Fifth Metacarpal Neck fracture (aka Boxer’s fracture)
- usual mechanism of injury with metacarpal neck fractures involves direct trauma to a clenched fist
- Dorsum of the hand is swollen and bony tenderness is found over the fractured metacarpal.
- Three views of the hand (anteroposterior (AP), lateral, and oblique) adequately display metacarpal neck fractures
- Angulation occurs in an apex dorsal direction due to the pull of interosseous muscles.
- Functional bracing with custom or off-the shelf orthoses are effective and commonly used in the management of metacarpal neck fractures
- Lacerations at the site of trauma (“fight bites”) are common and predispose to infection.
Closed Fist infection (aka Fight Bite)
- present with small wounds overlying the metacarpophalangeal joints (skin breaks over the knuckle when punching face and hitting teeth) – most comonly third, fourth, and/or fifth MCP
- highly prone to infection given the proximity of the skin over the knuckles to the joint capsule
- Clinical manifestations of bite wound infections may include fever, erythema, swelling, tenderness, purulent drainage and lymphangitis
- Deep bite wounds near joints warrant AP and lateral plain radiographs to evaluate for disruption of bone or joints and evidence of foreign bodies
- no signs of infection = empiric Augmentin (amoxicillin-clauvanate) 875/125mg PO BID x5days
- signs of infection = empiric Unasyn (ampicillin-sulbactam) 1.5-3g IV q6
- Tetanus and rabies prophylaxis should be provided as indicated