Favourable long-term functional and radiographical outcome after osteoautograft transplantation surgery of the knee: a minimum 10-year follow-up.

ABSTRACT

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 follow-up 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.