Objectives: Abrasion arthroplasty is a technically simple and low cost procedure compared to other treatments for full thickness chondral injury. Nevertheless, there is little data on the long-term outcomes of this procedure. We present our results of medial femoral condyle abrasion arthroplasty, with a minimum 10-year follow-up. To our knowledge, this is the longest follow-up to date for this procedure. Methods: From 3/1990 to 12/2001, 76 consecutive patients (37 male and 39 female) suffering from a full thickness chondral defect of the medial femoral condyle underwent abrasion arthroplasty performed by a single surgeon. The average age of the cohort was 65 yrs (range:24-79,SD 15.44 yrs). Inclusion criteria were having undergone abrasion arthroplasty, with a minimum 10-yr follow-up (mean 16.1 yrs, range 10.2yrs-20.1yrs,SD 3.26). Patients with ligament injuries, multiple compartment involvement, varus angulation >10° and inflammatory arthritis were excluded from the study. Preoperative weight bearing radiographs were obtained in all cases. At final f-u patients completed a questionnaire based on their current knee symptoms and need for further surgery. The questionnaire included the IKDC subjective score and a question regarding medication used for the operated knee. Patients were considered to have a successful result if they had no pain or only occasional pain with activity, no limitation of their activities due to the knee, and had not undergone repeat surgery. Results: 65 patients (85.5%) were available for follow-up (3 patients died and 8 were lost at f-u). Patients with lesions less that 4cm2 (n=30) had a 73% success rate at final f-u. Patients with lesions greater than 4cm2 (n=32) had a 21% success rate which was statistically significant (p