Ligament Injury and Healing: A Review of Current Clinical Diagnostics and Therapeutics

Abstract

Ligament injuries are among the most common causes of musculoskeletal joint pain and disability encountered in primary practice today. Ligament injures create disruptions in the balance between joint mobility and joint stability, causing abnormal force transmission through the joint, which results in damage to other structures in and around the joint. The long-term consequence of nonhealed ligament injury is osteoarthritis, the most common joint disorder in the world today. Ligaments heal through a distinct sequence of cellular events that take place in three consecutive stages: an acute inflammatory phase, a proliferative or regenerative phase, and a tissue remodeling phase. The process can take months to resolve itself, and despite advances in therapeutics, many ligaments do not regain their normal tensile strength. Various diagnostic procedures have been used to determine and assess ligament injury. Traditionally, MRI and X-rays have been the most utilized techniques; however, because ligaments do not show up clearly with these devices, there have been many false positives and negatives reported due to inconclusive or inaccurate readings. Newer technologies, such as ultrasound and digital motion X-ray, are able to provide a more detailed image of a ligament's structure and function. Numerous strategies have been employed over the years attempting to improve ligament healing after injury or surgery. One of the most important of these is based on the understanding that monitoring early resumption of activity can stimulate repair and restoration of function and that prolonging rest may actually delay recovery and adversely affect the tissue's response to repair. Likewise, there is a shift away from the use of steroid injections and nonsteroidal anti- inflammatory medications. Although these compounds have been shown effective in decreasing the inflammation and pain of ligament injuries for up to six to eight weeks, their use has been shown to inhibit the histological, biochemical, and biomechanical properties of ligament healing. For this reason their use is cautioned against in athletes who have ligament injuries. Such products are no longer recommended for chronic soft tissue injuries or for acute ligament injuries, except for the shortest possible time, if at all. Regenerative medicine techniques, such as prolotherapy, have been shown, in both case series and clinical studies, to resolve ligament injuries of the spine and peripheral joints. More research and additional studies are needed to better assess ligament injuries and healing properties.