Minimally invasive forefoot surgery: a cadaveric study

Minimally invasive surgery (MIS) aims to improve cosmesis and minimize soft tissue disruption by using small skin incisions. When using MIS in the forefoot, there is concern about iatrogenic neurovascular and tendon damage. The aim of this anatomical study was to assess the risk of iatrogenic injury while performing MIS techniques.

Ten normal cadaveric feet were used. All of the procedures were performed in a cadaveric lab using a mini-C-arm by two surgeons: a consultant who has attended a cadaveric MIS training course but does not perform MIS in his regular practice (eight feet) and a registrar (resident) who was supervised by the same consultant (two feet). In each foot, the surgeon performed a lateral release, a minimally invasive chevron and Akin (MICA) procedure for the correction of hallux valgus, and a minimally invasive distal metatarsal extra-articular osteotomy (DMO). Each foot was then dissected to identify any neurovascular or tendon injury and photographed.

The dorsal medial cutaneous and the plantar interdigital nerves were intact in all specimens. There was no apparent damage to the arterial plexus supplying the first metatarsal head. No flexor or extensor tendon injuries were identified. On examination of the osteotomies, the cuts were found not to be in the desired plane. In both MICA and DMO, the dissection also revealed some intact soft tissue at the osteotomy site, which may preserve vascularity and add stability to the osteotomy.

Although there has been concern regarding neurovascular and tendon injury, the findings were consistent with minimal risk, which is consistent with reports in the literature. This study also reflects the challenges associated with performing the osteotomy in the desired plane, which may be related to the learning curve.

This cadaveric study has demonstrated a minimal risk of neurovascular and tendon injury associated with minimally invasive techniques in the forefoot. However, the study emphasizes the need for excellent three-dimensional anatomy and suggests additional cadaveric training prior to attempting these techniques in clinical practice.