Anterior cruciate ligament tears treated with percutaneous injection of autologous bone marrow nucleated cells: a case series
The Regenerative Clinic's view on this research
Mr Ali Noorani “There have been studies looking in to the use of bone marrow aspirate concentrate (BMAC) for ACL tears, one particular study published in the Journal of Pain in 2015. This was a small study with only 10 patients, and it was a level 4 study. The current evidence is of low level, but this study indicated that there was some promise of bone marrow concentrate in the treatment of grade one/two and possibly grade three ACL tears without retraction. In our opinion, the evidence is insufficient and further investigations would need to be done using controlled groups to recommend the use of bone marrow aspirate concentrate (BMAC) in ACL injuries.”
INTRODUCTION: This was a prospective case series designed to investigate treatment for anterior cruciate ligament (ACL) tears using an injection of autologous bone marrow concentrate.
METHODS: Consecutive adult patients presenting to a private outpatient interventional musculoskeletal and pain practice with knee pain, ACL laxity on exam, and magnetic resonance imaging (MRI) evidence of a grade 1, 2, or 3 ACL tears with less than 1 cm retraction were eligible for this study. Eligible patients were treated with an intraligamentous injection of autologous bone marrow concentrate, using fluoroscopic guidance. Pre- and postprocedural sagittal MRI images of the ACLs were analyzed using ImageJ software to objectively quantify changes between pre- and posttreatment scans. Five different types of measurement of ACL pixel intensity were examined as a proxy for ligament integrity. In addition pain visual analog scale (VAS) and Lower Extremity Functional Scale (LEFS) values were recorded at baseline and at 1 month, 3 months, 6 months, and annually postinjection. Objective outcomes measured were pre- to post-MRI measurement changes, as analyzed by the ImageJ software. Subjective outcomes measured were changes in the VAS and LEFS, and a self-rated percentage improvement.
RESULTS: Seven of ten patients showed improvement in at least four of five objective measures of ACL integrity in their postprocedure MRIs. In the entire study group, the mean gray value, median, raw integrated density, and modal gray value all decreased toward low-signal ACLs (P=0.01, P=0.02, P=0.002, and P=0.08), indications of improved ligament integrity. Seven of ten patients responded to the self-rated metrics follow up. The mean VAS change was a decrease of 1.7 (P=0.25), the mean LEFS change was an increase of 23.3 (P=0.03), and mean reported improvement was 86.7%.
CONCLUSION: Based on this small case series, autologous bone marrow concentrate shows promise in the treatment of grade 1, 2, and possibly grade 3 ACL tears without retraction. Further investigation using a controlled study design is warranted.