What’s New in Orthopaedic Research

Abstract

Developments in several fields, including molecular and stemcell biology, biomaterials, biomechanics, and molecular genetics, have all contributed to advancements in orthopaedic research this past year. Improvements and refinements in laboratory techniques have hastened the pace of progress in research. The primary challenge for the clinician is to stay abreast of advances in areas related to the biology and biomechanics of musculoskeletal tissues. In this review, we have attempted to highlight advances that have the most potential for early translation to clinical practice in the areas of tendon biology, spinal disc degeneration and regeneration, meniscus repair and regeneration, and cartilage degeneration and repair. Tendon Healing and Tendon Repair TendinosisUnderstanding the underlying mechanism(s) involved in degenerative tendinosis continues to be an important area in tendon research. Recent work has focused on the signaling mechanisms that lead to degenerative phenotypic changes in tendon, such as glycosaminoglycan (GAG) accumulation and ectopic calcification. Treadmill running has been used in small animal models to induce overuse changes in tendon. With use of these models, increased expression of heparin affinity regulatory peptide (HARP)/pleiotrophin and SOX-9 were seen, which are known to regulate chondrocyte formation and result in chondrocytic phenotypic changes 1 . The adverse effect of excessive GAG in tendon matrix was also demonstrated by the altered tendon biomechanical properties in a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) knockout mice. ADAMTS5 plays an important role in removing pericellular and interfibrillar aggrecan, which maintains normal collagen architecture and matrix organization 2 .