Some radiological features of the lumbar spine of 84 patients with spastic diplegia were compared with 50 control subjects. The average age of the patients was 20.1 years (3 to 39). Spondylolysis of the fifth lumbar vertebra was found in 21%, four times more frequently than in normal subjects. No patient under nine years of age had spondylolysis and the frequency increased with age. The average angle of lumbar lordosis in spastic patients in the standing position was greater than in normal subjects, and increased with age. The patients had a decreased sacrofemoral angle which caused an increase in Ferguson's angle and explained the increased angle of lumbar lordosis.

We performed Kawamura's dome osteotomy of the pelvis, with simultaneous distal transfer of the greater trochanter on 101 hips in 91 patients with osteoarthritis secondary to hip dysplasia. The mean age at operation was 30 years (15 to 55), and follow-up was for a mean of 8.3 years (5 to 14). Clinical evaluation using the Merle d'Aubigne score showed 92% excellent or good results. Radiologically, 91 hips had good acetabular remodelling and showed no signs of progression of osteoarthritis. In ten hips the osteoarthritic process progressed despite the osteotomy and six of these eventually underwent total hip replacement. Factors which were significantly associated with a poor outcome included an advanced stage of osteoarthritis, valgus deformity of the proximal femur, old age at the time of operation and postoperative persistence of abductor insufficiency.