os peroneum

 Os peroneum

Location

Sesamoid in peroneus longus

- at level calcaneo-cuboid joint

- articulates with cuboid

Incidence

5 - 30% population

60% bilateral

Metatarsal Fractures

Indications for Surgery

1.  Displacement > 4 mm

2.  Angulation > 10^o

3.  Intra-articular

Base of 5th Metatarsal

Classification

Zone 1

- avulsion fractures

Anatomy

Lateral compartment of leg

- run through retromalleolar groove

- pass superior and inferior to peroneal tubercle

- covered by inferior peroneal retinaculum

Peroneus longus

- origin lateral condyle of tibia and head fibula

- tendon PL superficial and inferior to brevis in retromalleolar groove

- runs in cuboid groove 

- insert plantar surface base of 1st MT and lateral aspect medial cuneiform