A 16-year-old boy is brought to the emergency department by his mother due to a possible hand injury. She noticed that the patient's right hand was swollen and that he was not using it despite being right-handed. He has a history of oppositional defiant disorder and refuses to say how his hand was injured. Temperature is 38 C (100.4 F), blood pressure is 110/72 mm Hg, and pulse is 80/min. The dorsum of the right hand is swollen. There is erythema centered over the long finger metacarpophalangeal (MCP) joint, where there is a small, linear scab; the area is fluctuant on palpation, and passive movement of the joint elicits severe pain. Right hand x-ray reveals soft tissue swelling, no retained foreign body, and no underlying fractures or dislocations. Which of the following is the best next step in management of this patient?
Clenched-fist bite injury ("fight bite") | |
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IV = intravenous; MCP = metacarpophalangeal; PO = orally; ROM = range of motion. | |
This patient recently injured the tissue overlying his long finger metacarpophalangeal (MCP) joint and now has soft tissue swelling and erythema, fluctuance (likely representing trapped pus), severe pain with passive joint movement, and fever. This presentation is consistent with septic arthritis of the MCP joint and requires urgent surgical irrigation and debridement.
Infections of the long and ring finger MCP joints of the dominant hand (eg, right hand) are often caused by a clenched-fist punch to a human mouth ("fight bite"), which patients may be hesitant to disclose. Puncture (eg, tooth) through the thin soft tissue overlying the MCP joint inoculates the joint or its surrounding tissues with bacteria. The initial puncture wound may appear minor, but enclosed bacterial proliferation underneath the extensor tendon and/or within the joint capsule can quickly lead to septic arthritis, evidenced by swelling, erythema, fluctuance (or purulent drainage), and severe pain with passive range of motion.
All septic joints require drainage. Unlike larger joints (eg, knee), which can sometimes be drained via arthrocentesis or arthroscopy, the small MCP joints typically require open surgical irrigation and debridement. Intravenous (IV) antibiotics (eg, ampicillin/sulbactam) are started intraoperatively after obtaining joint cultures, and the wound is left open to drain and heal by secondary intention.
(Choice A) Intraarticular glucocorticoid injections are commonly used to reduce inflammation due to arthritis. This patient's fever, recent MCP joint trauma, and clinical findings of erythema, swelling, and pain on passive joint movement are more consistent with septic arthritis (ie, joint infection), for which suppression of the immune inflammatory response (ie, steroids) is contraindicated.
(Choices B and C) Although this patient should receive antibiotic therapy (eg, empiric IV antibiotics followed by culture-directed oral antibiotics) and pain control (eg, nonsteroidal anti-inflammatory drugs), urgent surgical intervention (vs outpatient follow-up) is required to drain the infected MCP joint and reduce the risk of permanent joint damage.
Educational objective:
Puncture of the thin soft tissue overlying the hand metacarpophalangeal joints (eg, clenched-fist punch to the human mouth) can result in septic arthritis, presenting with joint pain, erythema, swelling, fluctuance, and painful range of motion. Treatment requires urgent surgical irrigation and debridement and antibiotic therapy.