Limb alignment after open-wedge high tibial osteotomy and its effect on the clinical outcome.

The purpose of this study was to evaluate the accuracy of alignment after open-wedge high tibial osteotomy and its effect on the clinical outcome. A prospective case series of 56 consecutive patients underwent open-wedge high tibial osteotomy fixed with a TomoFix plate fixator (Synthes, West Chester, Pennsylvania). The correction angle was radiologically determined preoperatively and at 6 months postoperatively. The patients were clinically and radiologically examined preoperatively and at 3, 6, and 36 months postoperatively. The mechanical axis of 50 knees was corrected from an average of 5.7° varus to 1.3° valgus. Forty-three patients had an acceptable correction with Mikulicz line crossing the tibial plateau between 50% to 70% of the tibial plateau width measured from the medial border. Undercorrection (<50%, group II) and over-correction (>70%, group III) were found in 4 and 3 patients, respectively. The mean Lysholm-Gillquist score at 36 months had improved in all groups, with a statistically lower value for group II. Open-wedge high tibial osteotomy results in significant improvement of symptoms and function in all patients in the short term, even with under- and overcorrection of the osteotomy. Undercorrection was associated with a significantly lower clinical outcome in comparison to the accurate correction and overcorrection. Ligamentous laxity or soft tissue slackness of the knee can influence the overall correction after high tibial osteotomy and must be considered in preoperative planning. Patients with a high body mass index had inferior clinical results after open-wedge high tibial osteotomy.