title: The natural course of bridging osteophyte formation in diffuse idiopathic skeletal hyperostosis: retrospective analysis of consecutive CT examinations over 10 years.
abstract: OBJECTIVE
  The aim of this study was to evaluate the natural progression of bridging osteophyte formation in diffuse idiopathic skeletal hyperostosis (DISH) on CT by a newly proposed scoring system.
  
  
  METHODS
  CT examinations of the thoracic/lumbar spine of DISH patients (Resnick criteria) obtained at two or more time points within a minimum of 3 years were evaluated. Twenty-six patients (mean age at first CT 57 years, 21 males) fulfilled the entry criteria. A semi-quantitative scoring system for osteophyte progression was evaluated for intra- and interreader reliability on 68 vertebral units (VUs) in five patients. CT sagittal reformates of all 26 study patients were scored by two readers in consensus.
  
  
  RESULTS
  Scoring intra- and interobserver intraclass correlation coefficient values were high (0.971 and 0.893, respectively). The average time points per patient was 3.6 in 398 VUs analysed for 93 time points. The average time between the first and last scans was 5.6 years (range 3-10). The scores of six patients were unchanged. The scores of 20 patients increased by 3 units in 48 VUs over 5.6 (s.d. 3.1) years. The time for a DISH score to increase by 1 scoring unit was 1.6 (s.d. 0.4) years. Two bridging patterns were observed: osteophyte fusion associated with a calcified anterior longitudinal ligament (ALL, 66%) and osteophyte fusion without apparent ALL calcification (33%). Both patterns were observed concomitantly in 15 patients.
  
  
  CONCLUSIONS
  The new scoring system may enable earlier diagnosis and help predict disease progression into its final confluent osteophyte form. The two described patterns may indicate an underlying inflammatory rather than a degenerative pathogenesis.
authors.affiliation: Department of Diagnostic Imaging, Rheumatology Unit, Department of Orthopedic Surgery and Talpiot Medical Leadership Program, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Gal
authors.initials: G
authors.lastname: Yaniv
authors.affiliation: Department of Diagnostic Imaging, Rheumatology Unit, Department of Orthopedic Surgery and Talpiot Medical Leadership Program, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Salim
authors.initials: S
authors.lastname: Bader
authors.affiliation: Department of Diagnostic Imaging, Rheumatology Unit, Department of Orthopedic Surgery and Talpiot Medical Leadership Program, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Merav
authors.initials: M
authors.lastname: Lidar
authors.affiliation: Department of Diagnostic Imaging, Rheumatology Unit, Department of Orthopedic Surgery and Talpiot Medical Leadership Program, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. Department of Diagnostic Imaging, Rheumatology Unit, Department of Orthopedic Surgery and Talpiot Medical Leadership Program, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Amir
authors.initials: A
authors.lastname: Herman
authors.affiliation: Department of Diagnostic Imaging, Rheumatology Unit, Department of Orthopedic Surgery and Talpiot Medical Leadership Program, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Nachshon
authors.initials: N
authors.lastname: Shazar
authors.affiliation: Department of Diagnostic Imaging, Rheumatology Unit, Department of Orthopedic Surgery and Talpiot Medical Leadership Program, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Dvora
authors.initials: D
authors.lastname: Aharoni
authors.affiliation: Department of Diagnostic Imaging, Rheumatology Unit, Department of Orthopedic Surgery and Talpiot Medical Leadership Program, Sheba Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel. iriseshed@gmail.com.
authors.forename: Iris
authors.initials: I
authors.lastname: Eshed
mesh_terms: D000328:Adult; D000368:Aged; D018450:Disease Progression; D042241:Early Diagnosis; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D004057:Hyperostosis, Diffuse Idiopathic Skeletal / Q000150:complications / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D054850:Osteophyte / Q000000981:diagnostic imaging* / Q000209:etiology; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: CT; DISH; osteophyte; radiographic progression