Identification of portals and evaluation of their safeness for MIS arthrodesis of the 1st tarsometatarsal joint

Abstract

There has been a growing trend towards the use of minimally invasive surgical techniques in foot and ankle surgery. The aim of this study is to identify portal sites for minimally invasive arthrodesis of the 1st TMT joint and determine the safeness of each portal to the surrounding structures. 10 cadavers were utilized. 3 portal sites were utilized in preparing the 1st TMT joint which included dorsomedial, plantar medial and dorsolateral portals at the level of the 1st TMT joint. Fluoroscopic guided joint prep was performed. After joint prep, each specimen was dissected to evaluate structures at risk which included the deep peroneal nerve, dorsalis pedis artery, EHL Tendon, medial dorsal cutaneous nerve and medial marginal vein. In 1 specimen, there was noted to be disruption of the deep peroneal nerve, dorsalis pedis artery and partial tear of the EHL through the dorsolateral portal. No damage to any vital structures was noted at the dorsomedial or plantar medial portals. All but 1 specimen was determined to be underprepped with the dorsolateral aspect of the joint being the most common area. Additionally, upon open dissection to evaluate the joint prep, there was noted to be some small pieces of cartilage remaining despite thorough irrigation. The three-portal approach for the MIS 1st TMTJ arthrodesis is a relatively low risk procedure, with low risk of injury to the surround neurovasculature and tendon structures. However, care should be taken at each portal site with resecting cartilage to ensure no damage to surrounding vital structures occurs while also ensuring adequate joint preparation.