We reviewed 52 children, born between 1974 and 1985 with spina bifida affecting L3 and L4, who had dislocated hips. Their motor function was stable and they were able to walk at the time of dislocation. They were interviewed and examined physically and radiologically. Physical function was measured by the Rand Health Insurance Study questionnaire (HIS), the Childhood Health Assessment questionnaire (CHAQ), and by determining the functional level of ambulation according to Hoffer et al (1973). In a subgroup of 12 patients with L4 level of involvement from both treatment groups we measured the metabolic energy consumption while walking.

Thirty patients (49 hips) had been treated by operative relocation and 22 conservatively. Ten of the hips treated by operation subluxated or redislocated. The function in the two groups (conservative v operated) was similar (HIS score 7.8 v 8.0, p = 0.45; CHAQ 14 v 13, p = 0.2; level of mobility 0.61 v 0.63, p = 0.5). Patients in whom operation had failed had worse function than did those with successful surgery (HIS score 8.8 v 6.1, p = 0.025) and those with successful surgery had better function than patients treated conservatively (HIS score 8.8 v 8.0, p = 0.15). Function in patients with failed operations, however, was worse than in those who did not have surgical treatment (HIS score 6.6 v 7.8, p = 0.07). In the 12 so examined the operated group had a 30% more energy-efficient gait (0.271 v 0.361 ml O₂ kg/m, p = 0.05).

Patients with failed operations had worse function than those who were not operated on. The benefit of surgical relocation of the dislocated hips was marginal.