This approach is indicated for fractures of the two phalanges of the hallux with or without joint involvement. It can also be used for ORIF of the medial sesamoid bone and for ORIF of distal fractures of the first metatarsal. It can also be used for treatment of hallux rigidus (cheilectomy, osteotomy, fusion).
The head of the first metatarsal bone receives its blood supply from an artery which enters the metatarsal head on the plantar aspect of the distal metaphysis. The dorsomedial (collateral) digital nerve (in the majority of cases branch of the deep peroneal nerve) runs on the dorsal half of the medial side, and the medial plantar hallucal nerve runs along its plantar aspect. The abductor hallucis muscle inserts into the capsule of the metatarso-phalangeal (MTP) joint.
3. Skin incision
The skin incision starts at the mid point of the metatarsal head and runs distally towards the mid diaphysis of the distal phalanx.
In order to expose the metatarsal head the capsule must be freed from the bone on both the dorsal and plantar aspect. This allows visualization of the metatarso-phalangeal (MTP) joint, and of the metatarso-sesamoidal joint. To expose fractures involving the base of the distal phalanx one must make an interphalangeal capsulotomy and arthrotomy.
5. Extension of the approach
For diaphyseal fractures and diaphyseal osteotomies, one must extend the approach more proximally. If necessary the approach can be extended along the medial aspect of the foot. The guide throughout is the abductor hallucis, which is retracted plantarwards.
6. Visualization of the medial sesamoid
Visualize the medial aspect of the medial sesamoid by releasing the metatarsosesamoidal ligament.