Aims. Pain is the most frequent complaint associated with osteonecrosis of the femoral head (ONFH), but the factors contributing to such pain are poorly understood. This study explored diverse demographic, clinical, radiological, psychological, and neurophysiological factors for their potential contribution to pain in patients with ONFH. Methods. This cross-sectional study was carried out according to the “STrengthening the Reporting of OBservational studies in Epidemiology” statement. Data on 19 variables were collected at a single timepoint from 250 patients with ONFH who were treated at our medical centre between July and December 2023 using validated instruments or, in the case of hip pain, a numerical rating scale. Factors associated with pain severity were identified using hierarchical multifactor linear regression. Results. Regression identified the following characteristics as independently associated with higher pain score, after adjustment for potential confounders: Association Research Circulation Osseous classification stage IIIa or IIIb, bone marrow oedema, grade 3 joint effusion, as well as higher scores on pain catastrophizing, anxiety, and central sensitization. The final model explained 69.7% of observed variance in pain scores, of which clinical and radiological factors explained 37%, while psychological and neurophysiological factors explained 24% and demographic factors explained 8.7%. Conclusion. Multidimensional characteristics jointly contribute to the severity of pain associated with ONFH. These findings highlight the need to comprehensively identify potential contributors to pain, and to personalize management and treatment accordingly. Cite this article: Bone Joint Res 2024;13(11):673–681

Patients with acetabular dysplasia commonly undergo peri-acetabular osteotomy after skeletal maturity to reduce the risk of the late development of osteoarthritis. Several studies have suggested that deformity of the femoral head influences the long-term outcome. We radiologically examined 224 hips in 112 patients with acetabular dysplasia and early-stage osteoarthritis. There were 103 women and nine men with a mean age of 37.6 years (18 to 49). A total of 201 hips were placed in the acetabular dysplasia group and 23 in a normal group. The centre–edge angle and acetabular head index were significantly smaller (both p < 0.001), and the acetabular angle, acetabular roof angle and roundness index were significantly greater in the acetabular dysplasia group than those in the normal group (all p < 0.001). There were significant correlations between the roundness index and other parameters. Femoral head shape may be influenced by the severity of the acetabular dysplasia. Cite this article: Bone Joint J 2013;95-B:1192–6

We have assessed the long-term results of 292 cemented total hip replacements which were performed for developmental dysplasia of the hip in 206 patients. The mean age of the patients at operation was 42.6 years (15.9 to 79.5) and most (202) were women. The severity of dysplasia was graded according to both the Crowe and the Hartofilakidis classifications. A 22.25-mm Charnley head was always used and the acetabular components were inserted with cement into the true acetabulum. Bone grafting of the acetabulum, using the patient’s own femoral head, was performed on 48 occasions. At a mean follow-up of 15.7 years (2.2 to 31.2) the overall survival of the acetabular component was 78%. The main cause of revision was aseptic loosening (88.3%). The rate of survival at 20 years based on the Hartofilakidis classification was 76% in the dysplastic, 55% in the low-dislocation and 12% in the high-dislocation groups and on the Crowe classification, 72.7% for group I, 70.7% for group II, 36.7% for group III and 15.6% for group IV. There was no statistical correlation between bone grafting of the acetabulum and survival of the acetabular component. This study has shown a higher rate of failure of the acetabular component with increasing severity of hip dysplasia

Introduction. Acetabular dysplasia is associated with an increased risk of hip pain and early development of osteoarthritis (OA). The Bernese peri-acetabular osteotomy (PAO) is the most well-established technique in the Western world for the treatment of symptomatic acetabular dysplasia. This case-control study aims to assess whether the severity of acetabular dysplasia has an effect on outcome following Peri-Acetabular Osteotomy (PAO) and/or the ability to achieve desired acetabular correction. Patients/Materials & Methods. A prospective, multicentre, longitudinal cohort of consecutive PAOs was reviewed. Of the available 381 cases, 61 hips had pre-PAO radiographic features of lesser-dysplasia [Acetabular-Index (AI)<15° and Lateral-Centre-Edge-Angle (LCEA)>15°) and comprised the ‘study-group’. ‘Study-Group’ was matched for all factors known to influence outcome post-PAO [age, gender, BMI, Tönnis-grade and joint congruency (p=0.6–0.9)] with a ‘Comparison-Group’ of pronounced dysplasia (n=183). Clinical outcomes, complications and the ability to achieve optimum correction (LCEA: 25°–40°/AI: 0°–+10°) were compared. Results. At a mean follow-up of 4(±1.5) years, 3 hips had a THA and 13 underwent further procedures; 21 major complications occurred. The mean improvement in HOOS was 28(±23). No differences in complication- or re-operation- rates were detected between study- and comparison groups (p=0.29). Lesser-dysplastic hips had inferior HOOS compared to pronounced dysplastic hips, both pre- (52Vs.59) and post-operatively (73Vs.78); however, similar improvements were seen. Amongst the lesser dysplastic hips, those that required a femoral osteochondroplasty at PAO had significantly inferior pre-operative HOOS (48±18), compared to those that didn't require an osteochondroplasty (60±17) (p=0.04). Increased ability to achieve optimum acetabular correct was seen (80Vs59%, p=0.4) in the lesser dysplastic hip. Discussion. A PAO is safe and efficacious in the treatment of lesser dysplasia. The mildly dysplastic hips with cam deformity that required concurrent FOCP and PAO, were the most symptomatic. Future studies should aim to optimize diagnosis and management in this challenging, combined deformity cohort

We examined the relationship between the size of the femoral cam in femoroacetabular impingement (FAI) and acetabular pathomorphology to establish if pincer impingement exists in patients with a femoral cam.

CT scans of 37 symptomatic impinging hips with a femoral cam were analysed in a three-dimensional study and were compared with 34 normal hips. The inclination and version of the acetabulum as well as the acetabular rim angle and the bony acetabular coverage were calculated. These measurements were correlated with the size and shape of the femoral cams.

While the size of the femoral cam varied characteristically, the acetabular morphology of the two groups was similar in terms of version (normal mean 23° (sd 7°); cam mean 22° (sd 9°)), inclination (normal mean 57° (sd 5°); cam mean 56° (sd 5°)), acetabular coverage (normal mean 41% (sd 5%); cam mean 42% (sd 4%)) and the mean acetabular rim angle (normal mean 82° (sd 5°); cam mean 83° (sd 4°)).

We found no correlation between acetabular morphology and the severity of cam lesion and no evidence of either global or focal over-coverage to support the diagnosis of ‘mixed’ FAI. The femoral cam may provoke edge loading but removal of any acetabular bearing surface when treating cam FAI might induce accelerated wear.

Cite this article: Bone Joint J 2013;95-B:314–19.

Total hip arthroplasty (THA) is often performed in symptomatic patients with developmental dysplasia of the hip (DDH) who do not qualify for periacetabular osteotomy (PAO). The impact of osteoarthritis (OA) severity on postoperative outcomes in DDH patients who undergo THA is not well described. We hypothesized that DDH patients who undergo THA with mild OA have slower initial recovery postoperatively, but similar one-year patient reported outcome measures (PROMs) when compared to DDH patients with severe OA. We performed a retrospective review at a single academic institution over a six-year period of patients with DDH who underwent primary THA and compared them to patients without DDH who underwent THA. Within the DDH cohort, we compared PROMs stratified by DDH severity and OA severity. Diagnosis of DDH was verified using radiographic lateral center edge angle (LCEA). Minimum one-year follow-up was required. PROMs were collected through one-year postoperatively. Logistic and linear regression models were used adjusting for age, sex, body mass index, and Charlson Comorbidity Index. 263 patients with DDH were compared to 1,225 THA patients without DDH. No significant differences were found in postoperative PROMs or revision rates (p=0.49). When stratified by DDH severity, patients with LCEA<10° had worse preoperative pain (p=0.01), mental health (p<0.01) and physical function (p=0.03) scores but no significant difference in postoperative PROMs. Within the DDH group, when stratified by OA severity, patients with Grade 3 Tonnis score had worse preoperative pain (p=0.04) but no significant difference in postoperative PROMs. Recovery curves in DDH patients based upon severity of DDH and OA were not significantly different at 2-weeks, 6-weeks and 1-year. DDH patients who have mild OA have similar recovery curves compared to those with severe OA. THA is reasonable in symptomatic DDH patients who have mild arthritis and do not qualify for PAO

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

Finite element analysis (FEA) has been applied for the biomechanical analysis of acetabular dysplasia, but not for biomechanical studies of periacetabular osteotomy (PAO) or those performing analysis taking into consideration the severity of acetabular dysplasia. This study aimed to perform biomechanical evaluation of changes in stress distribution following PAO and to determine the effect of the severity of developmental dysplasia of the hip (DDH) using three-dimensional FEA. A normal model was designed with a 25° center-edge (CE) angle and a 25° vertical-center-anterior margin (VCA) angle. DDH models were designed with CE and VCA angles each of 10, 0, or −10°. Post-PAO models were created by separating each DDH model and rotating the acetabular bone fragment in the anterolateral direction so that the femoral head was covered by the acetabular bone fragment, with CE and VCA angles each at 25°. Compared to the normal hip joint model, the DDH models showed stress concentration in the acetabular edge and contacting femoral head, and higher stress values; stress increased with decreasing CE and VCA angles. Compared to the DDH models, the post-PAO models showed near-normal patterns of stress distribution in the acetabulum and femoral head, with stress concentration areas shifted from the lateral to medial sides. Stress dispersion was especially apparent in the severe acetabular dysplasia models. PAO provided greater decreases in the maximum values of von Mises stress in the load-bearing area of the acetabulum and femoral head when applied to the DDH models of higher degrees of severity, although the values increased with increasing severity of DDH. PAO is expected to provide biomechanical improvement of the hip joint, although the results also suggest a limitation in the applicability of PAO for the patients with severe acetabular dysplasia

Hyponatraemia is a potentially preventable post-operative complication following hip arthroplasty. There is a paucity of literature reporting its incidence and guidelines for prevention - unlike AKI which has been prioritised to great success. Hyponatraemia is now rife in elective orthopaedics causing multiple symptoms that delay ambulation and increase the length of hospital stay. We aim to assess the incidence of hyponatraemia and AKI as a benchmark following elective primary total hip arthroplasty (THA), as well as identify patients most at risk in a high volume arthroplasty centre. Between April 2018 and September 2018 all primary THA surgeries performed in one hospital were retrospectively reviewed. Pre-operative and 1 day post operative bloods were analysed. Patients included had normal pre-operative sodium. A total of 221 patients underwent THA. The mean age was 73.6 and ASA 2.1. No patients had a recorded AKI, however 42% of patients had a new post operative hyponatraemia. Of the hyponatraemia cases, 75% were mild, 18% were moderate, and 7% were severe. There was correlation between increased age and increased severity of hyponatraemia. The mean age of patients with mild hyponatraemia was 72.1, moderate was 77.7, and severe was 78.8. An association between ASA and severity of hyponatraemia was noted. In patients who had an ASA of 4 and hyponatraemia, 66% were moderate or severe, ASA 3 was 25%, ASA 2 was 24% and ASA 1 was 0%. The patients who had severe hyponatraemia received on average 3.5L fluid input perioperatively. Rates of post op hyponatraemia are significantly higher than AKI in primary THA. Severity of hyponatraemia increases with age and ASA. Due to its negative outcomes on recovery the high levels of hyponatraemia are worrying. We have identified which patient cohorts are more at risk and recommend more care should be taken in their perioperative fluid balance. It may be beneficial to consider successful AKI prevention and management campaigns and apply them to the prevention of hyponatraemia following hip arthroplasty

Although total hip arthroplasty (THA) is beneficial for many patients with hip osteoarthritis (OA), a subset of patients experience minimal benefit. It is therefore pertinent to understand the predictors of poor functional outcome to facilitate shared decision making. One such predictor is preoperative radiographic OA severity. The aim of this systematic review was to determine whether preoperative radiographic OA severity could predict postoperative patient-reported outcome measures (PROMs) and satisfaction rates after THA. This systematic review was conducted according to PRISMA guidelines, and the protocol published in PROSPERO (ID:Â CRD42023445918). A literature search was performed using Embase, MEDLINE and Cochrane Library databases. Demographics, radiographic OA severity, PROMs, satisfaction, and complications after THA were collected. A meta-analysis was performed, where appropriate, using a random-effects model. Of 631 identified articles, 12 were included in the final analysis (8,034 participants; mean age 65.2, 38.1% male, mean BMI 29.1 kg/m2). There were three key findings. Firstly, those with mild OA are less likely to achieve a meaningful clinical improvement in PROMs (odds ratio (OR) 0.50, 95% confidence interval (CI) 0.38, 0.65; p < 0.00001). Secondly, two studies indicates that postoperative patient satisfaction was lower in participants with mild OA. Thirdly, participants with mild arthritis experience less improvement in SF-36 physical functioning (mean difference (MD) -8.31, 95% CI -10.97, -5.64; p < 0.00001) and role physical (MD -5.59, 95% CI -8.40, -2.77; p < 0.0001), but showed higher improvement in general health (MD 1.68, 95% CI 0.31, 3.06; p = 0.02). Patients with mild OA, as determined radiographically, are less likely to achieve meaningful clinical improvements in PROMs and have lower postoperative satisfaction after THA. This information will improve collaborative decision-making in the preoperative period

Aims. Some patients presenting with hip pain and instability and underlying acetabular dysplasia (AD) do not experience resolution of symptoms after surgical management. Hip-spine syndrome is a possible underlying cause. We hypothesized that there is a higher frequency of radiological spine anomalies in patients with AD. We also assessed the relationship between radiological severity of AD and frequency of spine anomalies. Methods. In a retrospective analysis of registry data, 122 hips in 122 patients who presented with hip pain and and a final diagnosis of AD were studied. Two observers analyzed hip and spine variables using standard radiographs to assess AD. The frequency of lumbosacral transitional vertebra (LSTV), along with associated Castellvi grade, pars interarticularis defect, and spinal morphological measurements were recorded and correlated with radiological severity of AD. Results. Out of 122 patients, 110 (90.2%) were female and 12 (9.8%) were male. We analyzed the radiographs of 122 hips (59 (48.4%) symptomatic left hips, and 63 (51.6%) symptomatic right hips). Average age at time of presentation was 34.2 years (SD 11.2). Frequency of LSTV was high (39% to 43%), compared to historic records from the general population, with Castellvi type 3b being the most common (60% to 63%). Patients with AD have increased L4 and L5 interpedicular distance compared to published values. Frequency of pars interarticularis defect was 4%. Intraclass correlation coefficient for hip and spine variables assessed ranged from good (0.60 to 0.75) to excellent (0.75 to 1.00). Severity of AD did not demonstrate significant correlation with frequency of radiological spine anomalies. Conclusion. Patients with AD have increased frequency of spinal anomalies seen on standard hip radiographs. However, there exists no correlation between radiological severity of AD and frequency of spine anomalies. In managing AD patients, clinicians should also assess spinal anomalies that are easily found on standard hip radiographs. Cite this article: Bone Joint J 2021;103-B(8):1351–1357

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

Given the prolonged waits for hip arthroplasty seen across the U.K. it is important that we optimise priority systems to account for potential disparities in patient circumstances and impact. We set out to achieve this through a two-stage approach. This included a Delphi-study of patient and surgeon preferences to determine what should be considered when determining patient priority, followed by a Discrete Choice Experiment (DCE) to decide relative weighting of included attributes. The study was conducted according to the published protocol ([. https://boneandjoint.org.uk/article/10.1302/2633-1462.310.BJO-2022-0071. ](. https://boneandjoint.org.uk/article/10.1302/2633-1462.310.BJO-2022-0071. )). The Delphi study was performed online over 3 rounds with anonymous ranking and feedback. Included factors were voted as either Consensus in, Consensus out, or No Consensus• following an established scoring criterion. A final consensus meeting determined the prioritisation factors (and their levels) to be included in the DCE. The DCE was then conducted using an online platform, with surgeons performing 18 choice sets regarding which merited greater priority between two hypothetical patients. Results were collated and analysed using multinomial logit regression analysis (MNL). For the Delphi study there were 43 responses in the first round, with a subsequent 91% participation rate. Final consensus inclusion was achieved for Pain; Mobility/Function; Activities of Daily Living; Inability to Work/Care; Length of Time Waited; Radiological Severity and Mental Wellbeing. 70 individuals subsequently contributed to the DCE, with radiological severity being the most significant factor (Coefficient 2.27 \[SD 0.31\], p<0.001), followed by pain (Coefficient 1.08 \[SD 0.13\], p<0.001) and time waited (Coefficient for 1-month additional wait 0.12 \[SD 0.02\], p<0.001). The calculated trade-off in waiting time for a 1-level change in pain (e.g., moderate to severe pain) was 9.14 months. These results present a new method of determining comparative priority for those on primary hip arthroplasty waiting lists. Evaluation of potential implementation in clinical practice is now required

Aims. This study aimed to evaluate the accuracy of implant placement with robotic-arm assisted total hip arthroplasty (THA) in patients with developmental dysplasia of the hip (DDH). Methods. The study analyzed a consecutive series of 69 patients who underwent robotic-arm assisted THA between September 2018 and December 2019. Of these, 30 patients had DDH and were classified according to the Crowe type. Acetabular component alignment and 3D positions were measured using pre- and postoperative CT data. The absolute differences of cup alignment and 3D position were compared between DDH and non-DDH patients. Moreover, these differences were analyzed in relation to the severity of DDH. The discrepancy of leg length and combined offset compared with contralateral hip were measured. Results. The mean values of absolute differences (postoperative CT-preoperative plan) were 1.7° (standard deviation (SD) 2.0) (inclination) and 2.5° (SD 2.1°) (anteversion) in DDH patients, and no significant differences were found between non-DDH and DDH patients. The mean absolute differences for 3D cup position were 1.1 mm (SD 1.0) (coronal plane) and 1.2 mm (SD 2.1) (axial plane) in DDH patients, and no significant differences were found between two groups. No significant difference was found either in cup alignment between postoperative CT and navigation record after cup screws or in the severity of DDH. Excellent restoration of leg length and combined offset were achieved in both groups. Conclusion. We demonstrated that robotic-assisted THA may achieve precise cup positioning in DDH patients, and may be useful in those with severe DDH. Cite this article: Bone Joint Res 2021;10(10):629–638

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. Methods. In all, 202 consecutive patients who underwent PAO for developmental dysplasia of the hip (DDH) at our institution from 2015 to 2017 were included and followed up at 63 months (SD 10) postoperatively. Of these, 101 with complete data sets entered final analysis. Patients were assessed by questionnaire. Psychological status was measured by Brief Symptom Inventory (BSI-18), health-related quality of life was raised with 36-Item Short Form Survey (SF-36), hip functionality was measured by the short version 0f the International Hip Outcome Tool (iHOT-12), Subjective Hip Value (SHV), and Hip Disability and Outcome Score (HOS). Surgery satisfaction and pain were assessed. Dependent variables (endpoints) were postoperative quality of life (SF-36, HOS quality of life (QoL)), joint function (iHOT-12, SHV, HOS), patient satisfaction, and pain. Psychological distress was assessed by the Global Severity Index (GSI), somatization (BSI Soma), depression (BSI Depr), and anxiety (BSI Anx). Influence of psychological status was assessed by means of univariate and multiple multivariate regression analysis. Results. In multiple multivariate regression, postoperative GSI, BSI Soma, and BSI Depr had a negative effect on postoperative SF-36 (e -2.07, -3.05, and -2.67, respectively; p < 0.001), iHOT-12 (e -1.35 and -4.65, respectively; p < 0.001), SHV (e -1.20 and -2.71, respectively; p < 0.001), HOS QoL (e -2.09 and -4.79, respectively; p < 0.001), HOS Function (e -1.00 and -3.94, respectively; p < 0.001), and HOS Sport (e -1.44 and -5.29, respectively; p < 0.001), and had an effect on postoperative pain (e 0.13 and 0.37, respectively; p < 0.001). Conclusion. Psychological distress, depression, and somatization disorders affect health-related quality of life, perceived joint function, and sports ability. Pain perception is significantly increased by somatization. However, patient satisfaction with surgery is not affected. Cite this article: Bone Jt Open 2023;4(10):758–765

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

Injury of the lateral femoral cutaneous nerve (LFCN) is one of the known complications after periacetabular osteotomy (PAO) using anterior approach. We previously reported that the incidence of LFCN injury was 48% at 1 year after PAO. However, there was no study examining the sequential changes of LFCN injury status. In this study, we performed a prospective over 3-year follow-up study as to the incidence of LFCN injury as well as its clinical outcomes. This study included 40 consecutive hips in 40 patients (3 males and 37 females) who underwent PAO from May 2016 to July 2018. The mean age at surgery was 36.7 years (17 to 60). The mean observation period was 47.3 months (36 to 69). The incidence and severity of LFCN injury was evaluated, while clinical scores, including the Harris Hip Score (HHS), Short-Form 36 Health Survey (SF-36), and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ), were also investigated. At 3 years after PAO, LFCN injury was observed in 13 of 40 (33%) patients, in which 7 patients who had a symptom at 1 year have completely recovered. There was no significant difference in the HHS and SF-36 between patients with and without LFCN injury at 3 years. Regarding the JHEQ, a significant difference was recognized in the patient satisfaction and mental score between patients with and without LFCN injury, but there were no significant differences in the other clinical scores. The incidence of LFCN injury gradually decreased to 33% at 3 years after CPO. LFCN injury did not influence the clinician-reported outcome, while it had a negative impact on patient satisfaction and mental score based on the patient-reported outcome

Hypermobility Spectrum Disorder (HSD or hEDS) is attributed to a collagen abnormality associated with excessive joint flexibility. Approximately 90% of females with hip dysplasia have hypermobility. Manifestations of hypermobility in various body systems are unique to every patient, affecting different tissues of the body with varying degrees of severity. Our purposes were to identify the manifestations of hypermobility across multiple body systems and to study the recognition of hypermobility in the medical literature of multiple specialties over multiple decades. A literature search of the major medical disciplines for key words associated with HSD was performed. These specialties included gastroenterology, gynecology, neurology, psychiatry, oral-maxillofacial surgery, cardiology, and orthopaedic surgery. A specialty-specific impact factor (IF) score was calculated as the percentage of research articles that referenced hypermobility as a comorbidity over all articles within that specialty. Statistical differences were identified using single factor ANOVA with significance determined at p<0.05. We reviewed many published, specialty-specific manifestations of hypermobility, and describe them. All six non-orthopaedic specialties demonstrated a continually increasing relative IF ratio throughout the study period with a peak impact average of 0.22 (p<0.05 compared with other time ranges). There was a 93.3% overall increase in IF scores from the 1992–1998 period to the most recent period examined (p<0.05). Hypermobility is increasingly recognized as a significant health issue in multiple disciplines. Since dysplasia is associated with approximately 40% of all primary total hip arthroplasty cases, understanding the multi-system manifestations, and broad impact of hypermobility on patients, is relevant for every hip surgeon. We are expanding our research into other medical disciplines, including urology, ophthalmology, dermatology, clinical psychology, and others

An intra-articular steroid injection can be a useful diagnostic tool in patients presenting with debilitating hip pain and radiographically mild osteoarthritis. The clinical and patient reported outcomes associated with patients who have radiographically mild osteoarthritis and undergo total hip arthroplasty (THA) remain poorly studied. Patients undergoing primary, elective THA at a single academic medical center by a fellowship-trained adult reconstruction surgeon between 2017–2023 were identified. Only those patients who underwent an intra-articular corticosteroid injection into the operative hip within one year of surgery were included. Patients were divided into two cohorts based on the severity of their osteoarthritis as determined by preoperative radiographs; those with Kellgren-Lawrence (KL) grade I-II arthritis were classified as “mild” whereas those with KL grade III-IV arthritis were classified as “severe”. Clinical and patient reported outcomes at final follow-up were compared between cohorts. The final cohorts included 25 and 224 patients with radiographically mild and severe osteoarthritis, respectively. There were no baseline differences in age, gender or time between intra-articular corticosteroid injection and THA between cohorts. There were no significant differences in the preoperative or postoperative HOOS JR values between patients with mild or severe arthritis (all p>0.05). There were no significant differences in the change in HOOS JR scores from the preoperative to final follow-up timepoints between cohorts. There were no significant differences in the percentage of patients who achieved the minimal clinically important difference (MCID) on the HOOS JR questionnaire between cohorts. Patients with radiographically mild osteoarthritis who feel relief of their hip pain following an intra-articular corticosteroid injection report similar preoperative debility and demonstrate similar improvements in patient reported outcome scores following THA compared to patients with radiographically severe osteoarthritis

Different techniques have been described to address massive bone loss of the acetabulum in revision hip surgery. aMace has gained popularity as it provides customization aiming to restore hip centre and provide good initial stability in cases of large non-contained defects. It takes into account quality of host bone. Its porous defect filling scaffold provides an excellent surface for osteointegration. Our aim was to assess the short and mid-term outcomes of patients who underwent revision surgery using aMace system. Ethical approval was obtained. A retrospective study included all patients who had aMace between June 2013 and October 2022 allowing for a minimum of 12-months follow-up. Patients’ demographics, indication, bone-loss severity, reconstruction details, re-operation, complications, mortality, pain and function were assessed. 52 cases were performed by 13 surgeons with median 51 months follow-up. Median age was 72.7 years. 86.5% were female. Average BMI was 25.3. Average ASA grade was 3. 65% were classified as Paprosky IIIB and 32% were IIIA. 73% were found to have poor bone quality on CT. Main indication for aMace was massive bone loss/discontinuity secondary to aseptic loosening in 88.5%. 77% underwent single-stage revision. 53.8% had 2 or more previous revisions. 71% underwent stem revision in the same setting. 77% received a dual mobility bearing. Re-operation rate was 5.7% for instability and femoral PPF. LLD was reported in 9.6%. Permanent Sciatic nerve palsy occurred in 3.8% of the cases. 30-days mortality was 1.9%. Statistically significant post-op improvements in pain and mobility were reported (p<0.001). None of the acetabular components have been revised. Our study shows satisfactory surgical outcomes with a relatively low complication rate and significant pain and mobility improvements in the early to mid-term stages. We recommend these costly cases to be done in highly specialist centres adopting MDT approach