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
Up to 50% rate of infection
- septic arthritis
- tenosynovitis
- osteomyelitis
Organisms
Polymicrobial
- streptococci
- Staphylococci
- Eikenella
- anaerobes
Eikenella corrodens
- seen in 1/4 TKI
- gram negative rod / facultative anaerobe
- acts synergistically with strept and contributes to morbidity
- can be resistant to dicloxacillin
- usually sensitive to
Management
Intial treatment
- povidone-iodine + copious irrigation
Antibiotics
- augmentin oral
- IV penicillin
Surgery
- best to debrige and washout all wounds
- open skin
- inspect extensor tendon
- open capsule, washout +++
- closure capusle
- leave skin open
- day 2 steristrip skin close
Await cultures
- change antibiotics accordingly
Note
- failure of treatment with cephalosporin
- may be due to eikenella
- change to penicillin
Dog bites
Organisms
Mixed growth
- Streptococci
- Staphylocci
- Pasteurella
Management
Washout & debride
Augmentin
TMP-SMX if allergic to penicillin
Cat Bites
Organisms
More often become infected
Culture
- 50% Pasturella multocida
Management
Incision and drainage
Antibiotics
- Augmentin / penicillin
- 2nd or 3rd generation Cephalosporin