Comparative Computed Tomography with Stress Maneuvers for Evaluation of Distal Tibiofibular Syndesmosis Instability in Adults After Acute Ankle Sprain: a Test Accuracy Study

INTRODUCTION:

One specific type of sprain is a high ankle sprain with ligament damage to the distal tibiofibular syndesmosis. A syndesmotic lesion is the leading cause of persistent disability or chronic pain and frequently requires longer recovery times and receives significantly more treatments than low lateral ankle sprains.

The degree of instability in syndesmotic disruption guides the decision to operate or treat conservatively. Clinical examinations, routine radiographs, stress radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) are the available diagnostic tools to decide the correct treatment. Unfortunately, the clinical diagnosis has limited evidence. The best current practice considers that few clinical examination tests have some validity in identifying syndesmotic disruption. The mortise or anteroposterior radiographic view may promptly diagnose frank syndesmotic instability (SI), identifying the widening of the articular space on the injured side relative to the contralateral uninjured side. However, SI may be underdiagnosed when routine radiography shows a healthy articular relationship. Routine radiographs cannot reliably predict syndesmotic injuries. Stress radiographs are inaccurate for evaluating such injuries in a cadaveric model. CTNP is more sensitive than radiography for detecting syndesmotic widening. MRI can be used to visualize and diagnose damaged ligaments with high accuracy.

Notwithstanding, the traditional measurement of the anterior tibiofibular distance (ATFD), obtained by CTNP, has an unsatisfactory area under the receiver operator curve (ROC) performance of 0,58 in diagnosing SI. Despite all these available methods, SI is still challenging to diagnose correctly, and syndesmotic ligament disruption and real SI should be differentiated. CTSM is an alternative approach that could improve the diagnosis of SI. To the investigator's knowledge, the application of CTSM has not been previously described.

METHODS: