@article{JSS4153,
author = {Yasushi Ijima and Takeo Furuya and Mitsutoshi Ota and Satoshi Maki and Junya Saito and Mitsuhiro Kitamura and Takuya Miyamoto and Seiji Ohtori and Sumihisa Orita and Kazuhide Inage and Takane Suzuki and Masashi Yamazaki and Masao Koda},
title = {The K-line in the cervical ossification of the posterior longitudinal ligament is different on plain radiographs and CT images},
journal = {Journal of Spine Surgery},
volume = {4},
number = {2},
year = {2018},
keywords = {},
abstract = {Background: The K-line, which is a virtual line between the midpoints of the antero-posterior canal diameter at C2 and C7, can be useful for determination of surgical procedures for cervical ossification of the posterior longitudinal ligament (OPLL). Although K-line is originally measured with plain radiogram, computed tomography multiplanar reconstruction (CT-MPR) is applied for K-line measurement by several surgeons. The purpose of the present study was to analyze whether there is a difference in K-lines obtained from radiographs of standing patients and those obtained from CT-MPR images of supine patients.
Methods: The present study included 65 patients with cervical OPLL underwent surgical treatment. We investigated the K-line (+ or −) before surgery, measured from lateral cervical spine radiographs taken in standing patients in a neutral position (X-P-based K-line) and CT-MPR mid-sagittal images obtained in supine patients (CT-based K-line). The X-P-based and CT-based K-lines were compared and differences between them were assessed.
Results: The-X-P-based K-line was found to be (+) in 35 patients and (−) in 30 patients. Four of 35 patients with an X-P-based K-line (11%) showed a change from K-line (+) to (−) in CT-based K-line measurements. One of 30 patients with an X-P-based K-line (3%) showed a change from (−) to (+) in CT-based measurements.
Conclusions: The K-line should be measured with plain radiogram of standing patients because X-P-based K-line and CT-based K-line can be different.},
issn = {2414-4630}, url = {https://jss.amegroups.org/article/view/4153}
}