Slipped capital femoral epiphysis - Early mechanical damage to the acetabular cartilage by a prominent femoral metaphysis

On the basis of intraoperative observations in 13 consecutive adolescents ( 14 hips) with slipped capital femoral epiphysis (SCFE), we found that when the anterior femoral metaphysis was level with or extended past the epiphys is, it caused labrum and cartilage damage. As a result of an impingement be tween the metaphysis and the superomedial acetabular rim, the labrum reveal ed erosions, scars or tears. Further jamming of the metaphysis into the joi nt damaged the adjacent acetabular cartilage, varying from a partial- to a full-thickness cartilage loss. In all patients, the femoral head cartilage was intact; no avascular necrosis was present. Our findings suggest that ar throsis in SCFE can be triggered by early mechanical damage of the acetabul ar cartilage.