Equivalent 10-Year Outcomes After Implantation of Autologous Bone Marrow–Derived Mesenchymal Stem Cells Versus Autologous Chondrocyte Implantation for Chondral Defects of the Knee
The Regenerative Clinic's view on this research
Mr Ali Noorani “This study, published in The American Journal of Sports Medicine, shows that bone marrow derived ‘Stem cells’ can have a role in cartilage repair. This was a well powered cohort study with level 2 of evidence with a long follow up of ten years. The results show that both treatment options had equivalence i.e there was no difference between autologous bone marrow concentrate and first generation ACI (Autologous Chondrocyte Implantation). The study had a total of 72 patients who were matched in terms of age and lesion site. Validated knee scoring systems were used to observe the outcome. Although there was no difference in the clinical results, what is clear is that there is a huge difference in cost. This is important as Bone marrow cells, as a procedure, normally cost a fraction of the cost of the first generation ACI procedure.”
Background: The use of bone marrow–derived mesenchymal stem cells (BMSCs) in cartilage repair procedures circumvents some of the limitations of autologous chondrocyte implantation (ACI), but long-term outcomes for this newer procedure are lacking. The authors previously reported comparable outcomes for the 2 procedures at 2-year follow-up.
Purpose: The purpose was to compare the long-term clinical outcomes of ACI versus BMSCs. It was hypothesized that there would be no significant difference between the groups in terms of patient-reported outcome scores and safety outcomes at 10-year follow-up.
Study Design: Cohort study; Level of evidence, 2.
Methods: Seventy-two patients who underwent either ACI or BMSC implantation—matched in terms of age and lesion site— were followed up to a median of at least 10 years. Patients were assessed with the 36-item Short Form Health Survey (SF-36), the International Knee Documentation Committee knee evaluation form, the Lysholm Knee Score, and the Tegner Activity Scale. In addition, information was obtained regarding any additional surgical procedures as well as safety data, with particular attention to infection and tumor formation.
Results: There was an improvement in all patient-reported outcomes scores apart from the Mental Component Summary of the SF-36 after cartilage repair surgery. There was no significant difference in any of the patient-reported outcomes between cohorts at any time point. Six and 5 patients in the ACI and BMSC groups, respectively, underwent subsequent surgical procedures, including 1 total knee replacement in the BMSC group. None of the patients in either group developed any deep infection or tumor within the follow-up period.
Conclusion: BMSC implantation used for the treatment of chondral defects of the knee appears to result in equivalent clinical outcomes to first-generation ACI at up to 10 years, with no apparent increased tumor formation risk.