SLR - July 2021 - Vincent G. Vacketta

Consistency and Reliability of Ankle Stress Radiography in Patients with Chronic Lateral Ankle Instability

Reference: Choi JH, Choi KJ, Chung CY, Park MS, Sung KH, Lee KM. Consistency and Reliability of Ankle Stress Radiography in Patients with Chronic Lateral Ankle Instability. Orthop J Sports Med. 2021 May 18;9(5)23259671211004099

Level of Evidence: III

Scientific Literature Review

Reviewed By: Vincent G. Vacketta, DPM
Residency Program: West Penn Hospital – Pittsburgh, PA

Podiatric Relevance: Chronic lateral ankle instability (CLAI) is a common injury seen by foot and ankle surgeons. Both conservative and surgical management of this injury are quite common and the determination for operative intervention versus conservative care is based on a variety of patient-dependent factors, clinical examination, and imaging studies. Anterior-posterior and lateral ankle stress radiographs have been commonly utilized to better understand the degree of instability of the talus within the ankle mortise. This article investigates the consistency and reliability of ankle stress radiographs in the evaluation of patients with CLAI.

Methods: A level III, retrospective cohort series was performed evaluating 45 subjects suffering from CLAI between January 2014 and July 2019. Patients suffering from acute lateral ankle injuries were excluded. Each subject underwent two repeated ankle stress radiographs obtained upon initial presentation and at final follow-up. The angles measured included tibiotalar tilt angle measured on varus stress radiographs, and the amount of anterior talar translation on anterior drawer stress radiographs. All measurements were performed by three experienced foot and ankle orthopedic surgeons. Analysis was performed utilizing the intraclass correlation coefficient (ICC) to determine interobserver reliability and consistency of ankle stress radiographs.

Results:
This study demonstrated no statistically significant differences amongst tibiotalar tilt angle or anterior talar translation regarding the index side, the contralateral side, or the difference between index and contralateral sides. The ICC’s for interobserver reliability of radiographic measurements amongst the three surgeons revealed excellent agreement. In contrast, the ICCs regarding the consistency among the initial and final radiographs demonstrated good agreement in regard to the tibiotalar tilt angle and poor agreement in regard to anterior talar translation. Consistency in the difference between the injured extremity and contralateral extremity indicated moderate agreement for tibiotalar tilt angle and poor agreement for anterior talar translation angle. Lastly, in regard to indications for surgical management, 22.2 percent and 15.6 percent of patients were indicated for surgical treatment based on the initial and final varus stress radiographs, respectively. Utilizing the anterior drawer stress radiographs, 22.2 percent and 20 percent of patients were indicated for surgical treatment based on the initial and final radiographs, respectively. The agreement regarding indications for surgery between the initial and final radiographs was fair for the varus stress radiographs and the anterior drawer stress radiographs.

Conclusions: This study demonstrated variance within ankle stress radiographic measurements in patients with seemingly identical ankle ligament conditions. Findings of this study support the use of caution when determining to pursue surgical treatment options based on a single set of ankle stress radiographs. Based on these findings, these authors encourage repeated radiographic examinations in addition to a thorough physical examination to determine the true presence of ankle instability. In addition, these authors acknowledge the benefits of advanced imaging to allow for a greater understanding of the inherent ankle pathology. This article is important for the foot and ankle surgeon as it provides better understanding of the reliability of these radiographic tools and therefore may improve surgeons’ clinical decision-making as it pertains to treatment of CLAI.

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