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. 2022 Aug 19;38(1):31-41.
doi: 10.3171/2022.6.SPINE22454. Print 2023 Jan 1.

Effect of surgical experience and spine subspecialty on the reliability of the AO Spine Upper Cervical Injury Classification System

Mark J Lambrechts  1 , Gregory D Schroeder  1 , Brian A Karamian  1 , Jose A Canseco  1 , F Cumhur Oner  2 , Lorin M Benneker  3 , Richard J Bransford  4 , Frank Kandziora  5 , Shanmuganathan Rajasekaran  6 , Mohammad El-Sharkawi  7 , Rishi Kanna  6 , Andrei Fernandes Joaquim  8 , Klaus Schnake  9   10 , Christopher K Kepler  1 , Alexander R Vaccaro  1 ; AO Spine Upper Cervical Injury Classification International Members; AO Spine Upper Cervical Injury Classification International Members
Collaborators, Affiliations

Effect of surgical experience and spine subspecialty on the reliability of the AO Spine Upper Cervical Injury Classification System

Mark J Lambrechts et al. J Neurosurg Spine. .

Abstract

Objective: The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5-10 years, 10-20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery).

Methods: A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson's chi-square or Fisher's exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility.

Results: The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5-10 years: 0.69 vs 10-20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5-10 years: 0.62 vs 10-20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5-10 years: 0.61 vs 10-20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36).

Conclusions: The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system.

Keywords: AO Spine; neurosurgeon; orthopedic spine surgeon; reliability; reproducibility; trauma; upper cervical spine.

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Conflict of interest statement

The study was funded and supported by AO Spine; statistical support was provided. Dr. Benneker: consultant for Icotec and Kuros; and clinical or research support for the study described (includes equipment or material) from Sentryx. Dr. Bransford: speakers bureau for DePuy Synthes and Globus. Dr. Schnake: consultant for AO Spine International. Dr. Vaccaro: ownership in Advanced Spinal Intellectual Properties, Atlas Spine, Avaz Surgical, AVKN Patient Driven Care, Bonovo Orthopaedics, Computational Biodynamics, Cytonics, Deep Health, Dimension Orthotics LLC, Electrocore, Flagship Surgical, FlowPharma, Globus, Innovative Surgical Design, Jushi, NuVasive, Orthobullets, Parvizi Surgical Innovation, Progressive Spinal Technologies, Replication Medica, Spine Medica, Spineology, Stout Medical, Surgalign, and ViewFi Health; royalties from Aesculap, Atlas Spine, Globus, Medtronic, Spine Wave, and Stryker Spine; and board member of National Spine Health Foundation and Sentryx.

Figures

FIG. 1.
FIG. 1.
Depiction of the AO Spine Upper Cervical Injury Classification. The classification is based on injury location (occipital condyle and craniocervical junction, C1 ring and C1–2 joint, and C2 and C2–3 joint) and injury type (bony, tension band, and ligamentous). © 2020 AO Foundation, AO Spine, published with permission. CC BY-NC-ND (https://creativecommons.org/licenses/by-nc-nd/4.0/).
See this image and copyright information in PMC

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