Knee Replacement Austo orthorities AVN Best orthopedics hospital in pune The musculoskeletal system involves a diverse organization of tissues exposed to a complex series of biological and mechanical stimuli. A thorough understanding of the normal biology of the musculoskeletal tissues, the behavior of these tissues associated with disease and injury, and the underlying mechanisms of musculoskeletal tissue regeneration is necessary to address the growing burden of disease. Research programs, both in developed and developing countries, must target those orthopedic conditions of greatest importance to their populations in order to diminish the societal and economic burdens caused by an inability to resume necessary physical function. The potential areas for investigation within the field of orthopedics continue to grow, particularly as the basic and applied body of scientific knowledge and technology develop. While these areas for basic research in orthopedics are too numerous to list, below are examples of some of the current and future directions in the field. Musculoskeletal injury and repair Bone repair, whether it happens following a fracture or a bone graft, involves a well organized set of events that lead to reconstitution of the biological and mechanical integrity of bone. The regeneration process is initiated by an inflammatory response, which plays an important role in stimulating repair.1 Simultaneously, skeletal progenitor cells are recruited and begin differentiating into chondrocytes and osteoblasts that will deposit new cartilage and bone matrix necessary for bone bridging. The origins of these progenitor cells and the influence of the inflammatory response on their recruitment are not well understood. Following extracellular matrix deposition, cartilage is replaced by bone and new trabecular bone is converted to lamellar bone during the remodeling phase of repair.2–4 Numerous molecules and growth factors are keys to each step of the repair process and their functions are slowly being elucidated through analyses of various animal models of bone repair.2, 5 These investigations will lead to a better understanding of the cellular and molecular bases of bone repair, better diagnosis of skeletal repair defects, and development of new strategies to accelerate healing. Surgeons have now the choice between various surgical techniques, improved implants and biological approaches to treat complex injuries. Current approaches use autografts, allografts, or bone morphogenetic proteins (BMPs). However, these approaches are not always successful and are costly, which necessitates the development of new therapies. The muscles, tendons and ligaments along with blood vessels and nerves are closely associated with the bone. Musculoskeletal injuries may involve one or more of these tissues and the extent of injury is highly linked to the success of repair. For example, delayed union or non-union occurs in 5 to 10% of all fractures but is increased up to 46% in patients with extreme trauma and soft tissue damage.6 Therefore the role of numerous tissues must be taken in account in the majority of musculoskeletal diseases or injuries. Advances are being made in the basic biology of bone and individual soft tissues surrounding bone. The basic biology of muscle and muscle repair is well understood compared to other soft tissues. Muscle repair is composed of three phases including degeneration/ inflammation, regeneration and fibrosis. Many molecular markers and disease models are available. Muscle has been an ideal target to test new gene therapies and cell based therapies, however further advances are needed to treat devastating diseases such as Duchenne Muscular Dystrophy and to improve muscle repair. Vascular biology is also an area of intense investigation but more efforts need to be made to apply the data to the orthopedic field. The biology of tendons and ligaments is now being better understood with the identification of key molecular pathways involved in these tissues. Injury of tendons and/or ligament independent of bone can lead to complications and extended periods of recovery, which can also have debilitating effects. Like muscle and bone healing, tendon and ligament healing is initiated by an inflammatory response that may be modulated to stimulate repair. Little is know about the intrinsic capacities of tendon and ligament to heal and the cell sources that participate in repair.