Stem Cell-Infused Anterior Cruciate Ligament Reconstruction

Bone Marrow Aspirate Concentrate With Two-Staged-Revision ACL Reconstruction

Background:

The incidence of anterior cruciate ligament (ACL) injuries, reconstructions, and re-ruptures has rapidly increased. Patients with failed ACL reconstructions have been reported to suffer from far worse outcomes as compared with those with primary reconstructions, prompting the advancement of surgical and biologic techniques. Effective treatment of re-tears has been shown to be achieved either utilizing a 1-stage or 2-staged approach, with the latter preferred if the patient presents with significant bone loss, previously malpositioned tunnels, or unacceptable tunnel expansion. Recent literature has shown the efficacy of bone marrow aspirate concentrate (BMAC) in improving clinical outcomes and graft integration as well as accelerated ligamentization.

Indication:

Patients are indicated for surgery when presenting with chronic ACL graft failure and objective insufficiency as well as concerns regarding tunnel overlap, enlargement, or interference. Contraindications for revision involve influences of concurrent injuries that may be secondary causes of the ACL injury.

Technique Description:

After bone marrow aspiration is performed, the tibial and femoral tunnel apertures are debrided of fibrous tissue with a combination of a shaver and curettes. A threaded guide wire is passed and the interference screws are removed, revealing the residual ruptured graft. A shaver and radiofrequency ablation device are utilized to clean off remaining graft remnants. Sequential debridement and reaming are performed to remove any residual fibrous tissue or sclerotic bone from the tunnel. The demineralized bone matrix is then combined with the prepared BMAC in a syringe with a cannula extension and subsequently injected into the tunnels. A freer elevate is used to tamp and smooth the graft to match the surrounding contour. A 12-mm cannulated allograft bone dowel is then passed up into the tibial tunnel and gently tamped into place.

Results:

Within 2 years postoperatively, patients are expected to have improved overall knee-specific quality of life, reduced pain, and a successful return to activities. No differences in outcomes have been noted in the literature between 1-staged and 2-staged ACL reconstructions.

Discussion/Conclusion:

Recent advancements in our understanding of the effects of BMAC in the setting of an ACL reconstruction should prompt surgeons to consider such treatments in indicated patients.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Bone Marrow Aspirate Concentrate for the Treatment of Knee Osteoarthritis: A Systematic Review

BACKGROUND

Bone marrow aspirate concentrate (BMAC) has emerged as a therapeutic option for symptomatic knee osteoarthritis (OA).

PURPOSE

To systematically review the literature to evaluate the efficacy of isolated BMAC injection in the treatment of OA of the knee joint.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A systematic review was performed by searching the PubMed, Embase, and Cochrane Library databases up to July 2020 to identify human studies that assessed the clinical outcomes of isolated BMAC injection for the treatment of knee OA. The electronic search strategy used was "bone marrow aspirate concentrate knee osteoarthritis."

RESULTS

Eight studies met the inclusion criteria, including a total of 299 knees with a mean follow-up of 12.9 months (range, 6-30 months). Of all patient-reported outcomes assessed across studies, 34 of 36 (94.4%) demonstrated significant improvement from baseline to latest follow-up (P < .05). Five studies evaluating numerical pain scores (visual analog scale and Numeric Rating Scale) reported significant improvements in pain level at final follow-up (P < .01). However, 3 comparative studies evaluating BMAC in relation to other therapeutic injections failed to demonstrate the clinical superiority of BMAC.

CONCLUSION

The BMAC injection is effective in improving pain and patient-reported outcomes in patients with knee OA at short- to midterm follow-up. Nevertheless, BMAC has not demonstrated clinical superiority in relation to other biologic therapies commonly used in the treatment of OA, including platelet-rich plasma and microfragmented adipose tissue, or in relation to placebo. The high cost of the BMAC injection in comparison with other biologic and nonoperative treatment modalities may limit its utility despite demonstrable clinical benefit.