Ceramic unicompartmental knee arthroplasty for spontaneous osteonecrosis of the knee joint.

Unicompartmental replacement with a ceramic knee prosthesis was performed in 10 patients with spontaneous osteonecrosis. The follow-up period averaged 42 months, with a range of 24 to 68 months. All of the knees received a Kyocera unicompartmental knee arthroplasty and all patients were evaluated using The Knee Society Clinical Rating System. The mean knee score increased from 50.6 to 90.8 at the last follow-up, showing no deterioration with time. All of the patients showed marked improvement of pain and excellent or good results were obtained in all cases. None of the patients had progressive radiolucency wider than 2 mm at the final follow-up. Ceramic unicompartmental knee arthroplasty is an acceptable treatment for spontaneous osteonecrosis of the knee joint; a satisfactory postoperative range of motion can be achieved, there are few complications, and a high initial success rate.