satisfaction on a five-point Likert scale was also similar between both groups after two years (Avenir 1.38 (SD 0.88); Corail 1.33 (SD 0.57); p = 0.846). Conclusion. The performance of both femoral components was similar in terms of stability and patient outcomes. Cite this article: Bone Joint J 2023;105-B(10):1045–1051

Aims. The primary aim of this study was to assess whether patients waiting six months or more for a total hip (THA) or knee (KA) arthroplasty had a deterioration in their health-related quality of life (HRQoL). Secondary aims were to assess changes in frailty and the number of patients living in a state considered to be worse than death (WTD), and factors associated with changes in HRQoL and frailty. Methods. This cross-sectional study included 326 patients, 150 males (46.0%) and 176 females (54.0%), with a mean age of 68.6 years (SD 9.8) who were randomly selected from waiting lists at four centres and had been waiting for six months or more (median 13 months, interquartile range 10 to 21) for a primary THA (n = 161) or KA (n = 165). The EuroQol five-dimension questionnaire (EQ-5D) and visual analogue scores (EQ-VAS), Rockwood Clinical Frailty Scale (CFS), and 36-Item Short Form Survey subjective change in HRQoL were assessed at the time and recalled for six months earlier. A state that was WTD was defined as an EQ-5D of less than zero. Results. There were significant deteriorations in the EQ-5D (mean 0.175, 95% confidence interval (CI) 0.145 to 0.204; p < 0.001), EQ-VAS (mean 8.6, 95% CI 7.0 to 10.4; < 0.001), and CFS (from 3 “managing well” to 4 “vulnerable”; p < 0.001), and a significant increase in the number of those in a state that was WTD (n = 48; p < 0.001) during the previous six months for the whole cohort. A total of 110 patients (33.7%) stated that their health was much worse and 107 (32.8%) felt it was somewhat worse compared with six months previously. A significantly greater EQ-5D (-0.14, 95% CI 0.08 to 0.28; p = 0.038) and a state that was not WTD (-0.14, 95% CI 0.01 to 0.26; p = 0.031) were associated with a deterioration in the EQ-5D. THA (0.21, 95% CI 0.07 to 0.34; p = 0.002) or a lower (better) CFS (0.14, 95% CI 0.07 to 0.20; p < 0.001) were independently significantly associated with a deterioration in the CFS. Conclusion. Patients waiting more than six months for THA or KA had a significant deterioration in their HRQoL and increased frailty, with two-thirds of patients feeling that their health had worsened. Cite this article: Bone Joint J 2022;104-B(11):1215–1224

Aims. Excessive posterior pelvic tilt (PT) may increase the risk of anterior instability after total hip arthroplasty (THA). The aim of this study was to investigate the changes in PT occurring from the preoperative supine to postoperative standing position following THA, and identify factors associated with significant changes in PT. Methods. Supine PT was measured on preoperative CT scans and standing PT was measured on preoperative and one-year postoperative standing lateral radiographs in 933 patients who underwent primary THA. Negative values indicate posterior PT. Patients with > 13° of posterior PT from preoperative supine to postoperative standing (ΔPT ≤ -13°) radiographs, which corresponds to approximately a 10° increase in functional anteversion of the acetabular component, were compared with patients with less change (ΔPT > -13°). Logistic regression analysis was used to assess preoperative demographic and spinopelvic parameters predictive of PT changes of ≤ -13°. The area under receiver operating characteristic curve (AUC) determined the diagnostic accuracy of the predictive factors. Results. PT changed from a mean of 3.8° (SD 6.0°)) preoperatively to -3.5° (SD 6.9°) postoperatively, a mean change of -7.4 (SD 4.5°; p < 0.001). A total of 95 patients (10.2%) had ≤ -13° change in PT from preoperative supine to postoperative standing. The strongest predictive preoperative factors of large changes in PT (≤ -13°) from preoperative supine to postoperative standing were a large posterior change in PT from supine to standing, increased supine PT, and decreased standing PT (p < 0.001). Flexed-seated PT (p = 0.006) and female sex (p = 0.045) were weaker significant predictive factors. When including all predictive factors, the accuracy of the AUC prediction was 84.9%, with 83.5% sensitivity and 71.2% specificity. Conclusion. A total of 10% of patients had > 13° of posterior PT postoperatively compared with their supine pelvic position, resulting in an increased functional anteversion of > 10°. The strongest predictive factors of changes in postoperative PT were the preoperative supine-to-standing differences, the anterior supine PT, and the posterior standing PT. Surgeons who introduce the acetabular component with the patient supine using an anterior approach should be aware of the potentially large increase in functional anteversion occurring in these patients. Cite this article: Bone Joint J 2024;106-B(3 Supple A):74–80

Aims. To determine mortality risk after first revision total hip arthroplasty (THA) for periprosthetic femoral fracture (PFF), and to compare this to mortality risk after primary and first revision THA for other common indications. Methods. The study cohort consisted of THAs recorded in the National Joint Registry between 2003 and 2015, linked to national mortality data. First revision THAs for PFF, infection, dislocation, and aseptic loosening were identified. We used a flexible parametric model to estimate the cumulative incidence function of death at 90 days, one year, and five years following first revision THA and primary THA, in the presence of further revision as a competing risk. Analysis covariates were age, sex, and American Society of Anesthesiologists (ASA) grade. Results. A total of 675,078 primary and 74,223 first revision THAs were included (of which 6,131 were performed for PFF). Following revision for PFF, mortality ranged from 9% at 90 days, 21% at one year, and 60% at five years in the highest risk group (males, ≥ 75 years, ASA ≥ 3) to 0.6%, 1.4%, and 5.5%, respectively, for the lowest risk group (females, < 75 years, ASA ≤ 2). Mortality was greater in all groups following first revision THA for PFF than for primary THA. Compared to mortality risk after first revision THA for infection, dislocation, or aseptic loosening, revision for PFF was associated with higher five-year mortality in all groups except males < 75 years with an ASA ≤ 2. Conclusion. Mortality risk after revision THA for PFF is high, reaching 60% at five years in the highest risk patient group. In comparison to other common indications for revision, PFF demonstrated the highest overall risk of mortality at five years. These estimates can be used in the surgical decision-making process and when counselling patients and carers regarding surgical risk. Cite this article: Bone Joint J 2020;102-B(12):1670–1674

Aims. The aims were to assess whether preoperative joint-specific function (JSF) and health-related quality of life (HRQoL) were associated with level of clinical frailty in patients waiting for a primary total hip arthroplasty (THA) or knee arthroplasty (KA). Methods. Patients waiting for a THA (n = 100) or KA (n = 100) for more than six months were prospectively recruited from the study centre. Overall,162 patients responded to the questionnaire (81 THA; 81 KA). Patient demographics, Oxford score, EuroQol five-dimension (EQ-5D) score, EuroQol visual analogue score (EQ-VAS), Rockwood Clinical Frailty Score (CFS), and time spent on the waiting list were collected. Results. There was a significant correlation between CFS and the Oxford score (THA r = −0.838; p < 0.001, KA r = −0.867; p < 0.001), EQ-5D index (THA r = −0.663, p =< 0.001; KA r = −0.681; p =< 0.001), and EQ-VAS (THA r = −0.414; p < 0.001, KA r = −0.386; p < 0.001). Confounding variables (demographics and waiting time) where adjusted for using multiple regression analysis. For each 8.5 (THA, 95% CI 7.1 to 10.0; p < 0.001) and 9.9 (KA, 95% CI 8.4 to 11.4; p < 0.001) point change in the Oxford score, there was an associated change in level of the CFS. For each 0.16 (THA, 95% CI 0.10 to 0.22; p < 0.001) and 0.20 (KA, 95% CI 0.12 to 0.27; p < 0.001) utility change in EQ-5D, there was an associated change in level of the CFS. EQ-VAS (THA, B = −11.5; p < 0.001, KA B = −7.9; p = 0.005) was also associated with CFS. Conclusion. JSF and HRQoL in patients awaiting THA or KA for more than six months, were independently associated with level of clinical frailty. With further prospective studies, clinical frailty may prove to be a useful metric to assist in the prioritization of arthroplasty waiting lists. Cite this article: Bone Jt Open 2023;4(4):241–249

Aims. Registry studies on modified acetabular polyethylene (PE) liner designs are limited. We investigated the influence of standard and modified PE acetabular liner designs on the revision rate for mechanical complications in primary cementless total hip arthroplasty (THA). Methods. We analyzed 151,096 primary cementless THAs from the German Arthroplasty Registry (EPRD) between November 2012 and November 2020. Cumulative incidence of revision for mechanical complications for standard and four modified PE liners (lipped, offset, angulated/offset, and angulated) was determined using competing risk analysis at one and seven years. Confounders were investigated with a Cox proportional-hazards model. Results. Median follow-up was 868 days (interquartile range 418 to 1,364). The offset liner design reduced the risk of revision (hazard ratio (HR) 0.68 (95% confidence interval (CI) 0.50 to 0.92)), while the angulated/offset liner increased the risk of revision for mechanical failure (HR 1.81 (95% CI 1.38 to 2.36)). The cumulative incidence of revision was lowest for the offset liner at one and seven years (1.0% (95% CI 0.7 to 1.3) and 1.8% (95% CI 1.0 to 3.0)). No difference was found between standard, lipped, and angulated liner designs. Higher age at index primary THA and an Elixhauser Comorbidity Index greater than 0 increased the revision risk in the first year after surgery. Implantation of a higher proportion of a single design of liner in a hospital reduced revision risk slightly but significantly (p = 0.001). Conclusion. The use of standard acetabular component liners remains a good choice in primary uncemented THA, as most modified liner designs were not associated with a reduced risk of revision for mechanical failure. Offset liner designs were found to be beneficial and angulated/offset liner designs were associated with higher risks of revision. Cite this article: Bone Joint J 2022;104-B(7):801–810

Aims. Dual mobility (DM) implants have been shown to reduce the dislocation rate after total hip arthroplasty (THA), but there remain concerns about the use of cobalt chrome liners inserted into titanium shells. The aim of this study was to assess the clinical outcomes, metal ion levels, and periprosthetic femoral bone mineral density (BMD) at mid-term follow-up in young, active patients receiving a modular DM THA. Methods. This was a prospective study involving patients aged < 65 years, with a BMI of < 35 kg/m. 2. , and University of California, Los Angeles activity score of > 6 who underwent primary THA with a modular cobalt chrome acetabular liner, highly cross-linked polyethylene mobile bearing, and a cementless titanium femoral stem. Patient-reported outcome measures, whole blood metal ion levels (μg/l), and periprosthetic femoral BMD were measured at baseline and at one, two, and five years postoperatively. The results two years postoperatively for this cohort have been previously reported. Results. A total of 43 patients were enrolled. At minimum follow-up of five years, 23 (53.4%) returned for clinical and radiological review, 25 (58.1%) had metal ion analysis performed, 19 (44.2%) underwent dual energy x-ray absorptiometry scans, and 25 (58%) completed a pain-drawing questionnaire. The mean modified Harris Hip Scores improved significantly from 54.8 (SD 19) preoperatively to 93.08 (SD 10.5) five years postoperatively (p < 0.001). One patient was revised for aseptic acetabular loosening. The mean cobalt levels increased from 0.065 μg/l (SD 0.03) to 0.08 (SD 0.05) and the mean titanium levels increased from 0.35 (SD 0.13) to 0.78 (SD 0.29). The femoral BMD ratio decreased in Gruen Zone 1 (91.9%) at five years postoperatively compared with the baseline scores at six weeks potoperatively. The femoral BMD ratio was maintained in Gruen zones 2 to 7. Conclusion. The use of a modular DM component and a cementless, tapered femoral stem shows excellent mid-term survivorship with minimal concerns for corrosion and metal ion release in a cohort of young, active patients undergoing primary THA. Cite this article: Bone Joint J 2021;103-B(7 Supple B):73–77

Aims. A recent report from France suggested an association between the use of cobalt-chrome (CoCr) femoral heads in total hip arthroplasties (THAs) and an increased risk of dilated cardiomyopathy and heart failure. CoCr is a commonly used material in orthopaedic implants. If the reported association is causal, the consequences would be significant given the millions of joint arthroplasties and other orthopaedic procedures in which CoCr is used annually. We examined whether CoCr-containing THAs were associated with an increased risk of all-cause mortality, heart outcomes, cancer, and neurodegenerative disorders in a large national database. Methods. Data from the National Joint Registry was linked to NHS English hospital inpatient episodes for 374,359 primary THAs with up to 14.5 years' follow-up. We excluded any patients with bilateral THAs, knee arthroplasties, indications other than osteoarthritis, aged under 55 years, and diagnosis of one or more outcome of interest before THA. Implants were grouped as either containing CoCr or not containing CoCr. The association between implant construct and the risk of all-cause mortality and incident heart failure, cancer, and neurodegenerative disorders was examined. Results. There were 158,677 individuals (42.4%) with an implant containing CoCr. There were 47,963 deaths, 27,332 heart outcomes, 35,720 cancers, and 22,025 neurodegenerative disorders. There was no evidence of an association between patients with CoCr implants and higher rates of any of the outcomes. Conclusion. CoCr-containing THAs did not have an increased risk of all-cause mortality, or clinically meaningful heart outcomes, cancer, or neurodegenerative disorders into the second decade post-implantation. Our findings will help reassure clinicians and the increasing number of patients receiving primary THA worldwide that the use of CoCr-containing implants is not associated with significant adverse systemic effects. Cite this article: Bone Joint J 2022;104-B(3):359–367

Aims. Navigation devices are designed to improve a surgeon’s accuracy in positioning the acetabular and femoral components in total hip arthroplasty (THA). The purpose of this study was to both evaluate the accuracy of an optical computer-assisted surgery (CAS) navigation system and determine whether preoperative spinopelvic mobility (categorized as hypermobile, normal, or stiff) increased the risk of acetabular component placement error. Methods. A total of 356 patients undergoing primary THA were prospectively enrolled from November 2016 to March 2018. Clinically relevant error using the CAS system was defined as a difference of > 5° between CAS and 3D radiological reconstruction measurements for acetabular component inclination and anteversion. Univariate and multiple logistic regression analyses were conducted to determine whether hypermobile (. Δ. sacral slope(SS). stand-sit. > 30°), or stiff (. ∆. SS. stand-sit. < 10°) spinopelvic mobility contributed to increased error rates. Results. The paired absolute difference between CAS and postoperative imaging measurements was 2.3° (standard deviation (SD) 2.6°) for inclination and 3.1° (SD 4.2°) for anteversion. Using a target zone of 40° (± 10°) (inclination) and 20° (± 10°) (anteversion), postoperative standing radiographs measured 96% of acetabular components within the target zone for both inclination and anteversion. Multiple logistic regression analysis controlling for BMI and sex revealed that hypermobile spinopelvic mobility significantly increased error rates for anteversion (odds ratio (OR) 2.48, p = 0.009) and inclination (OR 2.44, p = 0.016), whereas stiff spinopelvic mobility increased error rates for anteversion (OR 1.97, p = 0.028). There were no dislocations at a minimum three-year follow-up. Conclusion. Despite high reliability in acetabular positioning for inclination in a large patient cohort using an optical CAS system, hypermobile and stiff spinopelvic mobility significantly increased the risk of clinically relevant errors. In patients with abnormal spinopelvic mobility, CAS systems should be adjusted for use to avoid acetabular component misalignment and subsequent risk for long-term dislocation. Cite this article: Bone Jt Open 2022;3(6):475–484

Aims. Traditionally, total hip arthroplasty (THA) templating has been performed on anteroposterior (AP) pelvis radiographs. Recently, additional AP hip radiographs have been recommended for accurate measurement of the femoral offset (FO). To verify this claim, this study aimed to establish quantitative data of the measurement error of the FO in relation to leg position and X-ray source position using a newly developed geometric model and clinical data. Methods. We analyzed the FOs measured on AP hip and pelvis radiographs in a prospective consecutive series of 55 patients undergoing unilateral primary THA for hip osteoarthritis. To determine sample size, a power analysis was performed. Patients’ position and X-ray beam setting followed a standardized protocol to achieve reproducible projections. All images were calibrated with the KingMark calibration system. In addition, a geometric model was created to evaluate both the effects of leg position (rotation and abduction/adduction) and the effects of X-ray source position on FO measurement. Results. The mean FOs measured on AP hip and pelvis radiographs were 38.0 mm (SD 6.4) and 36.6 mm (SD 6.3) (p < 0.001), respectively. Radiological view had a smaller effect on FO measurement than inaccurate leg positioning. The model showed a non-linear relationship between projected FO and femoral neck orientation; at 30° external neck rotation (with reference to the detector plane), a true FO of 40 mm was underestimated by up to 20% (7.8 mm). With a neutral to mild external neck rotation (≤ 15°), the underestimation was less than 7% (2.7 mm). The effect of abduction and adduction was negligible. Conclusion. For routine THA templating, an AP pelvis radiograph remains the gold standard. Only patients with femoral neck malrotation > 15° on the AP pelvis view, e.g. due to external rotation contracture, should receive further imaging. Options include an additional AP hip view with elevation of the entire affected hip to align the femoral neck more parallel to the detector, or a CT scan in more severe cases. Cite this article: Bone Jt Open 2022;3(10):795–803

Aims. The direct anterior (DA) approach has been associated with rapid patient recovery after total hip arthroplasty (THA) but may be associated with more frequent femoral complications including implant loosening. The objective of this study was to determine whether the addition of a collar to the femoral stem affects implant migration, patient activity, and patient function following primary THA using the DA approach. Methods. Patients were randomized to either a collared (n = 23) or collarless (n = 26) cementless femoral stem implanted using the DA approach. Canal fill ratio (CFR) was measured on the first postoperative radiographs. Patients underwent a supine radiostereometric analysis (RSA) exam postoperatively on the day of surgery and at two, four, six, 12, 26, and 52 weeks postoperatively. Patient-reported outcome measures (Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index, the 12-item Short Form Health Survey Mental and Physical Score, and University of California, Los Angeles (UCLA) Activity Score) were measured preoperatively and at each post-surgery clinic visit. Activity and function were also measured as the weekly average step count recorded by an activity tracker, and an instrumented timed up-and-go (TUG) test in clinic, respectively. Results. Comparing the RSA between the day of surgery baseline exam to two weeks postoperatively, subsidence was significantly lower (mean difference 2.23 mm (SD 0.71), p = 0.023) with collared stems, though these patients had a greater CFR (p = 0.048). There was no difference (p = 0.426) in subsidence between stems from a two-week baseline through to one year postoperatively. There were no clinically relevant differences in PROMs; and there was no difference in the change in activity (p = 0.078) or the change in functional capacity (p = 0.664) between the collared stem group and the collarless stem group at any timepoint. Conclusion. Presence of a collar on the femoral stem resulted in reduced subsidence during the first two postoperative weeks following primary THA using the DA approach. However, the clinical implications are unclear, and larger studies examining patient activity and outcomes are required. Cite this article: Bone Joint J 2020;102-B(12):1654–1661

Aims. The aim of this study was to determine if uncemented acetabular polyethylene (PE) liner geometry, and lip size, influenced the risk of revision for instability or loosening. Methods. A total of 202,511 primary total hip arthroplasties (THAs) with uncemented acetabular components were identified from the National Joint Registry (NJR) dataset between 2003 and 2017. The effect of liner geometry on the risk of revision for instability or loosening was investigated using competing risk regression analyses adjusting for age, sex, American Society of Anesthesiologists grade, indication, side, institution type, surgeon grade, surgical approach, head size, and polyethylene crosslinking. Stratified analyses by surgical approach were performed, including pairwise comparisons of liner geometries. Results. The distribution of liner geometries were neutral (39.4%; 79,822), 10° (34.5%; 69,894), 15° (21.6%; 43,722), offset reorientating (2.8%; 5705), offset neutral (0.9%; 1,767), and 20° (0.8%; 1,601). There were 690 (0.34%) revisions for instability. Compared to neutral liners, the adjusted subhazard ratios of revision for instability were: 10°, 0.64 (p < 0.001); 15°, 0.48 (p < 0.001); and offset reorientating, 1.6 (p = 0.010). No association was found with other geometries. 10° and 15° liners had a time-dependent lower risk of revision for instability within the first 1.2 years. In posterior approaches, 10° and 15° liners had a lower risk of revision for instability, with no significant difference between them. The protective effect of lipped over neutral liners was not observed in laterally approached THAs. There were 604 (0.3%) revisions for loosening, but no association between liner geometry and revision for loosening was found. Conclusion. This registry-based study confirms a lower risk of revision for instability in posterior approach THAs with 10° or 15° lipped liners compared to neutral liners, but no significant difference between these lip sizes. A higher revision risk is seen with offset reorientating liners. The benefit of lipped geometries against revision for instability was not seen in laterally approached THAs. Liner geometry does not seem to influence the risk of revision for loosening. Cite this article: Bone Joint J 2021;103-B(12):1774–1782

Aims. The aims of this study were to assess the exposure and preservation of the abductor mechanism during primary total hip arthroplasty (THA) using the posterior approach, and to evaluate gluteus maximus transfer to restore abductor function of chronically avulsed gluteus medius and minimus. Patients and Methods. A total of 519 patients (525 hips) underwent primary THA using the posterior approach, between 2009 and 2013. The patients were reviewed preoperatively and at two and five years postoperatively. Three patients had mild acute laceration of the gluteus medius caused by retraction. A total of 54 patients had mild chronic damage to the tendon (not caused by exposure), which was repaired with sutures through drill holes in the greater trochanter. A total of 41 patients had severe damage with major avulsion of the gluteus medius and minimus muscles, which was repaired with sutures through bone and a gluteus maximus flap transfer to the greater trochanter. Results. Abductor strength was maintained in the normal hips, but lateral hip pain progressed significantly, five years postoperatively (p < 0.0001). In the 54 patients with mild abductor tendon damage treated with simple repair, lateral hip pain also increased significantly during follow-up (p = 0.002). In the 35 patients with severe avulsion but good muscle repaired using a gluteus maximus flap transfer, abductor function was restored. The six patients with complete avulsion and poor muscle did not regain strong abductor power, but lateral hip pain decreased. Conclusion. The posterior approach offered excellent exposure and preservation of the abductor mechanism during primary THA. Augmentation of the repair with a gluteus maximus flap provided stable reconstruction of the abductor muscles and seemed to restore function in the hips with functioning muscles. Cite this article: Bone Joint J 2019;101-B(6 Supple B):116–122

Aims. It has been well documented in the arthroplasty literature that lumbar degenerative disc disease (DDD) contributes to abnormal spinopelvic motion. However, the relationship between the severity or pattern of hip osteoarthritis (OA) as measured on an anteroposterior (AP) pelvic view and spinopelvic biomechanics has not been well investigated. Therefore, the aim of the study is to examine the association between the severity and pattern of hip OA and spinopelvic motion. Methods. A retrospective chart review was conducted to identify patients undergoing primary total hip arthroplasty (THA). Plain AP pelvic radiographs were reviewed to document the morphological characteristic of osteoarthritic hips. Lateral spine-pelvis-hip sitting and standing plain radiographs were used to measure sacral slope (SS) and pelvic femoral angle (PFA) in each position. Lumbar disc spaces were measured to determine the presence of DDD. The difference between sitting and standing SS and PFA were calculated to quantify spinopelvic motion (ΔSS) and hip motion (ΔPFA), respectively. Univariate analysis and Pearson correlation were used to identify morphological hip characteristics associated with changes in spinopelvic motion. Results. In total, 139 patients were included. Increased spinopelvic motion was observed in patients with loss of femoral head contour, cam deformity, and acetabular bone loss (all p < 0.05). Loss of hip motion was observed in patients with loss of femoral head contour, cam deformity, and acetabular bone loss (all p < 0.001). A decreased joint space was associated with a decreased ΔPFA (p = 0.040). The presence of disc space narrowing, disc space narrowing > two levels, and disc narrowing involving the L5–S1 segment were associated with decreased spinopelvic motion (all p < 0.05). Conclusion. Preoperative hip OA as assessed on an AP pelvic radiograph predicts spinopelvic motion. These data suggest that specific hip osteoarthritic morphological characteristics listed above alter spinopelvic motion to a greater extent than others. Cite this article: Bone Joint J 2023;105-B(5):496–503

Aims. The practice of overlapping surgery has been increasing in the delivery of orthopaedic surgery, aiming to provide efficient, high-quality care. However, there are concerns about the safety of this practice. The purpose of this study was to examine the safety and efficacy of a model of partially overlapping surgery that we termed ‘swing room’ in the practice of primary total hip (THA) and knee arthroplasty (TKA). Methods. A retrospective review of prospectively collected data was carried out on patients who underwent primary THA and TKA between 2006 and 2017 in two academic centres. Cases were stratified as partially overlapping (swing room), in which the surgeon is in one operating room (OR) while the next patient is being prepared in another, or nonoverlapping surgery. The demographic details of the patients which were collected included operating time, length of stay (LOS), postoperative complications within six weeks of the procedure, unplanned hospital readmissions, and unplanned reoperations. Fisher's exact, Wilcoxon rank-sum tests, chi-squared tests, and logistic regression analysis were used for statistical analysis. Results. A total of 12,225 cases performed at our institution were included in the study, of which 10,596 (86.6%) were partially overlapping (swing room) and 1,629 (13.3%) were nonoverlapping. There was no significant difference in the mean age, sex, body mass index (BMI), side, and LOS between the two groups. The mean operating time was significantly shorter in the swing room group (58.2 minutes) compared with the nonoverlapping group (62.8 minutes; p < 0.001). There was no significant difference in the rates of complications, readmission and reoperations (p = 0.801 and p = 0.300, respectively) after adjusting for baseline American Society of Anesthesiologists scores. Conclusion. The new ‘swing room’ model yields similar short-term outcomes without an increase in complication rates compared with routine single OR surgery in patients undergoing primary THA or TKA. Cite this article: Bone Joint J 2020;102-B(7 Supple B):112–115

Aims. Golf is a popular pursuit among those requiring total hip arthroplasty (THA). The aim of this study was to determine if participating in golf is associated with greater functional outcomes, satisfaction, or improvement in quality of life (QoL) compared to non-golfers. Methods. All patients undergoing primary THA over a one-year period at a single institution were included with one-year postoperative outcomes. Patients were retrospectively followed up to assess if they had been golfers at the time of their surgery. Multivariate linear regression analysis was performed to assess the independent association of preoperative golfing status on outcomes. Results. The study cohort consisted of a total of 308 patients undergoing THA, of whom 44 were golfers (14%). This included 120 male patients (39%) and 188 female patients (61%), with an overall mean age of 67.8 years (SD 11.6). Golfers had a greater mean postoperative Oxford Hip Score (OHS) (3.7 (95% confidence interval (CI) 1.9 to 5.5); p < 0.001) and EuroQol visual analogue scale (5.5 (95% CI 0.1 to 11.9); p = 0.039). However, there were no differences in EuroQoL five-dimension score (p = 0.124), pain visual analogue scale (p = 0.505), or Forgotten Joint Score (p = 0.215). When adjusting for confounders, golfers had a greater improvement in their Oxford Hip Score (2.7 (95% CI 0.2 to 5.3); p < 0.001) compared to non-golfers. Of the 44 patients who reported being golfers at the time of their surgery, 32 (72.7%) returned to golf and 84.4% of those were satisfied with their involvement in golf following surgery. Those who returned to golf were more likely to be male (p = 0.039) and had higher (better) preoperative health-related QoL (p = 0.040) and hip-related functional scores (p = 0.026). Conclusion. Golfers had a greater improvement in their hip-specific function compared to non-golfers after THA. However, less than three-quarters of patients return to golf, with male patients and those who had greater preoperative QoL or hip-related function being more likely to return to play. Cite this article: Bone Jt Open 2022;3(2):145–151

Aims. The aim of this study was to assess medium-term improvements following total hip arthroplasty (THA), and to evaluate what effect different preoperative Oxford Hip Score (OHS) thresholds for treatment may have on patients’ access to THA and outcomes. Methods. Patients undergoing primary THA at our institution with an OHS both preoperatively and at least four years postoperatively were included. Rationing thresholds were explored to identify possible deprivation of OHS improvement. Results. Overall, 2,341 patients were included. Mean OHS was 19.7 (SD 8.2) preoperatively and 39.7 (SD 9.8) at latest follow-up. An improvement of at least eight-points, the minimally important change (MIC), was seen in 2,072 patients (88.5%). The mean improvement was 20.0 points (SD 10.5). If a rationing threshold of OHS of 20 points had been enforced, 90.8% of those treated would have achieved the MIC, but only 54.3% of our cohort would have had access to surgery; increasing this threshold to 32 would have enabled 89.5% of those treated to achieve the MIC while only depriving 6.5% of our cohort. The ‘rationed’ group of OHS > 20 had significantly better OHS at latest follow-up (42.6 vs 37.3; p < 0.001), while extending the rationing threshold above 32 showed postoperative scores were more significantly affected by the ceiling effect of the OHS. Conclusion. The OHS was not designed as a tool to ration healthcare, but if it had been used at our institution for this cohort, applying an OHS threshold of 20 to routine THA access would have excluded nearly half of patients from having a THA; a group in which over 85% had a significant improvement in OHS. Where its use for rationing is deemed necessary, use of a higher threshold may be more appropriate to ensure a better balance between patient access to treatment and chances of achieving good to excellent outcomes. Cite this article: Bone Jt Open 2022;3(3):196–204

Aims. Due to the opioid epidemic in the USA, our service progressively decreased the number of opioid tablets prescribed at discharge after primary hip (THA) and knee (TKA) arthroplasty. The goal of this study was to analyze the effect on total morphine milligram equivalents (MMEs) prescribed and post-discharge opioid repeat prescriptions. Methods. We retrospectively reviewed 19,428 patients undergoing a primary THA or TKA between 1 February 2016 and 31 December 2019. Two reductions in the number of opioid tablets prescribed at discharge were implemented over this time; as such, we analyzed three periods (P1, P2, and P3) with different routine discharge MME (750, 520, and 320 MMEs, respectively). We investigated 90-day refill rates, refill MMEs, and whether discharge MMEs were associated with represcribing in a multivariate model. Results. A discharge prescription of < 400 MMEs was not a risk factor for opioid represcribing in the entire population (p = 0.772) or in opioid-naïve patients alone (p = 0.272). Procedure type was the most significant risk factor for narcotic represcribing, with unilateral TKA (hazard ratio (HR) = 5.62), bilateral TKA (HR = 6.32), and bilateral unicompartmental knee arthroplasty (UKA) (HR = 5.29) (all p < 0.001) being the highest risk for refills. For these three procedures, there was approximately a 5% to 6% increase in refills from P1 to P3 (p < 0.001); however, there was no significant increase in refill rates after any hip arthroplasty procedures. Total MMEs prescribed were significantly reduced from P1 to P3 (p < 0.001), leading to the equivalent of nearly 500,000 fewer oxycodone 5 mg tablets prescribed. Conclusion. Decreasing opioids prescribed at discharge led to a statistically significant reduction in total MMEs prescribed. While the represcribing rate did not increase for any hip arthroplasty procedure, the overall refill rates increased by about 5% for most knee arthroplasty procedures. As such, we are now probably prescribing an appropriate amount of opioids at discharge for knee arthroplasty procedure, but further reductions may be possible for hip arthroplasty procedures. Cite this article: Bone Joint J 2021;103-B(7 Supple B):103–110

Aims. Total hip arthroplasties (THAs) are performed by surgeons at various stages in training with varying levels of supervision, but we do not know if this is safe practice with comparable outcomes to consultant-performed THA. Our aim was to examine the association between surgeon grade, the senior supervision of trainees, and the risk of revision following THA. Methods. We performed an observational study using National Joint Registry (NJR) data. We included adult patients who underwent primary THA for osteoarthritis, recorded in the NJR between 2003 and 2016. Exposures were operating surgeon grade (consultant or trainee) and whether or not trainees were directly supervised by a scrubbed consultant. Outcomes were all-cause revision and the indication for revision up to ten years. We used methods of survival analysis, adjusted for patient, operation, and healthcare setting factors. Results. We included 603,474 THAs, of which 58,137 (9.6%) procedures were performed by a trainee. There was no association between surgeon grade and all-cause revision up to ten years (crude hazard ratio (HR) 1.00 (95% confidence interval (CI) 0.94 to 1.07); p = 0.966), a finding which persisted with adjusted analysis. Fully adjusted analysis demonstrated an association between trainees operating without scrubbed consultant supervision and an increased risk of all-cause revision (HR 1.10 (95% CI 1.00 to 1.21); p = 0.045). There was an association between trainee-performed THA and revision for instability (HR 1.14 (95% CI 1.01 to 1.30); p = 0.039). However, this was not observed in adjusted models, or when trainees were supervised by a scrubbed consultant. Conclusion. Within the current training system in England and Wales, appropriately supervised trainees achieve comparable THA survival to consultants. Trainees who are supervised by a scrubbed consultant achieve superior outcomes compared to trainees who are not supervised by a scrubbed consultant, particularly in terms of revision for instability. Cite this article: Bone Joint J 2022;104-B(3):341–351

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