Three cases of chronic knee-joint contractures in patients with severe hemophilia A were corrected to near full extension without significant hemorrhage by using a human antihemophilic factor concentrate, fraction I-0, prepared by the glycine method of Blombäck and Blombäck. The amount of substitution needed was adjusted on the basis of serial determinations of the antihemophilic factor concentration in the patient's plasma. The flexion contractures were corrected by skin traction for two to three weeks followed by an extension brace for a few more weeks. In one of these patients, a supracondylar wedge osteotomy was subsequently done to correct a 30-degree valgus deformity of the knee. Prior to intervention, the children were unable to walk. Postoperatively they could walk unaided and even cycle and ski despite persistent limitation or absence of knee flexion.
It is emphasized that adequate substitution therapy in hemophilia, based on serial determinations of the plasma antihemophilic factor levels, is now feasible.