Christopher J DeFrancesco1, Saba Pasha1, Daniel J Miller1, Randal R Betz2, David H Clements3, Nicholas D Fletcher4, Michael G Glotzbecker5, Steven W Hwang6, Michael P Kelly7, Ronald A Lehman8, Baron S Lonner9, Peter O Newton10, Benjamin D Roye8, Paul D Sponseller11, Vidyadhar V Upasani10, Patrick J Cahill12. 1. Division of Orthopedics, Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104, USA. 2. Institute for Spine and Scoliosis, 3100 Princeton Pike, Lawrenceville, NJ 08648, USA. 3. Cooper University Orthopedics, One Cooper Plaza, Camden, NJ 08103, USA. 4. Emory Orthopedics & Spine Center, 59 Executive Park S, Atlanta, GA 30329, USA. 5. Orthopedic Center, Boston Children's Hospital, 300 Longwood Ave, Boston, MA 02115, USA. 6. Shriner's Hospitals for Children, 3551 N Broad St., Philadelphia, PA 19140, USA. 7. Washington University Orthopedics, 660 S. Euclid Ave., Campus Box 8233, St. Louis, MO 63110, USA. 8. Columbia Orthopedics, 161 Fort Washington Ave., 2nd Floor, New York, NY 10032, USA. 9. Scoliosis and Spine Associates, 820 2nd Ave., New York, NY 10017, USA. 10. Rady Children's Hospital, 3020 Children's Way, San Diego, CA 92123, USA. 11. Johns Hopkins Children's Center, 1800 Orleans St, Baltimore, MD 21287, USA. 12. Division of Orthopedics, Children's Hospital of Philadelphia, 3401 Civic Center Blvd, Philadelphia, PA 19104, USA. Electronic address: cahillp1@email.chop.edu.
Abstract
STUDY DESIGN: Survey-based cross-sectional study. OBJECTIVES: To describe interobserver agreement among experienced spine surgeons in choosing neutral vertebra (NV) based on manual measurements from radiographs. Secondarily, to use axial vertebral rotation (AVR) values obtained from low-dose stereoradiography (SR) post-processing software (SterEOS 2D/3D) to separately designate the NV in subject cases and to compare manually derived and software-derived NV designations. SUMMARY OF BACKGROUND DATA: Investigators have previously suggested that parameters such as Lenke classification, stable vertebra level, end vertebra level, and NV level be used to decide on fusion levels in adolescent idiopathic scoliosis (AIS). Studies have revealed suboptimal interobserver reliability in these vertebral designations. SR post-processing software may represent a useful tool for standardizing NV designation. METHODS: Thirty-two subjects with idiopathic scoliosis and Lenke 1-4 curves were assessed. Experienced surgeons (range of 7-35 years in practice) assigned NV based on preoperative radiographs. Interobserver reliability was quantified using the Fleiss Kappa statistic. Surgeon responses were compared with NV designations made using AVR values provided by SR postprocessing software. Agreement between these values was quantified using percentage agreement. RESULTS: Surgeons exhibited moderate agreement in choosing NV based on radiographs (Kappa 0.444). Surgeon responses agreed with the SR-derived NV in 26.9% of cases, lay within 1 level in 82.1% of cases, and lay within 2 levels in 97.5% of cases. Surgeons were more likely to choose distal to the SR NV rather than proximal. CONCLUSIONS: Variability in instrumented level selection and outcomes in idiopathic scoliosis may be partially related to inconsistency in selection of the NV. The use of SR post-processing software may provide a more reliable method for choosing NV. LEVEL OF EVIDENCE: Level II.
STUDY DESIGN: Survey-based cross-sectional study. OBJECTIVES: To describe interobserver agreement among experienced spine surgeons in choosing neutral vertebra (NV) based on manual measurements from radiographs. Secondarily, to use axial vertebral rotation (AVR) values obtained from low-dose stereoradiography (SR) post-processing software (SterEOS 2D/3D) to separately designate the NV in subject cases and to compare manually derived and software-derived NV designations. SUMMARY OF BACKGROUND DATA: Investigators have previously suggested that parameters such as Lenke classification, stable vertebra level, end vertebra level, and NV level be used to decide on fusion levels in adolescent idiopathic scoliosis (AIS). Studies have revealed suboptimal interobserver reliability in these vertebral designations. SR post-processing software may represent a useful tool for standardizing NV designation. METHODS: Thirty-two subjects with idiopathic scoliosis and Lenke 1-4 curves were assessed. Experienced surgeons (range of 7-35 years in practice) assigned NV based on preoperative radiographs. Interobserver reliability was quantified using the Fleiss Kappa statistic. Surgeon responses were compared with NV designations made using AVR values provided by SR postprocessing software. Agreement between these values was quantified using percentage agreement. RESULTS: Surgeons exhibited moderate agreement in choosing NV based on radiographs (Kappa 0.444). Surgeon responses agreed with the SR-derived NV in 26.9% of cases, lay within 1 level in 82.1% of cases, and lay within 2 levels in 97.5% of cases. Surgeons were more likely to choose distal to the SR NV rather than proximal. CONCLUSIONS: Variability in instrumented level selection and outcomes in idiopathic scoliosis may be partially related to inconsistency in selection of the NV. The use of SR post-processing software may provide a more reliable method for choosing NV. LEVEL OF EVIDENCE: Level II.