Aims

It has been well documented in the arthroplasty literature that lumbar degenerative disc disease (DDD) contributes to abnormal spinopelvic motion. However, the relationship between the severity or pattern of hip osteoarthritis (OA) as measured on an anteroposterior (AP) pelvic view and spinopelvic biomechanics has not been well investigated. Therefore, the aim of the study is to examine the association between the severity and pattern of hip OA and spinopelvic motion.

In Japan, osteoarthritis (OA) of the hip secondary to acetabular dysplasia is very common, and there are few data concerning the pathogeneses and incidence of femoroacetabular impingement (FAI). We have attempted to clarify the radiological prevalence of painful FAI in a cohort of Japanese patients and to investigate the radiological findings. We identified 176 symptomatic patients (202 hips) with Tönnis grade 0 or 1 osteoarthritis, whom we prospectively studied between August 2011 and July 2012. There were 61 men (65 hips) and 115 women (137 hips) with a mean age of 51.8 years (11 to 83). Radiological analyses included the α-angle, centre–edge angle, cross-over sign, pistol grip deformity and femoral head neck ratio. Of the 202 hips, 79 (39.1%) had acetabular dysplasia, while 80 hips (39.6%) had no known aetiology. We found evidence of FAI in 60 hips (29.7%). Radiological FAI findings associated with cam deformity were the most common. There was a significant relationship between the pistol grip deformity and both the α-angle (p < 0.001) and femoral head–neck ratio (p = 0.024). Radiological evidence of symptomatic FAI was not uncommon in these Japanese patients.

Cite this article: Bone Joint J 2013;96-B:172–6.

Arthroscopy of the native hip is an established diagnostic and therapeutic procedure. Its application in the symptomatic replaced hip is still being explored. We describe the use of arthroscopy of the hip in 24 symptomatic patients following total hip replacement, resurfacing arthroplasty of the hip and partial resurfacing (study group), and compared it with arthroscopy of the native hip in 24 patients (control group). A diagnosis was made or confirmed at arthroscopy in 23 of the study group and a therapeutic arthroscopic intervention resulted in relief of symptoms in ten of these. In a further seven patients it led to revision hip replacement. In contrast, arthroscopy in the control group was diagnostic in all 24 patients and the resulting arthroscopic therapeutic intervention provided symptomatic relief in 21.

The mean operative time in the study group (59.7 minutes (35 to 93)) was less than in the control group (71 minutes (40 to 100), p = 0.04) but the arthroscopic approach was more difficult in the arthroplasty group. We suggest that arthroscopy has a role in the management of patients with a symptomatic arthroplasty when other investigations have failed to provide a diagnosis.

The aim of this study was to assess whether a femoral component which retained the neck reduced the incidence of leg-length inequality following total hip arthroplasty. A retrospective review was undertaken of 130 consecutive primary total hip arthroplasties performed between April 1996 and April 2004 using such an implant. There were 102 suitable patients for the study. Standardised pre- and post-operative pelvic radiographs were measured by an independent investigator to the nearest millimetre.

The leg-length inequality was reduced from a mean pre-operative value of −0.71 cm to a mean of 0.11 cm post-operatively. Of the 102 patients 24 (23.5%) had an equal leg-length post-operatively, and 95 (93.1%) had a leg-length inequality between −1 cm and 1 cm.