High Ankle Sprains

A high ankle sprain, or syndesmosis injury, is a common injury amongst athletes (11-17% of all ankle sprains)(1). The syndesmosis, pictured below , is a group of ligaments that connects the distal tibia and fibula. The name high ankle sprain comes from the fact that this region is actually above the ankle joint. These ligaments, the anterior tibiofibular ligament, posterior tibiofibular ligament, transverse ligament,  interosseous ligament, and interosseous membrane (higher up the leg between the tibia and fibula) combine to give stability to this region and prevent the bones of the distal leg from widening during walking, running, and cutting maneuvers (6).

Mechanism of Injury and Diagnosis: The most common mechanism of injury to the syndesmosis is a combination of dorsiflexion and ankle external rotation. The figure shown on the lower left helps demonstrate these motions. A football player would experience this injury if they’re running and are tackled in such a way that their lower leg rotates inward on a fixed foot (ankle external rotation). The talus (the bone on top of the ankle – see above) is not positioned normally to allow for much rotation. But with enough force the talus will rotate externally, stressing the aforementioned ligaments as the fibula is forced outward. The injury can be diagnosed through X-Ray, specifically a stress X-Ray in which the foot is stressed into the aforementioned provocative positions (6) or a CT Scan/MRI. MRI can also be helpful in diagnosis other injuries such as deltoid ligament sprains, chondral defects, and lateral ligament sprains. In addition to these diagnostic tests, a physical examination can also quite accurately diagnose a high ankle sprain.

Physical Exam and Diagnosis:  Two tests that should be done in a physical examination are the squeeze test and the dorsiflexion and external rotation(DF and ER) test. The squeeze test involves squeezing the mid-point of the calf, with a positive test producing pain at the syndesmosis (distal tib-fib joint). In the DF and ER test, the foot is passively dorsiflexed (ankle going upward) before the foot is moved into external rotation. Another test of clinical utility may be a stabilization test described by Williams in which the patient is asked to perform a series of functional tasks (heel raises, walking, running, vertical hopping), and then again with athletic tape applied around the area of the injury to stabilize the syndesmosis. If there are reduced symptoms with the tape on the test indicates pathology(5). Palpation of the syndesmosis will also be painful during physical examination, with some recent evidence published by the University of Michigan to show that the further the distance from the distal tip of the fibula to the most proximal point of tenderness along the interosseous membrane indicates increasing severity of injury(3).

Treatment of a High Ankle Sprain: Most of the time a high ankle sprain can be treated non-surgically, although in severe cases screw fixation through the distal tibia and fibula may be required. Physical therapy for non-surgical sprains is essential to maximizing recovery and expediting a safe return to play. In the acute phase the primary goal is to reduce inflammation and regaining any lost range of motion (ROM) and/or weakness in a pain-free manner. Often a walking boot is prescribed in order to minimize external rotation of the ankle. Dorsiflexion is allowed as tolerated (4). Modalities including high frequency electrical stim, ultrasound, laser treatment, and ice may be valuable during this time(3,4).

The sub-acute phase focuses on continued strengthening, mobility, and return to function, again in a pain-free range of motion and intensity. As flat-footedness contributes to tibial internal rotation (and therefore ankle external rotation) gluteus maximus and medius, as well as posterior tibialis and foot intrinsic exericses are important muscles to target during this time. A progression from bike–>elliptical/stairmaster–> jogging can be useful to help the patient slowly return to upright weight bearing exercises. Pool jogging can also help maintain cardiovascular endurance. Once the patient can jog and hop with minimal discomfort the patient can begin to progress towards return to sport activities. Jogging, backpedaling, shuffling, carioca’s , and figure 8 running should be evaluated before sharp cutting is allowed. It may be helpful during this phase to tape the patient’s leg with athletic tape or leukotape in order to help stabilize the syndesmosis.  Proper footwear and arch support should be used at all times. Once the patient can perform the aforementioned low-level agility exercises then cutting, ladder drills, advanced proprioceptive exercises, and plyometrics should be used to evaluate appropriateness for return to sport. If there is minimal pain, the patient is ready to return to play. Keep in mind that athletes should always be monitored for pain and/or feelings of instability throughout the rehabilitation process.

Return to Play: High ankle sprains take longer to heal than most typical ankle sprains (1,3,4,).  Hopkinson and colleagues reported 55 days as an average return to full participation in activity following a high ankle sprain (2). The Michigan study on football players showed a much different mean of 15.5 days +/- 9.5 days to return to play(3). However, clinical experience and observation of athletes such as Ron Gronkowski in the super bowl last year, Dion Sims this year against Michigan, David Molk 2010, and many others demonstrate that a return to 100% in two weeks from a properly diagnosed ankle sprain is unlikely. A study of NHL players with syndesmotic sprains supports this conclusion as return to play occured at a mean of 45 days(7).

Conclusion: High ankle sprains are a significant injury that is best treated with a prompt,  accurate diagnosis following a physical examination. It has been documented that upwards of 60% of people who’ve sustained syndesmotic sprains have chronic ankle pain and instability 6 months after injury (1). Return to play too early will only exacerbate these complaints. A proper progression of strength and tissue tolerance is crucial in returning athletes to their sport when rehabbing patients with high ankle sprains.

References:

1. Gerber JP, Williams GN, Scoville CR, Arciero RA, Taylor DC. Persistent disability associated with ankle sprains: a prospective examination of an athletic population. Foot Ankle Int. 1998; 19(10): 653-660

2. Hopkinson WJ, St Pierre P, Ryan JB, Wheeler JK. Syndesmosis sprains of the ankle. Foot Ankle. 1990; 10(6): 325-330

3. Miller BS et al. Time to Return to Play After High Ankle Sprains in Collegiate Football Players: A prediction Model. Sports Health. 2012; 4(6). 504-509

4. Williams GN, Allen EJ. Rehabilitation of Syndesmotic Ankle Sprains. Sports Health. 2010; 2(6): 460-470

5. Williams GN, Hones MH, Amendola A. Syndesmotic ankle sprains in athletes. Am J Sports Med. 2007; 35(7): 1197-1207

6. Winnegge, T. High Ankle Sprains. Mikereinold.com , 10-9-12.

7. Wright RW, Barile RJ, Surprenant DA, Matava MJ. Ankle syndesmosis sprains in national hockey players. Am J Sports Med. 2004;32(8): 1941-1945

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