Abstract. Objectives. The purpose of this study was to determine the cost of inpatient admissions for developmental dysplasia of the hip (DDH) at a UK tertiary referral centre, and identify any association between newborn screening (NIPE) status and the cost of treatment. Methods. This was a retrospective study, using hospital episodes data from a single NHS trust. All inpatient episodes between 01/01/2014 to 30/06/2019 with an ICD-10 code stem of Q65 ‘congenital deformities of hip’ were screened to identify admissions for management of DDH. Data was subsequently obtained from electronic and paper records. Newborn screening status was recorded, and patients were divided into ‘NIPE-positive’ (diagnosed through selective screening) and ‘NIPE-negative’ (not diagnosed through screening). Children with neuromuscular conditions or concomitant musculoskeletal disease were excluded. The tariff paid for each inpatient episode was identified, and the number of individual clinic attendances, surgical procedures and radiological examinations performed (USS, XR, CT, MRI) were recorded. Results. 41 patients with DDH were admitted for inpatient management. 44% (n = 18) were NIPE-positive, diagnosed mean age 6.7 weeks. 56% (n = 23) were NIPE-negative, diagnosed mean age 26 months. The total cost of inpatient care in the NIPE-positive group was £171,471 (£9,526.18 per-patient) compared to £306,615 (£13,331.10 per-patient) for NIPE-negative. In the NIPE-positive group, there were 99 clinic attendances, 47 inpatient admissions and 160 radiological examinations performed (36 USS, 107 XR, 17 CT). This compared to 148 clinic attendances, 59 inpatient admissions and 215 radiological examinations (187 XR, 26 CT, 2 MRI) in the NIPE-negative group. Conclusion. A greater proportion of inpatient admissions for DDH are among NIPE-negative children. They incur a higher cost of treatment per patient and necessitate more inpatient resources. This study adds to the ongoing conversation around the cost-effectiveness of selective screening for DDH in the UK. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Abstract. OBJECTIVES. Although surgical periacetabular osteotomy (PAO) for hip dysplasia aims to optimise acetabular coverage and restore hip function, it is unclear how surgery affects capsular mechanics and joint stability. The purpose was to examine how the reoriented acetabular coverage affects capsular mechanics and joint stability in dysplastic hips. METHODS. Twelve cadaveric dysplastic hips (n = 12) were denuded to the capsule and mounted onto a robotic tester. The robot positioned each hip in multiple flexion angles (Extension, Neutral 0°, Flexion 30°, Flexion 60°, Flexion 90°) and performed internal-external rotations and abduction-adduction to 5 Nm in each rotational or planar direction. Each hip underwent a PAO, preserving the capsule, and was retested postoperatively in the robot. Paired sample t-tests compared the range of motion before and after PAO surgery (CI = 95%). RESULTS. Pre-operatively, the dysplastic hips demonstrated large ranges of internal-external rotations and abduction-adduction motions throughout all flexion positions. Post-operatively, the PAO slackenend the anterosuperior capsule and tightened the inferior capsule. This increased external rotation in Flexion 60° and Flexion 90° (∆. ER. = +16 and +23%) but provided lateral coverage to decrease internal rotation at Flexion 90° (∆. IR. = –15%). The PAO also reduced abduction throughout, but increased adduction in Neutral 0°, Flexion 30°, and Flexion 60° (∆. ADD. = +34, +30%, +29% respectively). CONCLUSIONS. The PAO provided crucial osseous structural coverage to the femoral head, decreasing hypermobility and adverse loading at extreme hip flexion-extension. However, it also slackened the anterosuperior capsule and increased adduction and external rotation, which may lead to ischiofemoral impingement and adductor irritations. Capsular instability may be secondary to acetabular undercoverage, thus capsular alteration may be warranted for larger corrections or rotational osteotomies. To preserve native hip and delay joint degeneration, it is crucial to preserve capsule and elucidate amount of reorientation needed without causing iatrogenic instability. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction. Intra-articular injury has been described as primary cause of pain in hip dysplasia. At this point it is unknown whether external muscle-tendon related pain coexists with intra-articular pathology. The primary aim was to identify muscle-tendon related pain in 100 dysplasia patients. The secondary aim was to test if muscle-tendon related pain is linearly associated to self-reported hip disability and muscle strength in patient with hip dysplasia. Materials and methods. One hundred patients (17 men) with a mean age of 29 years (SD 9) were included. Clinical entity approach was carried out to identify muscle-tendon related pain. Muscle strength was assessed with a handheld dynamometer and self-reported hip disability was recorded with the Copenhagen Hip and Groin Outcome Score (HAGOS). Results. Iliopsoas- and abductor-related pain were most prevalent with prevalences of 56% (CI 46; 66) and 42% (CI 32; 52), respectively. Adductor-, hamstrings- and rectus abdominis-related pain were less common. There was a significant inverse linear association between muscle-tendon related pain and self-reported hip disability ranging from −3.35 to −7.51 points in the adjusted analysis (p<0.05). Likewise an inverse linear association between muscle-tendon related pain and muscle strength was found ranging from −0.11 Nm/kg to −0.12 Nm/kg in the adjusted analysis (p<0.05). Conclusion. Muscle-tendon related pain seem to exist in about half of patients with hip dysplasia with a high prevalence of muscle-tendon related pain in the iliopsoas and the hip abductors and affects patients” self-reported hip disability and muscle strength negatively

Purpose. Ultrasound of the neonatal and infantile hip is a useful tool in diagnosis and treatment of the developmental dysplasia of the hip (DDH), especially given the fact that numerous cases of DDH do not present any findings in the clinical examination. Methods. Between January 2014 and May 2020, 10536 (5273 neonates and infants, 53% girls, 47% boys) consecutive neonatal and infantile hip joints were studied using the Graf Hip Ultrasound method. Results. 607 hips were diagnosed as abnormal. 523 (5%) hip joints were type IIA, 18 (0.17%) were type ΙΙΒ, 19 (0.18%) were type ΙΙC, 33 (0.31%) were type ΙΙΙ and 14 (0.13%) were type IV. 72% of patients were girls, 55% of patients were firstborns, 35,7% presented breech, 8,2% had a positive family history of DDH, 6% were part of a multiple pregnancy, while 27,2% had no predisposing factor for the disease. Type ΙΙΑ hips were treated with follow- up only and had all matured (turned to normal- type I hips) within a trimester. Type ΙΙΒ και ΙΙC hips were treated using an abductor harness and were normal (type I) within three months. 35.7% of type ΙΙΙ were treated with an abductor harness and 64.3% with hip spica. All type IV hips were treated with hip spica. The duration of therapy for type III and type IV hips was 3 months. Conclusion. The early use of a hip ultrasound provides us with the ability to diagnose and treat DDH efficiently, resulting in a normal hip joint within the first months of life

In the congenital hip dysplasia, patients treated with total hip replacement (THR) often report persistent disability and pain, with unsatisfactory function and quality of life. A major challenge is to restore the center of rotation of the hip and a satisfactory abduction function [1]. The position of the acetabular cup during THR might be crucial, as it affects abduction moment and motor function. Recently, several software systems have been developed for surgical planning of endoprostheses. Previously developed software called HipOp [2], which is routinely used in clinics, allows surgeons to properly position the prosthetic components into the 3D space of CT data. However, this software did not allow to simulate the articular range of motion and the condition of the abductor muscles. Our aim is to present HipOpCT, an advanced version of the software that includes 3D musculoskeletal planning, through the application to hip dysplasia patients to add knowledge in the diagnosis and treatment of such patients who need THR. 40 hip dysplasia patients received pre-operative CT scanning of pelvis and thighs and had their THR surgery planned using HipOpCT. The base planning includes import of CT data, positioning of prosthetic components interactively through multimodal display, as well as geometrical measurements of the implant and the host bone. The advanced planning additionally includes evaluation of femoro-acetabular impingement and calculation of leg lengths, abductor muscle lengths and lever arms through the automatic creation of a musculoskeletal model. The musculoskeletal parameters in all patients were calculated during the surgical planning, and the data were processed to evaluate pre- and post-operative differences in leg length discrepancy, length and lever arm of the abductor muscles, and how these parameters correlated. The surgical planning led to an increase in the operated leg length of 7.6 ± 5.7 mm. The variation in abductors lever arm was −0.9% ± 4.8% and significantly correlated with the variation in the operated leg length (r = −0.49), pre-operative leg length discrepancy (r = 0.32) and variation in abductors length (r = −0.32). The variation in abductors length was 6.6% ± 5.5%, and significantly correlated with the variation in the operated leg length (r = 0.92), post-operative leg length discrepancy (r = 0.37), pre-operative abductors length (r = −0.37) and variation in abductors lever arm (r = −0.32). The increase in the operated leg length was strongly correlated to the increase in abductor muscle length. Conversely, abductor lever arms slightly decreased on average, and were inversely correlated to leg length variation and abductors lengths. This interactive technology for surgical planning represent a powerful tool for orthopaedic surgeons to consider the best muscle reconstruction, and for rehabilitation specialists to achieve the best functional recovery based on biomechanical outcomes. In a parallel study, we are investigating how these advanced planning is reflected onto the function, pain and biomechanical outcome after a rehabilitation protocol is completed

Introduction. Progressive resistance training (PRT) as a mean to reduce symptoms in patients with hip dysplasia (HD) has not yet been tried out. The aim of this study was to examine if PRT is feasible in patients with HD. A secondary purpose was to report data on changes of patient reported outcomes, muscle performance and hip muscle strength following PRT. Materials and methods. Patients diagnosed with HD on the waiting list for a periacetabular osteotomy (PAO) were offered to participate in a PRT feasibility study. The PRT intervention consisted of 8-weeks of supervised PRT consisting of 20 training sessions with exercises for the hips and knees. Feasibility was evaluated as adherence, the number of dropouts and adverse events. Furthermore, pain was reported after each exercise and one day after a training session using a 100mm visual analog scale (VAS). Pain was categorized as “safe” (VAS ≤20), “acceptable” (VAS >20–50) and “high risk” (VAS >50). Pre- and post the intervention patients completed the Copenhagen Hip and Groin Outcome Score (HAGOS), performed two hop-tests on each leg and had their peak torque of the hip extensors and flexors assessed by isokinetic dynamometry. Results. 16 patients, mean age 28 (range 22–40) years, completed the PRT intervention. Adherence was high (90.3% ±9.0%). Acceptable pain levels (VAS ≤50) were reported on average of 95% during the completed PRT sessions and after 92.3% of the sessions when assessed on the following day. Four out of six HAGOS subscales improved (P <0.05) after the intervention, as did standing distance jump and countermovement jump (8.3 cm 95% CI [1.2, 15.3], 1.8 cm [0.7, 2.9]) on the affected side. Dynamometry showed significant improved peak torque during isokinetic concentric hip flexion (15.8 Nm 95% CI [5.9, 25.8]) on the affected side. A similar improvement was seen during isometric hip flexion on the non-affected side. Conclusion. Supervised preoperative PRT is feasible in terms of drop outs, adherence, adverse events and pain levels in patients with HD scheduled for PAO. Furthermore, this feasibility study suggests that PRT may improve pain levels, patient reported outcomes, functional performance and hip flexion muscle strength

Ganz peri-acetabular osteotomy is commonly used to treat symptomatic hip dysplasia. It aims to increase the load bearing contact area of the hip to reduce the risk of subsequent osteoarthritis. In this study we assess the radiographic and clinical results of the procedure since its introduction to our unit. All patients undergoing Ganz osteotomies at our unit were followed up prospectively. Data collected included patient demographics and pre- and post-operative functional scores (Harris and Non-arthritic hip scores). In addition, acetabular correction was evaluated on pre-and post-operative radiographs (using Centre-Edge angle and Tonnis angle). Complications were also noted. Overall 50 procedures were performed between 2007 and 2013 with median follow-up of 3 years (1 – 7 years). The majority of patients (90%) were female. Average age at time of surgery was 29 years (16–49). There were significant improvements in pre- and post-operative median functional scores (Modified Harris Hip Score = 49 versus 64, p=0.001), Non-arthritic Hip Score = 42 versus 56, p=0.007). Median Centre Edge Angle improved from 16 degrees pre-operatively (range = 7–31 degrees) to 30 degrees post-operatively (18–33) degrees), p<0.0001. Similarly, pre-operative Tonnis angle improved from 18 degrees (9–38) to 7 degrees (2–14), p<0.0001. Five patients developed post-operative complications: 2 superficial wound infection, 1deep infection requiring hip washout and antibiotic treatment and 2 patients subsequently requiring total hip replacements. We have shown that the Ganz peri-acetabular osteotomy can be effective for the treatment of painful hip dysplasia improving both functional and radiographic outcomes. However, patient selection is a key factor

We studied the morphometry of 35 femora from 31 female patients with developmental dysplasia of the hip (DDH) and another 15 from 15 age- and sex-matched control patients using CT and three-dimensional computer reconstruction models. According to the classification of Crowe et al 15 of the dysplastic hips were graded as class I (less than 50% subluxation), ten as class II/III (50% to 100% subluxation) and ten as class IV (more than 100% subluxation). The femora with DDH had 10 to 14° more anteversion than the control group independent of the degree of subluxation of the hip. In even the most mildly dysplastic joints, the femur had a smaller and more anteverted canal than the normal control. With increased subluxation, additional abnormalities were observed in the size and position of the femoral head. Femora from dislocated joints had a short, anteverted neck associated with a smaller, narrower, and straighter canal than femora of classes I and II/III or the normal control group. We suggest that when total hip replacement is performed in the patient with DDH, the femoral prosthesis should be chosen on the basis of the severity of the subluxation and the degree of anteversion of each individual femur

In patients with developmental dysplasia of the hip (DDH) chronic joint dislocation induces remodeling of the soft tissue with contractures, muscle atrophy, especially of the hip abductors muscles, leading to severe motor dysfunction, pain and disability (1). The aim pf the present work is to explore if a correct positioning of the prosthetic implants through 3D skeletal modeling surgical planning technologies and an adequate customized rehabilitation can be beneficial for patients with DDH in improving functional performance. The project included two branches: a methodology branch of software development for the muscular efficiency calculation, which was inserted in the Hip-Op surgical planning system (2), developed at IOR to allow surgical planning for patients with complex hip joint impairment; and a clinical branch which involved the use of the developed software as part of a clinical multicentric randomized trial. 50 patients with DDH were randomized in two groups: a simple surgical planning group and an advanced surgical planning with muscular study group. The latter followed a customized rehabilitation program for the strenghtening of hip abductor muscles. All patients were assessed before surgery (T0) and at 3 (T1) and 6 months (T2) postoperatively using clinical outcome (WOMAC, HHS, ROM, MMT, SF12, 10mt WT) and instrumental measures (Dynamometric MT). Pre- and post-operative musculoskeletal parameters obtained by the software (i.e., leg length discrepancy, hip abductor muscle lengths and lever arms) using Hip-Op during the surgical planning were considered. One Way ANOVA for ROM measurement showed a significant improvement at T2 in patients included in experimental group, as well as WOMAC, HHS and SF12 score. The Dynamometric MT score showed significant differences between at T2 (p<0.009). Spearman's rank correlation coefficients showed a significant correlation between both pre- and post-operative abductors lever arm (mm) and hip abductor muscle strength at T2 (ρ = −0.55 pre-op and ρ = −0.51 post-op, p p<0.012 and p<0.02 respectively) and between the operated pre-postoperative leg length variation (mm) and the hip abductor muscle strength (ρ = −0.55, p p<0.013). Results so far obtained showed an improvement of functional outcomes in patients undergoing hip replacement surgery who followed therapeutic diagnostic pathway sincluding a preoperative planning including the assessment of the abductiors lever arm and a dedicated rehabilitation program for the strenghtening of abductios. Particularly interesting is the inverse relationship between the strength of the hip abductor muscles and the variation of the postoperative abductor lever arm

Late presentation of DDH continues to remain a major problem particularly in the developing countries. Femoro-Acetabular Zones (FAZ) system is created to find a relation between acetabular maturity and severity of dislocation, in one hand, and the success of closed reduction, on the other hand. We hypnosis that the lower the acetabular index and the closer the femoral head to the acetabulum, the more likely the success of treatment. Thus, a retrospective study was performed on late diagnosed DDH hips that underwent closed treatment at a particular hospital in the Middle East. FAZ are drawn on the AP view of the pelvic x-ray and is based on a perpendicular from the acetabular index at the lateral margin of the superior acetabular rim then another perpendicular to Perkin's line is drawn. This gives three zones, graded I-III. The center of femoral metaphysis is identified denoting the position of the femoral head in relation to the zone classification. FAZ system was applied on 65 pelvic radiographs; mean patient age was 24 months (range: 12 to 36 months) with a minimum follow up of 3 years. Overall, 37 of 65 hips (57%) achieved a satisfactory outcome (Severin I&II), while 22 hips (33%) were found to be unsatisfactory (Severin III). 6 hips (10%) needed an open reduction (p-value 0.001). FAZ could perfectly predict the successful cases. FAZ system is a simple and novel classification and if employed, could reasonably predict the outcome of non-surgical treatment of DDH after walking age.

Acetabular dysplasia was produced in 24 immature white rabbits. A rotational acetabular osteotomy was then carried out and radiological and histological studies of the articular cartilage were made.

In the hips which did not undergo osteotomy, radiographs at 26 weeks showed that residual subluxation remained and arthritic changes such as narrowing of the joint space or dislocation were still seen. However, in the operated group there was a remarkable increase in cover, but arthritic changes were not observed. After 24 weeks, the Mankin grading score in the operated group was significantly lower than that in the non-operated group. The latter hips showed an irregular surface of the cartilage, exfoliation and proliferation of synovial tissue. In those undergoing osteotomy, primary cloning of chondrocytes or hypercellularity was seen and at 24 weeks after operation and metaplasia of the cartilage in the fibrous tissue was observed in the boundary between the medial area of the acetabulum and the acetabular fossa.

Introduction and Objective. Several studies have described double and triple femoral neck lengthening osteotomies to correct coxa brevis deformity, however, no overview exists in literature. Our aim was to perform the first systematic review of the outcomes of double and triple femoral neck lengthening. Materials and Methods. After an extensive search in Pubmed, CINAHL and Embase libraries for published articles using the following search strategy: ‘(((proximal femoral deformity) OR hip dysplasia) OR coxa brevis) AND (((femoral neck lengthening) OR double proximal femoral osteotomy) OR triple proximal femoral osteotomy)’, we included studies reporting the results of double and triple femoral neck osteotomies. Clinical and radiological outcomes, and reported complications were extracted. The review process was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results. After evaluating 456 articles, we included 11 articles reporting 149 osteotomies in 143 patients (31% male, 64% female, 5% unspecified). Mean age of the patients was 20 years (range 7 years to 52 years). Indications were developmental hip dysplasia (51%), Perthes disease (27%), infection (6%), post-trauma (4%), congenital disorders (2%), slipped capital femoral epiphysis (1%), idiopathic (3%) and unknown (6%). The mean limb length discrepancy reduced by 12 mm (0 mm to 40 mm). In total, 65% of 101 positive Trendelenburg sign hips experienced improvement of abductor muscle strength. An 18% (9% to 36%) increase could be found in functional hip scores. Mean increase in articulo-trochanteric distance was 24 mm (10 mm to 34 mm). Five patients older than 30 years at the time of osteotomy and two younger patients with prior hip incongruency had disappointing results and required arthroplasty. In all, 12 complications occurred in 128 osteotomies, in which complications were reported. Conclusions. This first systematic review of double and triple femoral neck lengthening osteotomies shows that favorable outcomes and few complications can be expected in coxa brevis, however, excessive caution is required in older patients with incongruent hips

Abstract. OBJECTIVES. Cam femoroacetabular impingement (FAI – femoral head-neck deformity) and developmental dysplasia of the hip (DDH – insufficient acetabular coverage) constitute a large portion of adverse hip loading and early degeneration. Spinopelvic anatomy may play a role in hip stability thus we examined which anatomical relationships can best predict range of motion (ROM). METHODS. Twenty-four cadaveric hips with cam FAI or DDH (12:12) were CT imaged and measured for multiple femoral (alpha angles, head-neck offset, neck angles, version), acetabular (centre-edge angle, inclination, version), and spinopelvic features (pelvic incidence). The hips were denuded to the capsule and mounted onto a robotic tester. The robot positioned each hip in multiple flexion angles (Extension, Neutral 0°, Flexion 30°, Flexion 60°, Flexion 90°); and performed internal-external rotations to 5 Nm in each position. Independent t-tests compared the anatomical parameters and ROM between FAI and DDH (CI = 95%). Multiple linear regressions determined which anatomical parameters could predict ROM. RESULTS. The FAI group demonstrated restricted ROM in deep hip flexion, with DDH showing higher ROM in Flexion 30° (+20%, p = 0.03), 60° (+31%, p = 0.001), and 90° (+36%, p = 0.001). In Neutral 0° and Flexion 30°, femoral neck and version angles together predicted ROM (R. 2. = 60%, 58% respectively); whereas in Flexion 60°, pelvic incidence and femoral neck angle predicted ROM (R. 2. = 77%). In Flexion 90°, pelvic incidence and radial alpha angle together predicted ROM (R. 2. = 81%), where pelvic incidence alone accounted for 63% of this variance. CONCLUSIONS. Pelvic incidence is essential to predict hip ROM. Although a cam deformity or acetabular undercoverage can elevate risks of labral tears and progressive joint degeneration, they may not be primary indicators of restrictive hip impingement or dysplastic instability. Better delineating additional spinopelvic characteristics can formulate early diagnostic tools and improve opportunities for nonsurgical management. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

When performing total hip replacements in patients with hip dysplasia, acetabular augmentation may be required to prevent early component failure. Preoperative radiographic templating may help estimate acetabularcomponent coverage but has not previously been shown to predict the need for augmentation. We developed a simple method to estimate the percentage of acetabular component coverage from pre-operative radiographs (True: False cup ratio). We aimed to evaluate whether this couldpredict the need foracetabular augmentation at primary total hip replacement for patients with dysplastic hips. We reviewed all patients with hip dysplasia who underwent a primary total hip replacement from 2005–2012. Classification of hip dysplasia (Crowe), centre edge angle (CEA), Sharp and Tonnis angles were determined on pre-operative radiographs for each patient. Templating was performed on anteroposteriorand lateral view hip radiographs to determine the likely percentage of acetabular component coverage using the True: False cup ratio. Patients requiring acetabular augmentation at time of primary total hip arthroplasty were noted. 128 cases were reviewed, 31 (24%) required acetabularaugmentation. Comparison between augmented and non-augmented cases revealed no difference in the mean CEA (p = 0.19), Sharp angles (p = 0.76) or Tonnis angles (p = 0.32). A lower True Cup: False Cup ratio was observed in the augmented groupcompared to the non-augmented group(median = 0.68 vs 0.88, p < 0.01). Preoperative templating can help predict which dysplastic hips are likely to require acetabular augmentation at primary total hip replacement

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

Developmental dysplasia of the hip (DDH) is the most common post-natal skeletal abnormality. It is widely acknowledged that conditions which cause or result in reduced movement in utero are contributing factors to the incidence of DDH. However, the hypothesis that prenatal movement plays a role in normal development of the hip joint has not been tested using embryonic model systems. This research investigates the effects of immobilization in chick embryos on hip joint morphogenesis. Embryonic chicks were treated in ovo using a neuromuscular blocking agent from embryonic days 5 to 9. Limbs were stained for cartilage using alcian blue, and were scanned in 3-D. Standardized virtual sections of the femur were taken and a number of virtual sections from age-matched limbs were overlaid in order to compare between control and immobilized limbs. The results show that not all immobilised limbs were equally affected, with some immobilised embryos having almost normal joint shapes, and other immobilised embryos displaying decreased protuberance of the femoral head and decreased indentation at the femoral neck. Our results demonstrate that the mechanobiological response to immobilisation can vary between individuals, but also that preventing movement during embryonic development can lead to abnormal morphogenesis of the developing proximal femur in some individuals, providing evidence that reduced movement during development can lead to features of DDH

The outcome of periacetabular osteotomy in dysplastic hips is dependent on the absence of preoperative osteoarthritis [OA]. The purpose of this study was to analyze whether Tonnis grading is a reliable predictor of OA in patients with hip dysplasia. Thirty patients were identified who had undergone hip arthroscopy surgery to assess their suitability for periacetabular osteotomy. Radiographs were assessed for anterior centre edge angle, lateral centre edge angle, Tonnis angle and Tonnis grade for OA changes. The radiographic grading of OA was compared with arthroscopic findings. Results. The average age at the time of arthroscopy was 34.97 [16 – 53yrs] (28 females). Tonnis grade did not correlate with arthroscopic findings (p=0.082). There was a trend for patients with a higher Tonnis grade to have more OA changes. Of the 30 patients, all 3 with grade 0 were fit for periacetabular osteotomy, while only 8 out of 24 with grade I, and 1 out of 3 with grade II were fit for periacetabular osteotomy. This study reports that even when radiographic grading showed minimal OA changes, arthroscopy findings indicated significant OA changes. Hence radiographic grading is a poor indicator of OA and other diagnostic modality should be sought before proceeding with joint preserving surgery in this highly selected subgroup of dysplastic hips

Introduction. We present our experience of the coned hemi-pelvis (‘ice-cream’ cone) implant, using an extended posterior approach to the hip joint, in the management of pelvic bone loss and pelvic discontinuity. Methods. Retrospective study conducted utilising a prospectively collected database. Patients who underwent an ice-cream cone reconstruction between August 2004 – September 2011 were identified. All had a posterior approach to the hip. Femur prepared in the standard fashion. A variety of femoral components used. Demographic data was recorded along with the indication for surgery and outcomes. Results. 16 patients identified. Mean age was 62.2 years. 5 (31.25%) male. 11 (69.75%) female. Indications included; multiple hip revision surgery 4(25%); post Gridlestones for severe hip dysplasia 1 (6.25%); peri-acetabular metastatic deposits 11 (68.75%) from breast, renal, endometrial, prostatic, myeloma primary malignancies. Mean follow-up was 32.06 months. Complications; 1 intra-operative death from tumour embolus; 1 dislocation; 1 superficial surgical site infection. 3 deaths from their primary malignancy. Mean time from prosthesis implantation to death was 14.5 months. All patients at last follow-up were mobilizing. No implant has needed to be revised. Discussion. Pelvic bone loss provides reconstructive challenges. The coned hemi-pelvis is simple to make, easy and versatile to use even when there is little pelvis remaining. It provides a method of negotiating hip reconstruction in patients with severe pelvic bone loss. Orthopaedic surgeons are familiar with the posterior approach to the hip. The ice-cream cone implant can therefore be placed with ease using this well-known approach to the hip

The diagnosis and treatment of hip disease in young adults has rapidly evolved over the past ten years. Despite the advancements of improved diagnostic skills and refinement of surgical techniques, the psychosocial impact hip disease has on the young adult has not yet been elucidated. This observational study aimed to characterise the functional and psychosocial characteristics of a group of patients from our young hip clinic. 49 patients responded to a postal questionnaire which included the Oswestry Disability Index (ODI) and Hospital Anxiety and Depression Scale (HADS). Median age was 20 years (range 16-38) with a gender ratio of 2:1 (female: male). The most common diagnoses were Perthes' disease and developmental hip dysplasia. More than half of our patients had moderate to severe pain based on the Visual Analogue Scale (VAS) and at least a moderate disability based on the ODI. Thirty-two percent of patients were classified as having borderline to abnormal levels of depression and 49% of patients were classified as having borderline to abnormal levels of anxiety based on the HADS. Comparison of the ODI with the VAS and HADS anxiety and depression subscales showed a significant positive correlation (p<0.05). Multiple regression showed the ODI to be a significant predictor of the HADS anxiety and depression scores (regression coefficient 0.13, 95% confidence interval 0.06 to 0.21, p<0.05). This study highlights the previously unrecognised psychosocial effects of hip disease in the young adult. A questionnaire which includes HADS may be of particular value in screening for depression and anxiety in young people with physical illness. This study also highlights that collaboration with psychologists and other health care providers may be required to achieve a multidisciplinary approach in managing these patients

Summary Statement. Pincer deformities are involved in the genesis of femoro-acetabular impingement (FAI). Radiographic patterns suggestive of pincer deformities are common among general population. Prevalence of the pincer deformities among general population may be overestimated if only plain radiographs are considered. Background. Pincer deformities (coxa profunda, protrusio acetabuli, global retroversion, isolated cranial over-coverage) have been advocated as a cause of femoro-acetabular impingement (FAI) and early hip osteoarthritis (OA). Different radiographic patterns may advocate the presence of a pincer deformity. The prevalence of these radiographic patterns among general adult population, as their role in early hip OA, is poorly defined. Methods. From a database of 40.351 pelvic radiograms and CT collected at our institution between 2005 and 2010, we selected 118 caucasian individuals (56 females, 62 males), aged between 15 and 60 years, who underwent both plain radiographs and CT of the pelvis. A series of exclusion criteria were strictly applied to achieve a sample of adult general population as more representative as possible. In particular patients with presence of any disease involving hip joint, including: advanced hip OA (grade II or III of Tonnis scale), head necrosis, fractures, heterotopic ossifications, bone and soft tissue tumors, rheumatic pathologies, classic hip dysplasia with lateral center-edge angle (L-CEA) less than 20°, clinical diagnosis of FAI or hip pain, were excluded from the present study. We also excluded patients in which open growth plates, osteopenia, hardware or evidence of prior surgery were present. Radiographs were investigated for pelvic tilt, signs of retroversion, lateral center-edge angle (L-CEA), presence of coxa profunda or protrusio acetabuli. EAV was measured on CT scans at the equatorial plane of the acetabulum passing by the 3 o'clock position, while CAV was calculated at a more cranial level corresponding to the 1 o'clock position EAV and CAV were obtained in the axial plane by measuring the angle made by a line connecting the anterior and posterior rims of the acetabulum and a line perpendicular to the line connecting the ischial spines. A new parameter, Acetabular torsion (AT), has been introduced in order to discriminate between global retroversion and isolated cranial over-coverage. AT was defined as the difference between EAV and CAV. Cam deformity was assessed by calculating the alpha angle on the femoral side; an alpha angle > 55° was considered abnormal and suggestive of cam deformity. Radiological signs of chondrolabral degeneration were noticed. Results. Mean EAV and mean CAV were higher in females, mean AA was higher in males. L-CEA, EAV and CAV increased with age. Mean AT was 8.8±6.3. AT was inversely related to CAV (r=−0.799; p<0.0005) but independent from EAV (r=−0.076; p=0.244). EAV≤10.2° was defined as the marker of global retroversion, while AT≥21.2° was defined as the marker of isolated cranial over-coverage. Overall prevalence of pincer deformities was 21.6% (> females; p=0.02). Early OA changes were related to age (p<0.0005) and AA (p<0.0005), but not to pincer deformities (p=0.96). Radiological signs of retroversion showed good or excellent negative predictability but poor positive predictability. Conclusions. Radiographic patterns of pincer deformities are common among general population. Relationship with radiological signs of chondrolabral degeneration is poor. CT allows to discriminate between global retroversion and isolated cranial over-coverage. Prevalence of the pincer deformities among general population may be overestimated if only plain radiographs are considered