title: Metatarsophalangeal joint pain in psoriatic arthritis: a cross-sectional study.
abstract: OBJECTIVE
  The aim of this study was to identify independent predictors of pain at the MTP joints in patients with PsA.
  
  
  METHODS
  Thirty-four consecutive patients with PsA (mean age 45.3 years, 65% female, mean disease duration 9.9 years) and 22 control participants (mean age 37.9 years, 64% female) underwent clinical and US examination to determine the presence of pain, swelling, synovitis, erosions, effusions and submetatarsal bursae at the MTP joints. Mean barefoot peak plantar pressures were determined at each MTP joint. Levels of pain, US-determined pathology and peak pressures were compared between groups. Binary logistic regression was used to identify demographic, clinical examination-derived, US-derived and plantar pressure predictors of pain at the MTP joints in the PsA group.
  
  
  RESULTS
  The presence of pain, deformity, synovitis, erosions (P < 0.001) and submetatarsal bursae and peak plantar pressure at MTP 3 (P < 0.05) were significantly higher in the PsA group. MTP joint pain in PsA was independently predicted by high BMI, female gender and the presence of joint subluxation, synovitis and erosion.
  
  
  CONCLUSIONS
  These results suggest local inflammatory and structural factors, together with systemic factors (gender, BMI), are predominantly responsible for painful MTP joints in PsA, with no clear role for plantar pressure characteristics.
authors.affiliation: Institute for Applied Health Research, School of Health and Life Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow G4 0BA, UK. debbie.turner@gcu.ac.uk.
authors.forename: Deborah E
authors.initials: DE
authors.lastname: Turner
authors.forename: Elaine
authors.initials: E
authors.lastname: Hyslop
authors.forename: Ruth
authors.initials: R
authors.lastname: Barn
authors.forename: Iain B
authors.initials: IB
authors.lastname: McInnes
authors.forename: Martijn P M
authors.initials: MP
authors.lastname: Steultjens
authors.forename: James
authors.initials: J
authors.lastname: Woodburn
mesh_terms: D000328:Adult; D000368:Aged; D018771:Arthralgia / Q000209:etiology / Q000503:physiopathology*; D015535:Arthritis, Psoriatic / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015992:Body Mass Index; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D004204:Joint Dislocations / Q000209:etiology / Q000503:physiopathology*; D016015:Logistic Models; D008297:Male; D008683:Metatarsophalangeal Joint / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008875:Middle Aged; D050177:Overweight / Q000150:complications; D012307:Risk Factors; D012737:Sex Factors; D013585:Synovitis / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D014463:Ultrasonography; D055815:Young Adult
keywords: metatarsophalangeal joints; pain; plantar pressure; psoriatic arthritis; ultrasound