Osteoarthrosis in a knee joint due to chronic posttraumatic insufficiency of the medial collateral ligament. Nine-year follow-up.

The purpose of the present study was to examine and describe the osteoarthrotic changes that chronic, partial or complete medial collateral ligament (MCL) insufficiency causes to the knee joint. Forty-eight patients with partial and 25 with complete, isolated rupture of the MCL had a clinical and radiological reexamination of the knee on an average of nine years after the injury. In both groups the posttraumatic osteoarthrotic changes caused by the MCL insufficiency occurred very frequently on the medial side of the knee. The most characteristic findings were osteophytes and subchondral sclerosis of femoral and tibial medial condyles, tibial eminence and patella, ligament calcification of femoral medial condyle as well as narrowing of medial joint space. In patients with a partial tear 91% and in patients with complete tear 88% of all arthrotic changes caused by the insufficiency were one of these mentioned above, and other findings were only occasional. According to the radiological criteria of the authors none of the patients in the group with partial, but 17 (68%) of those with complete insufficiency of the MCL suffered from a clear posttraumatic osteoarthrosis of the injured knee. In complete tears the total extent of these pathological changes per patient was sixfold compared to the patients with a partial tear. It was concluded that chronic, posttraumatic insufficiency of the MCL causes characteristic medial side osteoarthrotic changes to the injured knee and that the amount of these changes seems to depend on the amount of the instability.(ABSTRACT TRUNCATED AT 250 WORDS)