Abstract
Although high tibial osteotomy for osteoarthrosis of the medial compartment of the knee joint is well recognized, the correctional angle in the management of this osteotomy is much less well established. Sixty-eight out of 92 joints were reviewed 1 to 14 years following tibial osteotomy.
The femorotibial angle (FTA) and the Mikulicz line (M line) were measured on anteroposterior radiographs of the lower extremities in standing position postoperatively. The region of the M line on the tibial joint surface was determined by the % M value described by Ogata. Clinical results were evaluated using the recovery rate of the Japan Orthopaedic Association score by Hirabayashi.
There was no significant correlation between either %M and the recovery rate or FTA and the recovery rate. A comparison of FTA and %M showed a correlation of R=0.446, but this was not statistically significant.
In the patients in whom the M line passed through the middle one-third of the lateral tibial plateau; that is, the %M (the portion from 66.67% to 83.33%), the postoperative recovery rate was much better than in other patients. Therefore, it was suggested that in performing a high tibial osteotomy, it is essential to choose the degree of axial correction in such a way that the postoperative M line passes through the middle one-third of the external tibial plateau.
