頸部椎弓形成術後の早期脊髄移動：術後1週間以内の前向きMRI研究

Cervical laminoplasty is widely used for multilevel cervical stenosis. However, a known complication is C5 palsy, which usually occurs within 1 week postoperatively and is attributed to nerve root traction associated with posterior spinal cord shift. Therefore, we conducted a prospective study to clarify early changes in spinal cord shift within 1 week after cervical laminoplasty.

The cohort comprised 51 patients who underwent cervical double-door laminoplasty including the C4/5 level. Spinal cord shift and dural expansion were evaluated on MRI obtained on postoperative day 1 and 1 week postoperatively. A spinal cord shift of ≥ 3 mm at C4/5 was defined as a "great shift," and contributing factors were analyzed based on demographic and radiographic data.

The mean spinal cord shift at C4/5 was 1.4 ± 0.9 mm on postoperative day 1 and 0.6 ± 0.6 mm 1 week postoperatively. The shift was significantly greater on postoperative day 1 than at 1 week from C2/3 to C6/7 (p < 0.001). Six patients exhibited a great shift (mean 3.2 ± 0.3 mm). Multivariate analysis showed that the preoperative anteroposterior diameter of the dura mater at C5/6 was significantly associated with a great shift (OR = 0.46, 95% CI = 0.214-0.971, p = 0.04).

Posterior spinal cord shift was significantly greater on postoperative day 1 than at 1 week after cervical laminoplasty. Severe C5/6 stenosis preoperatively contributed to pronounced spinal cord shift at C4/5. These findings reveal early postoperative changes in spinal cord shift and underscore the importance of preoperative MRI assessment to reduce neurological complications.