Correlation of stress radiographs to injuries associated with lateral ankle instability

Abstract

Background: Stress radiographs have demonstrated superior efficacy in the evaluation of ankle instability.

Aim: To determine if there is a degree of instability evidenced by stress radiographs that is associated with pathology concomitant with ankle ligamentous instability.

Methods: A retrospective review of 87 consecutive patients aged 18-74 who had stress radiographs performed at a single institution between 2014 and 2020 was performed. These manual radiographic stress views were then correlated with magnetic resonance imaging and operative findings.

Results: A statistically significant association was determined for the mean and median stress radiographic values and the presence of peroneal pathology (P = 0.008 for tendonitis and P = 0.020 for peroneal tendon tears). A significant inverse relationship was found between the presence of an osteochondral defect and increasing degrees of instability (P = 0.043).

Conclusion: Although valuable in the clinical evaluation of ankle instability, stress radiographs are not an independent predictor of conditions associated with ankle instability.

Keywords: Ankle stress radiographs; Arthroscopy; Lateral ankle instability; Osteochondral defect; Peroneal tendinopathy.

Figure 1

Stress radiographs. A: An example of a stable ankle which has previously undergone a modified Broström procedure is depicted; B: The contralateral ankle demonstrating instability on the talar tilt examination is depicted; C and D: The corresponding anterior drawer stress radiographs.

Figure 2

The measurements for stress radiographs are depicted here. A: The anterior drawer distance is obtained by drawing a line from the most posterior aspect of the distal tibial plafond to a point on the talus that is perpendicular to the articular surface of the talus. The distance ‘x’ is measured in millimeters; B: The anterior drawer is depicted. In order to measure the anterior drawer one line is drawn along the distal articular surface of the tibia and a second line is drawn along the proximal articular surface of the talus. The angle ‘y’ formed by the intersection of these two lines is the talar tilt angle and is measured in degrees.

Figure 3

The presence of an associated condition is listed next to the number of ankles that have that condition when organized according to the degree of instability as measured on the talar tilt image. MRI: Magnetic resonance imaging; OLT: Osteochondral lesions of the talus.