Core biopsy specimens of the proximal femoral growth plate from three
patients with slipped capital femoral epiphysis were studied by light and
electron microscopy. In the resting zone, the cartilage matrix was composed
of large, densely packed collagen fibrils. The cartilage matrix in the
zones of chondrocyte hypertrophy where the slippage occurred contained only
scattered fine collagen fibrils in a homogeneous ground substance. The
change in composition of cartilage matrix in the distal region of the
epiphyseal plate may predispose that region to slippage.