Effect of Antibiotic Therapy Before Arthrocentesis on Synovial Fluid Cell Count and Differential for Diagnosis of Native Joint Septic Arthritis.

We examined the effect of preoperative antibiotic exposure and duration on synovial fluid samples from patients with native joint septic arthritis of the hip/knee. While exposure before diagnostic arthrocentesis did not affect fluid parameters, increased duration was associated with a decreased total nucleated cell count, underscoring the complex antibiotic effects on synovial fluid parameters.