LONG TERM RESULTS OF HIGH OBLIQUE T1BIAL OSTEOTOMY FOR TREATMENT OF OSTEOARTHRITIS OF THE KNEE.

Abstract

This study evaluates the results of our technique of proximal tibial osteotomy for treatment of osteoarthritis of the medial compartment of the knee.

One hundred and thirty eight knees were operated upon from 1981 to 1990. The degree of appropriate correction was measured in standing radiographs of the whole limb. Our technique consists of the creation of an osteotomy running obliquely just above the tibial tuberosity to the posterior tibial surface. No wedge is removed. Realignment is obtained by sliding the two osteotomy surfaces until the desirable correction is obtained. The osteotomy is fixed by a 90° blade-plate. By this technique precise correction can be achieved.

One hundred and seventeen knees were evaluated after a mean FU of 5, 5 years with 91% excellent or good result. In a second evaluation of 93 knees in a mean FU of 7.8 years, the good results dropped to 72%. In a third evaluation of 81 knees, after a mean FU of 11.8 years (range 9 to 16), only 54% of the knees maintained acceptable results.

The best results in the last evaluation were seen in 43 knees in which the postoperative alignment of femorotibial angle was 178° to 182°. Undercorrected or excessively overcorrected knees showed deterioration of the results in 4 to 9 years depending on the degree of mal-correction.

The results deteriorate with passage of time especially if precise correction is not achieved. Accurate preoperative radiographic measurements and precise operative technique is required to obtain exact correction of the axis in order to maintain the good results for a long period of time.