title: [The distinctive characteristics of ultrasonic imaging of enthesitis in spondyloarthritis patients].
abstract: OBJECTIVE
  To explore the distinctive ultrasonographic characters of enthesitis in patients with spondyloarthritis (SpA) and evaluate the diagnostic value of ultrasonography in SpA by comparing ultrasonography of enthesis in the lower limbs of patients with SpA, rheumatoid arthritis (RA) and osteoarthritis (OA).
  
  
  METHODS
  Entheses in the lower limbs (quadriceps tendon, proximal patellar ligament, distal patellar ligament, achilles tendon and plantar aponeurosis) were detected in SpA, RA, OA patients and health controls by ultrasonographic examination.
  
  
  RESULTS
  A total of 46 SpA, 23 RA and 12 OA patients were enrolled in this study, with 26 SpA and 7 RA patients complaining of heel pain (P<0.05). There were 126 enthesal sites (126/460, 27.2%) were detected abnormal in SpA group, compared with 54 of 230 (23.5%) sites in RA group and 27 of 120 (22.5%) sites in OA group (P>0.05). Sixty five (70.7%) sites of the distal patellar ligaments were abnormal in SpA group, while that were 19 (41.3%) in RA group (P<0.05) and 13 (54.2%) in OA group. Twenty six sites of tendon thickness and 22 sites of bone erosion in the distal patellar ligaments were found in SpA group, while only one site of each in RA group (P<0.05) and 4 sites of tendon thickness in OA group (P<0.05) were found.Tendon thickness, bursal synovitis and bone erosion coexisting in one distal patellar ligament indicated SpA, the sensitivity, specificity and the area under the curve (AUC) of which were 70.7%, 65.5% and 0.740, respectively.
  
  
  CONCLUSIONS
  Tendon thickness and bone erosion of entheses were more likely the distinctive ultrasonographic characters of enthesitis in SpA patients. Tendon thickness, bursal synovitis and bone erosion in the distal patellar ligament could be an ideal tool for SpA diagnosis.
authors.affiliation: Department of Rheumatology, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: Jinshui
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Rheumatology, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Rheumatology, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Department of Rheumatology, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Rheumatology, Chinese PLA General Hospital, Beijing 100853, China; Email: zhjl1966@vip.sina.com.
authors.forename: Jianglin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Rheumatology, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Huang
mesh_terms: D000125:Achilles Tendon / Q000000981:diagnostic imaging; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D003952:Diagnostic Imaging; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025241:Spondylarthritis / Q000150:complications / Q000000981:diagnostic imaging*; D052256:Tendinopathy / Q000000981:diagnostic imaging* / Q000209:etiology; D013710:Tendons / Q000000981:diagnostic imaging*; D014465:Ultrasonics / Q000379:methods*; D014463:Ultrasonography