Single-site, Double Blinded, Randomized Investigation of Corticosteroid Versus Placebo Injection Under Ultrasound Guidance in Patients With Syndesmotic Ligament Injury or High Ankle Sprain

The term "high ankle sprain" refers to injury to the syndesmotic ligaments of the ankle. It has become a much more common injury comprising up to 24.6% of all ankle sprains , with an incidence of 2.4 per 1000 athlete exposures. These can present a significant therapeutic challenge for the sports physician and typically result in a prolonged morbidity and delayed return to activity. The literature shows a lack of information for definitive care of these athletes. Typical recovery for the high ankle sprain is almost twice as long as the more common lateral ankle inversion sprain with a mean time to return to play of 45 days. There is also a higher incidence of residual chronic pain comparing high ankle sprains to an isolated lateral ankle sprain. The current standard for treatment of this injury has been to depend on symptomatic treatment with an initial phase of rest and protected splinting. This is followed by the use of NSAID's with a graduated rehabilitation program to reduce swelling, improve range of motion, and regain strength and proprioception of the ankle. This is followed by protective taping or bracing and return to activities as tolerated. Inflammation is one of the body's first reactions to injury. Release of damaged cells and tissue debris occurs upon injury. These expelled particles act as antigens to stimulate a nonspecific immune response and to cause the proliferation of leukocytes. Local blood flow increases to transport the polymorphonuclear leukocytes, macrophages, and plasma proteins to the injured area. A redistribution of arteriolar flow produces stasis and hypoxia at the injury site. The resulting infiltration of tissues by the leukocytes, plasma proteins, and fluid causes the redness, swelling, and pain that are characteristic of inflammation. Initially, the inflammatory reaction serves several important purposes. The influx of leukocytes facilitates the process of phagocytosis and the removal of damaged cells and other particulate matter. Pain and tenderness remind the patient to protect the injured area; however, the inflammatory reaction eventually becomes counterproductive. The mechanism of corticosteroid action includes a reduction of the inflammatory reaction by limiting the capillary dilatation and permeability of the vascular structures. These compounds restrict the accumulation of polymorphonuclear leukocytes and macrophages and reduce the release of vasoactive kinins. They also inhibit the release of destructive enzymes that attack the injury debris and destroy normal tissue indiscriminately. Additionally, new research suggests that corticosteroids may inhibit the release of arachidonic acid from phospholipids, thereby reducing the formation of prostaglandins, which contribute to the inflammatory process. There are no previous prospective, randomized studies that look at utilization of corticosteroids in treatment of the high ankle sprain. Only anecdotal information is available in simple case reports for treatment. There was one study looking at treatment with platelet rich plasma injection which demonstrated shorter return to play times and less long term residual pain.