Case 1. A one-year-old boy had congenital persistent dislocation of the right patella, he was treated with modified Tavenier's procedure and medial hamstring lengthning. Case 2. A girl, aged twenty-two, had recurrent dislocation of the right patella, she was treated with the operation of Hauser. Case 3. A girl, aged seventeen, had bilateral dislocations of the patella. Operations of Hauser and Campbell was performed on both sides. Case 4. A boy, aged fifteen, had recurrent dislocation of the left patella, he was treated with quadricepsplasty. We discussed congenital factors and hereditary tendency of these cases and their treatments.
