Aims. Asphericity of the femoral head-neck junction is common in cam-type femoroacetabular impingement (FAI) and usually quantified using the alpha angle on radiographs or MRI. The aim of this study was to determine the natural alpha angle in a large cohort of patients by continuous circumferential analysis with CT. Methods. CT scans of 1312 femurs of 656 patients were analyzed in this cross-sectional study. There were 362 men and 294 women. Their mean age was 61.2 years (18 to 93). All scans had been performed for reasons other than hip disease. Digital circumferential analysis allowed continuous determination of the alpha angle around the entire head-neck junction. All statistical tests were conducted two-sided; a p-value < 0.05 was considered statistically significant. Results. The mean maximum alpha angle for the cohort was 59.0° (. sd. 9.4). The maximum was located anterosuperiorly at 01:36 on the clock face, with two additional maxima of asphericity at the posterior and inferior head-neck junction. The mean alpha angle was significantly larger in men (59.4°, . sd. 8.0) compared with women (53.5°, . sd. 7.4°; p = 0.0005), and in Caucasians (60.7°, . sd. 9.0°) compared with Africans (56.3°, . sd. 8.0; p = 0.007) and Asians (50.8°, . sd. 7.2; p = 0.0005). The alpha angle showed a weak positive correlation with age (p < 0.05). If measured at commonly used planes of the radially reconstructed CT or MRI, the alpha angle was largely underestimated; measurement at the 01:30 and 02:00 positions showed a mean underestimation of 4° and 6°, respectively. Conclusion. This study provides important data on the normal alpha angle dependent on age, gender, and ethnic origin. The normal alpha angle in men is > 55°, and this should be borne in mind when making a diagnosis of cam-type morphology. Cite this article: Bone Joint J 2018;100-B:570–8

Aims

Although the short stem concept in hip arthroplasty procedure shows acceptable clinical performance, we sometimes get unexplainable radiological findings. The aim of this retrospective study was to evaluate changes of radiological findings up to three years postoperatively, and to assess any potential contributing factors on such radiological change in a Japanese population.

Aims

The aim of this study was to inform the epidemiology and treatment of slipped capital femoral epiphysis (SCFE).

Open reduction of the prominence at the femoral head-neck junction in femoroacetabular impingement has become an established treatment for this condition. We report our experience of arthroscopically-assisted treatment of femoroacetabular impingement secondary to paediatric hip disease in 14 hips in 13 consecutive patients (seven women, six men) with a mean age of 30.6 years (24 to 39) at the time of surgery. The mean follow-up was 2.5 years (2 to 4). Radiologically, 13 hips had successful restoration of the normal geometry and only one had a residual deformity. The mean increase in the Western Ontario McMasters Osteoarthritis Index for the series at the last follow-up was 9.6 points (4 to 14). No patient developed avascular necrosis or sustained a fracture of the femoral neck or any other complication. These findings suggest that femoroacetabular impingement associated with paediatric hip disease can be treated safely by arthroscopic techniques

Hip disease occurs in between 8% and 28% of patients with Down’s syndrome, many of whom develop disabling pain. We have carried out total hip replacement in six adult patients (9 hips) with severe arthritis of the hip. The mean follow-up was 7.75 years (2 to 14). At the latest review, all had relief of pain and full hip function. Increasing longevity and a high incidence of hip disease in these patients suggest a greater role for total hip arthroplasty in the future

The long-term results following the correction of coxa vara by Pauwels' Y-shaped intertrochanteric osteotomy have been evaluated in 14 children. Ten of the children had unilateral hip disease and were otherwise normal while four had bilateral hip disease due to generalised skeletal dysplasias. In each case, the growth plate was vertical, the femoral head was displaced inferiorly and there were abnormalities in the metaphysis of the femoral neck. The results indicate that this osteotomy provides lasting correction of the deformity, regardless of the cause, as long as the inclination of the growth plate is corrected to 40 degrees or less and adequate support is provided for the metaphyseal defect and the displaced femoral head

Aims

This study aimed to evaluate sagittal spinopelvic alignment (SSPA) in the early stage of rapidly destructive coxopathy (RDC) compared with hip osteoarthritis (HOA), and to identify risk factors of SSPA for destruction of the femoral head within 12 months after the disease onset.

We studied prospectively the impact of a hip surveillance clinic on the management of spastic hip disease in children with cerebral palsy in a tertiary referral centre. Using a combination of primary clinical and secondary radiological screening we were able to detect spastic hip disease at an early stage in most children and to offer early surgical intervention. The principal effect on surgical practice was that more preventive surgery was carried out at a younger age and at a more appropriate stage of the disease. The need for reconstructive surgery has decreased and that for salvage surgery has been eliminated. Displacement of the hip in children with cerebral palsy meets specific criteria for a screening programme. We recommend that hip surveillance should become part of the routine management of children with cerebral palsy. The hips should be examined radiologically at 18 months of age in all children with bilateral cerebral palsy and at six- to 12-monthly intervals thereafter. A co-ordinated approach by orthopaedic surgeons and physiotherapists may be the key to successful implementation of this screening programme

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Spinopelvic mobility plays an important role in functional acetabular component position following total hip arthroplasty (THA). The primary aim of this study was to determine if spinopelvic hypermobility persists or resolves following THA. Our second aim was to identify patient demographic or radiological factors associated with hypermobility and resolution of hypermobility after THA.

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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.

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Acetabular edge-loading was a cause of increased wear rates in metal-on-metal hip arthroplasties, ultimately contributing to their failure. Although such wear patterns have been regularly reported in retrieval analyses, this study aimed to determine their in vivo location and investigate their relationship with acetabular component positioning.

Developmental dysplasia of the hip predisposes to premature degenerative hip disease. A number of operations have been described to improve acetabular cover and have achieved varying degrees of success. We present the case of an 84-year-old woman, who underwent a shelf procedure to reconstruct a dysplastic hip 75 years ago. To date, the shelf remains intact and the hip is asymptomatic. We believe this represents the longest documented outcome of any procedure to stabilise the hip

Aims

The effect of pelvic tilt (PT) and sagittal balance in hips with pincer-type femoroacetabular impingement (FAI) with acetabular retroversion (AR) is controversial. It is unclear if patients with AR have a rotational abnormality of the iliac wing. Therefore, we asked: are parameters for sagittal balance, and is rotation of the iliac wing, different in patients with AR compared to a control group?; and is there a correlation between iliac rotation and acetabular version?

We report the results at a mean of 24.3 years (20 to 32) of 61 previously reported consecutive total hip replacements carried out on 44 patients with severe congenital hip disease, performed with reconstruction of the acetabulum with an impaction grafting technique known as cotyloplasty. The mean age of the patients at operation was 46.7 years (23 to 68) and all were women. The patients were followed post-operatively for a mean of 24.3 years (20 to 32), using the Merle d’Aubigné and Postel scoring system as modified by Charnley, and with serial radiographs. At the time of the latest follow-up, 28 acetabular components had been revised because of aseptic loosening at a mean of 15.9 years (6 to 26), and one at 40 days after surgery because of repeated dislocations. The overall survival rate for aseptic failure of the acetabular component at ten years was 93.1% (95% confidence interval (CI) 86.5 to 96.7) when 53 hips were at risk, and at 23 years was 56.1% (95% CI 49.4 to 62.8), when 22 hips remained at risk. These long-term results are considered satisfactory for the reconstruction of an acetabulum presenting with inadequate bone stock and circumferential segmental defects. Cite this article: Bone Joint J 2013;95-B:887–92

Hip arthrodesis remains a viable surgical technique in well selected patients, typically the young manual labourer with isolated unilateral hip disease. Despite this, its popularity with patients and surgeons has decreased due to the evolution of hip replacement, and is seldom chosen by young adult patients today. The surgeon is more likely to encounter a patient who requests conversion to total hip replacement (THR). The most common indications are a painful pseudarthrosis, back pain, ipsilateral knee pain or contralateral hip pain. Occasionally the patient will request conversion because of difficulty with activities of daily living, body image and perceived cosmesis. The technique of conversion and a discussion of the results are presented. Cite this article: Bone Joint J 2013;95-B, Supple A:114–19