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.