Surgical interruption of patellar blood supply by total knee arthroplasty.

Arterial blood supply of the patella was demonstrated in 21 cadaver knees by intraarterial injection of radiopaque contrast. When the standard medial parapatellar approach or lateral retinacular release was carried out at a distance of at least 1 cm from the margin of the patella, some steps in total knee arthroplasty caused no impairment and others jeopardized the filling of intraosseous vessels. The radial intraosseous vessels are jeopardized by osteotomy of a deformed patella or excision of fat pad. The prepatellar vessels greatly contribute to intraosseous vascularization and should be carefully preserved.