The October 2024 Children’s orthopaedics Roundup³⁶⁰ looks at: Cost-effectiveness analysis of soft bandage and immediate discharge versus rigid immobilization in children with distal radius torus fractures: the FORCE trial; Percutaneous Achilles tendon tenotomy in clubfoot with a blade or a needle: a single-centre randomized controlled noninferiority trial; Treatment of hip displacement in children with cerebral palsy: a five-year comparison of proximal femoral osteotomy and combined femoral-pelvic osteotomy in 163 children; The Core outcome Clubfoot (CoCo) study: relapse, with poorer clinical and quality of life outcomes, affects 37% of idiopathic clubfoot patients; Retention versus removal of epiphyseal screws in paediatric distal tibial fractures: no significant impact on outcomes; Predicting the resolution of residual acetabular dysplasia after brace treatment in infant DDH; Low prevalence of acetabular dysplasia following treatment for neonatal hip instability: a long-term study; How best to distract the patient?.

The August 2024 Hip & Pelvis Roundup³⁶⁰ looks at: Understanding perceived leg length discrepancy post-total hip arthroplasty: the role of pelvic obliquity; Influence of femoral stem design on revision rates in total hip arthroplasty; Outcomes of arthroscopic labral treatment of femoroacetabular impingement in adolescents; Characteristics and quality of online searches for direct anterior versus posterior approach for total hip arthroplasty; Rapid return to braking after anterior and posterior approach total hip arthroplasty; How much protection does a collar provide?; Timing matters: reducing infection risk in total hip arthroplasty with corticosteroid injection intervals; Identifying pain recovery patterns in total hip arthroplasty using PROMIS data.

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. Methods. A prognostic cross-sectional cohort study was conducted involving patients from a single centre who underwent hip arthroscopy between January 2013 and April 2021. Radiological metrics measured on conventional radiographs and magnetic resonance arthrography were systematically assessed. The study analyzed the relationship between these metrics and complication rates, revision rates, and patient-reported outcomes. Results. Out of 810 identified hip arthroscopies, 359 hips were included in the study. Radiological risk factors associated with unsatisfactory outcomes after cam resection included a dysplastic posterior wall, Tönnis grade 2 or higher, and over-correction of the α angle. The presence of acetabular retroversion and dysplasia were also significant predictors for worse surgical outcomes. Notably, over-correction of both cam and pincer deformities resulted in poorer outcomes than under-correction. Conclusion. We recommend caution in performing hip arthroscopy in patients who have three positive acetabular retroversion signs. Acetabular dysplasia with a lateral centre-edge angle of less than 20° should not be treated with isolated hip arthroscopy. Acetabular rim-trimming should be avoided in patients with borderline dysplasia, and care should be taken to avoid over-correction of a cam deformity and/or pincer deformity. Cite this article: Bone Joint J 2024;106-B(8):775–782

Aims

The aim of this study was to determine the clinical outcomes and factors contributing to failure of transposition osteotomy of the acetabulum (TOA), a type of spherical periacetabular osteotomy, for advanced osteoarthritis secondary to hip dysplasia.

Aims. Radiological residual acetabular dysplasia (RAD) has been reported in up to 30% of children who had successful brace treatment of infant developmental dysplasia of the hip (DDH). Predicting those who will resolve and those who may need corrective surgery is important to optimize follow-up protocols. In this study we have aimed to identify the prevalence and predictors of RAD at two years and five years post-bracing. Methods. This was a single-centre, prospective longitudinal cohort study of infants with DDH managed using a published, standardized Pavlik harness protocol between January 2012 and December 2016. RAD was measured at two years’ mean follow-up using acetabular index-lateral edge (AI-L) and acetabular index-sourcil (AI-S), and at five years using AI-L, AI-S, centre-edge angle (CEA), and acetabular depth ratio (ADR). Each hip was classified based on published normative values for normal, borderline (1 to 2 standard deviations (SDs)), or dysplastic (> 2 SDs) based on sex, age, and laterality. Results. Of 202 infants who completed the protocol, 181 (90%) had two and five years’ follow-up radiographs. At two years, in 304 initially pathological hips, the prevalence of RAD (dysplastic) was 10% and RAD (borderline) was 30%. At five years, RAD (dysplastic) decreased to 1% to 3% and RAD (borderline) decreased to < 1% to 2%. On logistic regression, no variables were predictive of RAD at two years. Only AI-L at two years was predictive of RAD at five years (p < 0.001). If both hips were normal at two years’ follow-up (n = 96), all remained normal at five years. In those with bilateral borderline hips at two years (n = 21), only two were borderline at five years, none were dysplastic. In those with either borderline-dysplastic or bilateral dysplasia at two years (n = 26), three (12%) were dysplastic at five years. Conclusion. The majority of patients with RAD at two years post-brace treatment, spontaneously resolved by five years. Therefore, children with normal radiographs at two years post-brace treatment can be discharged. Targeted follow-up for those with abnormal AI-L at two years will identify the few who may benefit from surgical correction at five years’ follow-up. Cite this article: Bone Joint J 2024;106-B(7):744–750

Aims. The objective of this study was to present the outcomes of rotational acetabular osteotomy (RAO) over a 30-year period for osteoarthritis (OA) secondary to dysplasia of the hip in pre- or early-stage OA. Methods. Between September 1987 and December 1994, we provided treatment to 47 patients (55 hips) with RAO for the management of pre- or early-stage OA due to developmental hip dysplasia. Of those, eight patients (11 hips) with pre-OA (follow-up rate 79%) and 27 patients (32 hips) with early-stage OA (follow-up rate 78%), totalling 35 patients (43 hips) (follow-up rate 78%), were available at a minimum of 28 years after surgery. Results. In the pre-OA group, the mean Merle d'Aubigné score improved significantly from 14.5 points (SD 0.7) preoperatively to 17.4 points at final follow-up (SD 1.2; p = 0.004) and in the early-stage group, the mean score did not improve significantly from 14.0 (SD 0.3) to 14.6 (SD 2.4; p = 0.280). Radiologically, the centre-edge angle, acetabular roof angle, and head lateralization index were significantly improved postoperatively in both groups. Radiological progression of OA was observed in two patients (two hips) in the pre-OA group and 17 patients (18 hips) in the early-stage group. Kaplan-Meier survival analysis, with radiological progression of OA as the primary outcome, projected a 30-year survival rate of 81.8% (95% confidence interval (CI) 0.59 to 1.00) for the pre-OA group and 42.2% (95% CI 0.244 to 0.600) for the early-stage group. In all cases, the overall survival rate stood at 51.5% (95% CI 0.365 to 0.674) over a 30-year period, and when the endpoint was conversion to total hip arthroplasty, the survival rate was 74.0% (95% CI 0.608 to 0.873). Conclusion. For younger patients with pre-OA, joint preservation of over 30 years can be expected after RAO. Cite this article: Bone Joint J 2024;106-B(5 Supple B):25–31

Aims. Periacetabular osteotomy (PAO) is the preferred treatment for symptomatic acetabular dysplasia in adolescents and young adults. There remains a lack of consensus regarding whether intra-articular procedures such as labral repair or improvement of femoral offset should be performed at the time of PAO or addressed subsequent to PAO if symptoms warrant. The purpose was to determine the rate of subsequent hip arthroscopy (HA) in a contemporary cohort of patients, who underwent PAO in isolation without any intra-articular procedures. Methods. From June 2012 to March 2022, 349 rectus-sparing PAOs were performed and followed for a minimum of one year (mean 6.2 years (1 to 11)). The mean age was 24 years (14 to 46) and 88.8% were female (n = 310). Patients were evaluated at final follow-up for patient-reported outcome measures (PROMs). Clinical records were reviewed for complications or subsequent surgery. Radiographs were reviewed for the following acetabular parameters: lateral centre-edge angle, anterior centre-edge angle, acetabular index, and the alpha-angle (AA). Patients were cross-referenced from the two largest hospital systems in our area to determine if subsequent HA was performed. Descriptive statistics were used to analyze risk factors for HA. Results. A total of 16 hips (15 patients; 4.6%) underwent subsequent HA with labral repair and femoral osteochondroplasty, the most common interventions. For those with a minimum of two years of follow-up, 5.3% (n = 14) underwent subsequent HA. No hips underwent total hip arthroplasty and one revision PAO was performed. Overall, 17 hips (4.9%) experienced a complication and 99 (26.9%) underwent hardware removal. All PROMs improved significantly postoperatively. Radiologically, 80% of hips (n = 279) reached the goal for acetabular correction (77% for acetbular index and 93% for LCEA), with no significant differences between those who underwent subsequent HA and those who did not. Conclusion. Rectus-sparing PAO is associated with a low rate of subsequent HA for intra-articular pathology at a mean of 6.2 years’ follow-up (1 to 11). Acetabular correction alone may be sufficient as the primary intervention for the majority of patients with symptomatic acetabular dysplasia. Cite this article: Bone Joint J 2024;106-B(5 Supple B):17–24

Aims

The aim of this study was to investigate whether anterior pelvic plane-pelvic tilt (APP-PT) is associated with distinct hip pathomorphologies. We asked: is there a difference in APP-PT between young symptomatic patients being evaluated for joint preservation surgery and an asymptomatic control group? Does APP-PT vary among distinct acetabular and femoral pathomorphologies? And does APP-PT differ in symptomatic hips based on demographic factors?

Aims. Ganz’s studies made it possible to address joint deformities on both the femoral and acetabular side brought about by Perthes’ disease. Femoral head reduction osteotomy (FHRO) was developed to improve joint congruency, along with periacetabular osteotomy (PAO), which may enhance coverage and containment. The purpose of this study is to show the clinical and morphological outcomes of the technique and the use of an implemented planning approach. Methods. From September 2015 to December 2021, 13 FHROs were performed on 11 patients for Perthes’ disease in two centres. Of these, 11 hips had an associated PAO. A specific CT- and MRI-based protocol for virtual simulation of the corrections was developed. Outcomes were assessed with radiological parameters (sphericity index, extrusion index, integrity of the Shenton’s line, lateral centre-edge angle (LCEA), Tönnis angle), and clinical parameters (range of motion, visual analogue scale (VAS) for pain, Merle d'Aubigné-Postel score, modified Harris Hip Score (mHHS), and EuroQol five-dimension five-level health questionnaire (EQ-5D-5L)). Early and late complications were reported. Results. The mean follow-up was 39.7 months (standard deviation (SD) 26.4). The mean age at surgery was 11.4 years (SD 1.6). No major complications were recorded. One patient required a total hip arthroplasty. Mean femoral head sphericity increased from 46.8% (SD 9.34%) to 70.2% (SD 15.44; p < 0.001); mean LCEA from 19.2° (SD 9.03°) to 44° (SD 10.27°; p < 0.001); mean extrusion index from 37.8 (SD 8.70) to 7.5 (SD 9.28; p < 0.001); and mean Tönnis angle from 16.5° (SD 12.35°) to 4.8° (SD 4.05°; p = 0.100). The mean VAS improved from 3.55 (SD 3.05) to 1.22 (1.72; p = 0.06); mean Merle d’Aubigné-Postel score from 14.55 (SD 1.74) to 16 (SD 1.6; p = 0.01); and mean mHHS from 60.6 (SD 18.06) to 81 (SD 6.63; p = 0.021). The EQ-5D-5L also showed significant improvements. Conclusion. FHRO associated with periacetabular procedures is a safe technique that showed improved functional, clinical, and morphological outcomes in Perthes’ disease. The newly introduced simulation and planning algorithm may help to further refine the technique. Cite this article: Bone Joint J 2024;106-B(5 Supple B):40–46

Aims

Lateral femoral cutaneous nerve (LFCN) injury is a complication after periacetabular osteo-tomy (PAO) using an anterior approach, which might adversely affect the outcome. However, no prospective study has assessed the incidence and severity of this injury and its effect on the clinical outcomes over a period of time for longer than one year after PAO. The aim of this study was to assess the incidence and severity of the symptoms of LFCN injury for ≥ three years after PAO and report its effect on clinical outcomes.

The April 2024 Children’s orthopaedics Roundup³⁶⁰ looks at: Ultrasonography or radiography for suspected paediatric distal forearm fractures?; Implant density in scoliosis: an important variable?; Gait after paediatric femoral shaft fracture treated with intramedullary nail fixation: a longitudinal prospective study; The opioid dilemma: navigating pain management for children’s bone fractures; 12- to 20-year follow-up of Dega acetabuloplasty in patients with developmental dysplasia of the hip; Physeal fractures of the distal ulna: incidence and risk factors for premature growth arrest; Analysis of growth after transphyseal anterior cruciate ligament reconstruction in children; Management of lateral condyle humeral fracture associated with elbow dislocation in children: a retrospective international multicentre cohort study.

Aims. Periacetabular osteotomy (PAO) is widely recognized as a demanding surgical procedure for acetabular reorientation. Reports about the learning curve have primarily focused on complication rates during the initial learning phase. Therefore, our aim was to assess the PAO learning curve from an analytical perspective by determining the number of PAOs required for the duration of surgery to plateau and the accuracy to improve. Methods. The study included 118 consecutive PAOs in 106 patients. Of these, 28 were male (23.7%) and 90 were female (76.3%). The primary endpoint was surgical time. Secondary outcome measures included radiological parameters. Cumulative summation analysis was used to determine changes in surgical duration. A multivariate linear regression model was used to identify independent factors influencing surgical time. Results. The learning curve in this series was 26 PAOs in a period of six months. After 26 PAO procedures, a significant drop in surgical time was observed and a plateau was also achieved. The mean duration of surgery during the learning curve was 103.8 minutes (SD 33.2), and 69.7 minutes (SD 18.6) thereafter (p < 0.001). Radiological correction of acetabular retroversion showed a significant improvement after having performed a total of 93 PAOs, including anteverting PAOs on 35 hips with a retroverted acetabular morphology (p = 0.005). Several factors were identified as independent variables influencing duration of surgery, including patient weight (β = 0.5 (95% confidence interval (CI) 0.2 to 0.7); p < 0.001), learning curve procedure phase of 26 procedures (β = 34.0 (95% CI 24.3 to 43.8); p < 0.001), and the degree of lateral correction expressed as the change in the lateral centre-edge angle (β = 0.7 (95% CI 0.001 to 1.3); p = 0.048). Conclusion. The learning curve for PAO surgery requires extensive surgical training at a high-volume centre, with a minimum of 50 PAOs per surgeon per year. This study defined a cut-off value of 26 PAO procedures, after which a significant drop in surgical duration occurred. Furthermore, it was observed that a retroverted morphology of the acetabulum required a greater number of procedures to acquire proficiency in consistently eliminating the crossover sign. These findings are relevant for fellows and fellowship programme directors in establishing the extent of training required to impart competence in PAO. Cite this article: Bone Joint J 2024;106-B(4):336–343

Aims

Mechanical impingement of the iliopsoas (IP) tendon accounts for 2% to 6% of persistent postoperative pain after total hip arthroplasty (THA). The most common initiator is anterior acetabular component protrusion, where the anterior margin is not covered by anterior acetabular wall. A CT scan can be used to identify and measure this overhang; however, no threshold exists for determining symptomatic anterior IP impingement due to overhang. A case-control study was conducted in which CT scan measurements were used to define a threshold that differentiates patients with IP impingement from asymptomatic patients after THA.

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

We assessed the long-term outcomes of a large cohort of patients who have undergone a periacetabular osteotomy (PAO), and sought to validate a patient satisfaction questionnaire for use in a PAO cohort.

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

Research on hip biomechanics has analyzed femoroacetabular contact pressures and forces in distinct hip conditions, with different procedures, and used diverse loading and testing conditions. The aim of this scoping review was to identify and summarize the available evidence in the literature for hip contact pressures and force in cadaver and in vivo studies, and how joint loading, labral status, and femoral and acetabular morphology can affect these biomechanical parameters.

Aims. Metal-on-metal hip resurfacing (MoM-HR) has seen decreased usage due to safety and longevity concerns. Joint registries have highlighted the risks in females, smaller hips, and hip dysplasia. This study aimed to identify if reported risk factors are linked to revision in a long-term follow-up of MoM-HR performed by a non-designer surgeon. Methods. A retrospective review of consecutive MoM hip arthroplasties (MoM-HRAs) using Birmingham Hip Resurfacing was conducted. Data on procedure side, indication, implant sizes and orientation, highest blood cobalt and chromium ion concentrations, and all-cause revision were collected from local and UK National Joint Registry records. Results. A total of 243 hips (205 patients (163 male, 80 female; mean age at surgery 55.3 years (range 25.7 to 75.3)) with MoM-HRA performed between April 2003 and October 2020 were included. Mean follow-up was 11.2 years (range 0.3 to 17.8). Osteoarthritis was the most common indication (93.8%), and 13 hips (5.3%; 7M:6F) showed dysplasia (lateral centre-edge angle < 25°). Acetabular cups were implanted at a median of 45.4° abduction (interquartile range 41.9° - 48.3°) and stems neutral or valgus to the native neck-shaft angle. In all, 11 hips (4.5%; one male, ten females) in ten patients underwent revision surgery at a mean of 7.4 years (range 2.8 to 14.2), giving a cumulative survival rate of 94.8% (95% confidence interval (CI) 91.6% to 98.0%) at ten years, and 93.4% (95% CI 89.3% to 97.6%) at 17 years. For aseptic revision, male survivorship was 100% at 17 years, and 89.6% (95% CI 83.1% to 96.7%) at ten and 17 years for females. Increased metal ion levels were implicated in 50% of female revisions, with the remaining being revised for unexplained pain or avascular necrosis. Conclusion. The Birmingham MoM-HR showed 100% survivorship in males, exceeding the National Institute for Health and Care Excellence ‘5% at ten years’ threshold. Female sex and small component sizes are independent risk factors. Dysplasia alone is not a contraindication to resurfacing. Cite this article: Bone Jt Open 2023;4(11):853–858

Aims. Brace treatment is the cornerstone of managing developmental dysplasia of the hip (DDH), yet there is a lack of evidence-based treatment protocols, which results in wide variations in practice. To resolve this, we have developed a comprehensive nonoperative treatment protocol conforming to published consensus principles, with well-defined a priori criteria for inclusion and successful treatment. Methods. This was a single-centre, prospective, longitudinal cohort study of a consecutive series of infants with ultrasound-confirmed DDH who underwent a comprehensive nonoperative brace management protocol in a unified multidisciplinary clinic between January 2012 and December 2016 with five-year follow-up radiographs. The radiological outcomes were acetabular index-lateral edge (AI-L), acetabular index-sourcil (AI-S), centre-edge angle (CEA), acetabular depth ratio (ADR), International Hip Dysplasia Institute (IHDI) grade, and evidence of avascular necrosis (AVN). At five years, each hip was classified as normal (< 1 SD), borderline dysplastic (1 to 2 SDs), or dysplastic (> 2 SDs) based on validated radiological norm-referenced values. Results. Of 993 infants assessed clinically and sonographically, 21% (212 infants, 354 abnormal hips) had DDH and were included. Of these, 95% (202 infants, 335 hips) successfully completed bracing, and 5% (ten infants, 19 hips) failed bracing due to irreducible hip(s). The success rate of bracing for unilateral dislocations was 88% (45/51 infants) and for bilateral dislocations 83% (20/24 infants). The femoral nerve palsy rate was 1% (2/212 infants). At five-year follow-up (mean 63 months (SD 5.9; 49 to 83)) the prevalence of residual dysplasia after successful brace treatment was 1.6% (5/312 hips). All hips were IHDI grade I and none had AVN. Four children (4/186; 2%) subsequently underwent surgery for residual dysplasia. Conclusion. Our comprehensive protocol for nonoperative treatment of infant DDH has shown high rates of success and extremely low rates of residual dysplasia at a mean age of five years. Cite this article: Bone Joint J 2023;105-B(8):935–942

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. Methods. We reviewed patients with severe hip dysplasia, defined as Severin IVb or V (lateral centre-edge angle (LCEA) < 0°), who underwent TOA with a structural bone allograft between 1998 and 2019. A medical chart review was conducted to extract demographic data, complications related to the osteotomy, and modified Harris Hip Score (mHHS). Radiological parameters of hip dysplasia were measured on pre- and postoperative radiographs. The cumulative probability of TOA failure (progression to Tönnis grade 3 or conversion to total hip arthroplasty) was estimated using the Kaplan–Meier product-limited method, and a multivariate Cox proportional hazard model was used to identify predictors for failure. Results. A total of 64 patients (76 hips) were included in this study. The median follow-up period was ten years (interquartile range (IQR) five to 14). The median mHHS improved from 67 (IQR 56 to 80) preoperatively to 96 (IQR 85 to 97) at the latest follow-up (p < 0.001). The radiological parameters improved postoperatively (p < 0.001), with the resulting parameters falling within the normal range in 42% to 95% of hips. The survival rate was 95% at ten years and 80% at 15 years. Preoperative Tönnis grade 2 was an independent risk factor for TOA failure. Conclusion. Our findings suggest that TOA with structural bone allografting is a viable surgical option for correcting severely dysplastic acetabulum in adolescents and young adults without advanced osteoarthritis, with favourable mid-term outcomes. Cite this article: Bone Joint J 2023;105-B(7):743–750

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. 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. Methods. We identified 42 hips in 40 patients treated between January 2009 and January 2016 with BHD defined as a lateral centre-edge angle (LCEA) of ≥ 18° but < 25°. A minimum five-year follow-up was available. Patient-reported outcomes (PROMs) including Tegner score, subjective hip value (SHV), modified Harris Hip Score (mHHS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were assessed. The following morphological parameters were evaluated: LCEA, acetabular index (AI), α angle, Tönnis staging, acetabular retroversion, femoral version, femoroepiphyseal acetabular roof index (FEAR), iliocapsularis to rectus femoris ratio (IC/RF), and labral and ligamentum teres (LT) pathology. Results. The mean follow-up was 96 months (67 to 139). The SHV, mHHS, WOMAC, and Tegner scores significantly improved (p < 0.001) at last follow-up. According to SHV and mHHS, there were three hips (7%) with poor results (SHV < 70), three (7%) with a fair score (70 to 79), eight (19%) with good results (80 to 89), and 28 (67%) who scored excellent (> 90) at the last follow-up. There were 11 subsequent operations: nine implant removals due to local irritation, one resection of postoperative heterotopic ossification, and one hip arthroscopy for intra-articular adhesions. No hips were converted to total hip arthroplasty at last follow-up. The presence of preoperative labral lesions or LT lesions did not influence any PROMs at last follow-up. From the three hips that had poor PROMs, two have developed severe osteoarthritis (> Tönnis II), presumably due to surgical overcorrection (postoperative AI < -10°). Conclusion. PAO is reliable in treating BHD with favourable mid-term outcomes. Concomitant LT and labral lesions did not negatively influence outcomes in our cohort. Technical accuracy with avoidance of overcorrection is essential in achieving successful outcomes. Cite this article: Bone Joint J 2023;105-B(7):735–742

Aims

The aim of this study was to report the patterns of symptoms and insufficiency fractures in patients with tumour-induced osteomalacia (TIO) to allow the early diagnosis of this rare condition.

The February 2023 Children’s orthopaedics Roundup³⁶⁰ looks at: Trends in management of paediatric distal radius buckle fractures; Pelvic osteotomy in patients with previous sacral-alar-iliac fixation; Sacral-alar-iliac fixation in patients with previous pelvic osteotomy; Idiopathic toe walking: an update on natural history, diagnosis, and treatment; A prediction model for treatment decisions in distal radial physeal injuries: a multicentre retrospective study; Angular deformities after percutaneous epiphysiodesis for leg length discrepancy; MRI assessment of anterior coverage is predictive of future radiological coverage; Predictive scoring for recurrent patellar instability after a first-time patellar dislocation.

Aims

Femoroacetabular impingement (FAI) patients report exacerbation of hip pain in deep flexion. However, the exact impingement location in deep flexion is unknown. The aim was to investigate impingement-free maximal flexion, impingement location, and if cam deformity causes hip impingement in flexion in FAI patients.

Aims. Hip dysplasia (HD) leads to premature osteoarthritis. Timely detection and correction of HD has been shown to improve pain, functional status, and hip longevity. Several time-consuming radiological measurements are currently used to confirm HD. An artificial intelligence (AI) software named HIPPO automatically locates anatomical landmarks on anteroposterior pelvis radiographs and performs the needed measurements. The primary aim of this study was to assess the reliability of this tool as compared to multi-reader evaluation in clinically proven cases of adult HD. The secondary aims were to assess the time savings achieved and evaluate inter-reader assessment. Methods. A consecutive preoperative sample of 130 HD patients (256 hips) was used. This cohort included 82.3% females (n = 107) and 17.7% males (n = 23) with median patient age of 28.6 years (interquartile range (IQR) 22.5 to 37.2). Three trained readers’ measurements were compared to AI outputs of lateral centre-edge angle (LCEA), caput-collum-diaphyseal (CCD) angle, pelvic obliquity, Tönnis angle, Sharp’s angle, and femoral head coverage. Intraclass correlation coefficients (ICC) and Bland-Altman analyses were obtained. Results. Among 256 hips with AI outputs, all six hip AI measurements were successfully obtained. The AI-reader correlations were generally good (ICC 0.60 to 0.74) to excellent (ICC > 0.75). There was lower agreement for CCD angle measurement. Most widely used measurements for HD diagnosis (LCEA and Tönnis angle) demonstrated good to excellent inter-method reliability (ICC 0.71 to 0.86 and 0.82 to 0.90, respectively). The median reading time for the three readers and AI was 212 (IQR 197 to 230), 131 (IQR 126 to 147), 734 (IQR 690 to 786), and 41 (IQR 38 to 44) seconds, respectively. Conclusion. This study showed that AI-based software demonstrated reliable radiological assessment of patients with HD with significant interpretation-related time savings. Cite this article: Bone Jt Open 2022;3(11):877–884

Aims

The primary aim of this study was to determine the ten-year outcome following surgical treatment for femoroacetabular impingement (FAI). We assessed whether the evolution of practice from open to arthroscopic techniques influenced outcomes and tested whether any patient, radiological, or surgical factors were associated with outcome.

Aims

The aims of this study were to characterize the incidence and risk factors associated with stress fractures following periacetabular osteotomy, and to determine their effect on osteotomy union.

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.

Aims

The frequency of severe femoral retroversion is unclear in patients with femoroacetabular impingement (FAI). This study aimed to investigate mean femoral version (FV), the frequency of absolute femoral retroversion, and the combination of decreased FV and acetabular retroversion (AR) in symptomatic patients with FAI subtypes.

Aims

Although periacetabular osteotomies are widely used for the treatment of symptomatic dysplastic hips, long-term surgical outcomes and patient-reported outcome measures (PROMs) are still unclear. Accordingly, we assessed hip survival and PROMs at 20 years after transpositional osteotomy of the acetabulum (TOA).

Aims. The aim of this study was to compare outcomes of guided growth and varus osteotomy in treating Kalamchi type II avascular necrosis (AVN) after open reduction and Pemberton acetabuloplasty for developmental dysplasia of the hip (DDH). Methods. This retrospective study reviewed patients undergoing guided growth or varus osteotomy for Kalamchi type II AVN between September 2009 and January 2019. All children who had undergone open reduction and Pemberton acetabuloplasty for DDH with a minimum two-year follow-up were enrolled in the study. Demographic and radiological data, which included the head-shaft angle (HSA), neck-shaft angle (NSA), articulotrochanteric distance (ATD), Sharp angle (SA), and lateral centre-edge angle (LCEA) at baseline, two years, and at the extended follow-up, were compared. Revision rates were evaluated. Clinical outcomes using the Harris Hip Score were assessed two years postoperatively. Results. A total of 24 patients underwent guided growth and 19 underwent varus osteotomy, over a mean period of 3.3 years (95% confidence interval (CI) 2.8 to 3.8) and 5.2 years (95% CI 4.5 to 6.0), respectively. There were no differences in demographic and preoperative radiological data, except for a younger age at time of acetabuloplasty and larger ATD for the osteotomy group. The HSA did not differ at two years and the extended follow-up because of postoperative rebound in the osteotomy group. The NSA of the osteotomy group remained smaller postoperatively. There were no significant differences in the follow-up ATD, SA, and LCEA, except for a smaller two-year ATD of the osteotomy group. Seven patients (29.2%) in the guided growth group underwent revision surgery and none in the osteotomy group. The Harris Hip Score was similar between groups. Conclusion. Guided growth and varus osteotomy had comparable results in improving caput valgum deformity, given the rebound of lateral tilting of the physis after osteotomy correction. There were no differences in clinical outcomes at two years postoperatively. Cite this article: Bone Joint J 2022;104-B(7):902–908

Aims. Acetabular retroversion is a recognized cause of hip impingement and can be influenced by pelvic tilt (PT), which changes in different functional positions. Positional changes in PT have not previously been studied in patients with acetabular retroversion. Methods. Supine and standing anteroposterior (AP) pelvic radiographs were retrospectively analyzed in 69 patients treated for symptomatic acetabular retroversion. Measurements were made for acetabular index (AI), lateral centre-edge angle (LCEA), crossover index, ischial spine sign, and posterior wall sign. The change in the angle of PT was measured both by the sacro-femoral-pubic (SFP) angle and the pubic symphysis to sacroiliac (PS-SI) index. Results. In the supine position, the mean PT (by SFP) was 1.05° (SD 3.77°), which changed on standing to a PT of 8.64° (SD 5.34°). A significant increase in posterior PT from supine to standing of 7.59° (SD 4.5°; SFP angle) and 5.89° (SD 3.33°; PS-SI index) was calculated (p < 0.001). There was a good correlation in PT change between measurements using SFP angle and PS-SI index (0.901 in the preoperative group and 0.815 in the postoperative group). Signs of retroversion were significantly reduced in standing radiographs compared to supine: crossover index (0.16 (SD 0.16) vs 0.38 (SD 0.15); p < 0.001), crossover sign (19/28 hips vs 28/28 hips; p < 0.001), ischial spine sign (10/28 hips vs 26/28 hips; p < 0.001), and posterior wall sign (12/28 hips vs 24/28 hips; p < 0.001). Conclusion. Posterior PT increased from supine to standing in patients with symptomatic acetabular retroversion. The features of acetabular retroversion were less evident on standing radiographs. The low PT angle in the supine position is a factor in the increased appearance of acetabular retroversion. Patients presenting with symptoms of hip impingement should be assessed by supine and standing pelvic radiographs to highlight signs of acetabular retroversion, and to assist with optimizing acetabular correction at the time of surgery. Cite this article: Bone Joint J 2022;104-B(7):786–791

Aims

Developmental dysplasia of the hip (DDH) describes a pathological relationship between the femoral head and acetabulum. Periacetabular osteotomy (PAO) may be used to treat this condition. The aim of this study was to evaluate the results of PAO in adolescents and adults with persistent DDH.

Aims. The lateral centre-edge angle (LCEA) is a plain radiological measure of superolateral cover of the femoral head. This study aims to establish the correlation between 2D radiological and 3D CT measurements of acetabular morphology, and to describe the relationship between LCEA and femoral head cover (FHC). Methods. This retrospective study included 353 periacetabular osteotomies (PAOs) performed between January 2014 and December 2017. Overall, 97 hips in 75 patients had 3D analysis by Clinical Graphics, giving measurements for LCEA, acetabular index (AI), and FHC. Roentgenographical LCEA, AI, posterior wall index (PWI), and anterior wall index (AWI) were measured from supine AP pelvis radiographs. The correlation between CT and roentgenographical measurements was calculated. Sequential multiple linear regression was performed to determine the relationship between roentgenographical measurements and CT FHC. Results. CT-measured LCEA and AI correlated strongly with roentgenographical LCEA (r = 0.92; p < 0.001) and AI (r = 0.83; p < 0.001). Radiological LCEA correlated very strongly with CT FHC (r = 0.92; p < 0.001). The sum of AWI and PWI also correlated strongly with CTFHC (r = 0.73; p < 0.001). CT measurements of LCEA and AI were 3.4° less and 2.3° greater than radiological LCEA and AI measures. There was a linear relation between radiological LCEA and CT FHC. The linear regression model statistically significantly predicted FHC from LCEA, F(1,96) = 545.1 (p < 0.001), adjusted R. 2. = 85.0%, with the prediction equation: CT FHC(%) = 42.1 + 0.77(XRLCEA). Conclusion. CT and roentgenographical measurement of acetabular parameters are comparable. Currently, a radiological LCEA greater than 25° is considered normal. This study demonstrates that those with hip pain and normal radiological acetabular parameters may still have deficiencies in FHC. More sophisticated imaging techniques such as 3D CT should be considered for those with hip pain to identify deficiencies in FHC. Cite this article: Bone Jt Open 2022;3(1):12–19

Aims

The aim of this study was to determine the association between knee alignment and the vertical orientation of the femoral neck in relation to the floor. This could be clinically important because changes of femoral neck orientation might alter chondral joint contact zones and joint reaction forces, potentially inducing problems like pain in pre-existing chondral degeneration. Further, the femoral neck orientation influences the ischiofemoral space and a small ischiofemoral distance can lead to impingement. We hypothesized that a valgus knee alignment is associated with a more vertical orientation of the femoral neck in standing position, compared to a varus knee. We further hypothesized that realignment surgery around the knee alters the vertical orientation of the femoral neck.

Aims. The aims of this study were to compare clinically relevant measurements of hip dysplasia on radiographs taken in the supine and standing position, and to compare Hip2Norm software and Picture Archiving and Communication System (PACS)-derived digital radiological measurements. Methods. Preoperative supine and standing radiographs of 36 consecutive patients (43 hips) who underwent periacetabular osteotomy surgery were retrospectively analyzed from a single-centre, two-surgeon cohort. Anterior coverage (AC), posterior coverage (PC), lateral centre-edge angle (LCEA), acetabular inclination (AI), sharp angle (SA), pelvic tilt (PT), retroversion index (RI), femoroepiphyseal acetabular roof (FEAR) index, femoroepiphyseal horizontal angle (FEHA), leg length discrepancy (LLD), and pelvic obliquity (PO) were analyzed using both Hip2Norm software and PACS-derived measurements where applicable. Results. Analysis of supine and standing radiographs resulted in significant variation for measurements of PT (p < 0.001) and AC (p = 0.005). The variation in PT correlated with the variation in AC in a limited number of patients (R. 2. = 0.378; p = 0.012). Conclusion. The significant variation in PT and AC between supine and standing radiographs suggests that it may benefit surgeons to have both radiographs when planning surgical correction of hip dysplasia. We also recommend using PACS-derived measurements of AI and SA due to the poor interobserver error on Hip2Norm. Cite this article: Bone Joint J 2021;103-B(11):1662–1668

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).

Aims

We aimed to evaluate the long-term outcome of highly cross-linked polyethylene (HXLPE) cemented acetabular components and assess whether any radiolucent lines (RLLs) which arose were progressive.

Aims. Periacetabular osteotomy (PAO) is an established treatment for acetabular dysplasia. It has also been proposed as a treatment for patients with acetabular retroversion. By reviewing a large cohort, we aimed to test whether outcome is equivalent for both types of morphology and identify factors that influenced outcome. Methods. A single-centre, retrospective cohort study was performed on patients with acetabular retroversion treated with PAO (n = 62 hips). Acetabular retroversion was diagnosed clinically and radiologically (presence of a crossover sign, posterior wall sign, lateral centre-edge angle (LCEA) between 20° and 35°). Outcomes were compared with a control group of patients undergoing PAO for dysplasia (LCEA < 20°; n = 86 hips). Femoral version was recorded. Patient-reported outcome measures (PROMs), complications, and reoperation rates were measured. Results. The mean Non-Arthritic Hip Score (NAHS) preoperatively was 58.6 (SD 16.1) for the dysplastic hips and 52.5 (SD 12.7) for the retroverted hips (p = 0.145). Postoperatively, mean NAHS was 83.0 (SD 16.9) and 76.7 (SD 17.9) for dysplastic and retroverted hips respectively (p = 0.041). Difference between pre- and postoperative NAHS was slightly lower in the retroverted hips (18.3 (SD 22.1)) compared to the dysplastic hips (25.2 (SD 15.2); p = 0.230). At mean 3.5 years’ follow-up (SD 1.9), one hip needed a revision PAO and no hips were converted to total hip arthroplasty (THA) in the retroversion group. In the control group, six hips (7.0%) were revised to THA. No differences in complications (p = 0.106) or in reoperation rate (p = 0.087) were seen. Negative predictors of outcome for patients undergoing surgery for retroversion were female sex, obesity, hypermobility, and severely decreased femoral anteversion. Conclusion. A PAO is an effective surgical intervention for acetabular retroversion and produces similar improvements when used to treat dysplasia. Femoral version should be routinely assessed in these patients and when extremely low (< 0°), as an additional procedure to address this abnormality may be necessary. Females with signs of hypermobility should also be consulted of the likely guarded improvement. Cite this article: Bone Jt Open 2021;2(9):757–764

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.

Aims

Adverse local tissue reactions associated with abnormal wear considerably slowed down the general use of metal-on-metal (MoM) hip resurfacing arthroplasty (HRA), now limited to a few specialized centres. In this study, we provide the clinical results of 400 consecutive MoM HRAs implanted more than 20 years ago in one such centre.

Aims

Injury to the lateral femoral cutaneous nerve (LFCN) is one of the known complications after periacetabular osteotomy (PAO) performed using the anterior approach, reported to occur in between 1.5% and 65% of cases. In this study, we performed a prospective study on the incidence of LFCN injury as well as its clinical outcomes based on the Harris Hip Score (HHS), Short-Form 36 Health Survey (SF-36), and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ).

Aims

The prevalence of combined abnormalities of femoral torsion (FT) and tibial torsion (TT) is unknown in patients with femoroacetabular impingement (FAI) and hip dysplasia. This study aimed to determine the prevalence of combined abnormalities of FT and TT, and which subgroups are associated with combined abnormalities of FT and TT.

As our understanding of hip function and disease improves, it is evident that the acetabular fossa has received little attention, despite it comprising over half of the acetabulum’s surface area and showing the first signs of degeneration. The fossa’s function is expected to be more than augmenting static stability with the ligamentum teres and being a templating landmark in arthroplasty. Indeed, the fossa, which is almost mature at 16 weeks of intrauterine development, plays a key role in hip development, enabling its nutrition through vascularization and synovial fluid, as well as the influx of chondrogenic stem/progenitor cells that build articular cartilage. The pulvinar, a fibrofatty tissue in the fossa, has the same developmental origin as the synovium and articular cartilage and is a biologically active area. Its unique anatomy allows for homogeneous distribution of the axial loads into the joint. It is composed of intra-articular adipose tissue (IAAT), which has adipocytes, fibroblasts, leucocytes, and abundant mast cells, which participate in the inflammatory cascade after an insult to the joint. Hence, the fossa and pulvinar should be considered in decision-making and surgical outcomes in hip preservation surgery, not only for their size, shape, and extent, but also for their biological capacity as a source of cytokines, immune cells, and chondrogenic stem cells.

Cite this article: Bone Joint Res 2020;9(12):857–869.

Aims

Morphological abnormalities are present in patients with developmental dysplasia of the hip (DDH). We studied and compared the pelvic anatomy and morphology between the affected hemipelvis with the unaffected side in patients with unilateral Crowe type IV DDH using 3D imaging and analysis.

Aims

Femoroacetabular impingement (FAI) describes abnormal bony contact of the proximal femur against the acetabulum. The term was first coined in 1999; however what is often overlooked is that descriptions of the morphology have existed in the literature for centuries. The aim of this paper is to delineate its origins and provide further clarity on FAI to shape future research.

Aims

This paper aims to review the evidence for patient-related factors associated with less favourable outcomes following hip arthroscopy.

Aims

When the present study was initiated, we changed the treatment for late-detected developmental dislocation of the hip (DDH) from several weeks of skin traction to markedly shorter traction time. The aim of this prospective study was to evaluate this change, with special emphasis on the rate of stable closed reduction according to patient age, the development of the acetabulum, and the outcome at skeletal maturity.

Aims

A borderline dysplastic hip can behave as either stable or unstable and this makes surgical decision making challenging. While an unstable hip may be best treated by acetabular reorientation, stable hips can be treated arthroscopically. Several imaging parameters can help to identify the appropriate treatment, including the Femoro-Epiphyseal Acetabular Roof (FEAR) index, measured on plain radiographs. The aim of this study was to assess the reliability and the sensitivity of FEAR index on MRI compared with its radiological measurement.

Aims. Rotational acetabular osteotomy (RAO) is an effective joint-preserving surgical treatment for acetabular dysplasia. The purpose of this study was to investigate changes in muscle strength, gait speed, and clinical outcome in the operated hip after RAO over a one-year period using a standard protocol for rehabilitation. Patients and Methods. A total of 57 patients underwent RAO for acetabular dysplasia. Changes in muscle strength of the operated hip, 10 m gait speed, Japanese Orthopaedic Association (JOA) hip score, and factors correlated with hip muscle strength after RAO were retrospectively analyzed. Results. Three months postoperatively, the strength of the operated hip in flexion and abduction and gait speed had decreased from their preoperative levels. After six months, the strength of flexion and abduction had recovered to their preoperative level, as had gait speed. At one-year follow-up, significant improvements were seen in the strength of hip abduction and gait speed, but muscle strength in hip flexion remained at the preoperative level. The mean JOA score for hip function was 91.4 (51 to 100)) at one-year follow-up. Body mass index (BMI) showed a negative correlation with both strength of hip flexion (r = -0.4203) and abduction (r = -0.4589) one year after RAO. Although weak negative correlations were detected between strength of hip flexion one year after surgery and age (r = -0.2755) and centre-edge (CE) angle (r = -0.2989), no correlation was found between the strength of abduction and age and radiological evaluations of CE angle and acetabular roof obliquity (ARO). Conclusion. Hip muscle strength and gait speed had recovered to their preoperative levels six months after RAO. The clinical outcome at one year was excellent, although the strength of hip flexion did not improve to the same degree as that of hip abduction and gait speed. A higher BMI may result in poorer recovery of hip muscle strength after RAO. Radiologically, acetabular coverage did not affect the recovery of hip muscle strength at one year’s follow-up. A more intensive rehabilitation programme may improve this. Cite this article: Bone Joint J 2019;101-B:1459–1463

Aims

Abnormal femoral torsion (FT) is increasingly recognized as an additional cause for femoroacetabular impingement (FAI). It is unknown if in-toeing of the foot is a specific diagnostic sign for increased FT in patients with symptomatic FAI. The aims of this study were to determine: 1) the prevalence and diagnostic accuracy of in-toeing to detect increased FT; 2) if foot progression angle (FPA) and tibial torsion (TT) are different among patients with abnormal FT; and 3) if FPA correlates with FT.

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.

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.

Aims. The aim of this study was to compare patient-reported outcome measures (PROMs), radiological measurements, and total hip arthroplasty (THA)-free survival in patients who underwent periacetabular osteotomy (PAO) for mild, moderate, or severe developmental dysplasia of the hip. Patients and Methods. We performed a retrospective study involving 336 patients (420 hips) who underwent PAO by a single surgeon at an academic centre. After exclusions, 124 patients (149 hips) were included. The preoperative lateral centre-edge angle (LCEA) was used to classify the severity of dysplasia: 18° to 25° was considered mild (n = 20), 10° to 17° moderate (n = 66), and < 10° severe (n = 63). There was no difference in patient characteristics between the groups (all, p > 0.05). Pre- and postoperative radiological measurements were made. The National Institute of Health’s Patient Reported Outcomes Measurement Information System (PROMIS) outcome measures (physical function computerized adaptive test (PF CAT), Global Physical and Mental Health Scores) were collected. Failure was defined as conversion to THA or PF CAT scores < 40, and was assessed with Kaplan–Meier analysis. The mean follow-up was five years (2 to 10) ending in either failure or the latest contact with the patient. Results. There was no significant difference in PROMs for moderate (p = 0.167) or severe (p = 0.708) groups compared with the mild dysplasia group. The numerical pain scores were between 2 and 3 units in all groups at the final follow-up (all, p > 0.05). There was no significant difference (all, p > 0.05) in the proportion of patients achieving target correction for the LCEA between groups. The mean correction was 12° in the mild, 15° in the moderate (p = 0.135), and 23° in the severe group (p < 0.001). Failure-free survival at five years was 100% for mild, 79% for moderate, and 92% for severely dysplastic hips (p = 0.225). Conclusion. Although requiring less correction than hips with moderate or severe dysplasia, we found PAO for mild dysplasia to be associated with promising PROMs, consistent with that of the general United States population, and excellent survivorship at five years. Future studies should compare these results with the outcome after arthroscopy of the hip in patients with mild dysplasia. Cite this article: Bone Joint J 2019;101-B(6 Supple B):16–22

Aims. The aim of this study was to report the long-term results of rotational acetabular osteotomy (RAO) for symptomatic hip dysplasia in patients aged younger than 21 years at the time of surgery. Patients and Methods. We evaluated 31 patients (37 hips) aged younger than 21 years at the time of surgery retrospectively. There were 29 female and two male patients. Their mean age at the time of surgery was 17.4 years (12 to 21). The mean follow-up was 17.9 years (7 to 30). The RAO was combined with a varus or valgus femoral osteotomy or a greater trochanteric displacement in eight hips, as instability or congruence of the hip could not be corrected adequately using RAO alone. Results. The mean Merle d’Aubigné clinical score improved significantly from 15.4 to 17.2 (p < 0.0001). The mean centre-edge (CE) angle improved from -2.6° to 26°, the mean acetabular roof angle improved from 3.0° to 5.2°, and the mean head lateralization index improved from 0.68 to 0.62. Progression of radiological osteoarthritis (OA) was seen in seven hips, but no patient underwent total hip arthroplasty. Conclusion. RAO is an effective form of correction for a severely dysplastic hip in adolescent and young adult patients. Cite this article: Bone Joint J 2019;101-B:390–395

Aims

The hip’s capsular ligaments passively restrain extreme range of movement (ROM) by wrapping around the native femoral head/neck. We determined the effect of hip resurfacing arthroplasty (HRA), dual-mobility total hip arthroplasty (DM-THA), conventional THA, and surgical approach on ligament function.

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.

Aims

We analyzed the acetabular morphology of Crowe type IV hips using CT data to identify a landmark for the ideal placement of the centre of the acetabular component, as assessed by morphometric geometrical analysis, and its reliability.

Aims

What represents clinically significant acetabular undercoverage in patients with symptomatic cam-type femoroacetabular impingement (FAI) remains controversial. The aim of this study was to examine the influence of the degree of acetabular coverage on the functional outcome of patients treated arthroscopically for cam-type FAI.

The mucopolysaccharidoses (MPS) are a group of inherited lysosomal storage disorders with clinical manifestations relevant to the orthopaedic surgeon. Our aim was to review the recent advances in their management and the implications for surgical practice.

The current literature about MPSs is summarised, emphasising orthopaedic complications and their management.

Recent advances in the diagnosis and management of MPSs include the recognition of slowly progressive, late presenting subtypes, developments in life-prolonging systemic treatment and potentially new indications for surgical treatment. The outcomes of surgery in these patients are not yet validated and some procedures have a high rate of complications which differ from those in patients who do not have a MPS.

The diagnosis of a MPS should be considered in adolescents or young adults with a previously unrecognised dysplasia of the hip. Surgeons treating patients with a MPS should report their experience and studies should include the assessment of function and quality of life to guide treatment.

Cite this article: Bone Joint J 2017;99-B:1132–9

Aims

To assess the long-term effect of distal trochanteric transfer (DTT) on the clinical and radiographic outcomes of patients with Legg-Calvé-Perthes’ disease (LCPD) following a varus derotational osteotomy (VDRO).

Objectives. We have previously investigated an association between the genome copy number variation (CNV) and acetabular dysplasia (AD). Hip osteoarthritis is associated with a genetic polymorphism in the aspartic acid repeat in the N-terminal region of the asporin (ASPN) gene; therefore, the present study aimed to investigate whether the CNV of ASPN is involved in the pathogenesis of AD. Methods. Acetabular coverage of all subjects was evaluated using radiological findings (Sharp angle, centre-edge (CE) angle, acetabular roof obliquity (ARO) angle, and minimum joint space width). Genomic DNA was extracted from peripheral blood leukocytes. Agilent’s region-targeted high-density oligonucleotide tiling microarray was used to analyse 64 female AD patients and 32 female control subjects. All statistical analyses were performed using EZR software (Fisher’s exact probability test, Pearson’s correlation test, and Student’s t-test). Results. CNV analysis of the ASPN gene revealed a copy number loss in significantly more AD patients (9/64) than control subjects (0/32; p = 0.0212). This loss occurred within a 60 kb region on 9q22.31, which harbours the gene for ASPN. The mean radiological parameters of these AD patients were significantly worse than those of the other subjects (Sharp angle, p = 0.0056; CE angle, p = 0.0076; ARO angle, p = 0.0065), and all nine patients required operative therapy such as total hip arthroplasty or pelvic osteotomy. Moreover, six of these nine patients had a history of operative or conservative therapy for developmental dysplasia of the hip. Conclusions. Copy number loss within the region harbouring the ASPN gene on 9q22.31 is associated with severe AD. A copy number loss in the ASPN gene region may play a role in the aetiology of severe AD. Cite this article: T. Sekimoto, M. Ishii, M. Emi, S. Kurogi, T. Funamoto, Y. Yonezawa, T. Tajima, T. Sakamoto, H. Hamada, E. Chosa. Copy number loss in the region of the ASPN gene in patients with acetabular dysplasia: ASPN CNV in acetabular dysplasia. Bone Joint Res 2017;6:439–445. DOI: 10.1302/2046-3758.67.BJR-2016-0094.R1

Aims. The purpose of this study was to evaluate whether an innovative templating technique could predict the need for acetabular augmentation during primary total hip arthroplasty for patients with dysplastic hips. Patients and Methods. We developed a simple templating technique to estimate acetabular component coverage at total hip arthroplasty, the True Cup: False Cup (TC:FC) ratio. We reviewed all patients with dysplastic hips who underwent primary total hip arthroplasty between 2005 and 2012. Traditional radiological methods of assessing the degree of acetabular dysplasia (Sharp’s angle, Tönnis angle, centre-edge angle) as well as the TC:FC ratio were measured from the pre-operative radiographs. A comparison of augmented and non-augmented hips was undertaken to determine any difference in pre-operative radiological indices between the two cohorts. The intra- and inter-observer reliability for all radiological indices used in the study were also calculated. Results. Of the 128 cases reviewed, 33 (26%) needed acetabular augmentation. We found no difference in the median Sharp’s angle (p = 0.10), Tönnis angle (p = 0.28), or centre-edge angle (p = 0.07) between the two groups. A lower TC:FC ratio was observed in the augmented group compared with the non-augmented group (median = 0.66 versus 0.88, p <  0.001). Intra-observer reliability was found to be high for all radiological indices analysed (interclass correlation coefficient (ICC) > 0.7). However, inter-observer reliability was more variable and was only high for the TC: FC ratio (ICC > 0.7). Conclusion. The TC: FC ratio gives an accurate estimate of acetabular component coverage. It can help predict which dysplastic hips are likely to need acetabular augmentation at primary total hip arthroplasty. It has high intra- and inter-observer reliability. Cite this article: Bone Joint J 2017;99-B:445–50

Aims

Joint-preserving surgery of the hip (JPSH) has evolved considerably and now includes a number of procedures, including arthroscopy, surgical dislocation, and redirectional osteotomies of the femur and acetabulum. There are a number of different factors which lead to failure of JPSH. Consequently, it is of interest to assess the various modes of failure in order to continue to identify best practice and the indications for these procedures.

Objectives

Bisphosphonates are widely used as first-line treatment for primary and secondary prevention of fragility fractures. Whilst they have proved effective in this role, there is growing concern over their long-term use, with much evidence linking bisphosphonate-related suppression of bone remodelling to an increased risk of atypical subtrochanteric fractures of the femur (AFFs). The objective of this article is to review this evidence, while presenting the current available strategies for the management of AFFs.

Nerve palsy is a well-described complication following total hip arthroplasty, but is highly distressing and disabling. A nerve palsy may cause difficulty with the post-operative rehabilitation, and overall mobility of the patient. Nerve palsy may result from compression and tension to the affected nerve(s) during the course of the operation via surgical manipulation and retractor placement, tension from limb lengthening or compression from post-operative hematoma. In the literature, hip dysplasia, lengthening of the leg, the use of an uncemented femoral component, and female gender are associated with a greater risk of nerve palsy. We examined our experience at a high-volume, tertiary care referral centre, and found an overall incidence of 0.3% out of 39 056 primary hip arthroplasties. Risk factors found to be associated with the incidence of nerve palsy at our institution included the presence of spinal stenosis or lumbar disc disease, age younger than 50, and smoking. If a nerve palsy is diagnosed, imaging is mandatory and surgical evacuation or compressive haematomas may be beneficial. As palsies are slow to recover, supportive care such as bracing, therapy, and reassurance are the mainstays of treatment.

Cite this article: Bone Joint J 2017;99-B(1 Supple A):46–9.

Aims. Periacetabular osteotomy is an effective way of treating symptomatic hip dysplasia. We describe a new minimally invasive technique using a modification of the Smith-Peterson approach. We performed a prospective, longitudinal cohort study to assess for any compromise in acetabular correction when using this approach, and to see if the procedure would have a higher complication rate than that quoted in the literature for other approaches. We also assessed for any improvement in functional outcome. Patients and Methods. From 168 consecutive patients (189 hips) who underwent acetabular correction between March 2010 and March 2013 we excluded those who had undergone previous pelvic surgery for DDH and those being treated for acetabular retroversion. The remaining 151 patients (15 men, 136 women) (166 hips) had a mean age of 32 years (15 to 56) and the mean duration of follow-up was 2.8 years (1.2 to 4.5). In all 90% of cases were Tönnis grade 0 or 1. Functional outcomes were assessed using the Non Arthritic Hip Score (NAHS), University of California, Los Angeles (UCLA) and Tegner activity scores. Results. The mean pre-operative lateral centre-edge angle was 14.2° (-5° to 30°) and the mean acetabular index was 18.4° (4° to 40°). Post-operatively these were 31° (18° to 46°) and 3° (-7° to 29°), respectively, a significant improvement in both (p < 0.001). Allogenic blood transfusion was required in two patients (1.2%). There were no major nerve or vascular complications, and no wound infections. At the time of last follow-up, we noted a significant improvement in functional outcome scores: UCLA improved by 2.31 points, Tegner improved by 1.08 points, and the NAHS improved by 25.4 points (p < 0.001 for each). Hypermobility and longer duration of surgery were significant negative predictors for a good post-operative UCLA score, while residual retroversion was a positive predictor of post-operative UCLA score. Conclusion. We have found this approach to be safe and effective, facilitating early recovery from surgery. Cite this article: Bone Joint J 2017;99-B:22–8

Aims

The influence of identifiable pre-operative factors on the outcome of eccentric rotational acetabular osteotomy (ERAO) is unknown. We aimed to determine the factors that might influence the outcome, in order to develop a scoring system for predicting the prognosis for patients undergoing this procedure.

Aims

Acetabular dysplasia is frequently associated with intra-articular pathology such as labral tears, but whether labral tears should be treated at the time of periacetabular osteotomy (PAO) remains controversial. The purpose of this study was to compare the clinical outcomes and radiographic corrections of PAO for acetabular dysplasia between patients with and without labral tears pre-operatively.

The December 2015 Hip & Pelvis Roundup³⁶⁰ looks at: Vitamin E infusion helpful in polyethylene; Hip replacement in fracture and arthritis; Non-surgical treatment for arthritis; Cost and approach in hip surgery; Who does well in FAI surgery?; AAOS Thromboembolism guidelines; Thromboprophylaxis and periprosthetic joint infection; Fluid collections not limited to metal-on-metal THR

The purpose of this study was to determine patient-reported outcomes of patients with mild to moderate developmental dysplasia of the hip (DDH) and femoroacetabular impingement (FAI) undergoing arthroscopy of the hip in the treatment of chondrolabral pathology. A total of 28 patients with a centre-edge angle between 15° and 19° were identified from an institutional database. Their mean age was 34 years (18 to 53), with 12 female and 16 male patients. All underwent labral treatment and concomitant correction of FAI. There were nine reoperations, with two patients requiring revision arthroscopy, two requiring periacetabular osteotomy and five needing total hip arthroplasty. Patients who required further major surgery were more likely to be older, male, and to have more severe DDH with a larger alpha angle and decreased joint space. . At a mean follow-up of 42 months (24 to 89), the mean modified Harris hip score improved from 59 (20 to 98) to 82 (45 to 100; p < 0.001). The mean Western Ontario and McMaster Universities Osteoarthritis Index score improved from 30 (1 to 61) to 16 (0 to 43; p < 0.001). Median patient satisfaction was 9.0/10 (1 to 10). Patients reported excellent improvement in function following arthroscopy of the hip. This study shows that with proper patient selection, arthroscopy of the hip can be successful in the young patient with mild to moderate DDH and FAI. . Cite this article: Bone Joint J 2015;97-B:1316–21

The October 2015 Hip & Pelvis Roundup³⁶⁰ looks at: Smoking and complications in arthroplasty; Smoking cessation beneficial in arthroplasty; Intermediate care and arthroplasty; Do we still need cell salvage?; Femoroacetabular impingement in the Japanese population; Trunnionosis or taperosis and geometry; Decontamination for staphylococcus aureus works!; Policeman or opportunity? Quality improvement with registries; Death rates higher in readmission to other hospitals

In this study we used subject-specific finite element analysis to investigate the mechanical effects of rotational acetabular osteotomy (RAO) on the hip joint and analysed the correlation between various radiological measurements and mechanical stress in the hip joint.

We evaluated 13 hips in 12 patients (two men and ten women, mean age at surgery 32.0 years; 19 to 46) with developmental dysplasia of the hip (DDH) who were treated by RAO.

Subject-specific finite element models were constructed from CT data. The centre–edge (CE) angle, acetabular head index (AHI), acetabular angle and acetabular roof angle (ARA) were measured on anteroposterior pelvic radiographs taken before and after RAO. The relationship between equivalent stress in the hip joint and radiological measurements was analysed.

The equivalent stress in the acetabulum decreased from 4.1 MPa (2.7 to 6.5) pre-operatively to 2.8 MPa (1.8 to 3.6) post-operatively (p < 0.01). There was a moderate correlation between equivalent stress in the acetabulum and the radiological measurements: CE angle (R = –0.645, p < 0.01); AHI (R = –0.603, p < 0.01); acetabular angle (R = 0.484, p = 0.02); and ARA (R = 0.572, p < 0.01).

The equivalent stress in the acetabulum of patients with DDH decreased after RAO. Correction of the CE angle, AHI and ARA was considered to be important in reducing the mechanical stress in the hip joint.

Cite this article: Bone Joint J 2015;97-B:492–7.

Obesity is a risk factor for complications following many orthopaedic procedures. The purpose of this study was to investigate whether obesity was an independent risk factor increasing the rate of complications following periacetabular osteotomy (PAO) and to determine whether radiographic correction after PAO was affected by obesity.

We retrospectively collected demographic, clinical and radiographic data on 280 patients (231 women; 82.5% and 49 men; 17.5%) who were followed for a mean of 48 months (12 to 60) after PAO. A total of 65 patients (23.2%) were obese (body mass index (BMI) > 30 kg/m²). Univariate and multivariate analysis demonstrated that BMI was an independent risk factor associated with the severity of the complications. The average probability of a patient developing a major complication was 22% (95% confidence interval (CI) 11.78 to 38.21) for an obese patient compared with 3% (95% CI 1.39 to 6.58) for a non-obese patient The odds of a patient developing a major complication were 11 times higher (95% CI 4.71 to 17.60, p <  0.0001) for an obese compared with a non-obese patient.

Following PAO surgery, there was no difference in radiographic correction between obese and non-obese patients. PAO procedures in obese patients correct the deformity effectively but are associated with an increased rate of complications.

Cite this article: Bone Joint J 2015;97-B:29–34.

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.

The aim of this study was to investigate the incidence of dysplasia in the ‘normal’ contralateral hip in patients with unilateral developmental dislocation of the hip (DDH) and to evaluate the long-term prognosis of such hips. A total of 48 patients (40 girls and eight boys) were treated for late-detected unilateral DDH between 1958 and 1962. After preliminary skin traction, closed reduction was achieved at a mean age of 17.8 months (4 to 65) in all except one patient who needed open reduction. In 25 patients early derotation femoral osteotomy of the contralateral hip had been undertaken within three years of reduction, and later surgery in ten patients. Radiographs taken during childhood and adulthood were reviewed. The mean age of the patients was 50.9 years (43 to 55) at the time of the latest radiological review. In all, eight patients (17%) developed dysplasia of the contralateral hip, defined as a centre-edge (CE) angle < 20° during childhood or at skeletal maturity. Six of these patients underwent surgery to improve cover of the femoral head; the dysplasia improved in two after varus femoral osteotomy and in two after an acetabular shelf operation. During long-term follow-up the dysplasia deteriorated to subluxation in two patients (CE angles 4° and 5°, respectively) who both developed osteoarthritis (OA), and one of these underwent total hip replacement at the age of 49 years. In conclusion, the long-term prognosis for the contralateral hip was relatively good, as OA occurred in only two hips (4%) at a mean follow-up of 50 years. Regular review of the ‘normal’ side is indicated, and corrective surgery should be undertaken in those who develop subluxation. Cite this article: Bone Joint J 2014; 96-B:1161–6

The June 2014 Children’s orthopaedics Roundup³⁶⁰ looks at: plaster wedging in paediatric forearm fractures; the medial approach for DDH; Ponseti – but not as he knew it?; Salter osteotomy more accurate than Pemberton in DDH; is the open paediatric fracture an emergency?; bang up-to-date with femoral external fixation; indomethacin, heterotopic ossification and cerebral palsy hips; lengthening nails for congenital femoral deformities, and is MRI the answer to imaging of the physis?

To confirm whether developmental dysplasia of the hip has a risk of hip impingement, we analysed maximum ranges of movement to the point of bony impingement, and impingement location using three-dimensional (3D) surface models of the pelvis and femur in combination with 3D morphology of the hip joint using computer-assisted methods. Results of computed tomography were examined for 52 hip joints with DDH and 73 normal healthy hip joints. DDH shows larger maximum extension (p = 0.001) and internal rotation at 90° flexion (p < 0.001). Similar maximum flexion (p = 0.835) and external rotation (p = 0.713) were observed between groups, while high rates of extra-articular impingement were noticed in these directions in DDH (p < 0.001). Smaller cranial acetabular anteversion (p = 0.048), centre-edge angles (p < 0.001), a circumferentially shallower acetabulum, larger femoral neck anteversion (p < 0.001), and larger alpha angle were identified in DDH. Risk of anterior impingement in retroverted DDH hips is similar to that in retroverted normal hips in excessive adduction but minimal in less adduction. These findings might be borne in mind when considering the possibility of extra-articular posterior impingement in DDH being a source of pain, particularly for patients with a highly anteverted femoral neck.

Cite this article: Bone Joint J 2014;96-B:580–9.

The medial approach for the treatment of children with developmental dysplasia of the hip (DDH) in whom closed reduction has failed requires minimal access with negligible blood loss. In the United Kingdom, there is a preference for these children to be treated using an anterolateral approach after the appearance of the ossific nucleus. In this study we compared these two protocols, primarily for the risk of osteonecrosis.

Data were gathered prospectively for protocols involving the medial approach (26 hips in 22 children) and the anterolateral approach (22 hips in 21 children) in children aged <  24 months at the time of surgery. Osteonecrosis of the femoral head was assessed with validated scores. The acetabular index (AI) and centre–edge angle (CEA) were also measured.

The mean age of the children at the time of surgery was 11 months (3 to 24) for the medial approach group and 18 months (12 to 24) for the anterolateral group, and the combined mean follow-up was 70 months (26 to 228). Osteonecrosis of the femoral head was evident or asphericity predicted in three of 26 hips (12%) in the medial approach group and four of 22 (18%) in the anterolateral group (p = 0.52). The mean improvement in AI was 8.8° (4° to 12°) and 7.9° (6° to 10°), respectively, at two years post-operatively (p = 0.18). There was no significant difference in CEA values of affected hips between the two groups.

Children treated using an early medial approach did not have a higher risk of developing osteonecrosis at early to mid-term follow-up than those treated using a delayed anterolateral approach. The rates of acetabular remodelling were similar for both protocols.

Cite this article: Bone Joint J 2014;96-B:406–13.

Orthopaedic surgeons have accepted various radiological signs to be representative of acetabular retroversion, which is the main characteristic of focal over-coverage in patients with femoroacetabular impingement (FAI). Using a validated method for radiological analysis, we assessed the relevance of these signs to predict intra-articular lesions in 93 patients undergoing surgery for FAI. A logistic regression model to predict chondral damage showed that an acetabular retroversion index (ARI) > 20%, a derivative of the well-known cross-over sign, was an independent predictor (p = 0.036). However, ARI was less significant than the Tönnis classification (p = 0.019) and age (p = 0.031) in the same model. ARI was unable to discriminate between grades of chondral lesions, while the type of cam lesion (p = 0.004) and age (p = 0.047) were able to. Other widely recognised signs of acetabular retroversion, such as the ischial spine sign, the posterior wall sign or the cross-over sign were irrelevant according to our analysis. Regardless of its secondary predictive role, an ARI > 20% appears to be the most clinically relevant radiological sign of acetabular retroversion in symptomatic patients with FAI.

Cite this article: Bone Joint J 2013;95-B:893–9.

The April 2013 Hip & Pelvis Roundup³⁶⁰ looks at: hip cartilage and magnets; labral repair or resection; who benefits from injection; rotational osteotomy for osteonecrosis; whether ceramic implants risk fracture; dual articulation; and hydroxyapatite.

The April 2013 Children’s orthopaedics Roundup³⁶⁰ looks at: improving stress distribution in dysplastic hips; the dangers of fashion; the natural history of supracondylar fractures; ankles that perform well as knees; intra-articular hip pathology at osteotomy; the safe removal of flexible nails; supracondylar fracture fixation; and talipes.

In Norway total joint replacement after hip dysplasia is reported more commonly than in neighbouring countries, implying a higher prevalence of the condition. We report on the prevalence of radiological features associated with hip dysplasia in a population of 2081 19-year-old Norwegians. The radiological measurements used to define hip dysplasia were Wiberg’s centre-edge (CE) angle at thresholds of < 20° and < 25°, femoral head extrusion index <  75%, Sharp’s angle > 45°, an acetabular depth to width ratio < 250 and the sourcil shape assessed subjectively. The whole cohort underwent clinical examination of their range of hip movement, body mass index (BMI), and Beighton hypermobility score, and were asked to complete the EuroQol (EQ-5D) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The prevalence of hip dysplasia in the cohort varied from 1.7% to 20% depending on the radiological marker used. A Wiberg’s CE angle <  20° was seen in 3.3% of the cohort: 4.3% in women and 2.4% in men. We found no association between subjects with multiple radiological signs indicative of dysplasia and BMI, Beighton score, EQ-5D or WOMAC. Although there appears to be a high prevalence of hip dysplasia among 19-year-old Norwegians, this is dependent on the radiological parameters applied. Cite this article: Bone Joint J 2013;95-B:279–85

The February 2013 Children’s orthopaedics Roundup³⁶⁰ looks at: ABC treated with suction and curettage; peri-acetabular osteotomy; cast index; Perthes’ disease associated with accidental injury; brachial plexus birth palsy; MRI assessment of DDH; total meniscectomy; and paediatric septic arthritis.

The purpose of this study was to investigate the development of the osseous acetabular index (OAI) and cartilaginous acetabular index (CAI) using MRI. The OAI and CAI were measured on the coronal MR images of the hip in 81 children with developmental dysplasia of the hip (DDH), with a mean age of 19.6 months (3 to 70), and 241 normal control children with a mean age of 5.1 years (1 month to 12.5 years). Additionally the developmental patterns of the OAI and CAI in normal children were determined by age-based cross-sectional analysis.

Unlike the OAI, the normal CAI decreased rapidly from a mean of 10.17° (sd 1.60) to a mean of 8.25° (sd 1.90) within the first two years of life, and then remained constant at a mean of 8.04° (sd 1.65) until adolescence. Although no difference in OAI was found between the uninvolved hips in children with unilateral DDH and normal hips (p = 0.639), the CAI was significantly different between them both (p < 0.001). The normal CAI has fully formed at birth, and is maintained constantly throughout childhood. The CAI in the unaffected hips in children with unilateral DDH is also mildly dysplastic.

Femoroacetabular impingement causes groin pain and decreased athletic performance in active adults. This bony conflict may result in femoroacetabular subluxation if of sufficient magnitude.

The ligamentum teres has recently been reported to be capable of withstanding tensile loads similar to that of the anterior cruciate ligament, and patents with early subluxation of the hip may become dependent on the secondary restraint that is potentially provided by the ligamentum teres. Rupture of the ligamentum may thus cause symptomatic hip instability during athletic activities.

An arthroscopic reconstruction of the ligamentum teres using iliotibial band autograft was performed in an attempt to restore this static stabiliser in a series of four such patients. Early clinical results have been promising. The indications, technique and early outcomes of this procedure are discussed.

Radiostereometric analysis (RSA) can detect early micromovement in unstable implant designs which are likely subsequently to have a high failure rate. In 2010, the Articular Surface Replacement (ASR) was withdrawn because of a high failure rate. In 19 ASR femoral components, the mean micromovement over the first two years after implantation was 0.107 mm (sd 0.513) laterally, 0.055 mm (sd 0.204) distally and 0.150 mm (sd 0.413) anteriorly. The mean backward tilt around the x-axis was -0.08° (sd 1.088), mean internal rotation was 0.165° (sd 0.924) and mean varus tilt 0.238° (sd 0.420). The baseline to two-year varus tilt was statistically significant from zero movement, but there was no significant movement from one year onwards.

We conclude that the ASR femoral component achieves initial stability and that early migration is not the mode of failure for this resurfacing arthroplasty.

The October 2012 Research Roundup³⁶⁰ looks at: whether you can escape your genes; oral prophylaxis for DVT; non-responders and the internet; metal-on-metal, mice and damaged livers; sleeping on the job; cartilage contact stress in the normal human hip; and a perfect reason to subscribe to 360.

Although good to excellent short-term results of arthroscopic partial limbectomy of the hip have been reported, there is little information on the long-term outcome of the procedure. We report a case with a 16-year follow-up.

A 34-year old woman presented with a three-month history of severe pain and limitation of movement of the hip. Plain radiographs and arthrography showed no abnormality. MRI showed an effusion and a deformity of the anterosuperior part of the labrum. This was confirmed as an inverted labral tear that was debrided arthroscopically.

At 16 years post-operatively, she remained symptom-free. Plain radiographs showed no abnormality and MRI suggested that the sealing effect of the scar tissue prevented articular damage and degeneration.

Over recent years hip arthroscopic surgery has evolved into one of the most rapidly expanding fields in orthopaedic surgery. Complications are largely transient and incidences between 0.5% and 6.4% have been reported. However, major complications can and do occur. This article analyses the reported complications and makes recommendations based on the literature review and personal experience on how to minimise them.

In order to clarify how intra-articular lesions influence the survival of a periacetabular osteotomy in patients with dysplasia of the hip, we performed an observational study of 121 patients (121 hips) who underwent a transposition osteotomy of the acetabulum combined with an arthroscopy. Their mean age was 40.2 years (13 to 64) and the mean follow-up was 9.9 years (2 to 18). Labral and cartilage degeneration tended to originate from the anterosuperior part of the acetabulum, followed by the femoral side. In all, eight hips (6.6%) had post-operative progression to Kellgren–Lawrence grade 4 changes, and these hips were associated with the following factors: moderate osteoarthritis, decreased width of the joint space, joint incongruity, and advanced intra-articular lesions (subchondral bone exposure in the cartilage and a full-thickness labral tear). Multivariate analysis indicated subchondral bone exposure on the femoral head as an independent risk factor for progression of osteoarthritis (p = 0.003). In hips with early stage osteoarthritis, femoral subchondral bone exposure was a risk factor for progression of the grade of osteoarthritis.

Although the outcome of transposition osteotomy of the acetabulum was satisfactory, post-operative progression of osteoarthritis occurred at a high rate in hips with advanced intra-articular lesions, particularly in those where the degenerative process had reached the point of femoral subchondral bone exposure.