STT fusion

Definition

OA of the scapho-trapezium-trapezoidal joints

Epidemiology

50% patients with CMC OA have STT OA

F > M

Xray

Management

Definition 

Avascular necrosis & subsequent disintegration of lunate

Aetiology

50-75% history of trauma

Occasionally seen in sickle cell / steroid use

Pathogenesis

Vascular Theory

Trauma disrupting vascularity

- single incident with disruption of blood supply