Vascular supply to slipped capital femoral epiphysis

The etiology of avascular necrosis associated with slipped capital femoral epiphysis has not been well understood. The aims of this study were to clar ify the blood supply to the slipped epiphysis and to examine whether this v ascular supply is damaged before the reduction. Twelve patients (12 hips) u nderwent selective angiography of the medial circumflex femoral artery. The re were seven stable slips and five unstable slips. All patients with slips underwent angiography before reduction, and one patient with an unstable s lip underwent angiography both before and after reduction. The superior ret inacular artery (SRA) was filled in all stable slips. This result was in ac cordance with the previous report that stable slips result in low rates of avascular necrosis. Of five unstable slips, the SRA was stained in two and was not filled in three. In one slip examined both before and after the man ipulative reduction, the SRA was not seen before it but was well stained af ter it. These results have suggested that in some unstable slips them vascu lar injury occurs at the time of injury, before reduction, and that the red uction dose not necessarily contribute to the risk of avascular necrosis af ter slipped capital femoral epiphysis.