title: First metatarsophalangeal joint aspiration using a 29-gauge needle.
abstract: OBJECTIVE
  To asses 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 within our department were prospectively recorded. The procedure was considered successful if SF volume was enough to perform a crystal search. Crystals were identified using a polarised light microscope (magnification x400) with a first order red compensator. Pain was recorded on 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
  A 29-gauge needle allows easy aspiration of the first MTP joint with only modest discomfort for the patients, and generally yields a SF sample of sufficient volume for crystal detection and identification.
authors.affiliation: Rheumatology Unit, Hospital General Universitario de Alicante, Universidad Miguel Hernándes, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Sivera
authors.forename: R
authors.initials: R
authors.lastname: Aragon
authors.forename: E
authors.initials: E
authors.lastname: Pascual
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle / Q000295:instrumentation / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006073:Gout / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008297:Male; D008683:Metatarsophalangeal Joint / Q000473:pathology*; D008875:Middle Aged; D011446:Prospective Studies; D013582:Synovial Fluid / Q000378:metabolism*; D016896:Treatment Outcome