ONLINE EXCLUSIVE John T. Nickless, MD; Jeremy A. Alland, MD High ankle sprains: Division of Primary Care Sports Medicine, Department of Orthopedic Surgery, Rush Easy to miss, so follow these tips University Medical Center, Chicago Misdiagnosis can result in increased loss of play time and [email protected] chronic ankle dysfunction. Here are the physical exam The authors reported no potential con ict of interest relevant maneuvers and imaging options to consider. to this article. CASE u PRACTICE A 19-year-old college football player presents to your outpa- RECOMMENDATIONS tient family practice clinic after suffering a right ankle injury ❯ Maintain a high level of during a football game over the weekend. He reports having suspicion for syndesmotic his right ankle planted on the turf with his foot externally ro- injury in any athlete tated when an opponent fell onto his posterior right lower ex- describing an external rotation or tremity. He reports having felt immediate pain in the area of hyper-dorsifl exion the right ankle and requiring assistance off of the fi eld, as he ankle injury. A had diffi culty walking. The patient was taken to the emergency department where x-rays of the right foot and ankle did not ❯ Obtain weight-bearing anteroposterior- and show any signs of acute fracture or dislocation. The patient was mortise-view ankle x-rays diagnosed with a lateral ankle sprain, placed in a pneumatic in all cases of suspected ankle walking brace, and given crutches. syndesmotic injuries. A high ankle sprain, or distal tibiofi bular syndesmotic in- ❯ Consider stress x-rays of the aff ected ankle, contralateral jury, can be an elusive diagnosis and is often mistaken ankle x-rays for comparison A for the more common lateral ankle sprain. Syndesmotic views, or advanced imaging injuries have been documented to occur in approximately 1% with magnetic resonance to 10% of all ankle sprains.1-3 Th e highest number of these in- imaging (MRI) or juries occurs between the ages of 18 and 34 years, and they are computed tomography more frequently seen in athletes than in nonathletes, particu- if initial x-rays are larly those who play collision sports, such as football, ice hock- unrevealing. A ey, rugby, wrestling, and lacrosse.1-9 In one study by Hunt et al,10 ❯ Treat stable syndesmotic syndesmotic injuries accounted for 24.6% of all ankle injuries in injuries with conservative National Collegiate Athletic Association (NCAA) football play- measures and ers. Incidence continues to grow as recognition of high ankle rehabilitation. A sprains increases among medical professionals.1,5 Identifi cation Strength of recommendation (SOR) of syndesmotic injury is critical, as lack of detection can lead to A Good-quality patient-oriented extensive time missed from athletic participation and chronic evidence ankle dysfunction, including pain and instability.2,4,6,11 B Inconsistent or limited-quality patient-oriented evidence C Consensus, usual practice, Back to basics: opinion, disease-oriented A brief anatomy review evidence, case series Stability in the distal tibiofi bular joint is maintained by the syndesmotic ligaments, which include the anterior inferior MDEDGE.COM/FAMILYMEDICINE VOL 68, NO 3 | APRIL 2019 | THE JOURNAL OF FAMILY PRACTICE E5 Nickless0419.indd 5 4/3/19 10:54 AM tibiofibular ligament (AITFL), the posterior sation of instability with weight bearing on inferior tibiofibular ligament (PITFL), the the affected ankle, or have persistent symp- transverse ligament, and the interosseous toms despite a course of conservative treat- ligament.3-6,8 This complex of ligaments stabi- ment. Also, they can have a variable amount lizes the fibula within the incisura of the tibia of edema and ecchymosis associated with and maintains a stable ankle mortise.1,4,5,11 their injury; a minimal extent of swelling or The deep portion of the deltoid ligament also ecchymosis does not exclude syndesmotic adds stability to the syndesmosis and may be injury.3 disrupted by a syndesmotic injury.2,5-7,11 A large percentage of patients will present with a concomitant sprain of the lateral liga- ments associated with lateral swelling and Mechanisms of injury: bruising. One study found that 91% of syndes- From most common to less likely motic injuries involved at least 1 of the lateral The distal tibiofibular syndesmosis is disrupt- collateral ligaments (anterior talofibular liga- ed when an injury forces apart the distal tib- ment [ATFL], calcaneofibular ligament [CFL], iofibular joint. The most commonly reported or posterior talofibular ligament [PTFL]).12 means of injury is external rotation with hy- Patients may have pain or a sensation of in- per-dorsiflexion of the ankle.1-3,5,6,11 With ex- stability when pushing off with the toes,5 and cessive external rotation of the forefoot, the patients with syndesmotic injuries often have Trauma talus is forced against the medial aspect of tenderness to palpation over the distal an- causing ankle the fibula, resulting in separation of the distal terolateral ankle or syndesmotic ligaments.7 syndesmotic tibia and fibula and injury to the syndesmotic ❚ A thorough examination of the ankle, injuries may be ligaments.2,3,5,6 Injuries associated with ex- including palpation of common fracture sites, associated with ternal rotation are commonly seen in sports is important. Employ the Ottawa Ankle Rules Weber B that immobilize the ankle within a rigid boot, (see http://www.theottawarules.ca/ankle_ or Weber C such as skiing and ice hockey.1,2,5 Some au- rules) to investigate for: tenderness to palpa- distal fibula thors have suggested that a planovalgus foot tion over the posterior 6 cm of the posterior fractures or a alignment may place athletes at inherent risk aspects of the distal medial and lateral malle- Maisonneuve for an external rotation ankle injury.5,6 oli; tenderness over the navicular; tenderness fracture. Syndesmotic injury may also occur with over the base of the fifth metatarsal; and/or hyper-dorsiflexion, as the anterior, widest por- the inability to bear weight on the affected tion of the talus rotates into the ankle mor- lower extremity immediately after injury or tise, wedging the tibia and fibula apart.2,3,5 upon evaluation in the physician’s office. Any There have also been reports of syndesmotic of these findings should raise concern for a injuries associated with internal rotation, possible fracture (see “Adult foot fractures: A plantar flexion, inversion, and eversion.3,5,11 guide,” at http://bit.ly/2Tm4Siv) and require Therefore, physicians should maintain a high an x-ray(s) for further evaluation.13 index of suspicion for injury to the distal ❚ Perform range-of-motion and tibiofibular joint, regardless of the mechanism strength testing with regard to ankle dor- of injury. siflexion, plantar flexion, abduction, ad- duction, inversion, and eversion. Palpate Presentation and evaluation the ATFL, CFL, and PTFL for tenderness, as Observation of the patient and visualization these structures may be involved to varying of the affected ankle can provide many clues. degrees in lateral ankle sprains. An anterior Many patients will have difficulty walking -af drawer test (see https://www.youtube.com/ ter suffering a syndesmotic injury and may watch?v=vAcBEYZKcto) may be positive with require the use of an assistive device.5 The injury to the ATFL. This test is performed by inability to bear weight after an ankle injury stabilizing the distal tibia with one hand and points to a more severe diagnosis, such as using the other hand to grasp the posterior an ankle fracture or syndesmotic injury, as aspect of the calcaneus and apply an anterior opposed to a simple lateral ankle sprain. Pa- force. The test is positive if the talus translates tients may report anterior ankle pain, a sen- forward, which correlates with laxity or rup- E6 THE JOURNAL OF FAMILY PRACTICE | APRIL 2019 | VOL 68, NO 3 Nickless0419.indd 6 4/3/19 10:54 AM HIGH ANKLE SPRAINS ture of the ATFL.13 The examiner should also FIGURE 1 palpate the Achilles tendon, peroneal ten- Maisonneuve fracture dons just posterior to the lateral malleolus, and the tibialis posterior tendon just posteri- or to the medial malleolus to inspect for ten- derness or defects that may be signs of injury to these tendons. ❚ An associated Weber B or C fracture? Trauma causing ankle syndesmosis injuries may be associated with Weber B or Weber C distal fibula fractures.7 Weber B fractures oc- cur in the distal fibula at the level of the ankle joint (see FIGURE 1). These types of fractures are typically associated with external rotation injuries and are usually not associated with disruption of the interosseous membrane. Weber C fractures are distal fibular frac- tures occurring above the level of the ankle RUSH, RUSH UNIVERSITY MEDICAL CENTER, CHICAGO AT OF: MIDWEST ORTHOPEDICS ALL IMAGES COURTESY joint. These fractures are also typically associ- ated with external ankle rotation injuries and include disruption of the syndesmosis and deltoid ligament.14 Also pay special attention to the proxi- mal fibula, as syndesmotic injuries are commonly associated with a Maisonneuve fracture, which is a proximal fibula fracture associated with external rotation forces of the ankle (see FIGURE 1).1,2,4,11,14,15 Further workup should occur in any patient with the possibil- ity of a Weber- or Maisonneuve-type fracture. ❚ Multiple tests are available to inves- tigate the possibility of a syndesmotic in- jury and to assess return-to-sport readiness, including the External Rotation Test, the Squeeze Test, the Crossed-Leg Test, the Dor- siflexion Compression Test, the Cotton Test, the Stabilization Test, the Fibular Transla- tion Test, and the Single Leg Hop Test (see TABLE1-3,5,6,16,17). The External Rotation Test is noted by some authors to have the highest This anteroposterior x-ray of the left tibia, fibula, and interobserver reliability, and is our preferred ankle demonstrates a Maisonneuve fracture (solid white arrow), as well as increased medial clear space 2 test.