Page 25 - ISAKOS 2020 Newsletter Volume 2
P. 25

Current Concepts in Managing Ankle Syndesmosis Injuries
Diagnosis and Classification of Syndesmosis Injuries
The first opportunity for the clinician to identify a syndesmotic injury is the physical examination. The most common clinical tests performed to assess syndesmotic injuries include the squeeze test, palpation over the anterior and posterior parts of the tibiofibular syndesmosis, lateral translation testing (e.g., the Cotton test), location of tenderness above the ankle joint line, and the fibular instability test.2 Imaging studies, including weight-bearing radiographs and CT scans as well as MRI scans of the affected ankle, are commonly used to assist with decision-making. However, no current classification system includes all diagnostic modalities, and no system has been found to have suitable sensitivity and specificity to diagnose syndesmotic instability or to identify injuries that are less likely to improve with conservative management or more likely to risk long-term dysfunction.
One of the original classification schemes is the West Point Ankle Grading System. The West Point system separates syndesmotic injuries into three grades. Grade I is characterized by injury to the anterior inferior tibiofibular ligament (AITFL) with no ankle instability or diastasis.2 Grade II is characterized by injury to the AITFL and partial tear of the interosseous ligament (IOL) with slight instability but no frank diastasis.2 Grade-II injuries should be further stratified into stable (Grade IIa) and unstable (Grade IIb) to better guide treatment decisions made by clinicians. Grade-III injuries are characterized by complete disruption of all syndesmotic ligaments with frank instability and / or diastasis.2 Compared with Grade-III injuries, which show mortise widening, Grade-I and II injuries do not display radiographic changes to the ankle mortise. Thus, it is challenging to assess injury severity for patients with Grade-II injuries with use of standard radiography. It is not until after the posterior inferior tibiofibular ligament (PITFL) and deltoid ligament are injured in association with the syndesmosis ligaments that changes are seen on two-dimensional (2D) radiography (Hunt et al., unpublished data).
The diagnostic advantage of MRI over 2D radiography is the reason why many support the Sikka classification system for syndesmotic injuries. This classification scheme separates ligament involvement into four different groups. Grade-I injuries involve an isolated injury to the AITFL, Grade-II injuries include involvement of the IOL and / or interosseous membrane (IOM), Grade-III injuries include involvement of the PITFL, and Grade-IV injuries include involvement of all ligaments and rupture of the deltoid ligament.2 While not a perfect tool, MRI is essential for the diagnosis of moderate unstable syndesmotic injuries because it effectively displays ligamentous structures, has excellent interobserver agreement, and identifies secondary findings such as bone bruises, osteochondral lesions, and joint incongruity (Fig. 2).2
Kenneth J. Hunt, MD
University of Colorado School
of Medicine
Aurora, Colorado, UNITED STATES
Jonathan Bartolomei-Aguillar
Florida State University College
of Medicine
Tallahassee, Florida UNITED STATES
Pieter D’Hooghe, MD
Aspetar Orthopedic and Sports Medicine Hospital
Injuries to the ankle syndesmosis have demonstrated an increased prevalence among athletes of all levels, with an estimated incidence of 0.05 injury per 1,000 hours of exposure.1 Impact and collision sports such as soccer, skiing, football, ice hockey, wrestling, and rugby exhibit a higher prevalence of injury.1 It is also widely recognized that ligamentous syndesmotic injuries result in substantially longer times missed from sport compared with other ankle ligament injuries, are much more likely to require surgical stabilization, and are associated with more long-term functional sequelae. These factors have contributed to an increased focus on the diagnosis and management of syndesmotic injuries in sports medicine and athletic training circles in recent years.
The goal of this article is to present state-of-the-art information related to the diagnosis and management of syndesmotic injuries in athletes. We will focus on three areas in which meaningful recent advances and even paradigm shifts have occurred: (1) classification of syndesmotic injuries, (2) current fixation constructs and devices, and (3) return-to- play protocols for athletes suffering from these injuries.

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