The radiology of the hip joints and pelvis in cerebral palsy.

Thw radiological appearances found in the pelvis and hip joints in 79 patients with cerebral palsy, aged 5--16 years, have been studied. These findings have been recorded and correlated with the clinical severity and distribution of the disease. Subluxation of the hip joints was found in 14% and dislocation in a further 6%. Spasticity was the predominant neuromuscular handicap in 69 out of 79 cases (88%). The acetabular angle and femoral neck shaft angle were related to the degree of migration of the femoral head. The acetabular angle, iliac angle, iliac index and femoral neck shaft angle were all significantly increased in the deranged group. In the dislocated group, the mean neck-shaft angle was 154 degrees. When the degree of spasticity was asymmetrical, there was a striking relationship between the laterality of the spasticity and the laterality of the deranged hip, pelvic obliquity and increased acetabular angle. A typical teardrop-shaped femoral head was seen in 48% spina bifida occulta of the lower lumbar and sacral spine in 32% and pseudoarthrosis in 3.8%. No ectopic calcification or ossification of soft tissue was noted. An awareness that these children are at risk from subluxation and dislocation of the hip and the importance of early diagnosis and treatment are emphasised.