Osteotomy around the knee vs. unicondylar knee replacement

Osteotomy around the knee and unicondylar knee replacement can both produce excellent results in unilateral knee osteoarthritis. The indications for these procedures differ significantly and are discussed in this article. A weight-bearing long-leg radiograph, clinical stability tests and varus-valgus-stress radiographs are mandatory for a preoperative analysis. Osteotomy is a safe and reproducible procedure when a biplanar cutting technique is used and fixation is achieved with a plate fixator. Unicondylar knee replacement can be performed minimally invasive with a quadriceps-sparing arthrotomy. High tibial osteotomy and unicondylar knee may produce good results in unilateral osteoarthritis of the knee. Our multicenter follow-up study with 533 patients revealed good functional outcome scores with a low complication rate. The subjective ratings were better than in comparable groups with unicondylar knee replacement and with total knee arthroplasty. The main criterium for osteotomy versus unicondylar knee replacement is constitutional deformity of femur or tibia. In constitutional deformity, osteotomy has a very good prognosis. The results are not dependent on age, BMI, or grade of osteoarthritis. Activity and ligament stability of the knee are secondary criteria in favor of osteotomy. Medial osteoarthritis without constitutional deformity should be treated with unicondylar knee replacement.