Bite Wounds



Bite Wounds


Mark Henry



INTRODUCTION



  • Pathoanatomy1,2,3,4,5



    • Skin wound—mixed pattern of crush, cut, tear damage to margins (Figure 49.1)


    • Deep structural injury to bone, tendon, nerve with powerful bites (dog, larger birds, human)


    • Introduction of oral bacteria to varying depths



      • Skin only


      • Deep space, nonsynovial


      • Joint (septic arthritis)


      • Tendon sheath (septic tenosynovitis)



    • Human bites also may transmit HIV, hepatitis B, hepatitis C


    • Clinical infection depends on burden of microorganisms and capacity of immune system to overcome it (greatest at the skin level, least in a contained synovial space), up to 50% in cat bites, 41% in dog bites.


    • Risk factors: smoking, immunocompromised status, diabetes, depth of penetration, delay in treatment >24 hours, wound closure6


    • Additional tissue necrosis is proportionate to the duration of infection prior to debridement and spread of infection along anatomic planes (along the course of tendon sheath, from joint cavity into bone)


  • Mechanism of injury7,8,9



    • Sharp penetration to deep target with little structural injury (cats and small dogs)


    • Crushing (2000 lb/sq in) and avulsion of soft tissue with fracture seen in up to 30% of large dog bites.


    • Cutting through tendon to bone or joint with impaction fracture (human bites: up to 62% metacarpophalangeal joint penetration and 20% tendon injury).


  • Epidemiology10,11,12

May 7, 2019 | Posted by in ORTHOPEDIC | Comments Off on Bite Wounds
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