Purpose: To report arthroscopic second look as well as clinical results after arthroscopic autologous chondrocyte implantation (ACI) for articular cartilage repair at the knee joint.
Methods: A second-look assessment after arthroscopic ACI using spheroides was performed in 41 patients with 57 full-size articular cartilage defects of the knee. The median time from ACI to second-look arthroscopy was 10 (6-72) months. The ACI was assessed macroscopically and by probing according to the International Cartilage Repair Score (ICRS)-Cartilage Repair Assessment (CRA) to get information on the amount and quality of regeneration. Clinical follow-up with subjective outcome scores was performed an average of 34.5 ± 19.2 months after ACI. Twenty-seven (65.8 %) of ACI's were combined with additional procedures.
Results: The ICRS-CRA was rated "normal" or "nearly normal" in 52 of 57 (91.3 %) and "abnormal" in 5 (8.8 %) of all cartilage defects. At follow-up, evaluation of KOOS was an average of 81.0 ± 12.9 for pain, 76.8 ± 16.6 for symptoms, 85.1 ± 14.9 for activities of daily living, 55.3 ± 27.7 for sport and recreation and 50.6 ± 23.8 for quality of live. IKDC was 63.0 ± 18.8, Lysholm score was 79.0 ± 18.0, and Tegner score was 4 (1-6). Subjective assessment according to the VAS scale was an average of 7.4 ± 2.1 for overall satisfaction and 6.7 ± 2.5 satisfaction for the operated knee. Seven patients (22.6 %) showed low subjective outcome scores at last follow-up-of these, 2 patients showed a CRA 3 and 5 a CRA 1 or 2.
Conclusion: At second-look arthroscopy, 52 (91.3 %) of all cartilage defects showed a normal or nearly normal macroscopic articular cartilage regeneration after arthroscopic ACI using spheroides. Twenty-four patients (77.4 %) showed good subjective clinical results. The high number of concomitant surgery reflexes the complex aetiology of cartilage lesions and complexity of treatment. Thus, a strict indication and surgical planing is necessary to avoid clinical failures.
Level of evidence: IV.
Keywords: Autologous chondrocyte implantation (ACI); CRA; Cartilage lesion; Cartilage repair; Second look; Spheroides.