Objectives: To assess the clinical feasibility of aspirating symptomatic and asymptomatic first metatarsophalangeal (MTP) joints with a 29-gauge needle in order to obtain a synovial fluid (SF) sample.
Methods: All consecutive aspirations of first MTP joints performed at our department were prospectively recorded. The procedure was considered successful if the SF sample volume was enough to perform a crystal search. Crystals were identified using a polarized light microscope (magnification 400x) with a first order red compensator. Pain was recorded in a 10-cm visual analogue scale (VAS).
Results: Aspirations were attempted in 33 first MTP joints in 31 patients. SF was drawn from 30 of the joints (91%), with little difference between asymptomatic (89%) and inflamed joints (93%). The technique was well tolerated (mean VAS 1.74). Urate monosodium crystals were identified in 22 samples (73%) and another sample contained calcium pyrophosphate dihydrate crystals.
Conclusions: 29-gauge needles allow easy aspiration of the 1st MTP joint with only modest discomfort for the patients and generally yield a SF sample of sufficient volume for crystal detection and identification.
- SYNOVIAL FLUID