To identify the incidence of sequential slip of the unaffected hips in patients presenting with unilateral SCFE managed with prophylactic fixation or observation.

A retrospective review of all unilateral SCFE treated during 1998 to 2012 was undertaken. The study compares the incidence of sequential slip of the initially unaffected hip in patients managed with prophylactic fixation or observation. The study also reports the incidence avascular necrosis, chondrolysis, and metal-work related problem in this group of patients. All patients included in this current work have at least 12 months of follow-up from the index slip.

A total of 44 cases had prophylactic fixation of the unaffected hip (mean age 12.6 years,) and 36 patients managed with regular observation (mean age 13.4 years). Sequential slip of the unaffected hip was noted in a total of 10 patients (28 %) managed with regular observation and only in 1 patient (2%) managed with prophylactic fixation. A Fishers exact test showed significantly high incidence of sequential slip in unaffected hips when managed by regular observation (p-value-0.002). There is no evidence of avascular necrosis or chondrolysis in the unaffected hip in both groups, 3 patients had metalwork related problem and one had superficial wound infection in prophylactic fixation group.

Simultaneous prophylactic fixation of the unaffected hips significantly reduces the incidence of sequential slip. This is a relatively safe procedure and should be advocated in all cases of unilateral SCFE to avoid potential complications and preserve function of the unaffected hip.