OBJECTIVETo investigate the short-term clinical outcome of unicompartmental knee arthroplasty for the treatment of spontaneous osteonecrosis of the knee.

METHODSFrom September 2013 to April 2014,5 patients with spontaneous osteonecrosis of the knee underwent unicompartmental knee arthroplasty, included 3 males and 2 females, aged from 65 to 80 years old with an average of 74 years. The courses of disease was from 1 to 6 years with the mean of 3 years. According to the radiographic staging criteria of Koshino, 1 case was stage II, 2 cases were stage III, 2 cases were stage IV. Clinical effects were assessed by VAS score, HSS score, and knee range of motion, tibiofemoral angle before and after operation.

RESULTSAll the patients were followed up from 6 to 7 months with an average of 6.4 months. All incisions obtained primary healing, and there were no complications such as infection, thrombosis, fracture of lower limbs. All 5 patients' pain relieved and their knee function improved significantly after operation, but knee range of motion had no obviously improved. Postoperative HSS scores, VAS scores, tibiofemoral angle were significantly improved than that of preoperative.

CONCLUSIONThe short-term effect of unicompartmental knee arthroplasty in treating spontaneous osteonecrosis of the knee is satisfactory.