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Updated: Jul 10, 2025

Laminectomy for the Removal of Thoracic Ossification of the Ligamentum Flavum TOLF Using Ultrasonic and Conventional Osteotomes
Published on: April 21, 2023
A Clinical Classification of Cervical Ossification of the Posterior Longitudinal Ligament to Guide Surgical Strategy
Xiaofei Sun1, Fudong Li1, Baolian Zhao2
1Department of Orthopedic Surgery, Changzheng Hospital, Naval Medical University, Shanghai, People's Republic of China.
Study Design:
A clinical classification of cervical ossification of the posterior longitudinal ligament (COPLL) was developed based on imaging findings.
Objective:
This study aimed to establish a clinical classification for COPLL and provide corresponding surgery strategies for each subtype.
Summary Of Background Data:
A practical and reliable classification is needed to guide the treatment of COPLL.
Materials And Methods:
This study retrospectively reviewed plain radiographs, computed tomography scans, and magnetic resonance images of patients diagnosed with COPLL between 2018 and 2022 at Shanghai Changzheng Hospital. The types of COPLL were classified according to the location, morphology, and canal-occupying ratio (OR) of the ossification mass. Interobserver and intraobserver reliability were evaluated using Cohen's kappa.
Results:
A total of 1000 cases were included, which were classified into five types: focal type (F type), short-sequential type (S type), long-sequential type (L type), high type (H type), and mixed type (M type). In addition, each type could be classified into subtype 1 or subtype 2 according to the canal-OR. Then each type could be further classified into other subtypes according to location and morphology. The interobserver reliabilities in the first and second rounds were 0.853 and 0.887, respectively. The intraobserver reliability was 0.888.
Conclusion:
The authors classified COPLL into a system comprised of five types and several subtypes according to canal-OR, location, and morphology. Surgical strategies for each subtype are also suggested. This provides a theoretical guide for the description and surgical management of COPLL.
