AVN

Diagnosis

Xray

- sclerosis

CT

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

Epidemiology

Much less common than hip OA

- usually presents late

Aetiology

Similar causes as hip (AS IT GRIPS 3C)

Alcohol / Steroid / Trauma / Idiopathic

Gauchers

RA / RTx

Sickle Cell 

Definition

Body Fracture

- fracture line exits inferior surface behind lateral process

- into posterior facet

- intra-articular body fracture

Neck Fracture

- fracture line exits inferior surface anterior to lateral process

- in front of sinus tarsi

- extra-articular neck fracture

Types

1.  Shear

2.  Crush

3.  Posterior Process

Types

1.  Dorsal lip fracture / Tuberosity fracture

- avulsion fractures

- most common

- beware avulsion T post

2.  Body fracture

3.  Stress Fractures

Body Fractures

Types

A.  Transverse fracture in coronal plane

B.  Transverse from dorsolateral to plantarmedial

C.  Central or lateral comminution