Slipped capital femoral epiphysis: an analysis of treatment outcome according to physeal stability.

INTRODUCTION Slipped capital femoral epiphysis (SCFE) is a common hip disorder in adolescents. Treatment can be associated with serious complications, mainly avascular necrosis (AVN). The objective of this study was to evaluate treatment outcomes and complications based on physeal stability at presentation. METHODS We reviewed retrospectively all children treated for SCFE from 1990 through 2000 at the Children's Hospital of Eastern Ontario, Ottawa. RESULTS Of a total of 87 patients (56 male) identified, 73 had slips classed as stable and 14, unstable; 42 involved the left side, 34 the right, and 19 were bilateral. Avascular necrosis (AVN) developed in 1 patient with a stable slip (morbidity 1.4%) and in 3 with unstable slips (21.4%; p = 0.001). Manipulative anatomical reduction was done in 11 cases (78.5%), all unstable slips. All slips complicated by AVN had been classified according to the traditional system as acute-on-chronic. Complication rates differed significantly between unstable slips (36%) and stable (20%). No statistically significant association was found between AVN and slip severity, time to fixation or use of reduction. CONCLUSIONS The treatment of stable slips exhibits a lower incidence of AVN. These results nevertheless suggest that gentle reduction of unstable slips is safe and unaccompanied by an increase in complications.