1. Slipping patella is probably a slight degree of congenital dislocation of the patella.
2. The pathology in the last three of the author's cases was practically the same.
3. The operation described should free the patella from an abnormal bed and allow it to be kept in the intercondylar-space.
4. The operation is simple and the convalescence is short. The patients are permitted to walk in three to four weeks.