Using an External Jig for Minimally Invasive Bunion Surgery Reduces the Number of Cases Required to Achieve Operative Proficiency and Efficiency

Research Type: Level 4 – Case series Introduction/Purpose: Minimally-Invasive Bunion Surgery (MIBS) has and continues to evolve. Fourth generation percutaneous hallux valgus correction involves extra-articular transverse 1st metatarsal and Akin osteotomies (META) stabilised with two fully threaded non-compressive champhered screws. Percutaneous hallux valgus correction has been shown to require 27 to 40 cases to acquire proficiency/efficiency in performing the procedure. Various commercially available jigs are available which claim to accelerate the "learning curve". The aim of this study is to analyse the effect of utilising such a jig on the operative proficiency/efficiency of a single surgeon with no prior experience of MIBS. Methods: Between March 2023 and August 2024, 20 consecutive META procedures on 16 patients were performed by the senior author using a jig for reduction, wire and screw placement and a standard-sized C-arm for image acquisition. The surgeon underwent extensive cadaveric training and multiple visitations of expert MIBS surgeons as well as a period of familiarisation with less demanding percutaneous surgeries prior to commencing MIBS. Prior to the present series, the surgeon had no direct personal experience of MIBS. Surgery duration (skin-to-skin tourniquet time), number of fluoroscopies, and surgery-associated complications were prospectively collected. The methods utilised by Palmanovich et al, Toepfer et al & Lewis et al were replicated to allow a comparison of number of fluoroscopies and surgery duration/tourniquet time with the existing literature. Results: The average surgery time was 45 min (SD 5.8, range 24-64 min). The median number of fluoroscopies required was 120 (IQR 49, range 36-215). Three cases required the jig to be abandoned and a free-hand technique was used. Calculation of plateauing of surgical time and radiographic image requirement was performed for cases where the external jig was able to be utilised. Spearman Rho manual removal method (Palmanovich et al), Conclusion: Previous studies of the "learning curve" (which represents the proficiency/efficiency plateau of a procedure) have consistently demonstrated initial operative times over 90 minutes and over 150 fluoroscopic images with 27 to 40 procedures being required to reach a plateau of surgical duration and/or radiographic images required to perform MIBS. In this series, the use of an external jig accelerated the achievement of these proficiency/efficiency measures substantially thereby supporting claims that these improve the "learning curve". We encourage surgeons who are beginning their MIBS journey to utilise such a jig to improve surgery duration and reduce radiation exposure.