Orthobiologics in Meniscus Pathology
摘要
Meniscal tears are a frequent orthopedic injury [1–4]. They often result in significant pain and mechanical issues, and if untreated, they can lead to the development of osteoarthritis [5, 6]. Over time, the approach to treating these injuries has progressed from total meniscectomy to partial meniscectomy and, finally, to meniscal repair and substitution with scaffolds or allografts [6]. Preserving as much of the meniscus as possible is preferable because losing any part of it can considerably increase stress on the articular cartilage compared to when it is intact [7, 8]. Nonetheless, the meniscus generally has a limited capacity for self-repair due to its poor blood supply, leading researchers to explore deeper into the biology of meniscal healing and seek ways to enhance this process [9–11]. Several elements affect the inherent healing ability of the meniscus, with the most critical factors including regional variations in blood supply, changes in the composition and density of the matrix, inadequate cellular density, and various soluble and mechanical influences. Healing is a complex process, involving cells that migrate into the damaged area, proliferate, and remodel the extracellular matrix. They also synthesize new matrix proteins, a crucial step in closing the wound. However, this process is not possible without a robust vascular supply. This supply delivers regenerative cells, nutrients, and growth factors, all of which are essential for effective repair. The observed region-specific healing in clinical settings is primarily due to variations in vascularity. Limited blood flow can impede the formation of a fibrin clot, which is necessary for cell infiltration and matrix remodeling in the inner, non-vascular zones of the tissue. In adults, the perimeniscal capillary plexus’s blood vessels do not extend beyond the outer third of the meniscus (known as the red-red zone), resulting in a central avascular area (white-white zone) that exhibits poor healing potential [12–15]. Recent advancements in orthopedics have continually aimed at improving surgical or non-surgical treatment outcomes and enhancing tissue regeneration. For very long time, a key area of interest has been the role of growth factors in healing processes, particularly in complex problems as cartilage repair, meniscus repair and ligament repair [16]. Those attempts were developing in two pathways; interventional—nonsurgical treatments and also to improve soft tissue healing in surgical procedures. Several studies have demonstrated the positive impact of various growth factors on meniscal cell activity. These include platelet-derived growth factor, fibroblast growth factors (basic and regular), transforming growth factor-β, insulin-like growth factor, bone morphogenetic protein, hepatocyte growth factor, and vascular endothelial growth factor. Conversely, other cytokines like interleukin-1, tumor necrosis factor-α, and matrix metalloproteinases have been shown to hinder meniscal healing in laboratory settings.