Two Cases of Avascular Necrosis After Prophylactic Pinning of the Asymptomatic, Contralateral Femoral Head for Slipped Capital Femoral Epiphysis: Case Report and Review of the Literature

Background: In a child with a unilateral slipped capital femoral epiphysis (SCFE), the treatment of the radiographically normal, asymptomatic contralateral hip remains controversial. The risks of a subsequent slip have to be measured against the risks involved with an additional surgical procedure. Proponents of prophylactic pinning believe that fixation with a single cannulated screw is a safe method to prevent secondary arthrosis from a missed minor slip. Others argue that in most cases it is an unnecessary procedure and with careful follow-up, any issues with the asymptomatic, normal hip can be identified early and addressed. Methods: We retrospectively look at 2 cases where avascular necrosis (AVN) developed in the prophylactically pinned asymptomatic and radiographically normal hip in the setting of an identified SCFE on the contralateral hip. Results: Two cases of AVN developed in the prophylactically pinned hips within 8 months of the initial pinning procedure. Conclusions: This case report demonstrates that prophylactic pinning of an asymptomatic, radiographically normal hip in the setting of a SCFE on the contralateral side is not a benign procedure and is one that has potential for significant complications. The risk of AVN in the prophylactically pinned hip needs to be taken into careful consideration as this risk can have devastating consequences to the patient.