[Early effectiveness and safety of mini open endoscopy assisted anterior cervical discectomy and fusion in treatment of cervical spondylotic myelopathy]

Abstract

Objective: To compare the early effectiveness and safety of mini open endoscopy assisted anterior cervical discectomy and fusion (MOEA-ACDF) versus traditional ACDF in the treatment of cervical spondylotic myelopathy (CSM).

Methods: A retrospective analysis was conducted on the clinical data of 60 patients with CSM admitted between January 2022 and January 2023 who met the selection criteria, including 30 cases each undergoing MOEA-ACDF and traditional ACDF. Except for age and height of the adjacent vertebral body (HAVB), no significant difference was observed between groups ( P>0.05) in the gender, body mass index, disease duration, surgical segment, preoperative visual analogue scale (VAS) scores for neck/upper limb pain, neck disability index (NDI), Japanese Orthopaedic Association (JOA) score, and C _2-7 Cobb angle. The operation time, postoperative drainage volume, and occurence of complications, as well as VAS scores for neck/upper limb pain, NDI, JOA score and its improvement rate, C _2-7 Cobb angle, HAVB, and bone graft fusion status (Bridwell classification) at the surgical segment were recorded and compared between groups.

Results: Both groups completed the operations successfully. The MOEA-ACDF group exhibited significantly longer operation time compared to the ACDF group ( P<0.05), and no significant difference was found in the postoperative drainage volume between groups ( P>0.05). Postoperatively, only 1 case in the MOEA-ACDF group developed subcutaneous ecchymosis in the neck, while the incidence of complications showed no significant difference between groups ( P>0.05). All patients were followed up 12-28 months (mean, 17.6 months). Over time, both groups demonstrated gradual improvement in NDI, VAS scores for neck/upper limb pain, and JOA scores ( P<0.05). At 1, 3, and 6 months, as well as at last follow-up, no significant difference was observed in all indicators between groups ( P>0.05). At last follow-up, the improvement rates of JOA scores in the two groups reached 90% (27/30), with no significant difference in the grading of improvement between groups ( P>0.05). Imaging re-examination revealed increased C _2-7 Cobb angle and HAVB in both groups postoperatively ( P<0.05), but no significant changes over time ( P>0.05). At 1 month after operation and last follow-up, no significant difference was observed in C _2-7 Cobb angle between groups ( P>0.05). Regarding the HAVB, ACDF group demostrated superior outcomes compared to MOEA-ACDF groups ( P<0.05). Both groups achieved bone graft fusion, and no significant difference between groups was observed in Bridwell classification at 6 months or last follow-up. During follow-up, no failure of internal fixation, sinking or displacement of cage, degeneration of adjacent segment was found.

Conclusion: MOEA-ACDF has good early effectiveness in the treatment of CSM, and can effectively improve the height and physiological curvature of cervical spine, which is equivalent to the traditional ACDF.

Keywords: Cervical spondylotic myelopathy; anterior cervical discectomy and fusion; unilateral biportal endoscopy.