Anatomical structures at risk in third- and fourth-generation minimally invasive hallux valgus surgery: A comprehensive review

Abstract

A critical limitation common to all minimally invasive surgery (MIS) approaches is the lack of direct visualization during osteotomy execution, which exposes arteries, nerves, and tendon insertions to iatrogenic injury within a confined anatomical space. This review synthesizes applied anatomical knowledge relevant to third- and fourth-generation MIS for hallux valgus (HV), incorporating findings from cadaveric dissection and micro-computed tomography (CT) vascular mapping to characterize the tendinous, neural, vascular, and sesamoid architecture of the first metatarsal head complex and to define quantitative safety zones for intraoperative reference. Micro- CT perfusion studies have established that the apex of the Chevron osteotomy should be positioned at a minimum distance of 25.6 mm (dorsal arm) and 23.9 mm (plantar arm) from the most distal point of the first metatarsal articular surface, with the excursion of the Shannon burr limited to 3.9 mm and 4.0 mm beyond the exit point on the lateral cortex. The Metaphyseal Extra-Articular Transverse and Akin Osteotomy (META) technique introduces a geometrically distinct risk profile by simultaneously addressing the dorsal and plantar metatarsal arteries in a single transverse plane; for this technique, a unified safety distance of approximately 26 mm is proposed for the osteotomy, pending specific anatomical application and micro-CT validation. Neurological risk for both osteotomy generations centers on the dorsomedial nerve of the first toe. Biomechanical and radiographic equivalence between third- and fourth generation constructs indicates that the choice of technique should be guided by surgical training rather than perceived mechanical superiority, and that safe execution depends on mastering the anatomical boundaries described in this review. Level of Evidence V; Expert Opinion, Basic Science Study