Effects of guttering on the lateral mass technique in the cross-sectional area of spinal canal after unilateral open-door cervical laminoplasty

English Keywords:Cervical vertebrae  Cervical spondylosis  Laminoplasty  Lateral mass  Guttering on the lateral mass

English Abstract:

  【Abstract】 Objectives: To explore the effects of guttering on the lateral mass technique in enlarging the cross-sectional area of the spinal canal after unilateral open-door cervical laminoplasty. Methods: A retrospective analysis was conducted on the clinical data of patients with cervical ossification of posterior longitudinal ligament treated with unilateral open-door cervical laminoplasty between February 2021 and February 2024. 37 patients who underwent the conventional technique were included in the conventional group; 31 patients undergone guttering on the lateral mass technique were included in the lateral mass group. The operative time, intraoperative blood loss, postoperative drainage volume, and incidence of complications were compared between the two groups. At preoperation, immediately after surgery, 2 months after surgery, and the final follow-up, the neck pain was evaluated using the visual analog scale(VAS), the cervical function was assessed with the neck disability index(NDI), and the neurological function was appraised with the Japanese Orthopaedic Association(JOA) score. C2-7 Cobb angle, C2-7 sagittal vertical axis(SVA), and T1 slope were measured on the cervical lateral X-rays to eliminate the possibilities of guttering on the lateral mass affecting cervical stability and cervical curvature; The spinal canal area was measured on the CT cross-sectional image and the percentage increase in spinal canal area was compared between the two groups. Results: All the patients underwent the surgery successfully. No serious complications such as spinal cord injury or infection occurred. There were no significant differences in operation time, intraoperative blood loss, postoperative drainage volume between the two groups(P>0.05). The neck pain VAS scores, NDI and JOA scores in both groups showed significant improvement immediately after surgery, 2 months after surgery, and at final follow-up(P<0.05). There were no differences in neck pain VAS scores and NDI between the two groups at preoperation, immediately after surgery, 2 months after surgery and final follow-up(P>0.05). There was no statistical difference in preoperative JOA scores between the two groups(P>0.05), but there were statistically significant differences in JOA scores between the two groups immediately after surgery, 2 months after surgery, and at final follow-up(P<0.05). There were no statistical differences in C2-7 Cobb angle, C2-7 SVA, and T1 slope in both groups immediately after surgery, at 2 months after surgery, and at final follow-up, comparing with those before operation(P>0.05). No significant differences were found between the two groups in C2-7 Cobb angle, C2-7 SVA, and T1 slope at preoperation, immediately after surgery, at 2-month after surgery, and at the final follow-up(P>0.05). The average cross-sectional area of the spinal canal in both groups showed significant improvement immediately after surgery, at 2-month after surgery, and at final follow-up(P<0.05). There was no statistical difference in the preoperative average cross-sectional area of the spinal canal between the two groups(P>0.05). However, the average cross-sectional area of the spinal canal in the lateral mass group immediately after surgery, at 2-month after surgery, and at the final follow-up was larger than that in the conventional group, and the differences were statistically significant(P<0.05). Conclusions: Compared with the conventional unilateral open-door cervical laminoplasty, guttering on the lateral mass technique can significantly expand the cross-sectional area of the spinal canal and improve postoperative neurological function recovery.