SLR - September 2018 - Joseph G. Wilson

Arthroscopic Debridement of Anterior Ankle Impingement in Patients with Chronic Lateral Ankle Instability

Reference: Yang Q, Zhou Y, Xu Y. Arthroscopic Debridement of Anterior Ankle Impingement in Patients with Chronic Lateral Ankle Instability. BMC Musculoskelet Disord. 2018 Jul 19;19(1):239.

Scientific Literature Review

Reviewed By: Joseph G. Wilson, DPM
Residency Program: Mercy Hospital and Medical Center, Chicago, IL

Relevance: Lateral ankle sprains are relatively common, especially in the athletic population. Despite most patients responding well to conservative treatment, patients with chronic ankle instability have shown reported rates of 63 percent to 86 percent associated soft-tissue impingement as well as 12 percent to 26 percent of associated bony anterior ankle impingement. Therefore, the purpose of this retrospective study was to evaluate functional and radiological outcomes after arthroscopic treatment of anterior ankle impingement in patients with mechanical chronic lateral ankle instability.

Methods: Patients from 2012 to 2015 who underwent a modified Broström-Gould procedure agreed to participate in this study. Chronic ankle instability was clinically defined as pain or repetitive sprains for more than three months with positive anterior drawer test and positive MRI findings. Patients with significant osteochondral lesions, prior surgery, neuromuscular or prior lateral ankle ligament reconstruction were excluded. All patients underwent ankle arthroscopy to evaluate ankle before lateral ankle repair. Osteochondral lesions were microfractured, impacted soft tissue or synovial membrane and all lose bodies were removed. Whenever present, anterior osteophytes on the distal tibial and anterior lip of the talus were debrided to restore full ankle joint ROM. After arthroscopy, open repair of ATFL/CFL was performed with one or two suture anchors. Patients were nonweightbearing for four weeks postoperatively. Functional scores were assessed pre- and postoperatively over a minimum of 24 months via the American Orthopaedic Foot and Ankle Society (AOFAS) score, Karlsson ankle function score and Tegner activity score. Radiographic evaluation was performed pre- and postoperatively, and all anterior tibio-talar osteophytes were classified according to Scranton and McDermott.

Results: Sixty patients were followed up at a mean of 37 ± 10 months, and 22 patients had anterior ankle impingent (AAI) and were grouped together and compared with the 38 who had pure chronic ankle instability (CAI). Preoperatively, the AAI group had a significantly lower AOFAS score (62.9 ± 11.7 vs 72.9 ± 11.1; p = 0.002) and Tegner activity score (1.5 ± 0.8 vs 2.1 ± 1.0; p = 0.04), respectively, when compared with the pure CAI group. The ankle dorsiflexion of the AAI group (13 ± 2.1) was also significantly lower than the CAI group (26.2 ± 2.1, p = 0.001). There was no significant difference in the AOFAS, Karlsson or Tegner scores or the ankle dorsiflexion between the two groups postoperatively. The postoperative X-ray images demonstrated complete osteophyte resection in all patients, and no recurrence of osteophyte in the AAI group. All patients returned to previous activity level.

Conclusion:
Previous studies have shown that addressing only anterior impingement without addressing chronic lateral ankle instability will often lead to recurrence of impingement and lower functional outcomes. This study showed that functional outcome scores and dorsiflexion were significantly improved and comparable to patients with just CAI up to three years after ligament repair without recurrence of anterior ankle impingement in the applicable cases. Hence, it is important to appreciate and address all aspects of ankle instability concurrently to optimize and maintain good functional outcomes.

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