Gel-based autologous chondrocyte implantation (ACI) over the years have shown encouraging results in repairing the articular cartilage. More recently, the use of cultured mesenchymal stem cells (MSC) has represented a promising treatment option with the potential to differentiate and restore the hyaline cartilage in a more efficient way. This study aims to compare the clinical and radiological outcome obtained in these two groups.

Twenty-eight consecutive symptomatic patients diagnosed with full-thickness cartilage defects were assigned to two treatment groups (16 patients cultured bone marrow-derived MSC and 12 patients with gel-type ACI). The MSC group patients underwent microfracture and bone marrow aspiration in the first stage and injection of cultured MSC into the knee in the second stage. Clinical and radiological results were compared at a minimum follow up of five years

There was excellent clinical outcome noted with no statistically significant difference between the two groups. Both ACI and MSC group showed significant improvement of the KOOS, Lysholm and IKDC scores as compared to their preoperative values and this was maintained at 5 years follow up. The average MOCART score for all lesions was also nearly similar in the two groups. The mean T2* relaxation-times for the repair tissue and native cartilage were 27.8 and 30.6 respectively in the ACI group and 28 and 29.6 respectively in the MSC group.

Use of cultured MSC is less invasive, technically simpler and also avoids the need for a second surgery as compared to an ACI technique. With similar encouraging clinical results seen and the proven ability to restore true hyaline cartilage, cultured MSC represent a favorable treatment option in articular cartilage repair.