tear

 Os peroneum

Location

Sesamoid in peroneus longus

- at level calcaneo-cuboid joint

- articulates with cuboid

Incidence

5 - 30% population

60% bilateral

Epidemiology

Adolescent apophyseal avulsion

- treat non operatively

- unless displaced > 2 cm

Adult

- soft tissue avulsion

Aetiology

Usually associated with sporting activities

- skiing

- water skiing

Violent contraction

- knee extended

- hip flexing

Anatomy