Medial displacement calcaneal osteotomy with minimally invasive surgery (MICO): mid-term results

Abstract

INTRODUCTION: Minimally invasive calcaneal osteotomies (MICO), with medial displacement, are atechnique increasingly used to correct foot deformities with progressive collapse, a pathology that we previously used to refer to as flatfoot valgus. The rise of the percutaneous and minimally invasive technique is mainly due to the excellent functional results and the low rate of complications.

OBJECTIVE: To describe the medium-term results of MICO with medial displacement, as a single or associated gesture, in the treatment of flexible foot deformities with progressive collapse. Compare pre- and postsurgical radiographic parameters and establish the frequency of complications related to the minimally invasive approach.

MATERIAL AND METHOD: An observational, retrospective and analytical study was carried out in which the data of patients who underwent surgery with MICO with medial sliding were analyzed, as a single or associated gesture, in the treatment of flexible foot deformities with progressive collapse, between January 2019. and January 2022. The pre-operative radiographic parameters analyzed were the Meary line and the Moreau and Costa Bertani angle. The postoperative radiographic parameters examined were, in addition to the mentioned angles, the degree of medial displacement of the posterior tuberosity of the calcaneus. Jointly, the time of exposure to X-rays, the operative time isolated from the osteotomy and the complications related to the minimally invasive approach were recorded. Statistical analysis: The data is shown with descriptive statistics. The comparison of pre- and postoperative Meary angles was performed with the paired Wilcoxon test, while the comparison of pre- and postoperative Moreau and Costa Bertani angles was performed with the paired t test. A p value ≤ 0.05 was considered significant.

RESULTS: 29 feet from 28 patients were analyzed. Of them, 18 (64.29%) patients were female and had a mean (standard deviation - SD) age of 42.57 (10.92) years. An associated procedure was performed in 27 of 29 (93.1%) feet. The minimum follow-up was 24 months. The median (interquartile range - IQR) of the preoperative Meary angle was 8.50 (3) degrees, while that of the postoperative angle was 1 (1) degrees (p<0.001). The mean (SD) of the preoperative Moreau and Costa Bertani angle was 141.9 (3.96) degrees, while the postoperative angle was 132.35 (4.16) degrees (p<0.001). The mean (SD) medial displacement of the posterior tuberosity of the calcaneus was 9.84 (1.13) millimeters. The mean (SD) average exposure time to X-rays was 25 (12) seconds, while the operating time isolated from the osteotomy was 21 minutes 46 seconds (16' 30''). There were no neurovascular or wound-related complications from the minimally invasive approach.

CONCLUSION: MICO are a safe and effective option to treat flexible foot deformities with progressive collapse, as a single gesture or in combination.