Alterations in the patella after a high tibial or distal femoral osteotomy

Knee osteotomies realign the knee in an attempt to better distribute forces across the knee. The anatomic and physiologic function of the extensor mec hanism, which includes the quadriceps tendon, patella, and patella ligament , may be altered during this procedure. An understanding of these changes i s important especially when additional surgery becomes necessary, such as a conversion to a total knee arthroplasty. The current authors discuss patel la mechanics and changes in the patella associated with osteotomies about t he knee and the influence on normal patella biomechanics. Although patella changes are uncommon after a distal femoral osteotomy, poor total knee arth roplasty outcomes after a high tibial osteotomy attributable to patella alt erations exist. Surgical technique during the primary high tibial osteotomy and the conversion to the total knee arthroplasty can reliably improve the final outcome. Rigid internal fixation with early knee mobilization after high tibial osteotomy reduces the incidence of patella baja and improves to tal knee arthroplasty outcome after a high tibial osteotomy, whereas while patella changes after a distal femoral osteotomy are minimal and largely ig nored.