SLR - December 2023 - Redzematovic
Title: Clinical significance of the anteromedial talus osteophyte in anteromedial ankle impingement in chronic lateral ankle instabilityReference: Zhang J, Li X, Fu S, Yang K, Shi Z. Clinical significance of the anteromedial talus osteophyte in anteromedial ankle impingement in chronic lateral ankle instability. J Orthop Surg Res. 2023 Mar 1;18(1):151. doi: 10.1186/s13018-023-03630-x. PMID: 36859336; PMCID: PMC9976382.
Level of Evidence: Level IV
Reviewed By: Kenan Redzematovic, DPM
Residency Program: St. Mary’s General Hospital, Passaic, NJ
Podiatric Relevance: Chronic lateral ankle instability is a common pathology encountered in the field of foot and ankle surgery and it warrants a proper evaluation of both the lateral ankle and associated biomechanical abnormalities. While the lateral ligament complex imparts the most stability to the lateral ankle, an appreciation of anteromedial ankle impingement and associated osteophytes is warranted as well.
Recently, ankle impingement has been increasingly recognized as a contributor to lateral ankle instability which can confound the diagnosis. This study sheds light on the anteromedial ankle osteophytes that may be limiting lateral ankle ligament repair.
Methods: A level IV retrospective study was performed which included 43 patients with chronic ankle pain and mechanical instability. Patients were separated into two groups: anteromedial ankle impingement group that included resection of osteophytes causing impingement and pure chronic lateral ankle group with osteophytes not causing impingement and no resection. Preoperative and 2-year follow up values of ankle dorsiflexion, AOFAS ankle-hindfoot scores and VAS scores were obtained from all patients. All patients underwent arthroscopic repair of the anterior talofibular ligament and the anteromedial ankle impingement group underwent further resection of osteophytes. Pre- and post-operative ankle CT scans of all patients were obtained, superimposed on another and analyzed by artificial intelligence in order to quantify morphologic changes and protrusion of osteophytes both pre- and post-resection.
Results: The ankle impingement group’s pre-operative ankle dorsiflexion was significantly lower than the purely ligamentous group. Post resection, the ankle impingement group’s ankle dorsiflexion improved. Although not statistically significant, the anteromedial ankle impingement group improved in each category of ankle dorsiflexion, AOFAS score and VAS at 2-year follow up. Purely chronic lateral ankle instability group improved as well however not as dramatically. Statistically significant differences in pre- and post-resection of osteophytes in the anteromedial ankle impingement group was noted at 2-year follow up as well.
Conclusions: Chronic lateral ankle instability can often be complicated by anteromedial ankle impingement which, if not recognized and addressed appropriately, may lead to suboptimal patient outcomes including reduced ankle dorsiflexion, lower AOFAS and higher VAS scores. This study was limited by its relatively small sample size of 43 patients and the nonuniformity of anteromedial ankle osteophytes within the patient population. This study highlights the need for an appreciation of the possibility of anteromedial ankle impingement is prudent and warrants preoperative clinical examination in every patient with lateral ankle symptoms. In addition, appropriate imaging modalities are necessary in order to fully address and impart most optimal patient outcomes.