organisms

Human / Tooth Knuckle Injuries

Mechanism

Clenched knuckle

- tooth often penetrates capsule of MCPJ (60%)

- can injure the bone (58%)

- usually 3 / 4 th MCPJ

Associated Injury

Boxer's fracture

- 4th / 5th metacarpal head

Extensor tendon Laceration

Pathology

Epidemiology

M:F =2:1

30-40 years

20% diabetic

50-80% identifiable source

Site

Lumbar (50%) > Thoracic > Cervical (<10%)

Pathogenesis

1.  Haematogenous

- arterial rather than venous

Risk factors

- UTI (40% of all cases)

- IVDU

- elderly