Patello-femoral disorders with anterior knee pain have become one of the most important subjects in orthopaedic surgery. The greater part of them are those with chondromalacia patella, patello-femoral compartment osteoarthritis, mal-tracking patella and painful shelf. The synovial impingement syndrome in the lateral patello-femoral facets, however, was rarely found and reported here as a new disease entity. Lateral shift and degree of lateral tilt of the patella shown on roentgenograms were found to be the most useful indications for deciding to perform medialization of the tibial tuberosity. Measurements were done in knees with surgical indication of patients with ages of less than 40 years. The former was 9.9 mm±4.8 mm in 13 knees. The latter was 24.6°±9.7°in 18 knees. Subluxation of the patella is, thus, defined by either more than 5 mm of the former or more than 15°of the latter.
Clinical results of medialization or advancement of the tibial tuberosity revealed that improvements of symptoms were noted in 75-85% of the 26 knees operated on, except for those with retropatellar crepitation, improvement of which was found only in 20% of the cases. The position of the patella, however, was lowered after the above surgeries in 58.8% of 34 knees operated on, especially in the elderly. Fracture of the fragment was observed in 2 of 50 operated knees as a complication, but ended in there being satisfactory results. In 9 knees articular cartilages were observed at surgery and at the time of removal of internal fixation, usually one to two years after the initial surgery. All of the knees showed regeneration of degenerated cartilage postoperatively. The dege-neration grading and regeneration staging attempted were found to be satisfactory for evaluation of disorders.
