Conceptual model of the process of formation of immobilization contractures

Abstract

Contractures — limitation of passive movements in the joint — are a fairly frequent complication after immobilization or limitation of mobility and loading of the limb due to injuries, but the exact cause of their formation has not been clarified. Objective. Based on the meta-analysis of the results of experimental modeling and clinical studies of immobilization contractures, create a conceptual model of their formation. Methods. Literature sources from scientific bases were analyzed: Cochrane Library, Scopus, National Library of Medicine, ReLAB-HS Rehabilitation Resources Repository, Mendeley Reference Manager, The Physiological Society library, Google Scholar. Results. A conceptual model of the development of contractures was created. It is shown that immobilization of the joint of the injured limb blocks the execution of the signal of motor impulses. The lack of movement in the joint leads to a decrease in muscle strength and a slowdown in blood circulation. These processes are interrelated: hypotonia of the muscle is due to the restriction of nutrition through the blood supply, and the lack of contractile activity of the muscles leads to the rearrangement of the blood vessels. Articular cartilage is nourished through the subchondral bone and due to osmosis from the synovial fluid during movements. The lack of movement limits nutrition, protein synthesis is disrupted, the surface of the cartilage, synovial membrane and fluid begins to be rebuilt, the joint capsule, ligaments, and tendons thicken. At the same time, the structure of the muscles changes, they shorten and become denser. With long-term immobilization, degenerative processes in the tissues of the joint worsen its general condition, which can eventually lead to complete immobilization. Conclusions. The created conceptual model of the formation of immobilization contractures of joints takes into account the morphological changes of tissues as a result of immobilization. Immobilization affects all components of the joint and adjacent tissues from the first days, the changes progress over time. The use of the model will allow the development of a system of treatment measures to prevent the development of contractures.