Safety area for proximal metatarsal procedures.

Background: Forefoot and tarsometatarsal surgery may be performed on the first and second metatarsal through the intermetatarsal space. However, no study has identified the safety area of the proximal metatarsal bone to avoid vascular injury.

Methods: One hundred and twenty-two uninjured embalmed feet of 31 female and 33 male cadavers aged 15 to 91 years (mean, 69.9 years) were studied. The dorsalis pedis artery was identified and dissected from its origin to the deep plantar artery. The distances from the artery to the dorsomedial aspect of first metatarsal bone, from the artery to the first tarsometatarsal joint, and from dorsalis pedis artery to the most plantar surface of second metatarsal bone were measured.

Results: The distance from the artery to the first tarsometatarsal joint averaged 23.1 mm (range, 12-31 mm) and the distance from the artery to the most plantar surface of the second metatarsal bone averaged 6.3 mm (range, 3-13 mm).

Conclusions: The safety area for proximal metatarsal procedure is about a 69-mm(2) triangular area (23 mm from first tarsometatarsal joint and 6 mm from the most plantar surface of the second metatarsal bone).

Clinical Relevance: The study provides information of normal location and variation of deep plantar artery is which related to medial midfoot complex. This information may be used during proximal metatarsal procedures.