title: Four-dimensional computed tomography scans facilitate preoperative planning in snapping scapula syndrome.
abstract: OBJECTIVE
  Because a 4-dimensional CT scan (4D CT) is able to provide a moving 3-dimensional (3D) image in real time in patients with snapping scapula syndrome, a 4D CT scan should be able to demonstrate bony impingement of the scapula on the posterior thorax. This study was performed to determine if 4D CT scans aid the clinician in defining the size and location of the scapular bone causing impingement in patients with snapping scapula syndrome.
  
  
  METHODS
  Between October 2009 and August 2013, 12 patients (median age, 26.5 years; range 15-55 years) with snapping scapula syndrome were investigated with 4D CT. The images formed produced a dynamic volume-rendered reconstruction of the scapulothoracic joint that displayed its movements and any dynamic area of impingement of the scapula on surrounding bony structures. Asymmetry between symptomatic and asymptomatic scapulae was used to determine the radiologic cause of the patient's symptoms. After the failure of conservative management, 8 patients underwent surgery for their condition.
  
  
  RESULTS
  Five patients demonstrated bony contact of the scapula on the posterior thoracic ribs. Four patients demonstrated no bony contact but close apposition of the scapula to the posterior thoracic ribs. Three patients demonstrated no bony impingement but abnormal movement of the second and third rib caused by a soft-tissue tethering structure.
  
  
  CONCLUSIONS
  The 4D CT scan images defined pathology well in patients with snapping scapula syndrome and improved assessment of the amount and location of the scapular bone and soft tissue causing symptoms.
authors.affiliation: Melbourne Shoulder and Elbow Centre, Melbourne, VIC, Australia; Department of Surgery, Monash University, Melbourne, VIC, Australia.
authors.forename: Simon N
authors.initials: SN
authors.lastname: Bell
authors.affiliation: Department of Diagnostic Imaging, Monash Health, Melbourne, VIC, Australia; Monash Cardiovascular Research Centre, Monash University, Melbourne, VIC, Australia; Department of Medical Imaging and Radiation Sciences, Monash University, Melbourne, VIC, Australia.
authors.forename: John M
authors.initials: JM
authors.lastname: Troupis
authors.affiliation: Mid Cheshire Hospitals NHS Foundation Trust, Cheshire, UK.
authors.forename: David
authors.initials: D
authors.lastname: Miller
authors.affiliation: Orthopaedic Clinic "Orthopedium", Delft, The Netherlands.
authors.forename: Tjarco D
authors.initials: TD
authors.lastname: Alta
authors.affiliation: Melbourne Shoulder and Elbow Centre, Melbourne, VIC, Australia; Department of Surgery, Monash University, Melbourne, VIC, Australia.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Coghlan
authors.affiliation: Melbourne Shoulder and Elbow Centre, Melbourne, VIC, Australia; Department of Surgery, Monash University, Melbourne, VIC, Australia. Electronic address: malinwijeratna@doctors.net.uk.
authors.forename: Malin D
authors.initials: MD
authors.lastname: Wijeratna
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D056973:Four-Dimensional Computed Tomography; D006801:Humans; D007592:Joint Diseases / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009068:Movement; D059352:Musculoskeletal Pain / Q000601:surgery; D057234:Preoperative Period; D012189:Retrospective Studies; D012272:Ribs / Q000000981:diagnostic imaging; D012540:Scapula / Q000000981:diagnostic imaging* / Q000601:surgery*; D013577:Syndrome; D035441:Thoracic Wall / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: 4-dimensional computed tomography; 4D CT; dynamic tethering; scapula impingement; scapular dyskinesis; snapping scapula