Abstract:

Objective To evaluate the clinical efficacy of selective expansive open-door laminoplasty (SEOLP) with preservation of C7 spinous process in the treatment of multisegmental cervical spondylotic myelopathy and its impact on changes in sagittal parameters of cervical spine. Methods A retrospective analysis was conducted on the clinical data and radiological information of 73 patients who underwent expansive open-door laminoplasty (EOLP) for cervical spondylotic myelopathy in our department between March 2018 and June 2022. Patients were divided into the SEOLP group (n=35) and the EOLP group (n=38) based on the surgical method. Follow-up was conducted for one year. The operation time, blood loss, axial symptom scores, JOA scores, VAS scores and neck disability index (NDI) were recorded in two groups of patients. Radiological data were also recorded for both groups during the perioperative period, and the C2-7 Cobb angle, C2-7 SVA and T1 slope were measured. The cervical curvature index (CCI) and cervical range of motion (ROM) were calculated. The perioperative clinical outcomes and changes in cervical sagittal parameters were observed, and their correlations were analyzed. Results There were no significant differences in blood loss, operation time, JOA scores at various follow-up time points between the two groups (P>0.05). During postoperative follow-up, axial symptoms were observed in 5 patients in SEOLP group and 14 patients in EOLP group. There were statistically significant differences in axial symptom scores, incidence and severity of axial symptoms between the two groups (P<0.05). The NDI indices at one year after operation were 21.1±2.3 for SEOLP group and 24.8±3.5 for EOLP group respectively (P<0.01). There were no statistically significant differences in T1 slope and C2-7 Cobb angle at various follow-up time points after surgery between the two groups (P>0.05). One year after operation, CCI indices for two groups were (13.4±2.7) and (12.1±2.4), respectively, with a statistically significant difference (t=2.178, P<0.05). The C2-C7 SVA values for two groups at one year after operation were (22.4±3.8) mm and (26.7±5.9) mm, respectively (t=3.667, P<0.01). The results of the correlation analysis showed that there was a significant negative correlation between clinical functional improvement (NDI) and changes of the radiological parameter C2-C7 SVA in both groups of patients. Conclusion After SEOLP, the recovery of C2-C7 SVA is faster and has less impact on cervical spine function, and the occurrence degree and incidence of axial symptoms are lower.

Key words: cervical spondylotic myelopathy, posterior cervical single open-door laminoplasty, axial symptoms, sagittal parameters, clinical efficacy