Infections

Abstract

It is important to know the anatomy of the various spaces in the hand (Fig. 9-1), and the location and extent of the various flexor tendon sheaths (Fig. 9-2). Infectious processes follow anatomic plains and spaces when they spread. A purulent flexor tenosynovitis of the third, fourth, and fifth fingers that extends proximally can involve the midpalmar space. Involvement of the index finger and thumb with proximal extension would involve the thenar space. The hypothenar space contains the hypothenar muscles and rarely is involved with a deep space infection. Improper treatment, as well as delay in beginning treatment of infections of the hand, can result in disastrous outcomes. Human bites of the hand can result in severe infections. A common mechanism of injury is when one individual strikes another person in the mouth with a clenched fist and sustains a puncture wound, usually into the knuckle, from a tooth of the individual that was struck. One organism commonly associated with human bites is Eikenella corrodens, a microaerophilic, anaerobic, gram-negative rod. Penicillin and ampicillin are effective against Eikenella. Although Eikenella corrodens is commonly associated with human bites, the most common infecting organism is still Staphylococcus aureus. Appropriate treatment of this so-called “fight bite” should include irrigation and debridement, and administration of appropriate antibiotic coverage. Exploration of the wound should include not only debridement of the wound, but also irrigation and debridement of the metacarpal phalangeal joint if the fight bite wound overlies the MCP joint. The wound should be left open and the digit should be splinted. The most frequent long-term complication of this injury is osteomyelitis and pyarthrosis. Dog and cat bites of the hand can also result in severe infections. The organism often associated with domestic animal bites is Pasturella multocida, a small, gram-negative coccus. The antibiotic of choice for this organism is penicillin.