SLR - September 2014 - Jill F. Ashcraft

Treatment of Chronic Syndesmotic Injury: A Systematic Review and Meta-Analysis

References: George Parlamas, Charles P. Hannon, Christopher D. Murawski, Niall A. Smyth, Yan Ma, Gino M. Kerkhoffs, C. Niek van Dijk, Jon Karlsso, John G. Kennedy. Treatment of Chronic Syndesmotic Injury: Systematic Review and Meta-Analysis. Knee Surg Sports Traumatol Arthrosc. 2013; 21:1931–1939.

Scientific Literature Review

Reviewed By: Jill F. Ashcraft, DPM
Residency Program: Mount Auburn Hospital, Cambridge, MA

Podiatric Relevance: Syndesmotic injuries of the lower extremity are a condition that foot and ankle surgeons encounter routinely. Injuries to the syndesmosis can occur following a sprain or fracture of the ankle, and may be an isolated injury or a component of a more extensive injury complex. In any scenario, a syndesmotic injury can be difficult to detect. Syndesmotic instability is not clearly visible on plain film radiography, and clinical evaluations have been shown to have varied consistency with the aid of diagnosis. Often under diagnosed, injury to the syndesmosis can be seen in up to 18 percent of all ankle injuries, so a high index of clinical suspicion is paramount. Stress films and advanced imaging can often be necessary, especially when establishing a chronic injury. Patients with symptoms at 6 months post initial injury are considered to have chronic syndesmotic injury.  Surgical intervention is routinely necessary to stabilize the ankle and reduce pain in this population. A foot and ankle surgeon needs to be able to determine if a syndesmotic injury is present, identify chronicity, and finally determine need for surgical intervention, including the most appropriate procedure of choice.  

Methods: This was a systematic review of studies that reported the outcomes of the treatment of chronic syndesmotic injuries. In this study inclusion criteria were those populations that had a chronic syndesmotic injury, whose symptoms persisted for six months or greater. The search strategy included two authors performing a broad database search PubMed/MEDLINE and EMBASE databases from July 1967 to August 2012. Determination of chronic instability was assessed in all studies and varied between medial clear space, diastasis, and total clear space. Tibiofibular overlap in some studies was assessed as well as tibiofibular space. Exclusion criteria included studies not published in English, case reports, studies that reported outcomes after acute syndesmotic injury or studies that did not provide radiographic or functional outcome scores.  

Data was extracted by two observers who were unblinded. Variables collected from each study included number of patients, mean age, percent male or female, mean follow-up time, mean duration of symptoms, functional outcomes and success rate. Treatment methods were placed into three subsets: screw fixation, arthrodesis and arthroscopic debridement. Article quality was evaluated by a modified, non-validated Newcastle Ottawa Scale to assess the methods behind of articles in the study. In this modification, studies were rated based on study design, selection and assessment of outcome.  

Statistical analysis was done by a meta-analysis and Freeman Turkey type arcsine square root transformation to identify the pooled proportion of success for screw fixation, arthrodesis, and arthroscopic debridement. A Forest plot was utilized for the presentation of the proportions and confidence intervals from individual studies. Meta-regression based on random-effects logistic model was conducted to determine success after screw fixation, and to identify the effects of gender, age, average follow-up, mean duration of symptoms and method of diagnosis.

Results: This systematic review search yielded 15 full text documents that met review requirements. Screw fixation was the most common treatment modality, and was included in 11 of the studies. Two additional studies were reviewed that utilized arthrodesis and two that utilized arthroscopic debridement as the sole treatment for chronic instability. Several different scoring systems were utilized by the included studies. The most common was the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale (AOFAS), which was used to evaluate 8 of the 15 studies included. Quality assessment of included studies was done by the total Newcastle Ottawa Scale. Utilizing this scale, the outcome described in each study was found to total 15 of 30 stars. The average Newcastle Ottawa Scale for each study was 1.8 stars out of a possible five stars. Meta-analysis of the pooled rates of success for screw fixation, arthrodesis and arthroscopic debridement were 87.9 percent, 79.4 percent, and 78.7 percent, respectively. The meta-regression indicated that gender, age, average follow-up, mean duration of symptoms and method of diagnosis did not significantly affect success rates after screw fixation.

Conclusions: The primary aim of this study was to collect and analyze the data on the treatment of chronic syndesmotic injuries. A meta-analysis was meant to help determine what the most effective treatment option is for these injuries based on the available literature. The results from this study demonstrate that screw fixation is a successful treatment method for chronic syndesmotic injuries with an 87.9 percent success rate. The two other treatment groups in this study, arthrodesis and arthroscopic debridement, also had good success rates of 79.4 and 78.7 percent, respectively, however there was little literature to support this.

This meta-analysis and systematic review showed that several studies report successful outcomes after treatment of chronic syndesmotic injuries with screw fixation, arthrodesis and arthroscopic debridement. However there is a significant lack of literature to back up the surgical methods, and the invalidated analysis of success is unclear. Overall this study suggests that there are other factors that may be more important in determining treatment outcomes of chronic syndesmotic instability then the method of fixation. These factors include the extent of injury and other patient-related factors. This study was essentially not able to establish a gold standard of care as the current literature review did not have reproducible treatment outcomes that could be compared. Not only was there a lack of literature to back up differing surgical methods, but the outcomes for success were varied and analyzed by a non-validated tool.  When considering treatment methods for syndesmotic injuries, future research is warranted to identify when it is appropriate to utilize screw fixation alone, and when arthroscopic debridement and anatomical reconstruction is required. As per the authors, there is “a lack of homogeneity of the literature on the treatment of chronic syndesmotic injuries, no conclusions can be drawn and a gold standard remains to be established.” 

Educational Opportunities