Two siblings with multiple epiphyseal dysplasia and slipped capital femoral epiphysis are reported. In one an osteosarcoma developed in the femur necessitating amputation.
The tibial growth plates of the amputated extremity were profoundly disorganized, with disordered cartilage-cell columns, clefts, and areas of degeneration in the matrix. The process of enchondral ossification was in complete disarray; whereas, remodeling, both in regard to osteoblastic and osteoclastic activity, appeared normal.
The galactosamine content of the epiphyseal-plate cartilage was decreased while the glucosamine and hydroxyproline were unchanged. In the light protein-polysaccharide fraction the amino acids were within normal limits; whereas, less chondroitin sulphate and more keratosulphate were found than in normal persons. These results point to an abnormality mainly in the chondroitin sulphate of the growth-plate cartilage.
The urinary mucopolysaccharides in our two patients were within normal limits, as has been observed in all our patients with multiple epiphyseal dysplasia.