title: Relationship between structural joint damage and urate deposition in gout: a plain radiography and dual-energy CT study.
abstract: OBJECTIVE
  The aim of this work was to examine the relationship between joint damage and monosodium urate (MSU) crystal deposition in gout.
  
  
  METHODS
  Plain radiographs and dual-energy CT (DECT) scans of the feet were prospectively obtained from 92 people with tophaceous gout. Subcutaneous tophus count was recorded. The ten metatarsophalangeal joints were scored on plain radiography for Sharp-van der Heijde erosion and joint space narrowing (JSN) scores, and presence of spur, osteophyte, periosteal new bone and sclerosis (920 total joints). DECT scans were analysed for the presence of MSU crystal deposition at the same joints.
  
  
  RESULTS
  DECT MSU crystal deposition was more frequently observed in joints with erosion (OR (95% CI) 8.5 (5.5 to 13.1)), JSN (4.2 (2.7 to 6.7%)), spur (7.9 (4.9 to 12.8)), osteophyte (3.9 (2.5 to 6.0)), periosteal new bone (7.0 (4.0 to 12.2)) and sclerosis (6.9 (4.6 to 10.2)), p<0.0001 for all. A strong linear relationship was observed in the frequency of joints affected by MSU crystals with radiographic erosion score (p<0.0001). The number of joints at each site with MSU crystal deposition correlated with all features of radiographic joint damage (r>0.88, p<0.05 for all). In linear regression models, the relationship between MSU crystal deposition and all radiographic changes except JSN and osteophytes persisted after adjusting for subcutaneous tophus count, serum urate concentration and disease duration.
  
  
  CONCLUSIONS
  MSU crystals are frequently present in joints affected by radiographic damage in gout. These findings support the concept that MSU crystals interact with articular tissues to influence the development of structural joint damage in this disease.
authors: Bone and Joint Research Group, Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
authors: Nicola
authors: N
authors: Dalbeth
authors: Bone and Joint Research Group, Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
authors: Opetaia
authors: O
authors: Aati
authors: Bone and Joint Research Group, Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
authors: Ramanamma
authors: R
authors: Kalluru
authors: Bone and Joint Research Group, Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
authors: Gregory D
authors: GD
authors: Gamble
authors: Bone and Joint Research Group, Department of Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
authors: Anne
authors: A
authors: Horne
authors: Department of Anatomy with Radiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
authors: Anthony J
authors: AJ
authors: Doyle
authors: Department of Molecular Medicine, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.
authors: Fiona M
authors: FM
authors: McQueen
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000844:Ankylosis / Q000000981:diagnostic imaging; D005260:Female; D033023:Foot Joints / Q000000981:diagnostic imaging / Q000473:pathology; D006073:Gout / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008683:Metatarsophalangeal Joint / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D054850:Osteophyte / Q000000981:diagnostic imaging*; D010521:Periosteum / Q000000981:diagnostic imaging; D011446:Prospective Studies; D012598:Sclerosis; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D014527:Uric Acid; D055815:Young Adult
chemical_list: D014527:Uric Acid
keywords: Bone Mineral Density; Gout; Inflammation