Diagnosis and Treatment of Chronic Lateral Ankle Instability: Review of Our Biomechanical Evidence

Abstract

Definitive diagnosis and optimal surgical treatment of chronic lateral ankle instability remains controversial. This review distills available biomechanical evidence as it pertains to the clinical assessment, imaging work up, and surgical treatment of lateral ankle instability. Current data suggest that accurate assessment of ligament integrity during physical examination requires the ankle to ideally be held in 16° of plantar flexion when performing the anterior drawer test and 18° of dorsiflexion when performing the talar tilt test, respectively. Stress radiographs are limited by their low sensitivity, and MRI is limited by its static nature. Surgically, both arthroscopic and open repair techniques appear biomechanically equivalent in their ability to restore ankle stability, although sufficient evidence is still lacking for any particular procedure to be considered a superior construct. When performing reconstruction, grafts should be tensioned at 10 N and use of nonabsorbable augmentations lacking viscoelastic creep must factor in the potential for overtensioning. Anatomic lateral ligament surgery provides sufficient biomechanical strength to safely enable immediate postoperative weight bearing if lateral ankle stress is neutralized with a boot. Further research and comparative clinical trials will be necessary to define which of these ever-increasing procedural options actually optimizes patient outcome for chronic lateral ankle instability.

The clinical outcomes of surgical treatment for chronic ankle instability by anatomical reconstruction of the anterior talofibular ligament with autologous half-bundle peroneal longus tendon: A retrospective study

“…The anterior drawer test (ADT) and the talar tilt angle are commonly used in clinical practice to assess lateral ankle ligament injury. The ATFL is an anatomic linkage between the distal fibula and the talus, which limits the sagittal talar translation and axial rotation (12). Phisitkul et al (13) studied that the ADT is more accurate in diagnosing ATFL injury than standard direct AD testing.…”

“…However, MRI has a high sensitivity but low specificity. As a result, using MRI to recognize additional periarticular pathology rather than as a primary diagnostic tool for CLAI (12). Therefore, when the diagnosis of ankle ligament injury is clear, early surgical treatment should be actively performed.…”

Correlation of Stress Radiographs to Injuries Associated with Lateral Ankle Instability

“…MRI is commonly utilized and can document peroneal tendosynovitis or tears. The artifact that occurs as the tendons curve around the lateral malleolus, however, can decreased the sensitivity to 80% and the specificity to 75% [13].…”

Correlation of stress radiographs to injuries associated with lateral ankle instability

“…Although we were able to find an association between larger degrees of instability and the presence of peroneal pathology, we were not able to find a degree of instability that was predictive of instability. Threshold values of 10 mm on the anterior drawer test or 10° on the talar tilt test have been found to correlate with clinical instability[ 14 ]. We evaluated the statistical performance of stress radiographs in terms of peroneal pathology.…”