We performed MRI on 13 infants after operative reduction for developmental dysplasia of the hip (DDH). Using an axial gradient-echo sequence, MRI accurately depicted the acetabular anatomy and confirmed adequate reduction in 12 patients. The one patient with redislocation after surgery was correctly identified. MRI can be carried out quickly, inexpensively and without risk of radiation and is the investigation of choice to confirm adequate reduction in DDH

We performed superselective angiography in 28 hips in 25 patients with Perthes’ disease in order to study the blood supply of the lateral epiphyseal arteries (LEAs). Interruption of the LEAs at their origin was observed in 19 hips (68%). Revascularisation in the form of numerous small arteries was seen in ten out of 11 hips in the initial stage of Perthes’ disease, in seven of eight in the fragmentation stage and in five of nine in the healing stage. Penetration of mature arteries into the depths of the epiphysis was seen in four of nine hips in the healing stage. Vascular penetration was absent in the weight-bearing portion of the femoral head below the acetabular roof. Interruption of the posterior column artery was seen where it passed through the capsule in seven hips when they lay either in internal rotation or in abduction with internal rotation. We suggest that in Perthes’ disease the blood supply of the LEAs is impaired at their origin and that revascularisation occurs from this site by ingrowth of small vessels into the femoral epiphysis. This process may be the result of recurrent ischaemic episodes

We report the six-year results of a prospective, controlled demographic trial of developmental dysplasia of the hip (DDH) treated in the Pavlik harness using ultrasound supervision. Our aim was to assess the value of ultrasound and its role in monitoring reduction in the harness, in terms of progression or failure of reduction at an early state. From 1988 to 1994, a total of 221 patients with 370 ultrasonographically abnormal hips was treated in the Pavlik harness. This represents a treatment rate for the Southampton district of 5.1 per 1000 live births. Sixteen hips in 12 patients were not reduced in the harness and required surgical treatment; 95.7% were successfully reduced. One case of mild avascular necrosis (0.3%) was identified in those treated by harness alone. Of the 221 patients 87.8% remain under radiological review, with 3.2% of affected hips showing continued, mild acetabular dysplasia. We conclude that ultrasound monitoring has led to an acceptably low level of intervention, a high reduction rate and minimal iatrogenic complications. The trial is continuing