Ollivier M, et al. - Authors assessed the long-term clinical outcome and implant survivorship of patients that underwent unicompartmental knee arthroplasty (UKA) for medial knee osteonecrosis. They retrospectively reviewed 29 consecutive UKA performed by two senior surgeons (>50 UKA a year) in 28 patients with medial unicompartmental avascular osteonecrosis of the knee (AVN) of the knee between 1989 and 2001. The mean age of the patients included in this study was 67 years. In the longest series to date, findings suggested an association of medial UKA for treatment of AVN with high survival rates and stable clinical improvement. In order to treat patients with unicompartmental osteonecrosis of the knee, UKA is a durable and efficient option. The mean Knee Society Scoring system (KSS) at latest follow-up was 89 points (range 68-100) and 83 (range 66-96) for Function KSS.