Aims. The aim of this study was to estimate time to arthroplasty among patients with hip and knee osteoarthritis (OA), and to identify factors at enrolment to first-line intervention that are prognostic for progression to surgery. Methods. In this longitudinal register-based observational study, we identified 72,069 patients with hip and knee OA in the Better Management of Patients with Osteoarthritis Register (BOA), who were referred for first-line OA intervention, between May 2008 and December 2016. Patients were followed until the first primary arthroplasty surgery before 31 December 2016, stratified into a hip and a knee OA cohort. Data were analyzed with Kaplan-Meier and multivariable-adjusted Cox regression. Results. At five years, Kaplan-Meier estimates showed that 46% (95% confidence interval (CI) 44.6 to 46.9) of those with hip OA, and 20% (95% CI 19.7 to 21.0) of those with knee OA, had progressed to arthroplasty. The strongest prognostic factors were desire for surgery (hazard ratio (HR) hip 3.12 (95% CI 2.95 to 3.31), HR knee 2.72 (95% CI 2.55 to 2.90)), walking difficulties (HR hip 2.20 (95% CI 1.97 to 2.46), HR knee 1.95 (95% CI 1.73 to 2.20)), and frequent pain (HR hip 1.56 (95% CI 1.40 to 1.73), HR knee 1.77 (95% CI 1.58 to 2.00)). In hip OA, the probability of progression to surgery was lower among those with comorbidities (e.g. ≥ four conditions; HR 0.64 (95% CI 0.59 to 0.69)), with no detectable effects in the knee OA cohort. Instead, being overweight or obese increased the probability of OA progress in the knee cohort (HR 1.25 (95% CI 1.15 to 1.37)), but not among those with hip OA. Conclusion. Patients with hip OA progressed faster and to a greater extent to arthroplasty than patients with knee OA. Progression was strongly influenced by patients’ desire for surgery and by factors related to severity of OA symptoms, but factors not directly related to OA symptoms are also of importance. However, a large proportion of patients with OA do not seem to require surgery within five years, especially among those with knee OA. Cite this article: Bone Joint J 2022;104-B(7):792–800

Aims. Although there are various pelvic osteotomies for acetabular dysplasia of the hip, shelf operations offer effective and minimally invasive osteotomy. Our study aimed to assess outcomes following modified Spitzy shelf acetabuloplasty. Methods. Between November 2000 and December 2016, we retrospectively evaluated 144 consecutive hip procedures in 122 patients a minimum of five years after undergoing modified Spitzy shelf acetabuloplasty for acetabular dysplasia including osteoarthritis (OA). Our follow-up rate was 92%. The mean age at time of surgery was 37 years (13 to 58), with a mean follow-up of 11 years (5 to 21). Advanced OA (Tönnis grade ≥ 2) was present preoperatively in 16 hips (11%). The preoperative lateral centre-edge angle ranged from -28° to 25°. Survival was determined by Kaplan-Meier analysis, using conversions to total hip arthroplasty as the endpoint. Risk factors for joint space narrowing less than 2 mm were analyzed using a Cox proportional hazards model. Results. The mean Merle d'Aubigné clinical score improved from 11.6 points (6 to 17) preoperatively to 15.9 points (12 to 18) at the last follow-up. The survival rates were 95% (95% confidence interval (CI) 91 to 99) and 86% (95% CI 50 to 97) at ten and 15 years. Multivariate Cox regression identified three factors associated with radiological OA progression: age (hazard ratio (HR) 2.85, 95% CI 1.05 to 7.76; p = 0.0398), preoperative joint space (HR 2.41, 95% CI 1.35 to 4.29; p = 0.0029), and preoperative OA (HR 8.34, 95% CI 0.94 to 73.77; p = 0.0466). Conclusion. Modified Spitzy shelf acetabuloplasty is an effective joint-preserving surgery with a wide range of potential indications. Cite this article: Bone Jt Open 2023;4(12):932–941

Aims. Rotational acetabular osteotomy (RAO) has been reported to be effective in improving symptoms and preventing osteoarthritis (OA) progression in patients with mild to severe develomental dysplasia of the hip (DDH). However, some patients develop secondary OA even when the preoperative joint space is normal; determining who will progress to OA is difficult. We evaluated whether the preoperative cartilage condition may predict OA progression following surgery using T2 mapping MRI. Methods. We reviewed 61 hips with early-stage OA in 61 patients who underwent RAO for DDH. They underwent preoperative and five-year postoperative radiological analysis of the hip. Those with a joint space narrowing of more than 1 mm were considered to have 'OA progression'. Preoperative assessment of articular cartilage was also performed using 3T MRI with the T2 mapping technique. The region of interest was defined as the weightbearing portion of the acetabulum and femoral head. Results. There were 16 patients with postoperative OA progression. The T2 values of the centre to the anterolateral region of the acetabulum and femoral head in the OA progression cases were significantly higher than those in patients without OA progression. The preoperative T2 values in those regions were positively correlated with the narrowed joint space width. The receiver operating characteristic analysis revealed that the T2 value of the central portion in the acetabulum provided excellent discrimination, with OA progression patients having an area under the curve of 0.858. Furthermore, logistic regression analysis showed T2 values of the centre to the acetabulum’s anterolateral portion as independent predictors of subsequent OA progression (p < 0.001). Conclusion. This was the first study to evaluate the relationship between intra-articular degeneration using T2 mapping MRI and postoperative OA progression. Our findings suggest that preoperative T2 values of the hip can be better prognostic factors for OA progression than radiological measures following RAO. Cite this article: Bone Joint J 2021;103-B(9):1472–1478

Aims. Pelvic incidence (PI) is considered an important anatomical parameter for determining the sagittal balance of the spine. The contribution of an abnormal PI to hip osteoarthritis (OA) remains controversial. In this study, we aimed to investigate the relationship between PI and hip OA, and the difference in PI between hip OA without anatomical abnormalities (primary OA) and hip OA with developmental dysplasia of the hip (DDH-OA). Methods. In this study, 100 patients each of primary OA, DDH-OA, and control subjects with no history of hip disease were included. CT images were used to measure PI, sagittal femoral head coverage, α angle, and acetabular anteversion. PI was also subdivided into three categories: high PI (larger than 64.0°), medium PI (42.0° to 64.0°), and low PI (less than 42.0°). The anterior centre edge angles, posterior centre edge angles, and total sagittal femoral head coverage were measured. The correlations between PI and sagittal femoral head coverage, α angle, and acetabular anteversion were examined. Results. No significant difference in PI was observed between the three groups. There was no significant difference between the groups in terms of the category distribution of PI. The DDH-OA group had lower mean sagittal femoral head coverage than the other groups. There were no significant correlations between PI and other anatomical factors, including sagittal femoral head coverage, α angle, and acetabular anteversion. Conclusion. No associations were found between mean PI values or PI categories and hip OA. Furthermore, there was no difference in PI between patients with primary OA and DDH-OA. From our evaluation, we found no evidence of PI being an independent factor associated with the development of hip OA. Cite this article: Bone Joint J 2021;103-B(11):1656–1661

Aims. Septic arthritis of the hip often leads to irreversible osteoarthritis (OA) and the requirement for total hip arthroplasty (THA). The aim of this study was to report the mid-term risk of any infection, periprosthetic joint infection (PJI), aseptic revision, and reoperation in patients with a past history of septic arthritis who underwent THA, compared with a control group of patients who underwent THA for OA. Methods. We retrospectively identified 256 THAs in 244 patients following septic arthritis of the native hip, which were undertaken between 1969 and 2016 at a single institution. Each case was matched 1:1, based on age, sex, BMI, and year of surgery, to a primary THA performed for OA. The mean age and BMI were 58 years (35 to 84) and 31 kg/m. 2. (18 to 48), respectively, and 100 (39%) were female. The mean follow-up was 11 years (2 to 39). Results. The ten-year survival free of any infection was 91% and 99% in the septic arthritis and OA groups, respectively (hazard ratio (HR) = 13; p < 0.001). The survival free of PJI at ten years was 93% and 99% in the septic arthritis and OA groups, respectively (HR = 10; p = 0.002). There was a significantly higher rate of any infection at ten years when THA was undertaken within five years of the diagnosis of septic arthritis compared with those in whom THA was undertaken > five years after this diagnosis was made (14% vs 5%, respectively; HR = 3.1; p = 0.009), but there was no significant difference in ten-year survival free of aseptic revision (HR = 1.14; p = 0.485). The mean Harris Hip Scores at two and five years postoperatively were significantly lower in the septic arthritis group compared with the OA group (p = 0.001 for both). Conclusion. There was a ten-fold increased risk of PJI in patients with a history of septic arthritis who underwent THA compared with those who underwent THA for OA with a ten-year cumulative incidence of 7%. The risk of any infection had a strong downward trend as the time interval between the diagnosis of septic arthritis and THA increased, highlighted by a 3.1-fold higher risk when THAs were performed within five years of the diagnosis being made. Cite this article: Bone Joint J 2022;104-B(2):227–234

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. Pelvic tilt is believed to affect the symptomology of osteoarthritis (OA) of the hip by alterations in joint movement, dysplasia of the hip by modification of acetabular cover, and femoroacetabular impingement by influencing the impingement-free range of motion. While the apparent role of pelvic tilt in hip pathology has been reported, the exact effects of many forms of treatment on pelvic tilt are unknown. The primary aim of this study was to investigate the effects of surgery on pelvic tilt in these three groups of patients. Methods. The demographic, radiological, and outcome data for all patients operated on by the senior author between October 2016 and January 2020 were identified from a prospective registry, and all those who underwent surgery with a primary diagnosis of OA, dysplasia, or femoroacetabular impingement were considered for inclusion. Pelvic tilt was assessed on anteroposterior (AP) standing radiographs using the pre- and postoperative pubic symphysis to sacroiliac joint (PS-SI) distance, and the outcomes were assessed with the Hip Outcome Score (HOS), International Hip Outcome Tool (iHOT-12), and Harris Hip Score (HHS). Results. The linear regression model revealed a significant negative predictive association between the standing pre- and postoperative PS-SI distances for all three groups of patients (all p < 0.001). There was a significant improvement in all three outcome measures between the pre- and postoperative values (p < 0.05). Conclusion. There is a statistically significant decrease in pelvic tilt after surgery in patients with OA of the hip, dysplasia, and femoroacetabular impingement. These results confirm that surgery significantly alters the pelvic orientation. Pelvic tilt significantly decreased after total hip arthroplasty, periacetabular osteotomy, and arthroscopy/surgical hip dislocation. The impact of surgery on pelvic tilt should be considered within the therapeutic plan in order to optimize pelvic orientation in these patients. Cite this article: Bone Joint J 2022;104-B(9):1025–1031

Aims. To evaluate the effect of ultrasound-targeted simvastatin-loaded microbubble destruction (UTMDSV) for alleviation of the progression of osteoarthritis (OA) in rabbits through modulation of the peroxisome proliferator-activated receptor (PPARγ). Methods. In vitro, OA chondrocytes were treated with ultrasound (US), US-targeted microbubble destruction (UTMD), simvastatin (SV), and UTMDSV on alternate days for four weeks. Chondrocytes were also treated with PPARγ inhibitor, PPARγ inhibitor+ UTMDSV, and UTMDSV. The cholesterol efflux rate and triglyceride levels were measured using an assay kit and oil red O staining, respectively. In vivo, the OA rabbits were treated with a single intra-articular injection of UTMD, SV, and UTMDSV every seven days for four weeks. Cartilage histopathology was assessed by safranin-O staining and the Mankin score. Total cholesterol (TC) and high-density lipoprotein-cholesterol (HDL-C) in rabbit knee synovial fluid were detected by enzyme-marker assay. Aggrecan, collagen II, and PPARγ expression levels were analyzed by Western blotting (WB). Results. In vitro, UTMDSV significantly increased the cholesterol efflux rate and aggrecan, collagen II, and PPARγ levels in OA chondrocytes; these effects were blocked by the PPARγ inhibitor. In vivo, UTMD. SV. significantly increased aggrecan, collagen II, PPARγ, and HDL-C levels, while TC levels and Mankin scores were decreased compared with the UTMD, SV, OA, and control groups. Conclusion. UTMDSV promotes cartilage extracellular matrix synthesis by modulating the PPARγ-mediated cholesterol efflux pathway in OA rabbits. Cite this article: Bone Joint Res 2021;10(10):693–703

Aims. The gluteus minimus (GMin) and gluteus medius (GMed) have unique structural and functional segments that may be affected to varying degrees, by end-stage osteoarthritis (OA) and normal ageing. We used data from patients with end-stage OA and matched healthy controls to 1) quantify the atrophy of the GMin and GMed in the two groups and 2) describe the distinct patterns of the fatty infiltration in the different segments of the GMin and GMed in the two groups. Methods. A total of 39 patients with end-stage OA and 12 age- and sex frequency-matched healthy controls were prospectively enrolled in the study. Fatty infiltration within the different segments of the GMin and the GMed was assessed on MRI according to the semiquantitative classification system of Goutallier and normalized cross-sectional areas were measured. Results. The GMin was smaller in the OA-group (p < 0.001) compared to the control group, but there was no group difference in the size of the GMed (p = 0.101). Higher levels of fatty infiltration were identified in the anterior segment of the GMin (p = 0.006) and the anterior (p = 0.006) and middle (p = 0.047) segments of the GMed in the OA group. All subjects in the control group had fatty infiltration of the anterior segment of the GMin, but all except one had no fatty infiltration in the entire GMed. Conclusion. End-stage OA was associated with significant atrophy of the GMin and higher levels of fatty infiltration, particularly in the anterior segments of the GMin and GMed. Minor fatty infiltration of the anterior segment of GMin appears to be a normal part of ageing. Our study has demonstrated different patterns of atrophy and fatty infiltration between patients with end-stage OA and healthy matched peers. Cite this article: Bone Jt Open 2021;2(1):40–47

Aims. This study aims to answer the following questions in patients with hip osteoarthritis (OA) who underwent total hip arthroplasty (THA): are patient-reported outcome measures (PROMs) affected by the location of the maximum severity of pain?; are PROMs affected by the presence of non-groin pain?; are PROMs affected by the severity of pain?; and are PROMs affected by the number of pain locations?. Methods. We reviewed 336 hips (305 patients) treated with THA for hip OA from December 2016 to November 2019 using pain location/severity questionnaires, modified Harris Hip Score (mHHS), Hip Outcome Score (HOS), international Hip Outcome Tool (iHOT-12) score, and radiological analysis. Descriptive statistics, analysis of covariance (ANCOVA), and Spearman partial correlation coefficients were used. Results. There was a significant difference in iHOT-12 scores between groups experiencing the most severe pain in the groin and the trochanter (p = 0.039). Additionally, more favourable mHHS scores were related to the presence of preoperative pain in trochanter (p = 0.049), lower back (p = 0.056), lateral thigh (p = 0.034), and posterior thigh (p = 0.005). Finally, the maximum severity of preoperative pain and number of pain locations had no significant relationship with PROMs (maximum severity: HHS: p = 0.928, HOS: p = 0.163, iHOT-12 p = 0.233; number of pain locations: HHS: p = 0.211; HOS: p = 0.801; iHOT-12: p = 0.112). Conclusion. Although there was a significant difference in iHOT-12 scores between patients with the most severe pain in the groin or trochanter, and the presence of pain in the trochanter, lower back, lateral thigh, or posterior thigh was related to higher mHHS scores, the majority of preoperative pain characteristics did not have a significant impact on outcomes. Therefore, a broad array of patients with hip OA might expect similar, favourable outcomes from THA notwithstanding preoperative pain characteristics. Cite this article: Bone Jt Open 2022;3(4):332–339

Aims. The aim of the study was to compare two methods of calculating pelvic incidence (PI) and pelvic tilt (PT), either by using the femoral heads or acetabular domes to determine the bicoxofemoral axis, in patients with unilateral or bilateral primary hip osteoarthritis (OA). Methods. PI and PT were measured on standing lateral radiographs of the spine in two groups: 50 patients with unilateral (Group I) and 50 patients with bilateral hip OA (Group II), using the femoral heads or acetabular domes to define the bicoxofemoral axis. Agreement between the methods was determined by intraclass correlation coefficient (ICC) and the standard error of measurement (SEm). The intraobserver reproducibility and interobserver reliability of the two methods were analyzed on 31 radiographs in both groups to calculate ICC and SEm. Results. In both groups, excellent agreement between the two methods was obtained, with ICC of 0.99 and SEm 0.3° for Group I, and ICC 0.99 and SEm 0.4° for Group II. The intraobserver reproducibility was excellent for both methods in both groups, with an ICC of at least 0.97 and SEm not exceeding 0.8°. The study also revealed excellent interobserver reliability for both methods in both groups, with ICC 0.99 and SEm 0.5° or less. Conclusion. Either the femoral heads or acetabular domes can be used to define the bicoxofemoral axis on the lateral standing radiographs of the spine for measuring PI and PT in patients with idiopathic unilateral or bilateral hip OA. Cite this article: Bone Joint J 2021;103-B(8):1345–1350

Aims. The aim of this study was to determine whether total hip arthroplasty (THA) for chronic hip pain due to unilateral primary osteoarthritis (OA) has a beneficial effect on cognitive performance. Methods. A prospective cohort study was conducted with 101 patients with end-stage hip OA scheduled for THA (mean age 67.4 years (SD 9.5), 51.5% female (n = 52)). Patients were assessed at baseline as well as after three and months. Primary outcome was cognitive performance measured by d2 Test of Attention at six months, Trail Making Test (TMT), FAS-test, Rivermead Behavioural Memory Test (RBMT; story recall subtest), and Rey-Osterrieth Complex Figure Test (ROCF). The improvement of cognitive performance was analyzed using repeated measures analysis of variance. Results. At six months, there was significant improvement in attention, working speed and concentration (d2-test; p < 0.001), visual construction and visual memory (ROCF; p < 0.001), semantic memory (FAS-test; p = 0.009), verbal episodic memory (RBMT; immediate recall p = 0.023, delayed recall p = 0.026), as well as pain (p < 0.001) with small to large effect sizes. Attention, concentration, and visual as well as verbal episodic memory improved significantly with medium effect sizes over η. 2. partial. = 0.06. In these cognitive domains the within-group difference exceeded the minimum clinically important difference. Conclusion. THA is associated with clinically relevant postoperative improvement in the cognitive functions of attention, concentration, and memory. These data support the concept of a broad interaction of arthroplasty with central nervous system function. Cite this article: Bone Joint J 2022;104-B(3):331–340

Aims. Recently, there has been considerable interest in quantifying the associations between bony abnormalities around and in the hip joint and osteoarthritis (OA). Our aim was to investigate the relationships between acetabular undercoverage, acetabular overcoverage, and femoroacetabular impingement (FAI) with OA of the hip, which currently remain controversial. . Materials and Methods. A total of 545 cadaveric skeletons (1090 hips) from the Hamann-Todd osteological collection were obtained. Femoral head volume (FHV), acetabular volume (AV), the FHV/AV ratio, acetabular version, alpha angle and anterior femoral neck offset (AFNO) were measured. A validated grading system was used to quantify OA of the hip as minimal, moderate, or severe. Multiple linear and multinomial logistic regression were used to determine the factors that correlated independently with the FHV, AV, and the FHV/AV ratio. . Results. Female cadavers had smaller FHVs (standardised beta -0.382, p < 0.001), and AVs (standardised beta -0.351, p < 0.001), compared with male patients, although the FHV/AV ratio was unchanged. Every 1° increase in alpha angle increased the probability of having moderate OA of the hip compared with minimal OA by 7.1%. Every 1 mm decrease in AFNO increased the probability of having severe or moderate OA of the hip, compared with minimal OA, by 11% and 9%, respectively. The relative risk ratios of having severe OA of the hip compared with minimal OA were 7.2 and 3.3 times greater for acetabular undercoverage and overcoverage, respectively, relative to normal acetabular cover. . Conclusion . Acetabular undercoverage and overcoverage were independent predictors of increased OA of the hip. The alpha angle and AFNO had modest effects, supporting the hypothesis that bony abnormalities both in acetabular dysplasia and FAI are associated with severe OA. Cite this article: Bone Joint J 2017;99-B:432–9

Aims. Total hip arthroplasty (THA) is gaining popularity as a treatment for displaced femoral neck fractures (FNFs), especially in physiologically younger patients. While THA for osteoarthritis (OA) has demonstrated low complication rates and increased quality of life, results of THA for acute FNF are not as clear. Currently, a THA performed for FNF is included in an institutional arthroplasty bundle without adequate risk adjustment, potentially placing centres participating in fracture care at financial disadvantage. The purpose of this study is to report on perioperative complication rates after THA for FNF compared with elective THA performed for OA of the hip. Patients and Methods. The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database between 2008 and 2016 was queried. Patients were identified using the THA Current Procedural Terminology (CPT) code and divided into groups by diagnosis: OA in one and FNF in another. Univariate statistics were performed. Continuous variables were compared between groups using Student’s t-test, and the chi-squared test was used to compare categorical variables. Multivariate and propensity-matched logistic regression analyses were performed to control for risk factors of interest. Results. Analyses included 139 635 patients undergoing THA. OA was the indication in 135 013 cases and FNF in 4622 cases. After propensity matching, mortality within 30 days (1.8% vs 0.3%; p < 0.001) and major morbidity (24.2% vs 19%; p < 0.001) were significantly higher among FNF patients. Re-operation (3.7% vs 2.7%; p = 0.014) and re-admission (7.3% vs 5.5%; p = 0.002) were significantly higher among FNF patients. Hip fracture patients had significantly longer operative time and length of stay (LOS), and were significantly less likely to be discharged to their home. Multivariate analyses gave similar results. Conclusion. This large database study showed a higher risk of postoperative complications including mortality, major morbidity, re-operation, re-admission, prolonged operative time, increased LOS, and decreased likelihood of discharge home in patients undergoing THA for FNF compared with OA. While THA is a good option for FNF patients, there are increased costs and financial risks to centres with a joint arthroplasty bundle programme participating in fracture care. Cite this article: Bone Joint J 2019;101-B(6 Supple B):84–90

Aims. Spinopelvic mobility plays an important role in functional acetabular component position following total hip arthroplasty (THA). The primary aim of this study was to determine if spinopelvic hypermobility persists or resolves following THA. Our second aim was to identify patient demographic or radiological factors associated with hypermobility and resolution of hypermobility after THA. Methods. This study investigated patients with preoperative posterior hypermobility, defined as a change in sacral slope (SS) from standing to sitting (ΔSS. stand-sit. ) ≥ 30°. Radiological spinopelvic parameters, including SS, pelvic incidence (PI), lumbar lordosis (LL), PI-LL mismatch, anterior pelvic plane tilt (APPt), and spinopelvic tilt (SPT), were measured on preoperative imaging, and at six weeks and a minimum of one year postoperatively. The severity of bilateral hip osteoarthritis (OA) was graded using Kellgren-Lawrence criteria. Results. A total of 136 patients were identified as having preoperative spinopelvic hypermobility. At one year after THA, 95% (129/136) of patients were no longer categorized as hypermobile on standing and sitting radiographs (ΔSS. stand-sit. < 30°). Mean ΔSS. stand-sit. decreased from 36.4° (SD 5.1°) at baseline to 21.4° (SD 6.6°) at one year (p < 0.001). Mean SS. seated. increased from baseline (11.4° (SD 8.8°)) to one year after THA by 11.5° (SD 7.4°) (p < 0.001), which correlates to an 8.5° (SD 5.5°) mean decrease in seated functional cup anteversion. Contralateral hip OA was the only radiological predictor of hypermobility persisting at one year after surgery. The overall reoperation rate was 1.5%. Conclusion. Spinopelvic hypermobility was found to resolve in the majority (95%) of patients one year after THA. The increase in SS. seated. was clinically significant, suggesting that current target recommendations for the hypermobile patient (decreased anteversion and inclination) should be revisited. Cite this article: Bone Joint J 2021;103-B(12):1766–1773

Aims. Patients may present with concurrent symptomatic osteoarthritis (OA) of the hip and degenerative disorders of the lumbar spine, with surgical treatment being indicated for both. Whether arthroplasty of the hip or spinal surgery should be performed first remains uncertain. Materials and Methods. Clinical scenarios were devised for a survey asking the preferred order of surgery and the rationale for this decision for five fictional patients with both OA of the hip and degenerative lumbar disorders. These were symptomatic OA of the hip and: 1) lumbar spinal stenosis with neurological claudication; 2) lumbar degenerative spondylolisthesis with leg pain; 3) lumbar disc herniation with leg weakness; 4) lumbar scoliosis with back pain; and 5) thoracolumbar disc herniation with myelopathy. This survey was sent to 110 members of The Hip Society and 101 members of the Scoliosis Research Society. The choices of the surgeons were compared among scenarios and between surgical specialties using the chi-squared test. The free-text comments were analyzed using text-mining. Results. Responses were received from 51 hip surgeons (46%) and 37 spine surgeons (37%). The percentages of hip surgeons recommending ‘hip first’ differed significantly among scenarios: 59% for scenario 1; 73% for scenario 2; 47% for scenario 3; 47% for scenario 4; and 10% for scenario 5 (p < 0.001). The percentages of spine surgeons recommending ‘hip first’ were 49% for scenario 1; 70% for scenario 2; 19% for scenario 3; 78% for scenario 4; and 0% for scenario 5. There were significant differences between the groups for scenarios 3 (more hip surgeons recommended ‘hip first’; p = 0.012) and 4 (more hip surgeons recommended ‘spine first’; p = 0.006). Conclusion. In patients with coexistent OA of the hip and degenerative disorders of the spine, the question of ‘hip or spinal surgery first’ elicits relatively consistent answers in some clinical scenarios, but remains controversial in others, even for experienced surgeons. The nature of neurological symptoms can influence surgeons’ decision-making. Cite this article: Bone Joint J 2019;101-B(6 Supple B):37–44

Objective

In ex vivo hip fracture studies femoral pairs are split to create two comparable test groups. When more than two groups are required, or if paired femurs cannot be obtained, group allocation according to bone mineral density (BMD) is sometimes performed. In this statistical experiment we explore how this affects experimental results and sample size considerations.

Aims. To our knowledge, no study has compared the long-term results of cemented and hybrid total hip arthroplasty (THA) in patients with osteoarthritis (OA) secondary to congenital hip disease (CHD). This is a demanding procedure that may require special techniques and implants. Our aim was to compare the long-term outcome of cemented low-friction arthroplasty (LFA) and hybrid THA performed by one surgeon. Patients and Methods. Between January 1989 and December 1997, 58 hips (44 patients; one man, 43 woman; mean age 56.6 years (25 to 77)) with OA secondary to CHD were treated with a cemented Charnley LFA (group A), and 55 hips (39 patients; two men, 37 women; mean age 49.1 years (27 to 70)) were treated with a hybrid THA (group B), by the senior author (GH). The clinical outcome and survivorship were compared. Results. At all timepoints, group A hips had slightly better survivorship than those in group B without a statistically significant difference, except for the 24-year survival of acetabular components with revision for aseptic loosening as the endpoint, which was slightly worse. The survivorship was only significantly better in group A compared with group B when considering reoperation for any indication as the endpoint, 15 years postoperatively (74% vs 52%, p = 0.018). Conclusion. We concluded that there was not a substantial difference at almost any time in the outcome of cemented Charnley LFAs compared with hybrid THAs when treating patients with OA of the hip secondary to CHD. We believe, however, that after improvements in the design of components used in hybrid THA, this could be the method of choice, as it is technically easier with a shorter operating time. Cite this article: Bone Joint J 2019;101-B:1050–1057

Aims. The aim of this study was to examine whether hips with unilateral osteoarthritis (OA) secondary to developmental dysplasia of the hip (DDH) have significant asymmetry in femoral length, and to determine potential related factors. Patients and Methods. We enrolled 90 patients (82 female, eight male) with DDH showing unilateral OA changes, and 43 healthy volunteers (26 female, 17 male) as controls. The mean age was 61.8 years (39 to 93) for the DDH groups, and 71.2 years (57 to 84) for the control group. Using a CT-based coordinate measurement system, we evaluated the following vertical distances: top of the greater trochanter to the knee centre (femoral length GT), most medial prominence of the lesser trochanter to the knee centre (femoral length LT), and top of the greater trochanter to the medial prominence of the lesser trochanter (intertrochanteric distance), along with assessments of femoral neck anteversion and neck shaft angle. Results. The percentages of hips with an absolute difference of > 5 mm in femoral GT and LT lengths were significantly larger in the DDH group (24% for both) compared with those of the control group (2% and 7%, respectively). The femoral length GT of the affected femur was significantly shorter in Crowe I and longer in Crowe IV than that of the unaffected side. The affected-to-unaffected difference of the intertrochanteric distance showed positive correlation with that of the femoral length GT in Crowe I and Crowe II/III, and negative correlation with that of the femoral length LT in the Crowe I and Crowe IV groups. Conclusion. Hips with unilateral end-stage OA secondary to DDH show significant asymmetry in femoral length between both the greater and lesser trochanter and the knee compared with controls. The intertrochanteric distance was a morphological factor related to femoral-length asymmetry. When undertaking total hip arthroplasty (THA) in the presence of DDH, long leg radiographs or CT measurements should be used to assess true leg-length discrepancy. Cite this article: Bone Joint J 2019;101-B:297–302

There have been several studies examining the association between the morphological characteristics seen in acetabular dysplasia and the incidence of the osteoarthritis (OA). However, most studies focus mainly on acetabular morphological analysis, and few studies have scrutinised the effect of femoral morphology. In this study we enrolled 36 patients with bilateral acetabular dysplasia and early or mid-stage OA in one hip and no OA in the contralateral hip. CT scans were performed from the iliac crest to 2 cm inferior to the tibial tuberosity, and the morphological characteristics of both acetabulum and femur were studied. . In addition, 200 hips in 100 healthy volunteer Chinese adults formed a control group. The results showed that the dysplastic group with OA had a significantly larger femoral neck anteversion and a significantly shorter abductor lever arm than both the dysplastic group without OA and the controls. Femoral neck anteversion had a significant negative correlation with the length of the abductor lever arm and we conclude that it may contribute to the development of OA in dysplastic hips. Cite this article: Bone Joint J 2014; 96-B:1586–93

Aims. The primary aim of this study was to compare the hip-specific functional outcome of robotic assisted total hip arthroplasty (rTHA) with manual total hip arthroplasty (mTHA) in patients with osteoarthritis (OA). Secondary aims were to compare general health improvement, patient satisfaction, and radiological component position and restoration of leg length between rTHA and mTHA. Methods. A total of 40 patients undergoing rTHA were propensity score matched to 80 patients undergoing mTHA for OA. Patients were matched for age, sex, and preoperative function. The Oxford Hip Score (OHS), Forgotten Joint Score (FJS), and EuroQol five-dimension questionnaire (EQ-5D) were collected pre- and postoperatively (mean 10 months (SD 2.2) in rTHA group and 12 months (SD 0.3) in mTHA group). In addition, patient satisfaction was collected postoperatively. Component accuracy was assessed using Lewinnek and Callanan safe zones, and restoration of leg length were assessed radiologically. Results. There were no significant differences in the preoperative demographics (p ≥ 0.781) or function (p ≥ 0.383) between the groups. The postoperative OHS (difference 2.5, 95% confidence interval (CI) 0.1 to 4.8; p = 0.038) and FJS (difference 21.1, 95% CI 10.7 to 31.5; p < 0.001) were significantly greater in the rTHA group when compared with the mTHA group. However, only the FJS was clinically significantly greater. There was no difference in the postoperative EQ-5D (difference 0.017, 95% CI -0.042 to 0.077; p = 0.562) between the two groups. No patients were dissatisfied in the rTHA group whereas six were dissatisfied in the mTHA group, but this was not significant (p = 0.176). rTHA was associated with an overall greater rate of component positioning in a safe zone (p ≤ 0.003) and restoration of leg length (p < 0.001). Conclusion. Patients undergoing rTHA had a greater hip-specific functional outcome when compared to mTHA, which may be related to improved component positioning and restoration of leg length. However, there was no difference in their postoperative generic health or rate of satisfaction. Cite this article: Bone Joint Res 2021;10(1):22–30

Aims. This study presents the long-term survivorship, risk factors for prosthesis survival, and an assessment of the long-term effects of changes in surgical technique in a large series of patients treated by metal-on-metal (MoM) hip resurfacing arthroplasty (HRA). Patients and Methods. Between November 1996 and January 2012, 1074 patients (1321 hips) underwent HRA using the Conserve Plus Hip Resurfacing System. There were 787 men (73%) and 287 women (27%) with a mean age of 51 years (14 to 83). The underlying pathology was osteoarthritis (OA) in 1003 (75.9%), developmental dysplasia of the hip (DDH) in 136 (10.3%), avascular necrosis in 98 (7.4%), and other conditions, including inflammatory arthritis, in 84 (6.4%). Results. The mean follow-up time was 10.5 years (1 to 20). Using revision for any reason as the endpoint, the overall survivorship at 15 years was 89.4% (95% confidence interval (CI) 86.8 to 91.4). There was a substantial increase between the first and second generation of surgical technique (86.6% vs 90.1%; p = 0.05). Men with idiopathic OA had a 15-year survivorship of 94.5% and women, 82.2% (p = 0.001); gender was not a risk factor after stratification by component size and aetiology. Using revision for excessive wear (ion levels > 7 µg/l associated with symptoms or adverse local tissue reactions) as the endpoint, the 15-year survivorship was 98.5%. Risk factors for revision for all modes of failure were an underlying pathology of hip dysplasia, a contact patch to rim (CPR) distance of 7 mm or less, an age at surgery of 55 years or less, and a femoral component size of 46 mm or less. Specific risk factors for aseptic failure of the femoral component were early surgical technique, a cementless metaphyseal stem, and a body mass index of 24 kg/m. 2. or less. Conclusion. HRA is a viable concept; metal-on-metal bearings are well suited for this procedure when a well-designed device is properly implanted. The best results were obtained in men with OA, but survivorship was better for other underlying pathologies and for women after changes were made to the technique of implantation. Lifetime durability is a possible outcome for many patients despite a high level of activity. Cite this article: Bone Joint J 2018;100-B:1424–33

Aims

Better prediction of outcome after total hip arthroplasty (THA) is warranted. Systemic inflammation and central neuroinflammation are possibly involved in progression of osteoarthritis and pain. We explored whether inflammatory biomarkers in blood and cerebrospinal fluid (CSF) were associated with clinical outcome, and baseline pain or disability, 12 months after THA.

Aims

Hip arthroscopy (HA) has become the treatment of choice for femoroacetabular impingement (FAI). However, less favourable outcomes following arthroscopic surgery are expected in patients with severe chondral lesions. The aim of this study was to assess the outcomes of HA in patients with FAI and associated chondral lesions, classified according to the Outerbridge system.

Aims

This study aimed to investigate the incidence of ≥ 5 mm asymmetry in lower and whole leg lengths (LLs) in patients with unilateral osteoarthritis (OA) secondary to developmental dysplasia of the hip (DDH-OA) and primary hip osteoarthritis (PHOA), and the relationship between lower and whole LL asymmetries and femoral length asymmetry.

Aims

The aims of this study were to validate the Forgotten Joint Score-12 (FJS-12) in the postoperative evaluation of periacetabular osteotomy (PAO), identify factors associated with joint awareness after PAO, and determine the FJS-12 threshold for patient-acceptable symptom state (PASS).

Aims. The modified Dunn procedure has the potential to restore the anatomy in hips with severe slipped capital femoral epiphyses (SCFE). However, there is a risk of developing avascular necrosis of the femoral head (AVN). In this paper, we report on clinical outcome, radiological outcome, AVN rate and complications, and the cumulative survivorship at long-term follow-up in patients undergoing the modified Dunn procedure for severe SCFE. Patients and Methods. We performed a retrospective analysis involving 46 hips in 46 patients treated with a modified Dunn procedure for severe SCFE (slip angle > 60°) between 1999 and 2016. At nine-year-follow-up, 40 hips were available for clinical and radiological examination. Mean preoperative age was 13 years, and 14 hips (30%) presented with unstable slips. Mean preoperative slip angle was 64°. Kaplan–Meier survivorship was calculated. Results. At the latest follow-up, the mean Merle d’Aubigné and Postel score was 17 points (14 to 18), mean modified Harris Hip Score was 94 points (66 to 100), and mean Hip Disability and Osteoarthritis Outcome Score was 91 points (67 to 100). Postoperative slip angle was 7° (1° to 16°). One hip (2%) had progression of osteoarthritis (OA). Two hips (5%) developed AVN of the femoral head and required further surgery. Three other hips (7%) underwent implant revision due to screw breakage or change of wires. Cumulative survivorship was 86% at ten-year follow-up. Conclusion. The modified Dunn procedure for severe SCFE resulted in a low rate of AVN, low risk of progression to OA, and high functional scores at long-term follow-up. The slip deformities were mainly corrected but secondary impingement deformities can develop in some hips and may require further surgical treatment. Cite this article: Bone Joint J 2019;101-B:403–414

Aims. This study of patients with osteoarthritis (OA) of the hip aimed to: 1) characterize the contribution of the hip, spinopelvic complex, and lumbar spine when moving from the standing to the sitting position; 2) assess whether abnormal spinopelvic mobility is associated with worse symptoms; and 3) identify whether spinopelvic mobility can be predicted from static anatomical radiological parameters. Patients and Methods. A total of 122 patients with end-stage OA of the hip awaiting total hip arthroplasty (THA) were prospectively studied. Patient-reported outcome measures (PROMs; Oxford Hip Score, Oswestry Disability Index, and Veterans RAND 12-Item Health Survey Score) and clinical data were collected. Sagittal spinopelvic mobility was calculated as the change from the standing to sitting position using the lumbar lordosis angle (LL), sacral slope (SS), pelvic tilt (PT), pelvic-femoral angle (PFA), and acetabular anteinclination (AI) from lateral radiographs. The interaction of the different parameters was assessed. PROMs were compared between patients with normal spinopelvic mobility (10° ≤ ∆PT ≤ 30°) or abnormal spinopelvic mobility (stiff: ∆PT < ± 10°; hypermobile: ∆PT > ± 30°). Multiple regression and receiver operating characteristic (ROC) curve analyses were used to test for possible predictors of spinopelvic mobility. Results. Standing to sitting, the hip flexed by a mean of 57° (. sd. 17°), the pelvis tilted backwards by a mean of 20° (. sd. 12°), and the lumbar spine flexed by a mean of 20° (. sd. 14°); strong correlations were detected. There was no difference in PROMs between patients in the different spinopelvic mobility groups. Maximum hip flexion, standing PT, and standing AI were independent predictors of spinopelvic mobility (R. 2. = 0.42). The combined thresholds for standing was PT ≥ 13° and hip flexion ≥ 88° in the clinical examination, and had 90% sensitivity and 63% specificity of predicting spinopelvic stiffness, while SS ≥ 42° had 84% sensitivity and 67% specificity of predicting spinopelvic hypermobility. Conclusion. The hip, on average, accounts for three-quarters of the standing-to-sitting movement, but there is great variation. Abnormal spinopelvic mobility cannot be screened with PROMs. However, clinical and standing radiological features can predict spinopelvic mobility with good enough accuracy, allowing them to be used as reliable screening tools. Cite this article: Bone Joint J 2019;101-B:902–909

Aims

To clarify the mid-term results of transposition osteotomy of the acetabulum (TOA), a type of spherical periacetabular osteotomy, combined with structural allograft bone grafting for severe hip dysplasia.

Cartilage defects of the hip cause significant pain and may lead to arthritic changes that necessitate hip replacement. We propose the use of fresh osteochondral allografts as an option for the treatment of such defects in young patients. Here we present the results of fresh osteochondral allografts for cartilage defects in 17 patients in a prospective study. The underlying diagnoses for the cartilage defects were osteochondritis dissecans in eight and avascular necrosis in six. Two had Legg-Calve-Perthes and one a femoral head fracture. Pre-operatively, an MRI was used to determine the size of the cartilage defect and the femoral head diameter. All patients underwent surgical hip dislocation with a trochanteric slide osteotomy for placement of the allograft. The mean age at surgery was 25.9 years (17 to 44) and mean follow-up was 41.6 months (3 to 74). The mean Harris hip score was significantly better after surgery (p < 0.01) and 13 patients had fair to good outcomes. One patient required a repeat allograft, one patient underwent hip replacement and two patients are awaiting hip replacement. Fresh osteochondral allograft is a reasonable treatment option for hip cartilage defects in young patients.

Cite this article: Bone Joint J 2014;96-B(11 Supple A):11–16.

Aims

Hip arthroscopy has gained prominence as a primary surgical intervention for symptomatic femoroacetabular impingement (FAI). This study aimed to identify radiological features, and their combinations, that predict the outcome of hip arthroscopy for FAI.

Aims

This study aimed to determine clinical outcomes; relationships between postoperative anterior, lateral, and posterior acetabular coverage and joint survival; and prognostic factors for joint survival after transposition osteotomy of the acetabulum (TOA).

Aims. Psychological factors play a critical role in patient presentation, satisfaction, and outcomes. Pain catastrophizing, anxiety, and depression are important to consider, as they are associated with poorer outcomes and are potentially modifiable. The aim of this study was to assess the level of pain catastrophizing, anxiety, and depression in patients with a range of hip pathology and to evaluate their relationship with patient-reported psychosocial and functional outcome measures. Patients and Methods. Patients presenting to a tertiary-centre specialist hip clinic were prospectively evaluated for outcomes of pain catastrophizing, anxiety, and depression. Validated assessments were undertaken such as: the Pain Catastrophizing Scale (PCS), the Hospital Anxiety Depression Scale (HADS), and the 12-Item Short-Form Health Survey (SF-12). Patient characteristics and demographics were also recorded. Multiple linear regression modelling, with adaptive least absolute shrinkage and selection operator (LASSO) variable selection, was used for analysis. Results. A total of 328 patients were identified for inclusion, with diagnoses of hip dysplasia (DDH; n = 50), femoroacetabular impingement (FAI; n = 55), lateral trochanteric pain syndrome (LTP; n = 23), hip osteoarthrosis (OA; n = 184), and avascular necrosis of the hip (AVN; n = 16) with a mean age of 31.0 years (14 to 65), 38.5 years (18 to 64), 63.7 years (20 to 78), 63.5 years (18 to 91), and 39.4 years (18 to 71), respectively. The percentage of patients with abnormal levels of pain catastrophizing, anxiety, or depression was: 22.0%, 16.0%, and 12.0% for DDH, respectively; 9.1%, 10.9%, and 7.3% for FAI, respectively; 13.0%, 4.3%, and 4.3% for LTP, respectively; 21.7%, 11.4%, and 14.1% for OA, respectively; and 25.0%, 43.8%, and 6.3% for AVN, respectively. HADS Anxiety (HADSA) and Hip Disability Osteoarthritis Outcome Score Activities of Daily Living subscale (HOOS ADL) predicted the PCS total (adjusted R. 2. = 0.4599). Age, HADS Depression (HADSD), and PCS total predicted HADSA (adjusted R. 2. = 0.4985). Age, HADSA, patient’s percentage of perceived function, PCS total, and HOOS Quality of Life subscale (HOOS QOL) predicted HADSD (adjusted R. 2. = 0.5802). Conclusion. Patients with hip pathology may exhibit significant pain catastrophizing, anxiety, and depression. Identifying these factors and understanding the impact of psychosocial function could help improve patient treatment outcomes. Perioperative multidisciplinary assessment may be a beneficial part of comprehensive orthopaedic hip care. Cite this article: Bone Joint J 2019;101-B:800–807

Aims

The aims of the study were to report for a cohort aged younger than 40 years: 1) indications for HRA; 2) patient-reported outcomes in terms of the modified Harris Hip Score (HHS); 3) dislocation rate; and 4) revision rate.

Aims

This study reports mid-term outcomes after periacetabular osteotomy (PAO) exclusively in a borderline hip dysplasia (BHD) population to provide a contrast to published outcomes for arthroscopic surgery of the hip in BHD.

Aims

The Birmingham Hip Resurfacing (BHR) was introduced in 1997 to address the needs of young active patients using a historically proven large-diameter metal-on-metal (MoM) bearing. A single designer surgeon’s consecutive series of 130 patients (144 hips) was previously reported at five and ten years, reporting three and ten failures, respectively. The aim of this study was to extend the follow-up of this original cohort at 25 years.

Aims

The aim of this study was to evaluate the reliability and validity of a patient-specific algorithm which we developed for predicting changes in sagittal pelvic tilt after total hip arthroplasty (THA).

Aims

It is important to analyze objectively the hammering sound in cup press-fit technique in total hip arthroplasty (THA) in order to better understand the change of the sound during impaction. We hypothesized that a specific characteristic would present in a hammering sound with successful fixation. We designed the study to quantitatively investigate the acoustic characteristics during cementless cup impaction in THA.

Aims

It is important to analyze objectively the hammering sound in cup press-fit technique in total hip arthroplasty (THA) in order to better understand the change of the sound during impaction. We hypothesized that a specific characteristic would present in a hammering sound with successful fixation. We designed the study to quantitatively investigate the acoustic characteristics during cementless cup impaction in THA.

Aims

The Exeter short stem was designed for patients with Dorr type A femora and short-term results are promising. The aim of this study was to evaluate the minimum five-year stem migration pattern of Exeter short stems in comparison with Exeter standard stems.

Aims

Young adults undergoing total hip arthroplasty (THA) largely have different indications for surgery, preoperative function, and postoperative goals compared to a standard patient group. The aim of our study was to describe young adult THA preoperative function and quality of life, and to assess postoperative satisfaction and compare this with functional outcome measures.

Aims

Psychological status may be an important predictor of outcome after periacetabular osteotomy (PAO). The aim of this study was to investigate the influence of psychological distress on postoperative health-related quality of life, joint function, self-assessed pain, and sports ability in patients undergoing PAO.

An uncemented hemispherical acetabular component is the mainstay of acetabular revision and gives excellent long-term results.

Occasionally, the degree of acetabular bone loss means that a hemispherical component will be unstable when sited in the correct anatomical location or there is minimal bleeding host bone left for biological fixation. On these occasions an alternative method of reconstruction has to be used.

A major column structural allograft has been shown to restore the deficient bone stock to some degree, but it needs to be off-loaded with a reconstruction cage to prevent collapse of the graft. The use of porous metal augments is a promising method of overcoming some of the problems associated with structural allograft. If the defect is large, the augment needs to be protected by a cage to allow ingrowth to occur. Cup-cage reconstruction is an effective method of treating chronic pelvic discontinuity and large contained or uncontained bone defects.

This paper presents the indications, surgical techniques and outcomes of various methods which use acetabular reconstruction cages for revision total hip arthroplasty.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):73–7.

Aims

It may not be possible to undertake revision total hip arthroplasty (THA) in the presence of massive loss of acetabular bone stock using standard cementless hemispherical acetabular components and metal augments, as satisfactory stability cannot always be achieved. We aimed to study the outcome using a reconstruction cage and a porous metal augment in these patients.

Aims

Contemporary outcomes of primary total hip arthroplasties (THAs) with highly cross-linked polyethylene (HXLPE) liners in patients with inflammatory arthritis have not been well studied. This study examined the implant survivorship, complications, radiological results, and clinical outcomes of THA in patients with inflammatory arthritis.

Aims

Perthes’ disease (PD) is a childhood hip disorder that can affect the quality of life in adulthood due to femoral head deformity and osteoarthritis. There is very little data on how PD patients function as adults, especially from the patients’ perspective. The purpose of this study was to collect treatment history, demographic details, the University of California, Los Angeles activity score (UCLA), the 36-Item Short Form survey (SF-36) score, and the Hip disability and Osteoarthritis Outcome score (HOOS) of adults who had PD using a web-based survey method and to compare their outcomes to the outcomes from an age- and sex-matched normative population.

We reviewed 249 consecutive Charnley primary low-friction arthroplasties in 191 patients performed by one surgeon using a transtrochanteric approach at a minimum follow-up of ten years. Of these, 37 hips in 32 patients showed osteolysis and were compared with 41 hips in 37 matched patients with no osteolysis.

We assessed in each case the wear rate, stability of the prosthesis, acetabular angle, socket angle, thickness of the acetabular and femoral cement mantle, canal flare index, femoral score, stem alignment, implant:canal ratio and stem:canal ratio.

We found that a high rate of wear, component instability and osteolysis were associated. Osteolysis was three times more common in men than in women. Factors which reduced osteolysis were cement mantles of 6 mm at the acetabulum and of 3 mm in all zones of the femur, a stem:canal ratio of 60% to 70% and an implant:canal ratio of over 99%.

The overall incidence of osteolysis was 14.9% but when these technical criteria were met, the incidence was 5.2%. This suggests that careful technique can dramatically reduce the risk of this complication.

Aims

Obesity is associated with an increased risk of hip osteoarthritis, resulting in an increased number of total hip arthroplasties (THAs) performed annually. This study examines the peri- and postoperative outcomes of morbidly obese (MO) patients (BMI ≥ 40 kg/m²) compared to healthy weight (HW) patients (BMI 18.5 to < 25 kg/m²) who underwent a THA using the anterior-based muscle-sparing (ABMS) approach.

Aims

The aim of this study was to evaluate the suitability of the tapered cone stem in total hip arthroplasty (THA) in patients with excessive femoral anteversion and after femoral osteotomy.

Aims

This study aimed to develop and validate a fully automated system that quantifies proximal femoral bone mineral density (BMD) from CT images.