Clinical Outcomes Of Artificial Cervical Disc Replacement Versus Anterior Cervical Decompression And Fusion For Cervical Spondylosis

Objective:To compare the clinical outcome of artificial cervical disc replacement (ACDR) with that of anterior decompression and fusion (ACDF) in patients with cervical spondylosis.Methods:38patients who suffered symptomatic cervical spondylosis underwent artificial cervical disc replacement (ACDR group,17cases,19segments) and anterior cervical decompression and fusion (ACDF group,21cases,24segments) in our hospital from June2009to June2012. The patients were followed up for at least6months, the longest being36months, with an average of20.5months in ACDR group and19.1months in ACDF group. The Japanese Orthopedic Association (JOA) score, neck disability index (NDI) and visual analogue scale (VAS) were used to evaluate the clinical outcomes preoperatively and6months postoperatively. While the position of the prothesis in ACDR group, fusion status in ACDF group, the motility and stability of the cervical vertebra, and heterotopic ossification (HO) were observed preoperatively and1month,3,6,12,24and36months postoperatively by taking X-rays.Results:(1) ACDR group:The postoperative scores of the JOA, NDI and VAS improved compared with those of preoperative ones (P<0.01). The pre-and postoperative difference of the segmental range of motion (ROM), as well as adjacent ROM has no statistical significance (P>0.05). The functional spinal unit (FSU) and C2-7Cobb angle improved obviously (P<0.01).(2) ACDF group:The postoperative scores of the JOA, NDI and VAS improved obviously (P<0.01). Bony fusion was achieved in all cases6months postoperatively. The adjacent ROM increased significantly postoperatively (P<0.01). The functional spinal unit (FSU) and C2-7Cobb angle improved obviously (FSU Cobb angle P<0.05, C2-7Cobb angle P<0.01).(3) Comparison between the two groups:the neurological function was significantly improved during the follow-up period in both groups. The difference between the two groups regarding adjacent ROM was noted (P<0.01). The FSU and C2-7Cobb angle postoperatively improved more in ACDR group (P<0.01).(4) No serious complications in both groups during the follow-up period. No loosening or subsidence of the prosthesis in ACDR group, no segmental instability or kyphosis was observed. Grade I HO occurred in2cases, the incidence was11.8%. The difference between the incidence of AS in the two groups has statistical significance (P<0.01). No secondary operations were taken.Conclusion:Artificial cervical disc replacement leads to a satisfying clinical outcome. The motion of the implanted level and the dynamic stability of the cervical vertebra are well preserved.