Minimally Invasive versus Open Hallux Valgus Surgery

Abstract

Category: Bunion Introduction/Purpose: About 20% of patients suffer from stiffness (arthrofibrosis) after hallux valgus surgery. Minimally Invasive Surgery (MIS) has been invented to reduce the rate of unfavorable result, MIS enjoys increasing popularity with both surgeons and patients and is applied in a growing number of cases. It is being advertised as delivering better results due to reduced soft tissue injury and quicker recovery while effecting a similar amount of deformity correction. However, to date there are no scientific data to support this claim. The aim of the current project is to fill this lacuna by comparing the outcomes of MIS and open hallux valgus surgeries prospectively at our institution. Methods: From 01/2014 to 12/2015, 123 patients were operated: 75 open (average age 51 years, 91% female) and 48 MIS (age 47 years, 88% female). Inclusion criteria were either open Chevron/Scarf or MIS-Chevron at our Foot and Ankle Center with 5 different hospitals and three surgeons. Exclusion criteria were radiological signs of osteoarthritis, extension of less than 30°, pain on motion or during the night, and all other hallux valgus surgeries (lapidus, open wedge, Akin and buniektomy only). Radiographs were taken of all patients 6 weeks and 1 year postop. All patient charts were screened by an independent research assistant for complications and reoperations. All radiographs were measured by two independent observers. All patients were examined in a blinded control by an independent study nurse at 24±6 months after surgery for the clinical results (for parameters please see Tab. 1). Results: All clinical and radiographic results, as well as all additional surgeries, reoperations and complications are shown in Tab.1. The results show that open and MIS surgery achieved a similar gain in AOFAS-score, flexion, extension, VAS and subjective foot value. The scar was significantly smaller in MIS than open, but the satisfaction with the scar was similar. The radiographic correction was equal. Open surgery was combined with more additional procedures than MIS, especially Weil osteotomies and plantar plate repairs. The rate of CRPS, prolonged pain, and stiffness was equal. The reoperation rate was significantly higher for MIS due to a screw removal rate of 34%. Conclusion: MIS is an interesting concept, but it enjoys no advantages over open surgery, at least when carried out with current methods. Calls for open-trained surgeons to switch to MIS are therefore premature. Both surgical techniques have similar clinical and radiological outcomes, while MIS had a higher screw removal rate. Furthermore, complex cases have to be operated with open surgery.