title: Dedicated Spine Measurement Software Quantifies Key Spino-Pelvic Parameters More Reliably Than Traditional Picture Archiving and Communication Systems Tools.
abstract: METHODS
  Measurement reliability study of adult spinal deformity (ASD) patient radiographs using intraclass correlation coefficients (ICC) and variance.
  
  
  OBJECTIVE
  The aim of the study was to compare picture archiving and communication systems (PACS) to dedicated spine measurement software (SMS).
  
  
  BACKGROUND
  Accurate radiographic measurement of sagittal alignment is essential for evaluating ASD. PACS measurements often necessitate rudimentary techniques and estimations of anatomic landmarks and angles. Though SMS has been studied and validated, no studies directly compare PACS to SMS.
  
  
  METHODS
  Eleven independent observers (7 spine surgeons, 4 researchers) digitally measured 20 ASD radiographs for pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), PI-LL, thoracic kyphosis (TK), and sagittal vertical axis (SVA). Round 1 used PACS basic line/angle tools; Round 2 used a validated SMS that automatically calculates spino-pelvic parameters from 6 user-identified landmarks. Means, coefficient of variance (CV), and intraclass correlation coefficients (ICC) were analyzed.
  
  
  RESULTS
  PACS measurements were significantly greater than SMS (PI, PT, PI-LL: P < 0.0001), though within clinical and measurement margins of error. Excluding TK, the variations in measurement (CV) were significantly greater for PACS (14-34%) vs. SMS (11-23%). Reliability was greater in SMS than PACS for PI, PT, PI-LL, LL, and SVA. The greatest differences in intraclass correlation coefficients (ICC) between PACS and SMS were in PI (PACS: 0.647; SMS: 0.810) and PI-LL (PACS: 0.921; SMS: 0.970). Among surgeons, the differences between PACS and SMS were augmented, and SMS had higher intraclass correlation coefficients (ICC) than PACS for all parameters (mean intraclass correlation coefficients [ICC] 0.931 vs. 0.861). Among surgeons, PI had the lowest reliability (
  0.505; SMS: 0.752) and SVA had the highest (
  0.985; SMS: 0.994).
  
  
  CONCLUSIONS
  SMS provides significantly more reliable measurements than PACS, especially among surgeons. Consistent use of SMS in the evaluation and surgical planning of ASD patients appears necessary given the significant differences in values, variance, and reliability between PACS and SMS.
authors.affiliation: *Department of Orthopaedic Surgery, University of California, Davis, CA†Department of Orthopaedic Surgery, Spine Division, NYU Hospital for Joint Diseases, New York, NY‡Department of Neurosurgery, University of Virginia, Charlottesville, Virginia§Norton Leatherman Spine Center, Louisville, KY||Department of Orthopedic Surgery, University of Minnesota, Minneapolis, MN¶Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA#Division of Orthopaedic Surgery, Scripps Clinic, La Jolla, CA**Department of Orthopaedic Surgery, University of Kansas Medical Center, Kansas City, KS.
authors.forename: Munish
authors.initials: M
authors.lastname: Gupta
authors.forename: Jensen K
authors.initials: JK
authors.lastname: Henry
authors.forename: Frank
authors.initials: F
authors.lastname: Schwab
authors.forename: Eric
authors.initials: E
authors.lastname: Klineberg
authors.forename: Justin S
authors.initials: JS
authors.lastname: Smith
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Gum
authors.forename: David W
authors.initials: DW
authors.lastname: Polly
authors.forename: Barthelemy
authors.initials: B
authors.lastname: Liabaud
authors.forename: Bassel G
authors.initials: BG
authors.lastname: Diebo
authors.forename: D Kojo
authors.initials: DK
authors.lastname: Hamilton
authors.forename: Robert
authors.initials: R
authors.lastname: Eastlack
authors.forename: Peter G
authors.initials: PG
authors.lastname: Passias
authors.forename: Douglas
authors.initials: D
authors.lastname: Burton
authors.forename: Themistocles
authors.initials: T
authors.lastname: Protopsaltis
authors.forename: Virginie
authors.initials: V
authors.lastname: Lafage
mesh_terms: D000704:Analysis of Variance; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D010388:Pelvis / Q000000981:diagnostic imaging*; D011859:Radiography; D015203:Reproducibility of Results; D012984:Software; D013131:Spine / Q000033:anatomy & histology / Q000000981:diagnostic imaging*