Bone Marrow Aspirate Concentrate Augmentation May Accelerate Allograft Ligamentization in Anterior Cruciate Ligament Reconstruction: A Double-Blinded Randomized Controlled Trial

The Second Annual Musculoskeletal Biologics Special Issue Highlights Evidence-Based Therapies

Orthopaedic biologics continues to hold great promise. The editors of Arthroscopy; Arthroscopy Techniques; and Arthroscopy, Sports Medicine, and Rehabilitation once again Call for Papers and invite authors to submit clinical musculoskeletal biologics original scientific research and technical notes with video. Our top articles are awarded inclusion in the Annual Musculoskeletal Biologics Special Issue.

Orthopaedic Musculoskeletal Biologics Research Impacts Patient Care: The Second Annual Arthroscopy Orthobiologics Virtual Special Issue

The field of orthobiologics is rapidly evolving, offering clinicians a shift in treatment from symptom relief to the potential for disease modification and tissue repair. These agents, derived from autologous tissues, components of blood, and growth factors, are used as surgical adjuncts or as standalone treatments. Their clinical applications are expanding to encompass a variety of conditions, supported by a growing base of research efforts. Arthroscopy and its companion publications are committed to evidence-based research with a robust history of publications that enhance clinical decision-making and impact patient care. This curated collection of articles highlights the year's most compelling advancements in orthopaedic musculoskeletal biologics research.

Anterior Cruciate Ligament Reconstruction using Bone-Tendon-Bone Allograft: Surgical Technique Using Augmentation with Bio-Composite Scaffold

Anterior cruciate ligament (ACL) rupture rates remain high; the incidence of isolated ACL ruptures is 68.6 per 100,000. This Technical Note introduces a technique for ACL reconstruction (ACLR) using a bone-tendon-bone (BTB) allograft augmented with BioBrace, a biocomposite scaffold. The BioBrace scaffold is sutured onto the BTB allograft to reinforce the ligament and accelerate healing. Graft preparation with BioBrace, ACLR, and graft passage is described. This technique aims to reduce re-rupture risk, enhance graft healing, and improve patient-reported outcomes. BioBrace offers advantages over other augmentation approaches and synthetic materials, providing improved remodeling, biologic integration, and increased mechanical strength. Feasibility and efficacy have been demonstrated in animal models and human applications. This technique presents a promising approach to enhance ACLR outcomes.

Cells Remain Viable When Collected With an In-Line-Suction Tissue Collector From Byproducts of Anterior Cruciate Ligament Reconstruction Surgery

Purpose

To investigate the viability of cells collected with an in-line-suction autologous tissue collector from the tissue byproducts of arthroscopic anterior cruciate ligament (ACL) reconstruction, to characterize cells from different tissue types, and to identify mesenchymal stem cells.

Methods

Patients aged 14 to 50 years with ACL injuries requiring arthroscopic reconstruction surgery were offered enrollment and screened for participation. In total, 12 patients were enrolled in the descriptive laboratory study. Arthroscopic byproduct tissue was collected with an in-line-suction autologous tissue collector from 4 intraoperative collection sites for each patient: ACL stump, ACL fat pad, notchplasty debris, and tunnel drilling debris. All tissue samples were digested using collagenase, and the derived cellular populations were analyzed in vitro, characterizing cellular viability, proliferative potential, qualitative multipotent differentiation capacity, and cell-surface marker presence.

Results

An equivalent mass of arthroscopic byproduct tissue was taken from each of the 4 intraoperative collection sites (1.12-1.61 g, P = .433), which all showed an average viability of at least 99.95% and high average total nucleated cells (≥1.37 × 107 cells/mL). No significant differences in collected mass (P = .433), cellular viability (P = .880), or total nucleated cells (P = .692) were observed between the 4 byproduct tissues. The byproduct tissues did exhibit significant differences in monocyte (P = .037) and red blood cell (P = .038) concentrations, specifically with greater values present in the ACL stump tissue. Cells from all byproduct tissues adhered to plastic cell culture flasks. Significant differences were found between colony-forming unit fibroblast counts of the 4 byproduct tissues when plated at 106 (P = .003) and 103 (P = .016) cells as the initial seeding density. There was a significant relationship found between both the starting concentration (χ2 = 32.7, P < .001) and the byproduct tissue type (χ2 = 30.4, P < .001) to the presence of ≥80% confluency status at 10 days. Cells obtained from all 4 byproduct tissues qualitatively showed positive tri-lineage (adipocyte, osteoblast, chondroblast) differentiation potential compared with negative controls under standardized in vitro differentiation conditions. Cells derived from all 4 byproduct tissues expressed cell-surface antigens CD105+, CD73+, CD90+, CD45-, CD14-, and CD19- (>75%), and did not express CD45 (<10%). There were no statistically significant differences in cell-surface antigens between the four byproduct tissues.

Conclusions

This descriptive laboratory study demonstrated that cells derived from arthroscopic byproduct tissues of ACL reconstruction remain viable when collected with an in-line-suction autologous tissue collector and these cells meet the ISCT criteria to qualify as mesenchymal stem cells.

Clinical Relevance

It is known that viable mesenchymal stem cells reside in byproduct tissue of anterior cruciate ligament reconstruction surgery (ACLR). Practical methods to harvest these cells at the point of care require further development. This study validates the use of an in-line-suction autologous tissue collector for the harvest of viable mesenchymal stem cells after ACLR.

Bone Marrow Aspirate Concentrate Harvest Techniques for the Sports Medicine Surgeon

The use of bone marrow aspirate concentrate (BMAC) as a surgical augment to enhance biologic healing has been gaining popularity in a variety of sports medicine procedures. Due to its reliable availability from multiple sites, including the proximal tibia, proximal humerus, and anterior superior iliac spine, BMAC can be harvested at a location selected to be adjacent to the primary procedure. This Technical Note aims to highlight 3 different harvest sites for BMAC, allowing orthopaedic sports medicine surgeons to localize their harvest site based on the proximity of the planned procedure and ultimately increase efficiency.

Anterior Cruciate Ligament Reconstruction With Quadriceps Tendon Autograft: Surgical Technique Using Augmentation With a Biocomposite Scaffold

Anterior cruciate ligament (ACL) reconstruction augmentation continues to be widely studied. Both biologic and synthetic augments have been employed to enhance ACL healing and provide early protection. The BioBrace is a biocomposite scaffold that both mechanically reinforces the graft while biologically enhancing graft healing. The purpose of this article is to describe augmentation of an ACL reconstruction with BioBrace.

Management of Bone Loss and Tunnel Widening in Revision ACL Reconstruction

➤ Both mechanical and biological factors can contribute to bone loss and tunnel widening following primary anterior cruciate ligament (ACL) reconstruction.➤ Revision ACL surgery success is dependent on graft position, fixation, and biological incorporation.➤ Both 1-stage and 2-stage revision ACL reconstructions can be successful in correctly indicated patients.➤ Potential future solutions may involve the incorporation of biological agents to enhance revision ACL surgery, including the use of bone marrow aspirate concentrate, platelet-rich plasma, and bone morphogenetic protein-2.

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.

Arthroscopy Honors Award-Winning Articles and Authors: Our Annual Research Awards

With genuine gratitude to the AANA Education Foundation for their unstinting support, it is our honor to announce Arthroscopy's Annual Awards for the best Clinical Research, Basic Science Research, Resident/Fellow Research, and Systematic Reviews published in 2022, as well as the Most Downloaded and Most Cited papers published 5 years ago. And as is customary in January, our editors update their disclosures of potential conflicts of interest, as we require of authors, and we update our masthead to introduce new members of our Editorial Board and Social Media Board.

Editorial Commentary: Bone Marrow Aspirate Concentrate May Accelerate Anterior Cruciate Ligament Allograft Using Bone Patellar Tendon Bone Maturation on Magnetic Resonance Imaging, but Clinical Differences Have Not Been Demonstrated

Accelerating graft healing in anterior cruciate ligament reconstruction (ACLR) continues to be an elusive proposition. In vivo assessments of graft histology are challenging to perform, especially in human subjects. Multiple authors have reported on the utility of magnetic resonance imaging as a noninvasive modality in characterizing postoperative changes, suggestive of graft maturation. However, previous literature, by and large, has been limited by heterogenous scanning protocols and underpowered comparisons of dissimilar treatment techniques, and these issues complicate efforts to assess the benefits (if any) of adjuncts focused on improving graft healing after ACLR. Particularly in cases of allograft ACLR, where concerns persist regarding the pace and quality of tissue healing and graft integration, the use of orthobiologic adjuncts represents a promising area for ongoing investigation. Although there has been great enthusiasm for the use of bone marrow aspirate concentrate as an adjunct in a variety of applications, high level evidence substantiating its use in ACLR is lacking. Even when significant differences between groups treated with and without such adjuncts may be apparent radiographically, demonstrating a concrete, clinical benefit will continue to be a difficult proposition.