The lateral head of FHB inserts via the lateral sesamoid and receives innervation from the lateral plantar nerve, unlike the medial head (medial plantar nerve). The lateral sesamoid is the more commonly displaced sesamoid in hallux valgus deformity.
| Origin | Cuboid plantar surface and lateral cuneiform |
|---|---|
| Insertion | Lateral base of the hallux proximal phalanx via the lateral sesamoid |
| Nerve Supply | Lateral plantar nerve (S2, S3) |
| Blood Supply | Lateral plantar artery |
| Actions | Flexes the hallux MTP joint — lateral contribution; Stabilises the lateral sesamoid during push-off |
|---|
The lateral sesamoid (within the lateral FHB head) is released from the lateral joint capsule and adductor hallucis during hallux valgus surgery lateral soft tissue release. Lateral sesamoid avascular necrosis can follow lateral release surgery if the sesamoid blood supply is disrupted.
Palpated plantar-lateral to the first MTP joint during hallux MTP flexion.
Avascular necrosis of the lateral sesamoid from disrupted blood supply during lateral FHB head release in hallux valgus surgery, producing persistent forefoot pain.
