title: Inflammatory bone spur formation in psoriatic arthritis is different from bone spur formation in hand osteoarthritis.
abstract: OBJECTIVE
  To investigate the different patterns of bone spur formation in psoriatic arthritis (PsA) and hand osteoarthritis (OA), using high-resolution peripheral quantitative computed tomography (QCT).
  
  
  METHODS
  The study group comprised 70 subjects (25 patients with PsA, 25 patients with hand OA, and 20 healthy controls). The 2 patient groups were similar with regard to age and sex distribution and clinical involvement of the metacarpophalangeal (MCP) joints. All patients underwent high-resolution peripheral QCT scanning of the second, third, and fourth MCP joints of the dominantly affected hand. Demographic and disease-specific data were recorded, and the number, size, and distribution of bone spurs were assessed and compared between patients with PsA and patients with hand OA.
  
  
  RESULTS
  The overall number and size of bone spurs were similar in patients with PsA and patients with hand OA. However, localization of lesions within individual joints was substantially different between patients with PsA and those with hand OA. In PsA, bone spurs dominated the radial sides of the joints (for the metacarpal head of the second joint, P < 0.001 versus hand OA; for the base of the second phalangeal joint, P < 0.001 versus hand OA), whereas the palmar and dorsal quadrants were the predilection sites in hand OA. Detailed anatomic analysis showed that bone spurs in the entheseal regions were prominent in patients with PsA but rare in patients with hand OA, and that bone spurs in patients with hand OA typically emerged at the cartilage-bone interphase and the joint margins.
  
  
  CONCLUSIONS
  Our findings show that the overall number and size of bone spurs are similar in patients with PsA and patients with hand OA. Nonetheless, the anatomic sites of bone proliferation are different between these 2 groups of patients.
authors.affiliation: University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Finzel
authors.forename: Enijad
authors.initials: E
authors.lastname: Sahinbegovic
authors.forename: Roland
authors.initials: R
authors.lastname: Kocijan
authors.forename: Klaus
authors.initials: K
authors.lastname: Engelke
authors.forename: Matthias
authors.initials: M
authors.lastname: Englbrecht
authors.forename: Georg
authors.initials: G
authors.lastname: Schett
mesh_terms: D000328:Adult; D015535:Arthritis, Psoriatic / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D001842:Bone and Bones / Q000473:pathology; D016022:Case-Control Studies; D049109:Cell Proliferation / Q000502:physiology; D018450:Disease Progression; D005260:Female; D006225:Hand; D006801:Humans; D008297:Male; D008662:Metacarpophalangeal Joint / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D010012:Osteogenesis / Q000502:physiology*; D054850:Osteophyte / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed