High tibial osteotomy. A prospective clinical and roentgenographic review.

In a prospective clinical and roentgenographic analysis of 79 knees treated by a valgus closing wedge high tibial osteotomy, the average follow-up period was 5.8 years (three to nine years); 80% of the patients had good or excellent results. Correction to a femorotibial angle between 6 degrees and 14 degrees of femorotibial valgus was associated with an optimal clinical result. Undercorrection to less than 5 degrees of femorotibial valgus was associated with a high (62.5%) failure rate. Patients whose distal femur had a femoral shaft-transcondylar (FS-TC) angle of less than 9 degrees have an increased incidence of undercorrection. A poor prognosis was noted in knees whose patellofemoral joint preoperatively had moderate or severe roentgenographic evidence of osteoarthritis (OA) when compared to the group whose patellofemoral compartment had no or mild roentgenographic evidence of OA. Accurate femorotibial realignment was essential for success. The slope of the distal femoral articular surface, the FS-TC angle, affects the degree of correction and should be considered in preoperative planning.