[Effect of preoperative anterior bony impingement on lateral collateral ankle ligament reconstruction]

Objective: To explore whether the combination of anterior bony impingement before surgery will affect the efficacy of the lateral collateral ankle ligament reconstruction surgery in patients with chronic ankle instability (CAI). Methods: A prospective cohort study. Patients with CAI who underwent lateral collateral ankle ligament reconstruction from January 2014 to October 2017 in the Department of Sports Medicine, Huashan Hospital, Fudan University were enrolled in this study. The patients were divided into no bony impingement group (NI group) and bony impingement group (BI group) according to the presence of bone impingement in front of the ankle during the operation. Preoperative American Orthopedic Foot and Ankle Society (AOFAS) score, Karlsson ankle functional socre (KAFS), Tegner score, visual analogue scale (VAS) of pain were extracted and were reevaluated at least 2 years after surgery as well as imaging evaluation of ankle. Results: A total of 59 patients were enrolled in this study. There were 29 patients in the NI group, 23 males and 6 females with a mean age of (28.4±7.1) years. And there were 30 cases in the BI group, 28 males and 2 females with a mean age of (31.9±8.6) years. The AOFAS, KAFS and Tegner scores in NI group increased from 65.8±10.6, 65.9±10.1 and 3.0 (3.0, 4.0) before the operation to 97.5±4.3, 97.8±4.7 and 6.0(5.0,6.0) after the operation, respectively; and the VAS decreased from 3.0(3.0, 4.0) to 0(0, 0); there were significant differences in those indexes before and after the operation (all P<0.05). The scores of AOFAS, KAFS and Tegner in BI group increased from 65.2±11.0, 64.2±10.0 and 3.0(3.0, 4.0) before the operation to 97.1±4.3, 97.3±4.3 and 5.0(4.0, 6.0) post the operation, respectively; and the VAS scores decreased from 3.0(3.0, 5.0) to 0(0, 1.0); there were significant differences in up-mentioned indexes before and after the surgery (all P<0.05). There was no significant differences in baseline and preoperative clinical function scores between the two groups (all P>0.05). No significant difference was found in postoperative AOFAS, KAFS and VAS scores between the two groups (all P>0.05), while postoperative Tegner score in the NI group was significantly higher than that in the BI group [6.0(5.0, 6.0) vs 5.0(4.0, 6.0), P=0.026]. Imaging evaluation of all patients showed that the reconstructed ligament was clearly visible, and the intraarticular injuries existing before surgery showed obvious signs of healing. Conclusion: Ankle lateral collateral ligament reconstruction for CAI with or without anterior bony impingement results in similar outcomes in ankle function, stability and pain levels.