Skeletal Structure Of The Base Of The Metatarsal Base

Description

Metatarsal bases form the proximal row of the forefoot, flaring where each shaft widens to articulate with the tarsus at the tarsometatarsal (Lisfranc) joints. From a superior (dorsal) viewpoint, the first metatarsal base sits most medial and robust, the second metatarsal base lies recessed between the medial and lateral cuneiforms, and the fourth and fifth metatarsal bases align laterally with the cuboid. The tuberosity (styloid) of the fifth metatarsal projects posterolaterally, a palpable landmark at the lateral border of the foot. Bony surfaces dominate the frame. These relationships matter in midfoot stability and injury pattern recognition: the mortised position of the second metatarsal base explains why subtle diastasis or malalignment at the Lisfranc complex can destabilize the entire transverse arch. Avulsion fractures at the fifth metatarsal tuberosity follow traction from the fibularis (peroneus) brevis tendon, while more distal metaphyseal fractures (Jones region) carry higher nonunion risk because of vascular watershed considerations. Lighting that emphasizes cortical margins and articular contours helps you trace joint lines, appreciate the widening of each base, and distinguish the stepped geometry that guides reduction in tarsometatarsal fracture-dislocations. Use this illustration in gross anatomy and podiatry teaching to orient learners to the proximal metatarsals before layered ligament work, including the interosseous Lisfranc ligament between the medial cuneiform and second metatarsal base. It also fits operative technique guides and radiology correlation pages that discuss dorsal foot anatomy, TMT joint alignment on AP and oblique radiographs, and landmark-based incision planning over the first and second rays. Anatomical accuracy verified by SciePro's Medical Advisory Board.