Minimally invasive Vs open medial displacement calcaneal osteotomy. A cadaveric study

Category: Hindfoot; Hindfoot Introduction/ Purpose: Medial displacement calcaneal osteotomy (MDCO) is routinely used to correct hindfoot valgus in flexible pes planovalgus deformities. Classically MDCO was described through a lateral heel oblique incision with soft tissue dissection and the use of sagittal saw. Recently, minimally invasive surgical (MIS) techniques have gained popularity among foot and ankle surgeons, with the aim to reduce wound complications and postoperative pain and swelling. MIS calcaneal osteotomy was reported to be safe and effective as compared to open techniques. The aim of this cadaveric study was to compare the degree of deformity correction (coronal calcaneal displacement) using MIS vs open MDCO. Methods: Eight matched pairs foot and ankle cadaveric specimen were used. All specimens were checked radiographically for any previous foot and ankle operations or deformities. For each pair, one foot (right or left) was randomly assigned to either open or MIS MDCO. After the completion of osteotomy, the calcaneal tuberosity was maximally displaced medially and fixed with 2 mm wire. The displacement was measured manually using a flexible metric ruler. All osteotomies and manual measurement was done by the same Orthopaedic surgeon. Displacement was measured on standardized axial calcaneal radiographs by three blinded foot and ankle Orthopaedic surgeons independently using an image processing software with standard scaling for magnification. The displacement was measured laterally on the anterior body fragment and medially on the posterior tuberosity fragment Figures 1. Data was compared using the Wilcoxon-Mann-Whitney U test with the P value of < 0.05 considered significant. Results: Five right and three left ankles underwent MIS osteotomy. On manual measurement the mean medial displacement was 7.87 mm and 8.66 mm for MIS and open technique respectively P=0.21). On radiographs, on medial measurements the average displacement of MIS osteotomy was 5.83 mm compared to 6.36 mm for the open group with a P value of 0.34. On lateral measurements the average displacement of MIS osteotomy was 5.94 mm compared to 6.17 mm for the open group with a P value of 0.67. Conclusion: This cadaveric study reported comparable coronal displacement using MIS vs open techniques for medical displacement calcaneal osteotomy. MIS calcaneal osteotomy offers a reliable alternative to open techniques with the potential advantages of lower wound related complications.