Various radiological parameters are used to evaluate [[cervical ossification of the posterior longitudinal ligament]] and to determine the surgical strategy.
Factors such as the number of involved spinal segments, [[cervical alignment]] or [[T1 slope]], the relationship between OPLL and the [[C2–7 line]] (termed the “[[K-line]]”), occupying ratio of OPLL, and involvement of dural ossification need to be carefully considered before surgery
((Shimokawa N, Sato H, Matsumoto H, Takami T. Review of Radiological Parameters,
Imaging Characteristics, and Their Effect on Optimal Treatment Approaches and
Surgical Outcomes for Cervical Ossification of the Posterior Longitudinal
Ligament. Neurospine. 2019 Sep;16(3):506-516. doi: 10.14245/ns.1938268.134. Epub 
2019 Sep 30. PubMed PMID: 31607082; PubMed Central PMCID: PMC6790724.
)).