Indication and Problems of Unicompartmental Knee Arthroplasty

Abstract

Unicompartmental knee arthroplasty (UKA) is an advisable operation for medial or lateral compartmental osteoarthritis of the knee in the elderly. UKA has several good points: high satisfaction of the patient, excellent range of motion, gait pattern resembling normal, minimum of bone resection, easier and shorter time of operation, less blood loss, short period of postoperative management, and successful revision surgery. To obtain excellent long-term follow-up results, the indications for UKA have to be strictly determined and the surgical technique has to be mastered. The indications of UKA for medial compartmental osteoarthritis include patient and knee selection. Patient selection is as follows: more than 70-year-old patient, no obesity, low activity of work and activites of daily living, and patient whose general condition is too severe to be operated on with total knee arthroplasty or high tibial osteotomy. Knee selection is as follows: less than 180° of valgus stress femorotibial angle, no deficiency of anterior cruciate ligament, no severe patellofemoral osteoarthritis, less than 30° of flexion contracture, undercorrected case after high tibial osteotomy, and no past history of knee infection. Surgical techniques required are as follows: correction of malalignment to 172° femorotibial angle at standing for medial compartmental osteoarthritis of the knee, resection of osteophytes, notch plasty, subperiosteal medial tension band release, and subchondral bone-preserving surgery.