Urine Dipstick in the Rapid Diagnosis of Septic Arthritis

Q: What is the urine "dipstick" test, which can help in the diagnosis of septic arthritis?

Answer:

The two confirmatory (aka gold standard) tests for diagnosing a septic joint are synovial fluid culture or synovial biopsy. Said that many times: both are hard to obtain or require a wait for results.

Many adjuvant tests help to establish a probable diagnosis, along with clinical signs and other tests such as blood counts and blood cultures. Recently, nucleic acid amplification tests like polymerase chain reaction (PCR) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectometry have been used at advanced centers, particularly when routine cultures are negative but clinical suspicion is high. But these tests are time-consuming and not very cost-effective.

Interestingly, a simple, quick, and highly cost-effective urine "dipstick" test to measure synovial fluid leukocyte esterase can be used as an adjunct to diagnose septic arthritis (reference 1 for details).

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References:

1. Aslani H, Pasha Zanoosi MR, Navali AM. Urine Dipstick Leukocyte Esterase in the Rapid Diagnosis of Septic Arthritis. Arch Bone Jt Surg. 2022 Jan;10(1):38-44. doi: 10.22038/ABJS.2021.47573.2334. PMID: 35291247; PMCID: PMC8889425.

2. Dey M, Al-Attar M, Peruffo L, et al. Assessment and diagnosis of the acute hot joint: a systematic review and meta-analysis. Rheumatology (Oxford) 2023; 62:1740.

2. Sanpera I, Salom M, Alves C, Eastwood D. Diagnosis and management of septic arthritis: A current concepts review. J Child Orthop. 2025 Jan 2;19(1):14-19. doi: 10.1177/18632521241311302. PMID: 39758603; PMCID: PMC11694264.