Evaluation modalities for the anatomical repair of chronic ankle instability

Purpose: Several evaluation modalities are reported in the literature dealing with the operative treatment of chronic ankle instability (CAI) both to establish the CAI diagnosis leading to the surgical indication and to assess the effectiveness of ankle stabilisation procedure. The purpose of this study is to present an overview of the pre- and postoperative evaluation modalities reported in the literature dealing with CAI operative treatment. The comprehensive analysis of the different modalities chosen by researchers is expected to suggest critical points in current evaluation ability of CAI surgical treatment. Methods: Systematic review of the literature on surgical treatment of CAI through anatomic procedures. Pubmed, Embase and Cochrane electronic databases were analysed, from 2004 to 2018. Results: One-hundred-and-four studies met inclusion in this systematic review. 88 out of 104 studies analysed preoperative mechanical laxity of the ankle to depict the ligamentous insufficiency related to the subjective feeling of functional instability. Stress radiographs and manual stress examination of the ankle were the two most common modalities to evaluate joint laxity, reported in 67 and 53 studies, respectively. Clinical Outcome Measurement Scales (COMs) is the most common evaluation modality (102 out of 104 studies) to assess CAI surgical outcome. The American Orthopaedic Foot and Ankle Society Ankle-Hindfoot scale (AOFAS) and the Karlsson score are the most frequent COMs, reported in the 66% and 33%, respectively of the included literature. The radiographic analysis of ankle laxity after stabilisation procedures is the second most frequent postoperative evaluation modality, reported in 55 out 104 studies. Conclusions: There is a lack of standardization among researchers related to both the criteria to establish the CAI diagnosis leading to the surgical indication and the modality chosen to evaluate the effectiveness of surgical treatment. Future standardization of evaluation modalities in the CAI population is desirable to increase consistency of reported data. Level of evidence: Level IV, review of level I, II, III and IV studies.