When completing an ankle exam after an acute injury, it is imperative that it is performed from proximal to distal in a systematic and reproducible fashion. All potentially injured areas should be evaluated for injury. Once practitioners become proficient with this examination, it can be completed within a couple of minutes.

Following adequate assessment of peripheral pedal pulses and neurologic sensation, the following 15-step ankle analysis should be performed on every patient:

Evaluation of the integrity of the ATFL is achieved with an anterior drawer test. The examiner holds the lower leg locked from front to back and attempts to anteriorly translate the foot on the leg (Fig. 50.2). Although the test can be performed at any time, it is thought that the individual will have less guarding after 3 days from the initial injury. Accuracy is also improved if the test is performed under general anesthesia. The injured limb should be compared with the uninjured limb, and a difference of 4 mm or greater is considered to represent laxity within the ATFL (10). Less than 2 mm would be considered normal. Although this test is utilized to evaluate integrity of the ATFL, if the CFL is additionally injured, an increase in anterior translation will be seen (11).

Evaluation of the integrity of the CFL is achieved with a talar tilt test. The examiner holds the leg locked from side to side and inverts the heel. This is usually performed with the
assistance of an anteroposterior (AP) radiograph so that the angle between the tibia and talus can be measured. A comparison of the opposite limb should be performed. A difference of 5 to 15 degrees between limbs is considered significant for CFL disruption. Consideration should also be given to the fact that individuals may have a laxity within their CFL but may not have clinical symptoms of instability (Fig. 50.3).

When evaluating for syndesmotic injury, a number of clinical clues exist. Pain will usually be noted along the medial aspect of the ankle as well as along the length of the syndesmosis. Swelling will be seen proximal to the ankle joint in the early stages of injury (12). Two clinical tests can be performed to determine if the syndesmosis is injured. The “external rotation test” involves stabilizing the leg with one hand and externally rotating the foot on the leg with the other hand. If significant pain ensues, this is considered a positive finding. The “tibialfibular squeeze test” can also be performed. With this test, the tibia and fibula are compressed together about three centimeters proximal to the ankle joint. If pain ensues distally, this is also considered a positive test. Conflicting evidence exists in the literature as to which test is more accurate (Fig. 50.4).

Stress radiographs include additional evaluation of the anterior drawer and talar tilt with radiographs. Anterior drawer is performed and evaluated with a lateral radiographic study, and talar tilt is performed and evaluated with an AP view. These
views allow the clinician to quantify an exact degree of instability. Testing should be performed on both the injured and uninjured side so an adequate comparison can be made (Fig. 50.5).

The Ottawa Ankle Rules were developed from a prospective Canadian study performed by Stiell and colleagues in 1992. They evaluated 750 individuals with blunt ankle trauma and determined significant variables that would predict the likelihood of fracture versus soft tissue injury. These results were 100% sensitive and 42% specific, and it was predicted that with the use of their rules, unnecessary radiographic imaging would be reduced by 36% (13).

Ottawa Ankle Rules: