How To Manage Lateral Ankle Sprains
Ankle sprains occur at a rate of roughly 25,000 per day nationwide, account for 10 percent of all emergency department visits and represent 25 percent of all sports injuries (and 25 percent of all time lost from sports).1-3 Ankle sprains are particularly prevalent in sports such as basketball and soccer with ankle sprains representing approximately 50 percent of all basketball injuries and 30 percent of all soccer injuries.4 Yet an estimated 55 percent of people who experience an ankle sprain will not seek professional treatment.5 This is unfortunate since most of these individuals are young athletes with good rehab potential. It’s also important to emphasize that ankle sprains, specifically lateral ankle sprains without associated injury, are significant injuries. Consider that 40 percent of those with acute lateral ankle sprains will develop chronic symptoms of ankle dysfunction such as pain, swelling, recurrent injury and having the ankle give way. These chronic symptoms are most often due to functional instability and less frequently to mechanical instability.1,3,4,6 Furthermore, the severity of functional instability has been shown to be unrelated to the grade/severity of the initial injury. In his 1998 study of West Point military cadets, Gerber found that people with Grade I lateral ankle sprains developed chronic symptoms just as frequently as Grade II and III injuries.7 This evidence points to the fact that even mild sprains in athletes deserve our attention. Despite the high incidence of these injuries and the hundreds of articles published on them, there continues to be great variation in diagnosis and treatment strategies. This is partly due to the number of medical specialties and disciplines that treat ankle sprains. They include emergency department physicians, primary care physicians, physician’s assistants, nurse practitioners, physical therapists, athletic trainers, chiropractors, osteopaths, orthopedists and podiatrists. Even if we’re all reading the same literature, there is a lack of evidence-based management strategies. Indeed, there are relatively few high quality randomized, controlled trials relating to this topic. Moreover, there is a lack of proven measures to monitor treatment response. While most clinicians and researchers continue to rely on physical measures (strength, range-of-motion, swelling and joint laxity), recent studies suggest they are not as important as functional measures, particularly when treating athletes. What You Should Know About The Risk Factors A look at risk factors for ankle sprains reveals a lot of conflicting data in the literature. However, McKay recently found some interesting trends.5 In a prospective study of over 10,000 recreational, amateur and elite basketball players in Australia, the largest study of its kind, McKay found a history of previous sprain was the greatest predictor of lateral ankle sprain with these patients having a five times greater risk for the sprain. Interestingly, the second greatest predictor was the presence of an air cell in the heel of the basketball shoe (4.3 times greater risk). The third greatest predictor was failure to stretch (2.6 times greater risk). Beynnon recently published a review of prospective studies that looked at risk factors for ankle sprain.8 The factors that did not predict a higher risk of sprain were particularly interesting. These factors included gender, general laxity and anatomic foot type. Assessing And Grading The Severity Of Ankle Sprains When discussing the diagnostic approach to lateral ankle sprains (without associated injury), it’s important to note the initial exam is often unreliable due to pain, swelling and guarding. Van Dijk found that a delayed physical exam on the fifth day actually compared favorably to arthrography, radiography, sonography and MRI in diagnosing the grade/severity of lateral ankle sprains.9 He concluded, as most authors and clinicians would agree, that stress films are not indicated for acute sprains in that findings are unlikely to change treatment protocol. These ancillary studies are more appropriately utilized for chronic ankle instability and research purposes. The West Point and AAOS grading systems are the most commonly used assessment tools for lateral ankle sprains and can serve as a helpful guide to treatment interventions.