Question

A 29 year-old male presents complaining of a 24-hour history of a painful, warm, tender, swollen right knee. One-week prior, he relates a history of dysuria and penile discharge. Which of the following results of an arthrocentesis of the right knee would be most supportive of the gonococcal septic joint that you suspect?

a. synovial fluid is clear
b. synovial fluid glucose equals serum glucose
c. synovial fluid glucose is greater than serum glucose
d. total volume of aspirate from the joint exceeds 4 cc in volume
e. synovial fluid leukocyte count is < 1000 per microliter

Answer 1

The most supportive arthrocentesis result for a gonococcal septic joint would be a significantly elevated synovial fluid leukocyte count, which is expected to be much higher than 1000 per microliter.

Option (e) does not support the diagnosis

Step-by-step explanation:

The most indicative result for a gonococcal septic joint from an arthrocentesis of the knee of a 29 year-old male with a history of dysuria and penile discharge would be an increased leukocyte count in the synovial fluid. A finding supportive of this diagnosis is a leukocyte count typically exceeding several tens of thousands per microliter, often with a predominant number being neutrophils, as gonococcal infections are known to cause purulent arthritis. Therefore, option (e) synovial fluid leukocyte count is < 1000 per microliter would not support the suspected diagnosis, as it is far below the expected range for infectious arthritis such as gonococcal arthritis.

Key findings typically include a synovial fluid leukocyte count significantly higher than 1000 per microliter, low synovial fluid glucose levels compared to serum glucose, and possible presence of gram-negative diplococci on microscopic evaluation or PCR analysis of the synovial fluid.