Joints are surrounded by fibrous connective tissue, called ligaments, that attach bone to bone and help to stabilize the joint. A sprain occurs when these ligaments are stretched beyond the normal range of motion. Ligament sprains can be minor, but in more severe cases the ligaments can be torn, leading to joint instability. Chronic sprains occur when the ligament is repeatedly overstretched, creating increased laxity.
Following an injury, the mix of type III and I collagen changes. The new collagen fibers are smaller in diameter and less densely packed reducing the stiffness and strength of the ligament. The collagen fibers also exhibit an abnormal cross-linked pattern and can exhibit “greater stress relaxation” making the ligament elongate more when stressed (Frank et al 1999; Thornton et al 2000). This laxity can lead to extra stress on the joint and possibly early onset post-traumatic osteoarthritis (Øiestad et al 2009).
WHAT ARE THE SYMPTOMS OF A LIGAMENT SPRAIN?
Symptoms of ligament injury may include pain that worsens with activity, decreased range of motion or difficulty moving the affected area, buckling of the joint, swelling or tenderness of the injured area. Others may hear or feel a “pop” if the ligament is torn and may not experience any pain.
Chronic ligament sprains or complete ligament injury can lead to increased laxity, joint instability and increased risk of further injury.
HOW ARE THESE INJURIES DIAGNOSED?
Diagnosis of a ligament injury is based on detailed history, physical examination, and imaging. Certain physical tests may be utilized to reproduce symptoms and measure range of motion at time of exam. The majority of ligaments are superficial and can be assessed with musculoskeletal ultrasound.
Magnetic resonance imaging (MRI) can confirm the presence of injury to the ligament. X-ray imaging may also be utilized to determine presence of a bone injury in addition to ligament injury.
HOW ARE CHRONIC LIGAMENT SPRAINS TREATED?
Initial treatment of ligament injuries will vary based on the injury severity. Treatment may include a combination of rest, ice, NSAIDs, compression to help with swelling and stability, bracing or physical therapy.
Physical therapy may be utilized to decrease swelling, improve strength and range of motion and restore function of the injured area. Depending on the chronicity, severity and location of the injury, surgery may be recommended to repair or reconstruct the injured ligament.
Orthobiologics treatment have been found to be successful in the treatment of chronic ligament sprains, including prolotherapy injections and PRP injections.
PRP is a form of regenerative medicine that uses the patient’s own platelets to promote the healing of the injured ligament. PRP injections are prepared in the office by drawing a patient’s blood and concentrating the platelets before injecting them into the injured or diseased tissue. Recent meta-analysis concludes PRP may provide both short-term and long-term pain relief for tendon and ligament injuries and pathologies compared to alternative treatments (Chen et al 2018).
Prolotherapy: The mechanism of action behind prolotherapy is not completely understood, however, current theory holds that the injected irritating solution mimics the natural healing process of the body by initiating a local inflammatory cascade, which triggers the release of growth factors and a healing response within the injured ligament.
References
Chen X, Jones IA, Park C, Vangsness CT Jr. The Efficacy of Platelet-Rich Plasma on Tendon and Ligament Healing: A Systematic Review and Meta-analysis With Bias Assessment. Am J Sports Med. 2018 Jul;46(8):2020-2032. doi: 10.1177/0363546517743746. Epub 2017 Dec 21. PMID: 29268037; PMCID: PMC6339617.
Frank C, Shrive N, Hiraoka H, et al. Optimization of the biology of soft tissue repair. J Sci Med Sport 1999;2(3):190–210.
Øiestad BE, Engebretsen L, Storheim K, Risberg MA. Knee osteoarthritis after anterior cruciate ligament injury: a systematic review. Am J Sports Med. 2009 Jul;37(7):1434-43.
Thornton G, Leask G, Shrive N, et al. Early medial collateral ligament scars have inferior creep behavior. J Orthop Res 2000;18:238–46.
