Background: Autologous chondrocyte implantation (ACI) is frequently used to treat symptomatic defects of the articular cartilage.
Purpose: To test whether matrix-associated autologous chondrocyte implantation or the original periosteal flap technique provides superior outcomes in terms of clinical efficacy and safety.
Study design: Randomized controlled trial; Level of evidence, 2.
Methods: Twenty-one patients (mean age, 29.3 +/- 9.1 years) with symptomatic isolated full-thickness cartilage defects (mean 4.1 +/- 09 cm2) at the femoral condyle were randomized to matrix-associated autologous chondrocyte implantation or the original periosteal flap technique. The primary outcome parameter was the postoperative change in knee function as assessed by the International Knee Documentation Committee (IKDC) score at 12 months after ACI. In addition, the IKDC score was assessed at 3, 6, 12, and 24 months after surgery. Secondary outcome parameters were postoperative changes in health related quality of life (Short Form-36 Health Survey), knee functionality (Lysholm and Gillquist score), and physical activity (Tegner Activity Score) at 3, 6, 12, and 24 months after ACI. Magnetic resonance imaging was performed to evaluate the cartilage 6, 12, and 24 months after ACI and rated using the Magnetic Resonance Observation of Cartilage Repair Tissue score. Adverse events were recorded to assess safety.
Results: The primary outcome parameter showed improvement of patients 1 year after autologous chondrocyte implantation, but there was no difference between the periosteal flap technique and matrix-associated ACI (P = .5573); 2 years after ACI, a similar result was found (P = .4994). The study groups did not show differences in the Short Form-36 categories and in knee functionality as assessed by Tegner Activity Score 12 months (P = .4063) and 24 months (P = .1043) after ACI. There was a significant difference in the Lysholm and Gillquist score at 12 months (P = .0449) and 24 months (P = .0487) favoring the periosteal flap technique group. At 6 months after surgery, a significantly lower Magnetic Resonance Observation of Cartilage Repair score was obtained in the matrix-associated ACI group (P = .0123), corresponding to more normal magnetic resonance imaging diagnostic findings. Twelve and 24 months after ACI, the differences between the 2 groups were not significant (12 months, P = .2065; 24 months, P = .6926). Adverse events were related to knee problems such as transplant delamination, development of an osseous spur, osteochondral dissection, and transplant hypertrophy. Systemic (allergic, toxic, or autoimmune) reactions did not occur.
Conclusion: There was no difference in the efficacy between the original and the advanced ACI technique 12 and 24 months after surgery regarding International Knee Documentation Committee, Tegner Activity Score, and Short Form-36; however, with respect to the Lysholm and Gillquist score, better efficacy was observed in the periosteal flap technique group.