Multilevel anterior cervical discectomy and fusion using zero-profile anchored cages: a minimum 5-year follow-up study

Abstract

Background To evaluate the mid-term results of anterior cervical discectomy and fusion (ACDF) using zero-profile anchored cages for the treatment of multilevel degenerative cervical spondylosis. Methods Thirty-four patients aged 54.1±6.0 years (range, 41–64 years) who underwent 3- or 4-level ACDF with zero-profile anchored cages for degenerative cervical spondylosis in a single institute between 2014 and 2016 were included. Clinical outcomes were assessed using the visual analogue scale (VAS), modified Japanese Orthopaedic Association (mJOA) scores, and Neck Disability Index (NDI) preoperatively and postoperatively at the 1-, 2-, and 5-year follow-ups. Radiological outcomes including fusion rate, disc height (DH), subsidence, fused segment angle (FSA), and cervical lordosis (CL) were also assessed at the same intervals. Results The mean follow-up time was 68 months. All patients had significant recovery of neurological function. Compared with the preoperative scores, the postoperative VAS, JOA, and NDI scores were improved at each time point (p<0.05). The FSA and CL were improved at each follow-up time point after the operation(p<0.05). All surgical segments were fused and there was 32 cage subsidence (30.2%) observed at the 5-year follow-up. The differences in VAS, JOA scores, NDI, fused segment angle, and cervical lordosis between the 5-year and the 2-year follow-up were not statistically significant(p>0.05). The loss of lordosis was not related to symptoms. Conclusions ACDF using zero-profile anchored cages for multilevel cervical spondylopathy achieved satisfactory mid-term outcomes. Cage subsidence and loss of cervical lordosis mainly occurred duringthe first two years but remained stable afterward and were not related to symptoms.