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 outcome of displaced hips treated by Somerville and Scott’s method was assessed after more than 25 years. A total of 147 patients (191 displaced hips) was reviewed which represented an overall follow-up of 65.6%. The median age at the index operation was two years. During the first five years, 25 (13%) hips showed signs of avascular change.

The late development of valgus angulation of the neck, after ten years, was seen in 69 (36%) hips. Further operations were frequently necessary. Moderate to severe osteoarthritis developed at a young age in 40% of the hips. Total hip replacement or arthrodesis was necessary in 27 (14%) hips at a mean age of 36.5 years. Risk factors identified were high dislocation, open reduction, and age at the original operation. Two groups of patients were compared according to outcome. All the radiographic indices were different between the two groups after ten years, but most were similar before. It takes a generation to establish the prognosis, although some early indicators may help to predict outcome.