A study on bone marrow derived stem cells and its application on ACL graft regeneration in partial ACL tears

Background: Partial tears of the anterior cruciate ligament (ACL) are frequent, and there is still considerable controversy surrounding their diagnosis, natural history and treatment. Aim: To examine patient-reported outcomes, physical examination and magnetic resonance imaging (MRI) findings of partial ACL tears treated with an intraarticular injection of BMAC and to evaluate both subjective and objective clinical results as to compare the outcomes Pre Procedure, at 3 weeks and 3 months following the procedure, as well as functional recovery time. Methods: From April to July 2023, consecutive patients from a single institution with partial ACL tears treated nonoperatively were prospectively evaluated. Partial tears were defined as a positive Lachman test with clear endpoint, a negative pivot-shift and MRI were taken and were classified and graded on the basis of VAN MEER Radiological Classification. Patients were treated with one intraarticular injection of BMAC and specific physical therapy protocol. Prospective analyzed data included physical examination and Lysholm and International Knee Documentation Committee scores were taken Pre Procedure, at 3 weeks and 3 months. Baseline MRI findings and at 3 months follow-up were reviewed. Failure was defined as those patients with clinical instability at follow-up that required ACL reconstruction at 3 months. Results: A total of 30 patients where included, all 30 treated with BMAC injection with a mean follow-up of 3 months. Their Mean Age was 40. 20 (60%) of them were men and 40 % of them were females, Overall failure rate was (n = 3). One patient (5.0%) was unable to RTS due to subjective instability. The other 95.0% in each group were able to return to their previous sports level. Regarding objective stability, at 6 month follow-up in group 1, 19 presented a decrease in the side-to-side difference, 10 remained with the same difference, and 1 had 2 mm more, over all, mean RTS time was 3 months. Significant differences were observed regarding subjective outcomes, return to sport Following Procedure. MRI findings revealed an improvement in the ACL signal in half of the patients. However, we did not find a significant relationship between MRI findings and clinical outcomes. Conclusion: Overall, 95.0% of patients returned to sports at a mean follow-up of 3 mo. Mean time to return to sports was 3 months. The addition of BMAC 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.