Ligament injuries are encountered frequently in clinical orthopedics. When left untreated, they often result in disabling instability of the synovial joint involved, which in turn often leads to degenerative joint disease. Optimal treatment of injured skeletal ligaments is dependent on the particular structure that is injured, the acute or chronic nature of the injury, and the patient and his/her activity level and age. Despite the wealth of clinical experience with the repair of ligament injuries and a large volume of experimental studies, the optimal treatment of ligament injury still requires a great deal of study, including development of appropriate experimental methodologies and animal models. Detailed analyses of healing ligament structure and function are needed to provide a more rational approach to the clinical management of all ligament pathologies. The factors that affect the outcome of the healing process are just beginning to be understood.
Most extra-articular ligaments heal by a process that most closely resembles scar formation. Unlike normal ligaments, healed ligaments consist of a hypertrophic structure whose mass has been replaced primarily by type III collagen. This immature collagen is characterized by smaller diameter fibrils and results in a mechanically inferior structure. The compensatory processes involved in restoration of normal joint function provide an increased cross-sectional area. Nevertheless, the healed ligament often fails to provide adequate joint stability, which can lead to re-injury, a chronically lax joint, or progression to degenerative joint disease. It is imperative to obtain a basic science understanding of the fundamental biological processes that govern wound healing in the context of musculoskeletal soft tissues in order to design treatments that can improve the time course and end result of ligament healing.
Current research on ligament healing in the Weiss Biomechanics Lab is focused on understanding the role of the vascular inflammatory response in determining the time course and end result of ligament healing as evaluated using biomechanical measurements of joint function and ligament material properties, and correlating these measurements with gene expression. The links below describe some of our current and past research related to ligament healing.