Ortho-Biologics for Ligament Repair and Reconstruction

Jan 5

Ortho-Biologics for Ligament Repair and Reconstruction

Chahla et al. 2019

Over the past decade, the advancement in the use of orthobiologic therapies have evolved from stimulating the recovery process and restoring native or near-native tissue to incorporating symptom management. The most popular applications of biological modalities commonly treat acute and chronic musculoskeletal injuries; and in some respects, they have served as adjuvants for conservative and surgical approaches to care. However, inconsistencies and limitations remain a challenge to documenting efficacious results because there is no clear algorithm for clinical symptomatology, processing methods, treatment application, and reporting.  

Dr. Chahla and his colleagues review current concepts on utilizing common orthobiologic products in the treatment of common ligamentous injuries repair and reconstruction, notably in Knee ACL, Knee MCL, and Elbow UCL injuries.  Knee ACL repair/ reconstruction is the 6th most common procedure in the field of Orthopedics. Objective outcomes for a successful procedure focus on graft ligament incorporation, enhanced biomechanics in the knee joint, reduced Return-to-Play times and delaying degenerative changes in the joint.  

Researchers are optimistic that regenerative treatment protocols demonstrate a high potential to improve the outcomes of common treatment interventions.  With regard to Knee ACL repair and reconstruction, success depends on key biological influencers at each phase of the healing process. Researchers have found that various growth factors (GFs), namely Transforming GF beta-1(TGF-beta 1), Fibroblast GF (FGF), and Platelet-derived GF (PDGF) augments the biological processes that stimulate fibroblast growth, migration, and biosynthetic activity which outcomes demonstrating improved ligamentization of ACL grafts and reduced proinflammatory factors, as well as improved integration of grafts in bone.

Preclinical studies for Knee ACL repair and reconstruction show evidence of the use of biologic modalities as a less invasive approach to regulate cellular activities, improve proliferation and deposition in the extracellular matrix while influencing the differentiation of mesenchymal stem cells into fibroblasts. TGF-beta 1 plays a key role in these processes, all the while, researchers have found that Vascular Endothelial growth factors (VEGF) supports vascularization and graft infiltration but may increase graft laxity at 12 weeks. An animal model showed evidence-based outcomes in the treatment of ACL partial tears with intra-articular bone marrow transplantation using whole bone marrow cells. Clinical studies for Knee ACL repair and reconstruction support the use of intraligamentous placement of PDGFs, PRP-soaked grafts, PRP injection, and bone marrow aspirate concentrate (BMAC) injections to improve knee stability and function, and decrease pain scales.

Despite the MCL being the most common knee ligament injured, conservative treatment and surgical intervention do not correlate with mechanical and histological properties returning to a pre-injury normal. Researchers believe biological modalities may be used as adjuvant techniques to augment clinical outcomes in the treatment of MCL repair and reconstruction.  Preclinical studies are limited. Investigators conclude that MCL tears treated with PRP immediately after injury or surgery may not improve healing at low doses, and could actually impede ligament healing at higher doses. Furthermore, literature on clinical studies is limited. In one case reviewed by Chahla and colleagues, competitive soccer athletes who opted for conservative treatment with multiple PRP injections and rehabilitation experienced good functional outcomes with no recurrence of injury or complications at 16 months follow-up, but radiographic did not show complete healing of partial ligament tears.

Lastly, Dr. Chahla and colleagues reviewed literature concerning treatment options for ulnar cruciate ligament repair and reconstruction that is prevalent among baseball pitchers due to the overhead throwing mechanics. Three to 40% of surgical reconstructions result in complications, and researchers are hopeful that PRP and mesenchymal stem cells (MSCs) may provide adjunctive treatment to improve overall outcomes. In the absence of preclinical studies, two clinical studies utilized biological adjuncts for nonoperative treatment for partial UCL tears in which 88% of athletes with partial UCL tears returned to normal play intensity after a single PRP injection, and 73% of athletes experienced excellent outcomes following a single PRP injection when supplemented with a return-to-play rehabilitation program.

Congratulations to TOBI Faculty Dr. Jorge Chahla and colleagues for your work being published in the Clinics in Sports Medicine journal by Elsevier. See the published study here https://www.ncbi.nlm.nih.gov/pubmed/30466725

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