Group I consisting of 53 knees (60 cases) of avulsion fracture of the femorotibial joint treated in the last 9 years was compared Group II consisting of 65 knees of intraligamentous rupture treated in the last 3 years. Average age at the time of Group I was 30 years which was slightly higher than that of Group II whose average age was 26 years. Injury of combined ligaments was 34.0% for Group I and 18.5% for Group II. Cartilage injury was 22.6% for Group I and 40.0% for Group II. Especially many lateral meniscus injuryies in Group I and medial injuries in Group II were observed. Major causes of trauma in Group I were traffic accidents and of Group II were sport injuries. Our conclusion was that avulsion fracture of this joint was caused by high rates of loading combined with sheer force rather than low rates of loading (sprain).
