Clinical and radiological outcomes of dynamic cervical implant arthroplasty: A 5-year follow-up

BACKGROUND Dynamic cervical implant(DCI) stabilization has been reported to have satisfactory clinical and radiological results with short-and mid-term follow-up in the treatment of cervical degenerative disc disease. However, few reports about the clinical and radiological outcome with more than 5-year follow-up exist.AIM To investigate the long-term clinical and radiological results of DCI arthroplasty.METHODS A total of 40 patients who received DCI arthroplasty were consecutively reviewed from May 2010 to August 2015. Visual analogue scale(VAS), neck disability index(NDI) score, Japanese Orthopaedic Association(JOA) score, and SF-36 items were used to assess neural function rehabilitation. Static and dynamic radiographs and 3-dimentional computed tomography were used to evaluate the radiological outcomes.RESULTS The scores of neck/arm VAS, NDI, JOA, and 8-dimensions of SF-36 were significantly improved at the 1-mo follow-up(P < 0.05) and maintained until the last follow-up(P < 0.05). The range of motion(ROM) of C2-C7, functional spinal unit(FSU), upper/lower adjacent level, C2-C7 lateral bending, and FSU lateral bending decreased at the 1-mo follow-up(P < 0.05), whereas they increased to the preoperative level at the later follow-up intervals(P > 0.05), except the ROM of FSU lateral bending(P < 0.05). The C2-C7 alignment and FSU angle kept more lordotic at the last follow-up(P < 0.05). The intervertebral height increased significantly at the 1-mo follow-up(P < 0.05) and decreased at later follow-ups(P > 0.05). At the last follow-up, 12(26.1%) segments developed heterotopic ossification.CONCLUSION DCI arthroplasty is a safe and effective non-fusion technique to treat cervical degenerative disc disease in long-term follow-up.