title: Intra-articular distribution pattern after ultrasound-guided injections in wrist joints of patients with rheumatoid arthritis.
abstract: OBJECTIVE
  To investigate the distribution of an ultrasound-guided intra-articular (IA) injection in the wrist joint of patients with rheumatoid arthritis (RA).
  
  
  METHODS
  An ultrasound-guided IA drug injection into the wrist joint was performed in 17 patients with 1 ml methylprednisolone (40 mg/ml), 0.5 ml Lidocaine (5mg/ml) and 0.15 ml gadolinium (Omniscan 0.5 mmol/ml). The drug solution was placed in the central proximal part of the wrist between the distal radius and the lunate bone. Coronal and axial MRI sequences were performed after the injection to visualize the distribution. Carpal distribution (radio-carpal, inter-carpal, and carpo-metacarpal) as well as radio-ulnar distribution was recorded. Full distribution in one compartment was given the value 1, partial distribution 0.5 and no distribution 0. A sum of the total distribution for all four compartments was calculated and correlated to the clinical parameters and the MRI OMERACT scores.
  
  
  RESULTS
  No uniform pattern was seen in the distribution of the contrast. Only two patients had full contrast distribution to all four compartments, and the mean distribution count for all patients was 2.4 (range 0.5-4). The distribution count correlated with the MRI OMERACT synovitis score (r=0.60, p=0.014), but not with the erosions, bonemarrow oedema scores or any clinical parameters.
  
  
  CONCLUSIONS
  The distribution of contrast on MRI showed patient specific and random patterns after IA injections in active RA wrist joints. The degree of distribution increased with the MRI synovitis score, while no association was found with the erosion- and bonemarrow oedema score. These results indicate that a single injection into a standard injection site in the proximal part of the wrist cannot be assumed to distribute--and treat--the whole joint.
authors.affiliation: The Parker Institute, Frederiksberg Hospital, Nordre Fasanvej 57, 2000 Frederiksberg, Copenhagen, Denmark.
authors.forename: Mikael
authors.initials: M
authors.lastname: Boesen
authors.forename: Karl Erik
authors.initials: KE
authors.lastname: Jensen
authors.forename: Søren
authors.initials: S
authors.lastname: Torp-Pedersen
authors.forename: Marco A
authors.initials: MA
authors.lastname: Cimmino
authors.forename: Bente
authors.initials: B
authors.lastname: Danneskiold-Samsøe
authors.forename: Henning
authors.initials: H
authors.lastname: Bliddal
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000493:pharmacokinetics; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism*; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006801:Humans; D007270:Injections, Intra-Articular / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D014018:Tissue Distribution; D018084:Ultrasonography, Interventional / Q000379:methods*; D014955:Wrist Joint / Q000000981:diagnostic imaging* / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000305:Adrenal Cortex Hormones; C064925:gadodiamide; D019786:Gadolinium DTPA