Axiom or Myth? Always X-Ray and Splint an Ankle Sprain

With summer coming, the general public spends more time outdoors — swimming, going to the beach, taking care of their yards, and athletic activities. Meanwhile, emergency departments across the country prepare for another brand of summer fun including taking care of heat exhaustion and dehydration, lacerations, and orthopedic casualties. Each year between one and 10 million people sustain ankle injuries, making it one of the most common extremity complaints we encounter.1,2 When evaluating a patient with an ankle complaint, it is crucial to obtain several pieces of historical information. Physicians should ask about the mechanism of injury, foot position at time of injury, and ability to ambulate after the event. It also is important to inquire about previous injuries, location of pain, and the presence or absence of sounds such as snaps or cracks at the time of injury. This information helps determine whether a fracture or ligamentous disruption of the ankle joint complex is present.1 Asking the patient to point to the exact location of his or her worst pain helps in directing the exam and further studies. The circumstances surrounding the injury are important to exclude more serious injuries to other parts of the body. Finally, chronic disease conditions should be documented because they influence treatment options and outcome.3 After taking a thorough history, it is time to examine the ankle. As with every other part of the body, it is important to first inspect it using the uninjured ankle for comparison. Inspect the injured ankle for obvious bony deformity as well as ecchymosis and swelling. Testing the injured and uninjured ankles for range of motion can be helpful. Next, palpate the ankle and surrounding joints. Start away from the area of the most pain and swelling, and pay particularly close attention to the posterior portion and inferior tips of the malleoli, base of the fifth metatarsal, and fibular head.1 Ottawa Ankle Rules Many factors influence the decision to obtain an x-ray-after an ankle injury, including the degree of suspicion of bony injury and the patient's expectations. The Ottawa Ankle Rules (OAR) are an excellent and widely accepted tool used to determine the need for radiographic evaluation of the ankle. They were developed and tested in a series of studies that derived the rules (750 patients), validated them (1,485 patients), implemented the rules locally (593 patients), and implemented the rules in a multicenter trial of eight community and teaching hospitals (200 physicians, 6,489 patients). When used, they reduce the need for unnecessary x-rays by one-fourth to one-third, and reduce cost and time savings for the patient and emergency department.4 The measured sensitivity varies, but most agree that properly applied use of the OAR approaches 100% sensitivity. A multimedia teaching web site accurately depicts the proper use of the OAR, and can be used by the hospital staff. www.ohri.ca/programs/clinical_epidemiology/OHDEC/ankle_rule/flash_ankle_rule.htm. Using the OAR, an ankle and foot series is required only if the patient has pain in the defined malleolar zone, has tenderness at the navicular, base of the fifth metatarsal, posterior edge, or tip of medial or lateral malleolus, or is unable to bear weight at the time of injury and in the emergency department for four steps.5 Being able to limp on the foot counts. Clinicians should image any patient who they believe has a condition that impairs the proper assessment of the ankle, such as massive swelling that makes precise palpation or determination of the area of pain difficult. Of course, in chemically impaired, uncooperative, or neurovascularly impaired patients (diabetics and those with peripheral vascular disease), clinical judgment about the need for x-rays should supercede.3 Remember, the goal is reduce the unnecessary radiographs, not to stop ordering them entirely. Fewer than one-third of U.S. physicians employ the Ottawa Ankle Rules despite nearly 100% sensitivity Low Use of Rules It has been 10 years since the OAR were developed so why explore the question of axiom or myth? One international study suggested that overall acceptance of the OAR in the United States is low.6,7 Fewer than one-third of U.S. physicians employed the OAR (vs. 70% in Canada and the UK). This suggests that clinicians are clinging to the myth that an ankle sprain still needs to be radiographed, despite the fact that these decision rules have been validated when used in children and adults by nurses, in clinics, and in EDs, even in specific ethnic and racial groups. A recent meta-analysis of all these studies concluded that the OAR has a sensitivity of almost 100%, a modest specificity, and its use should reduce the number of unnecessary radiographs by 30 percent to 40 percent.8 If fear of litigation is the motivating factor, we suggest a healthy discussion with the patient. It has been our experience that patients who are presented with the research in a simple fashion (e.g., “studies show that your type of ankle sprain does not need an xray”), and are given the autonomy of decision-making (e.g., “I'd be glad to order an x-ray if you still want it”), will choose to forego an x-ray with sufficient frequency to make the OAR a useful tool, even if you don't achieve a 30 percent reduction. After x-rays have been deemed unnecessary or read as normal, ligaments should be tested. This can be difficult if the patient experiences significant discomfort or if gross swelling has occurred. To test the anterior talofibular ligament, the examiner performs the Anterior Drawer Test. This is done by grasping the heel in one hand and pulling the heel forward while pushing the distal tibia posteriorly. The Squeeze Test consists of using one hand to squeeze the tibia and fibula together approximately six to eight inches below the knee. If the patient experiences ankle pain, this is consistent with injury to the syndesmotic ligaments attaching the tibia and fibula, and should be managed accordingly. Finally, use the Thompson Test to assess the integrity of the Achilles tendon. Squeezing the patient's mid-calf should cause plantar foot flexion, and the absence of this indicates a possible Achilles tendon injury.1 Approximately 85 percent of ankle injuries involve the lateral ligament complex consisting of the anterior talofibular, posterior talofibular, and calcaneofibular ligaments (connecting the lateral malleolus of the fibula to the anterior and posterior talus and calcaneus). Injury to this ligament complex generally results from an inversion injury of the foot. While the great majority (60% to 70%) of ankle sprains involve isolated anterior talofibular disruptions, injuries with great force can result in disruption of the calcaneofibular ligament next, and, in very rare cases, involve all three of these ligaments. Eversion injuries result in sprains to the much stronger medial (deltoid) ligament complex connecting the medial malleolus of the distal tibia to the navicular, calcaneus, and talus. Finally, injuries to the tibiofibular syndesmotic complex result from a hyperdorsiflexion injury, and are generally identified by the complaint of pain just above the plafond and a positive squeeze test. While these are uncommon injuries, they are often more serious and involve a prolonged recovery.1 The need to order a radiograph for every ankle sprain is a myth. Next month, this column will explore whether it is necessary to immobilize every ankle sprain. Axioms in Emergency Medicine is written specifically for emergency medicine residents to dispel myths and misconceptions about different clinical entities. The column is written each month by a resident from the Emergency Medicine Residency Program at MCP Hahnemann School of Medicine in Philadelphia.

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.