What are the challenges on day one when evaluating the acute ankle sprain?
The initial history of the injury should include questions about the mechanism of the injury. A lateral ankle sprain forces the foot into a position of inversion and adduction while the ankle is in a plantarflexed position. This is important to determine as a syndesmosis sprain, the so-called “high ankle sprain,” has the opposite mechanism: the foot is externally rotated or abducted when the ankle is in a dorsiflexed position. Indeed, the recommendations for treating the lateral ankle sprain are quite different from those relevant to the syndesmosis sprain.1,2
In regard to lateral ankle sprains, there is isolated injury of the anterior talofibular ligament 70 percent of the time while combined injury with the calcaneofibular ligament is present in 20 percent of patients with a lateral ankle sprain.3 Determining if there has been true rupture of either of these ligaments is important in directing treatment and return to sport. Grading an ankle sprain is only important when differentiating Grade I sprains, which have only minor soft tissue microtears, from Grade II and III sprains, which have true ligament rupture and varying levels of instability.1
When it comes to radiographs of the injured ankle on day one, one should use the Ottawa ankle rules to rule out a fracture.4 Clinicians should consider the Ottawa ankle rules when examination of the patient reveals:
- tenderness with palpation along the tip of the posterior edge of the lateral malleolus;
- tenderness over the medial malleolus;
- tenderness at the base of the fifth metatarsal;
- tenderness over the navicular bone; and/or
- the inability of the patient to bear weight for a minimum of four steps.
In terms of using other imaging techniques such as magnetic resonance imaging (MRI) or ultrasound to determine the extent of ligament injury, such studies are not normally indicated on day one or at any time during the initial treatment of the acute ankle sprain because proper physical examination can approach the accuracy of these studies and reduce unnecessary medical expense.5,6
Editor’s note: This DPM Blog is an excerpt from Dr. Richie’s upcoming feature article, “A Guide To Conservative Care For Ankle Sprains,” which will appear in the July 2016 issue of Podiatry Today.
1. Van den Bekerom MP, Kerkhoffs GM, McCollum GA, Calder JD, van Dijk CN. Management of acute lateral ankle ligament injury in the athlete. Knee Surg Sports Traumatol Arthrosc. 2013; 21(6):1390–1395.
2. McGovern RP, Martin RL. Managing ankle ligament sprains and tears: current opinion. Open Access J Sports Med. 2016;7:33-42.
3. Fong DT, Hong Y, Chan LK, Yung PS, Chan KM. A systematic review on ankle injury and ankle sprain in sports. Sports Med. 2007;37(1):73–94.
4. Stiell IG, Greenberg GH, McKnight RD, Wells GA. Ottawa ankle rules for radiography of acute injuries. N Z Med. 1995;108(996):111.
5. Van Dijk CN, Lim LS, Bossuyt PM, Marti RK. Physical examination is sufficient for the diagnosis of sprained ankles. J Bone Joint Surg Br. 1996; 78(6):958–962.
6. Van Dijk CN, Mol BW, Lim LS, Marti RK, Bossuyt PM. Diagnosis of ligament rupture of the ankle joint. Physical examination, arthrography, stress radiography and sonography compared in 160 patients after inversion trauma. Acta Orthop Scand. 1996; 67(6):566–570