Bacterial arthritis is a medical emergency. However, prompt diagnosis and differentiation from non-infectious diseases are challenging. As bacterial metabolism leads to glucose reduction, measurement of synovial fluid glucose seems to be a promising diagnostic approach. The purpose of this study was to determine whether synovial fluid glucose levels could be accurately measured by using a glucometer and to evaluate its diagnostic accuracy in diagnosing bacterial arthritis compared to currently available markers. In a prospective diagnostic study, 102 consecutive patients with atraumatic joint effusion were included. Synovial fluid glucose concentrations were determined using both glucometer and automated analyzer respectively. Synovial fluid culture, crystal analysis, and synovial cell analysis were performed. Blood samples were taken for blood cultures, analyses of serum infection markers, and serum glucose. There was a high correlation between synovial fluid glucose measured by the glucometer and the automated analyzer (r 2 = 0.92). According to the receiver operating characteristic curve, a threshold of 1.4 mmol/l had a sensitivity of 100 % (95 % CI 78.2-100 %), a specificity of 92.0 % (95 % CI 84.1-96.7 %), a positive predictive value of 68.2 % (95 % CI 45.1-86.1 %), and a negative predictive value of 100 % (95 % CI 95.5-100 %). These results suggest that synovial fluid glucose concentrations could be reliably measured using a glucometer. Due to its simplicity, this test has the potential to be an adjunct in the diagnostic cascade of bacterial arthritis.
Keywords: Bacterial arthritis; Diagnostics; Glucometer; Joint infection; Synovial fluid glucose.