Purpose
The aim of this study was to assess the progression of radiological cartilage changes and to document the functional, long-term results during a follow-up of 10 years after osteoautograft transplantation (OAT) knee surgery.

Methods
The study was a retrospective analysis of all patients who underwent OAT at Turku University Hospital from
1999 to 2007. Pre- and postoperative cartilage changes were estimated based on standardised radiographs. The extent of osteoarthritis (OA) was graded according to the Kellgren–Lawrence scale. Clinical outcomes were evaluated with the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire.

Results
A total of 60 patients (64 knees) with a median age of 30 years (range 14–62) were included. The median follow-up was 140 months (range 47–205). Of the 64 knees examined, 14 (22%) had a traumatic chondral lesion and 50 (78%) had osteochondritis dissecans (OCD). Preoperatively, 71% of the patients had Kellgren–Lawrence grades of 0–1; during the follow-up period, 50% of the patients showed radiographical progression of OA. OA progressed most significantly in patients with normal preoperative Kellgren–Lawrence grades (p = 0.0003). Patients with no progression in joint space narrowing had statistically significantly better overall KOOS (p = 0.02) than patients whose Kellgren–Lawrence grades worsened. Patients with defect sizes > 3.0 cm2 scored statistically significantly better in all subscales than patients with smaller defect sizes (p = 0.02). Patients with OCD had statistically significantly better KOOS than patients with chondral defects (p = 0.008).

Conclusions
OAT surgery for treating patients with cartilage defects of the knee had good clinical results after a mean followup of 11 years. Radiological analyses revealed a progression of cartilage degeneration in 50% of the operated knees. Patients with no progression of the degenerative changes scored statistically significantly better on the KOOS self-assessment test. These results indicate that OAT surgery appears to be a reasonable therapeutic option to restore knee function in patients with cartilage lesions.

Level of evidence IV.