Current status of a hinge prosthesis (GUEPAR).

Although a great many GUEPAR hinge knee prostheses have been successful, the early complications have been numerous. Also, long-term follow up studies have been hampered owing to the patients' advanced age. Many of the patients died of causes unrelated to their knee. The use of this prosthesis is limited to very old patients or individuals with grossly dislocated knees. Previous problems such as patellar pain have been resolved. Because the femoral and tibial stems have been reinforced, they are much stronger and cement is no longer necessary for fixation. The part that articulates with the patella has been changed so that it is now more shallow and better adapted to the shape of the patella.