Which joint infection is a medical emergency requiring prompt aspiration and antibiotics?

• A. Gout
• B. Osteoarthritis
• C. Septic arthritis
• D. Bursitis

Answer: (C)

Septic arthritis is a joint infection that is a medical emergency because infection inside a joint can destroy articular cartilage quickly and lead to sepsis if not treated promptly. The situation usually presents with a single, hot, swollen, and very painful joint, often with fever and reduced movement.

Because time matters, the first priority is urgent joint aspiration to obtain synovial fluid for analysis and culture. The fluid in septic arthritis typically shows a high white blood cell count with a neutrophil predominance, and Gram stain or culture can help identify the causative organism. While awaiting results, start empiric IV antibiotics that cover the most common pathogens (for example, Staphylococcus aureus, including MRSA depending on risk factors and local patterns; and gram-negative organisms as indicated by the clinical setting). Therapy is refined once culture data return.

In some situations, surgical drainage of the joint may be necessary to remove purulent material and relieve pressure. This distinction is important because gout or osteoarthritis can cause severe joint pain and swelling but do not involve an ongoing infection inside the joint space, while septic bursitis involves the bursa rather than the joint itself.