SLR - June 2015 - Douglas Appel

Concomitant Syndesmotic Instability and Medial Ankle Instability are Risk Factors for Unsatisfactory Outcomes in Patients with Chronic Ankle Instability

Reference:  Kim JS, Young KW, Cho HK, Lim SM, Park YU, Lee KT. Concomitant Syndesmotic Instability and Medial Ankle Instability are Risk Factors for Unsatisfactory Outcomes in Patients with Chronic Ankle Instability. Arthroscopy. 2015 April 13. 21 (2): 1-9.

Scientific Literature Review

Reviewed By: Douglas Appel, DPM
Residency Program: Morristown Medical Center

Podiatric Relevance: Ankle instability is a common pathology seen by the podiatric surgeon on a daily basis. It is often debilitating and has a high recurrence rate. There is an abundance of literature regarding lateral ankle instability and surgical intervention, however, this article underscores the importance of complete assessment including clinical exam and diagnostic imaging in order to increase satisfactory surgical outcomes.  There is a greater need for podiatric surgeons to address medial ankle instability and syndesmotic injury with surgical repair when presenting concomitantly with lateral ankle instability. This article shows that the satisfactory outcome score using the American Orthopaedic Foot & Ankle Society (AOFAS) scores improved when medial ankle structures and syndesmosis pathology was addressed when present. The article also highlights the fact that a patient presenting with chronic ankle instability cannot be treated with a “cookie cutter, one fits all” approach, but rather an individualized surgical plan that addresses all etiological pathologies of the ankle joint for each patient.

Methods: This article was a retrospective review of prospectively collected data from 276 military patients who presented with chronic ankle instability and who had undergone a modified Brostrom procedure over a three year period. There was a mean 26.7 month follow-up period. Clinical outcomes for surgical success were evaluated using AOFAS ankle hindfoot scoring, ankle functional satisfactory scale scores. The findings underwent statistical analysis using Pearson correlation coefficient and multivariate logistic regression analysis. Patients with ankle fractures, arthritis and generalized laxity were excluded. All patients had symptoms for more than six months and underwent conservative treatment with physical therapy for at least six weeks. Diagnostic tests included direct palpation, medial/lateral rotary drawer test, and arthroscopic examination of syndesmosis, lateral ankle structures, and medial structures. Diastasis of ankle joint and syndesmosis was evaluated and measured arthroscopically. Plain radiographs and MRI were also utilized for preoperative evaluation.

Results: Two-hundred thirty-six out of two-hundred seventy-six patients had satisfactory outcomes. Of patients with satisfactory outcomes 8 percent had medial ankle instability, 6 percent had syndesmotic instability. Of the 40/276 patients that had unsatisfactory outcomes 35% had medial ankle instability and 30 percent had syndesmotic instability. AOFAS scores in satisfactory result patients increased from 68.1 to 92.8 (P<.001) and from 65.9 to 76.8 (P <.001) in patients with unsatisfactory outcomes.

Conclusion: Chronic ankle instability with chronic medial ankle instability and syndesmotic instability had 11.7 fold higher risk of unsatisfactory outcome. Thus, the authors present the statistical case that if there is ankle instability, chronic medial ankle instability and syndesmotic injury should be assessed preoperatively. If medial ankle instability and/or syndesmotic injury is/are present then it must be surgically addressed. Higher rates of postoperative satisfaction can be expected with addressing medial ankle instability and syndesmotic injury when present. Also, patients with these concomitant pathologies were found to have overall lower postoperative satisfaction scores, thus, surgical treatment should be aggressive in these cases to augment correction and patient satisfaction. 

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