Evaluating Changes to The Modified K-line Using Kinematic MRIs.

When positioned in extension, patients experience a significant increase in distance from the dorsal aspect of a disc to the K-line compared to when positioned in neutral, especially between C3-C6. This is clinically relevant for surgeons considering a posterior cervical decompression and fusion in patients with a negative modified K line on preoperative MRI imaging, as these patients may have enough cervical cord drift back when fused in an extended position, maximizing likelihood of improving postoperative CSM functional outcomes.