gms | German Medical Science

Objectives: To investigate postoperative complications and associated risk factors for failure following autologous chondrocyte transplantation (ACT) as well as its long-term survival and clinical function. It was hypothesized, that ACT is a secure technique for cartilage repair with a low incidence of postoperative complications and rare rates of revision surgery combined with a high long-term survival and good to excellent clinical outcome in long-term-follow-up.

Methods: All patients undergoing ACT-C of the knee joint between 2006 and 2012 at the author’s institution were included in this retrospective study. Concomitant procedures were performed if necessary. Postoperative complications, revision surgeries, risk factors and failure were evaluated 6 months after the surgery. Long term clinical outcome was assessed using the Lysholm Score, the Tegner Score, a 10-grade scale for satisfaction and the Visual Analogue Scale (VAS) at a minimum follow-up of 9 years postoperatively. Long term survival was calculated using revision surgeries, failures and conversion procedures to create a Kaplan-Meier-analysis. A subgroup analysis for different defect locations was performed. 139 patients were included in this study (27% female/ 73% male; age 26.7 [21.7;35.2] years). The median defect size was 4.0 [3.0;6.0] cm² (40% medial femoral condyle (MFC), 17% lateral femoral condyle (LFC), 36% patella, 19% trochlea). 97 (70%) of the patients had undergone previous surgery and 84 (60%) underwent concomitant procedures.

Results: 8% of patients had postoperative complications (4% bleeding, 2% arthrofibrosis, 2% infection), 7% of patients needed revision surgery in the first 6 months. No significant difference was found between the patellofemoral and femorotibial group. 12% of patients had a prolonged deficit in ROM that did not require revision surgery. Patients showed good clinical long-term outcomes 9-15 years after the index surgery (Tegner: 4.7 ± 1.8; VAS: 2.4±2.1; Lysholm: 80±14; satisfaction with operation: 7.3±1.9). Survival rates were 88% at 9 years, 85% at 11 years, and 85% at 13 years after the index procedure. Reasons for failure were: 4 (5%) Debridement of ACT, 3 (3%) Re-ACT, 3 (3%) Prothesis, 1 (1%) HTO).

Conclusion: The present study indicates ACT-Cs as an effective treatment option for femorotibial- as well as patellofemoral cartilage defects with a high long-term survival and low conversion rate as well as good long-term results regarding knee function and satisfaction. Postoperative complications needing revision surgery are rare. Prolongated deficits of Range of Motion appear frequently up to six months especially in patellofemoral defects, but can often be successfully addressed by intensified physiotherapy without needing an arthrolysis.