Comparative efficacy and safety of minimally invasive dual‑axial endoscopy‑assisted anterior cervical discectomy and fusion versus conventional anterior cervical discectomy and fusion for cervical spondylosis: a retrospective cohort study

Anterior cervical discectomy and fusion (ACDF) is the standard surgical treatment for cervical spondylosis (CS) but has several limitations. Endoscopy-assisted ACDF has emerged as a minimally invasive alternative with potential advantages. This study compared the clinical efficacy and safety of minimally invasive dual-axial endoscopy-assisted anterior cervical discectomy and fusion (MDAE-ACDF) with ACDF in patients with CS. This retrospective study included 102 patients with CS who underwent MDAE-ACDF or ACDF between January 2023 and January 2025, with at least 12 months of follow-up. Patients were assigned to the MDAE-ACDF (n = 49) or ACDF (n = 53) group according to the procedure performed. Perioperative outcomes included operative time, postoperative drainage, and hospital stay after surgery. Early postoperative outcomes were assessed using visual analog scale (VAS) scores, C-reactive protein (CRP) levels, and erythrocyte sedimentation rate (ESR) measured preoperatively and on postoperative days 1 and 3. Functional outcomes were evaluated using the modified Japanese Orthopaedic Association (mJOA) score and neck disability index (NDI). Radiological outcomes, including the C2–7 Cobb angle and C2–7 range of motion (ROM), as well as postoperative complications were also recorded. The MDAE-ACDF group had a numerically longer operative time than the ACDF group, although the difference was not significant ( P = 0.109). However, postoperative drainage and hospital stay were significantly reduced (both P < 0.001). Early postoperative trajectories of neck VAS, ESR, and CRP differed between the two groups, while arm VAS did not differ. Subsequent comparisons identified lower neck VAS scores on postoperative day 1, lower ESR levels on postoperative day 3, and lower CRP levels on postoperative days 1 and 3 in the MDAE-ACDF group (all adjusted P < 0.05). mJOA and NDI scores improved over the 12-month follow-up in both groups, without evidence of different temporal trends between groups ( P > 0.05). At 12 months, no significant between-group differences were observed in the C2–7 Cobb angle or C2–7 ROM (all P > 0.05). The incidence of complications did not differ significantly between the two groups. MDAE-ACDF showed similar short-term outcomes to conventional ACDF and may offer potential advantages in early postoperative recovery, supporting its role as a minimally invasive option for CS.