title: Adult Spinal Deformity Surgeons Are Unable to Accurately Predict Postoperative Spinal Alignment Using Clinical Judgment Alone.
abstract: Adult spinal deformity (ASD) surgery seeks to reduce disability and improve quality of life through restoration of spinal alignment. In particular, correction of sagittal malalignment is correlated with patient outcome. Inadequate correction of sagittal deformity is not infrequent. The present study assessed surgeons' ability to accurately predict postoperative alignment.
  
  
  
  Seventeen cases were presented with preoperative radiographic measurements, and a summary of the operation as performed by the treating physician. Surgeon training, practice characteristics, and use of surgical planning software was assessed. Participants predicted if the surgical plan would lead to adequate deformity correction and attempted to predict postoperative radiographic parameters including sagittal vertical axis (SVA), pelvic tilt (PT), pelvic incidence to lumbar lordosis mismatch (PI-LL), thoracic kyphosis (TK).
  
  
  
  Seventeen surgeons participated: 71% within 0 to 10 years of practice; 88% devote >25% of their practice to deformity surgery. Surgeons accurately judged adequacy of the surgical plan to achieve correction to specific thresholds of SVA 69% ± 8%, PT 68% ± 9%, and PI-LL 68% ± 11% of the time. However, surgeons correctly predicted the actual postoperative radiographic parameters only 42% ± 6% of the time. They were more successful at predicting PT (61% ± 10%) than SVA (45% ± 8%), PI-LL (26% ± 11%), or TK change (35% ± 21%; p < .05). Improved performance correlated with greater focus on deformity but not number of years in practice or number of three-column osteotomies performed per year.
  
  
  
  Surgeons failed to correctly predict the adequacy of the proposed surgical plan in approximately one third of presented cases. They were better at determining whether a surgical plan would achieve adequate correction than predicting specific postoperative alignment parameters. Pelvic tilt and SVA were predicted with the greatest accuracy.
authors.affiliation: Department of Neurosurgery, University of British Columbia, 2329 West Mall, Vancouver, BC V6T 1Z4, Canada.
authors.forename: Tamir
authors.initials: T
authors.lastname: Ailon
authors.affiliation: Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave, Chicago, IL 60611, USA.
authors.forename: Justin K
authors.initials: JK
authors.lastname: Scheer
authors.affiliation: Department of Orthopedic Surgery, Hospital for Special Surgery, 535 E 70th St, New York, NY 10021, USA.
authors.forename: Virginie
authors.initials: V
authors.lastname: Lafage
authors.affiliation: Department of Orthopedic Surgery, Hospital for Special Surgery, 535 E 70th St, New York, NY 10021, USA.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Schwab
authors.affiliation: University of California Davis, 1 Shields Ave, Davis, CA 95616, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Klineberg
authors.affiliation: Department of Neurosurgery, The Johns Hopkins Medical Institutions, Johns Hopkins University, Baltimore, MD 21218, USA.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Sciubba
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, 302 E 17th St #835, New York, NY 10003, USA.
authors.forename: Themistocles S
authors.initials: TS
authors.lastname: Protopsaltis
authors.affiliation: Department of Orthopaedic Surgery, Washington University School of Medicine, 660 S Euclid Ave, St Louis, MO 63110, USA.
authors.forename: Lukas
authors.initials: L
authors.lastname: Zebala
authors.affiliation: Department of Orthopedic Surgery, Baylor Scoliosis Center, 4708 Alliance Blvd #800, Plano, TX 75093, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Hostin
authors.affiliation: Department of Orthopaedic Surgery, Bordeaux University Hospital, Bordeaux, France.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Obeid
authors.affiliation: Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, 303 E Chicago Ave, Chicago, IL 60611, USA.
authors.forename: Tyler
authors.initials: T
authors.lastname: Koski
authors.affiliation: Department of Orthopaedic Surgery, Washington University School of Medicine, 660 S Euclid Ave, St Louis, MO 63110, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Kelly
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, 302 E 17th St #835, New York, NY 10003, USA.
authors.forename: Shay
authors.initials: S
authors.lastname: Bess
authors.affiliation: Department of Neurosurgery, University of Virginia Medical Center, 1215 Lee St, Charlottesville, VA 22908, USA.
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Shaffrey
authors.affiliation: Department of Neurosurgery, University of Virginia Medical Center, 1215 Lee St, Charlottesville, VA 22908, USA. Electronic address: jss7f@virginia.edu.
authors.forename: Justin S
authors.initials: JS
authors.lastname: Smith
authors.affiliation: Department of Neurosurgery, University of California San Francisco, 505 Parnassus Ave, San Francisco, CA 94143, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
mesh_terms: D000328:Adult; D002983:Clinical Competence; D006801:Humans; D007600:Judgment; D007738:Kyphosis / Q000601:surgery*; D011379:Prognosis; D011788:Quality of Life; D012189:Retrospective Studies; D066231:Surgeons; D016896:Treatment Outcome
keywords: Adult scoliosis; Adult spinal deformity; Deformity correction; Spinal alignment; Surgical planning