Sequential magnetic resonance imaging in slipped capital femoral epiphysis: assessment of preslip in the contralateral hip.

Thirty-three images using magnetic resonance imaging (MRI) in 10 patients with slipped capital femoral epiphysis were evaluated. The MRI of affected hips delineated typical widening of the physis. Sequential MRI demonstrated the process of premature closure of the physis developing from the posterior portion anteriorly. In 4 of the 10 asymptomatic contralateral hips, physeal widening was clearly observed in the center or posteromedial region of the physis on T1-weighted images. We performed prophylactic pinning for the four cases showing physeal widening on MRI, and none of the other cases developed a slip. MRI accurately documented detailed features of slips, as well as physeal changes, and may provide indicative information on prophylactic pinning for contralateral hips.