Prophylactic contralateral fixation in slipped upper femoral epiphysis: is it safe?

Prophylactic stabilization with internal fixation of the asymptomatic hip in unilateral slipped upper femoral epiphysis is controversial. We present a retrospective analysis of 65 patients who had prophylactic fixation of the uninvolved hip at the same time as their opposite slipped femoral physis. None had an underlying systemic or endocrine abnormality and the average age was 12.5 years (range 11-15 years). A single 7.0 mm cannulated cancellous screw was used in all patients. The average time to fusion was 18 months (range 6-36 months) and duration of follow up ranged from 5 to 8 years (mean 6.5 years). None of the patients had implant removal and at latest review did not show any evidence of chondrolysis, avascular necrosis, premature physeal arrest or secondary arthrosis in the prophylactically fixed hip. One patient (1.5%) developed a superficial wound infection, which was successfully treated by antibiotics. This study demonstrates the safety of prophylactic fixation using a single cannulated cancellous screw and we recommend it for prevention of delayed slip and hence secondary osteoarthrosis.