Sports-Related Injuries of the Foot and Ankle



Sports-Related Injuries of the Foot and Ankle


Johnny Lin, MD


Dr. Lin or an immediate family member has received research or institutional support from Arthrex, Inc. and has received nonincome support (such as equipment or services), commercially derived honoraria, or other non-research-related funding (such as paid travel) from Medwest.


This chapter is adapted from Berkowitz MJ: Sports-Related Injuries of the Foot and Ankle in Chou LB, ed: Orthopaedic Knowledge Update: Foot and Ankle 5. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2014, pp 371-386.





Introduction

Acute traumatic injuries and cumulative stress injuries involving the foot and ankle can affect the sports participation and performance of both elite competitive athletes and people engaged in recreational or fitness activities. A thorough understanding of common injuries of the foot and ankle allows a logical and organized approach to treating these injuries and facilitates the patient’s return to play.


Ankle Anatomy

The stability of the ankle is the result of a combination of osseous, ligamentous, and musculotendinous components. The ankle generally is described as a mortise in which the talus is housed in the dome-shaped tibial plafond and the medial, lateral, and posterior malleoli. The talus is wider anteriorly than posteriorly so that the ankle intrinsically is most stable in the dorsiflexed position when the wider portion of the talus is engaged in the mortise. Conversely, in the plantarflexed position the narrower posterior talus is engaged in the mortise and the ankle therefore is more unstable. Therefore, in the plantarflexed position the stability of the ankle is more dependent on the lateral ligament complex. Not surprisingly, most acute inversion sprains occur when the ankle is somewhat plantarflexed.

The lateral ankle ligament complex primarily is composed of the anterior talofibular ligament (ATFL) and the calcaneofibular ligament (CFL). The ATFL prevents anterior translation of the plantarflexed ankle. The CFL is a collateral ligament that stabilizes both the ankle and the subtalar joint preventing varus of the ankle and subtalar joint. In more severe inversion sprains, the CFL is injured along with the ATFL.

The peroneal musculotendinous unit is an important contributor to ankle stability. The peroneal tendons rapidly contract to resist and prevent excessive inversion. The peroneal complex is also part of an important proprioceptive feedback loop that enables an athlete to instinctively sense and control the position of the foot and ankle in space.


Acute Lateral Ankle Ligament Injuries

Acute lateral ankle sprain is one of the most common injuries sustained during sports activity. An epidemiologic study of ankle sprains reported that more than three
million sprains occurred during the 4-year study period and that more than half of these injuries occurred during athletic activity.1 Acute ankle sprain was most common in individuals aged 10 to 19 years. Boys and men aged 15 to 24 years sustained more ankle sprains than girls and women in the same age range, but women older than 30 years sustained more sprains than their male counterparts.

An acute ankle sprain causes a variable amount of mechanical injury to the lateral ligament complex of the ankle. Such an injury can lead to lingering symptoms such as instability and pain, which can impede or preclude return to play. Proper initial management and detection of concomitant injuries (ie, talar chondral injuries, peroneal tendon pathology, fractures) minimizes the risk of long-term morbidity and speeds the resumption of athletic participation.



Radiographic Evaluation

Appropriate radiographic studies are helpful for avoiding a misdiagnosis and facilitating a prompt diagnosis of associated injuries. In the emergency department, the Ottawa ankle rules provide guidance as to whether radiographs are necessary or can be deferred. Ankle radiographs are indicated if the presence of a fracture is suggested by tenderness along the distal 6 cm of the posterior edge of the fibula or the tip of the lateral malleolus, tenderness along the distal 6 cm of the posterior edge of the tibia or the tip of the medial malleolus, or inability to tolerate weight bearing for at least four steps. In the absence of these findings, the diagnosis usually is an acute sprain, and radiographs are unnecessary. Adherence to these guidelines reduces the patient’s cost, time in the emergency department, and exposure to radiation.

The Ottawa ankle rules were designed for implementation and use in the emergency department. However, many patients who sustain an acute lateral ankle ligament injury are evaluated by an orthopaedic surgeon in an outpatient clinical office several days to a few weeks after injury. In this more specialized environment, the threshold for radiographic evaluation is lower because the definitive diagnosis and treatment plan are based on the evaluation. An orthopaedic surgeon should attempt to obtain a series of weight-bearing ankle radiographs for most patients with an acute lateral ankle sprain. Additional weight-bearing radiographs of the foot can be added when there is suspicion for a concomitant foot injury based on either the history or physical examination. Weight-bearing views provide substantially better imaging of relevant osseous structures than non-weight-bearing views and thereby minimize the possibility of missing an injury. Simulated weight-bearing views can be obtained at the initial evaluation if full weight bearing is too painful. Obtaining full weight-bearing views is deferred until symptoms improve. The AP and mortise ankle radiographs of the ankle should be evaluated for medial clear space and syndesmotic widening, malleolar fracture, lateral process of talus fracture, and talar osteochondral fracture (Figure 1). The lateral views of the ankle and foot can reveal dorsal talar avulsion fractures,
anterior process of the calcaneus fractures, or the presence of an os trigonum injury. The AP and oblique foot views can reveal navicular fractures, midfoot injuries, cuboid fractures, or fifth metatarsal fractures. Radiographic and physical examination findings always must be correlated to provide an accurate and complete diagnosis.






FIGURE 1 A, Mortise ankle radiograph in a patient with an acute ankle sprain. Lucency in the lateral talar dome suggests a fracture. B, Magnetic resonance image confirms that the patient has an acute unstable lateral talar osteochondral fracture.

CT and MRI have limited indications in the evaluation of an acute ankle sprain. CT is used to detect an associated fracture suspected on the basis of plain radiographs; these include fracture of the lateral process of the talus and the anterior process of calcaneus, posterior talar fracture, and osteochondral fracture. CT provides an accurate assessment of fracture size, displacement, and comminution that ultimately can guide treatment. CT, preferably weight-bearing, can also detect malalignment or displacement of the syndesmosis through visualizing the clear space in the axial plane. MRI rarely is indicated to evaluate an acute ankle sprain and should be obtained only if suspicion is high for an osteochondral lesion of the talus or an associated soft-tissue injury such as an Achilles tendon rupture or peroneal tendon dislocation. MRI is useful for distinguishing a preexisting chronic osteochondral lesion from an acute osteochondral fracture. MRI has also been found to be superior to physical examination for the detection of syndesmotic injuries in the setting of ambiguous plain radiographs.2



Chronic Lateral Ankle Ligament Injuries

With proper treatment, most patients who sustain an acute lateral ankle sprain successfully recover and return to their desired sports and preinjury level of activity. However, the outcome of a lateral ankle sprain, particularly a grade III injury, is not always favorable. A multiple database study of acute ankle sprains found that as many as 33% of patients still had pain 1 year after injury, and as many as 34% of patients sustained a recurrent sprain within a 3-year period after the initial injury.10 The evaluation of a patient with chronic symptoms after ankle ligament injury must help identify the source of the lingering symptoms and initiate appropriate nonsurgical treatment. When necessary, surgical intervention is required to facilitate a return to sports.


Patient History

The history should elicit details of the initial injury, subsequent reinjury, and current symptoms. It is important to assess whether the patient’s symptoms primarily involve instability, pain, or both. A detailed characterization of the instability and pain components of the patient’s symptoms should be sought. The duration, frequency, and severity of instability episodes should be recorded and should include the number of sprains per month or year. The examiner should assess whether the recurrent sprains occur only during sports activities or also during activities of daily living. Patients with severe chronic instability may report frequent sprains with seemingly innocuous mechanisms such as stepping on a pebble, a curb, or a crack in a sidewalk. The examiner should document the extent of earlier treatment, including physical therapy, and to what extent bracing treatment controls the instability.

The timing, severity, and location of the pain component should also be assessed. The patient should be asked whether pain is present constantly or only after a sprain. Patients sometimes report surprisingly little pain after recurrent ankle sprains because of the overall laxity of the ligaments. Other patients report pain as the primary symptom and describe pain that precipitates the giving way episode. This type of pain should alert the examiner to the possibility that functional instability symptoms may be the result of concomitant mechanical pathology. It is particularly important for the patient to identify the location of the pain as specifically as possible. Determining whether the pain primarily is medial, anterolateral, or retrofibular will suggest the most likely causes and guide the choice of imaging.



Radiographic Evaluation

Standard weight-bearing radiographs of the ankle and foot are used to evaluate a patient for chronic lateral ligament injury. AP and mortise views of the ankle should be scrutinized for lucent lesions in the talar dome that may signify osteochondral injury. The physician also should look for a large avulsion fracture off the distal tip of the fibula, which may accompany chronic ATFL injury. The lateral radiograph allows detection of anterior distal tibial osteophytes that can cause anterior ankle impingement. Radiographs can provide confirmation of subtle cavovarus malalignment. On a lateral radiograph of the foot, a cavus arch is suggested by a positive Meary angle formed by the axis of the talus and the axis of the first metatarsal. In cavovarus, a lateral radiograph fails to capture the talus in true profile, the fibula appears posterior, and the posterior facet is extremely well visualized, as in a Broden view. An AP foot radiograph may reveal so-called stacking of the metatarsals or metatarsus adductus. Each of these radiographic signs should raise the examiner’s suspicion for concomitant malalignment.

Stress evaluation of the ankle involves the anterior drawer and talar tilt maneuvers done with fluoroscopy
or plain radiography. Stress images are useful if it is desirable to quantify the severity of the instability, as for a research study. Stress fluoroscopy also is helpful for distinguishing true talar tilt from subtalar motion (Figure 3).






FIGURE 3 Stress fluoroscopic view showing laxity of the calcaneofibular ligament with a resulting increase in talar tilt.

MRI has a more significant role in chronic lateral ankle ligament injuries than in acute injuries. MRI is recommended if the patient’s history, physical examination, or plain radiographs suggest the possibility of osteochondral lesions of the talus or peroneal tendon injury. MRI also is indicated if the patient has poorly defined ankle pain because it can reveal conditions such as anterolateral soft-tissue impingement lesions, loose bodies, or subtle fractures.11 If possible, 1.5- or 3.0-Tesla MRI should be obtained; the image resolution of open MRI is inadequate to provide meaningful information.

A recent retrospective cohort study compared MRI with stress radiographs among 187 patients.12 Although MRI was highly sensitive compared with stress radiographs (83% versus 66%), the specificity of MRI was lower (53% versus 97%). The overall accuracy of stress radiographs was 74%, whereas the overall accuracy of MRI was 71%. The authors concluded that although MRI is a useful screening tool for concomitant ankle pathology associated with lateral ankle instability, it should not be used on its own for the diagnosis of chronic ankle instability.

Feb 27, 2020 | Posted by in ORTHOPEDIC | Comments Off on Sports-Related Injuries of the Foot and Ankle
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