Valgus slipped capital femoral epiphysis: prevalence, presentation, and treatment options.

BACKGROUND

Valgus slipped capital femoral epiphysis (SCFE), defined as posterolateral slippage of the proximal femoral epiphysis on the metaphysis, is an uncommon occurrence. The purpose of this study was to review our institution's experience with valgus SCFE to better describe its prevalence, clinical presentation, and treatment.

METHODS

Radiographs of patients undergoing treatment of SCFE between 1996 and 2008 were reviewed. Valgus SCFE was identified by increased prominence of the lateral femoral epiphysis relative to the lateral femoral neck and an increased anteroposterior physis shaft angle. We identified 12 patients (16 hips) with valgus SCFE and compared them with 123 cases identified as classic posteromedial SCFE.

RESULTS

The prevalence of valgus SCFE at our institution was 4.7% (12 of 258 patients). Significant differences between patients with valgus SCFE and those with classic SCFE were found for age at presentation (mean 1.1 y younger, P=0.033), sex (58% female vs. 28% male, P=0.044), and classification as atypical SCFE (42% vs. 3%, P<0.001), respectively. Four patients in the valgus group had pituitary and growth hormone dysfunction, and 1 was diagnosed with Stickler syndrome. Hips of valgus patients had a significantly higher mean femoral neck shaft angle (154.3 degrees) as compared with classic SCFE patients (140.5 degrees) (P<0.001). Difficulty placing hardware for in situ fixation was noted in 5 of 11 valgus cases, with 1 case complicated by articular surface penetration and chondrolysis.

CONCLUSIONS

Valgus displacement often presents with a relatively normal appearance on anteroposterior radiographs. Valgus SCFE may be associated with obesity, coxa valga, hypopituitarism, and Stickler syndrome. Posterolateral displacement of the femoral epiphysis makes in situ fixation of valgus SCFE more difficult, due to the necessity of a more medial starting point.

LEVEL OF EVIDENCE

Case series, Level IV.