title: Knee enthesitis and synovitis on magnetic resonance imaging in patients with psoriasis without arthritic symptoms.
abstract: OBJECTIVE
  This case-control study was designed to evaluate magnetic resonance imaging (MRI) findings of knee joints in patients with psoriasis without clinical peripheral or axial joint involvement, and to correlate MRI findings with disease and demographic variables.
  
  
  METHODS
  In total 48 patients with psoriasis and no clinical evidence of synovitis or enthesitis in any peripheral or axial joints were enrolled. A random sample of 20 healthy subjects without knee or other joint complaints and matched for age and sex served as controls. All patients and controls underwent enhanced MRI studies of both knee joints, and MRI findings were compared.
  
  
  RESULTS
  Among 48 patients (96 knees), a total of 90 entheseal lesions were detected, with no enthesitis in 2 cases (6.3%). Signs of continuing inflammation bilaterally were frequently found: soft tissue edema (STE; n = 52), bone marrow edema (BME; n = 20), perientheseal BME (n = 3), cartilaginous erosions (n = 42), and bone erosions (n = 27). In controls, 2 (10%) subjects had BME and another 5 (25%) showed cartilaginous erosions. None showed evidence of enthesitis. Significant correlations were observed between the number of entheseal lesions of both knees vs STE (present vs absent; r = 0.314, p = 0.030) and STE (number of lesions; r = 0.351, p = 0.014). Enthesitis (unilateral vs bilateral) was significantly and positively correlated with STE (r = 0.304, p = 0.036), cartilaginous erosions (r = 0.304, p = 0.036), and villous projections (r = 0.347, p = 0.016).
  
  
  CONCLUSIONS
  Subclinical synovitis and enthesitis are frequently found in the knee joint of patients with psoriasis. These may be an early sign of psoriatic arthritis.
authors.affiliation: Rheumatology and Rehabilitation Department, Radiology Department, Orthopedic Department, and Internal Medicine Department, Faculty of Medicine, Cairo University, Cairo, Egypt. yasseremad68@yahoo.com
authors.forename: Yasser
authors.initials: Y
authors.lastname: Emad
authors.forename: Yasser
authors.initials: Y
authors.lastname: Ragab
authors.forename: Tamer
authors.initials: T
authors.lastname: Gheita
authors.forename: Ashraf
authors.initials: A
authors.lastname: Anbar
authors.forename: Hoda
authors.initials: H
authors.lastname: Kamal
authors.forename: Ahmed
authors.initials: A
authors.lastname: Saad
authors.forename: Hanan
authors.initials: H
authors.lastname: Darweesh
authors.forename: Nashwa
authors.initials: N
authors.lastname: El-Shaarawy
authors.forename: Amr
authors.initials: A
authors.lastname: Azab
authors.forename: Ahmed
authors.initials: A
authors.lastname: Ismail
authors.forename: Johannes J
authors.initials: JJ
authors.lastname: Rasker
mesh_terms: D000328:Adult; D002358:Cartilage, Articular / Q000473:pathology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007249:Inflammation / Q000473:pathology*; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000473:pathology*; D013583:Synovial Membrane / Q000473:pathology; D013585:Synovitis / Q000473:pathology*