Children who suffer from cerebral palsy and do not walk before the age of 5 have a 58% incidence of hip dislocation (44% bilateral, 14% unilateral).1Other factors involved in the causation of hip dislocation include four limb cerebral palsy2 and tightness of the adductor and iliopsoas muscles with concomitant weakness in the abductor muscles at the hip.3 Whatever the cause, reconstructing the hip in these children involves complex surgery, and parents and their doctors need to be aware that management is not straightforward.

Investigations used to detect dislocation include x rays of the pelvis and whole spine; from the former the physician or surgeon can document any progressive tendency of the hip to dislocate by measuring the migration percentage.4Such monitoring is important. Associated radiological features of hip dislocation are femoral neck anteversion, valgus femoral neck …