Management of Acute Ankle Sprain With Sodium Hyaluronate (AdantTM) Periarticular Injections

Ankle sprains are among the most common of all sports injuries, with approximately two million people per year seeking medical treatment (1, 2, 3). An epidemiological study of professional, competitive, and recreational athletes found a prevalence of ankle sprain as high as 73% (4). Data from the National Hospital Ambulatory Medical Care Survey: 2000 Emergency Department (ED) Summary listed about 1.375 million ED visits in the US due to ankle sprains which represent about 1.3% of ED visits (5).

Ankle sprains most commonly affect the lateral ligament complex. The lateral ligament complex of the ankle consists of three separate ligaments: anterior talofibular, posterior talofibular and calcaneofibular. The anterior talofibular ligament is usually the ligament affected although in more severe injuries the calcaneofibular ligament may also be involved. Varus or inversion sprains include a spectrum of severity. Symptoms may include pain, swelling, tenderness and functional loss. Ankle sprains are classified as first-, second- or third-degree ankle sprains. A first-degree sprain represents a partial tear of a ligament with mild tenderness and swelling, a second-degree sprain represents incomplete tear of a ligament with moderate functional impairment, pain and swelling, and a third-degree sprain represents a complete tear and loss of integrity of a ligament and presents with severe swelling, ecchymosis, loss of function and mechanical instability (6, 7). The assessment and treatment of an ankle injury may be performed by emergency and primary health care physicians as well as orthopaedic and trauma surgeons (8).

The emphasis of therapy in ankle sprains is centered on reducing the inflammation and pain rapidly following injury (7, 9). Guidelines for the treatment of acute ankle sprain from the American Academy of Orthopaedic Surgeons recommend initial rehabilitation program (up to three weeks) with NSAIDs (non steroidal anti inflammatory drugs), RICE (rest, ice, compression and elevation) as well as protected weight bearing, early mobilization and isometrics (10). Conservative treatment may limit disability to an average of 8 days for a grade 1 and 15 days for a grade 2 (3). Failure to provide adequate therapy can limit a patient's efforts in rehabilitation and prolong the recovery period. In a study of ankle sprain, pain and dysfunction was found to persist 6 to 18 months (average 12.8 months) after initial ankle sprain in 73% of patients, with 40% reporting inability to walk one mile, and 11% continuing to use medications for ankle symptoms (11). In a long-term follow-up study, nearly 40% of patients reported residual long-term symptoms and dysfunction 6.5 years after initial ankle sprain (12). Also, long-term symptoms of ankle sprain have been noted by 40% of athletes 6 months after acute injury (6).

NSAIDs effectively reduce the inflammation, pain, and disability associated with acute ankle sprain (13, 14). The rationale for their use includes 1) pain control, 2) anti-inflammatory effect to allow early activity and 3) decrease inflammation to speed healing directly. However, NSAIDs are nonselective and may cause significant adverse events including UGI intolerance and serious events such as ulcers and bleeding.

Hyaluronic Acid is a naturally occurring biological substance which has shown to have a positive effect in viscosupplementation therapy. As it relieves pain and stiffness related to osteoarthritis, it may have a similar effect on the ligaments affected by acute ankle sprain in regards to anti-inflammatory effects. This would promote the mobility and decrease the pain associated with acute ankle sprains. Hyaluronic Acid has no effect on UGI and platelet function compared to traditional NSAIDs as it works locally within the site of injection.