Total Disc Arthroplasty and Anterior Cervical Discectomy and Fusion in Cervical Spine: Competitive or Complimentary? Review of the Literature

Anterior cervical discectomy and arthrodesis has come to represent standard of care for patients with persistent radicular and/or myelopathic symptoms that have failed to improve with conservative treatments. One potential complication of the procedure is the accelerated degeneration of the vertebrae and the intervertebral discs adjacent to the level fused and the effects of fusion on those levels. The concern that fusion may be a contributing factor to accelerated adjacent segment degeneration led to increased interest in cervical disc replacement after anterior decompressive surgery. Several studies analyzing the short-term outcomes of the disc replacement procedure have been published since then, and the pros and cons of both procedures continue to remain a topic of debate among the scientific community. The analysis of published literature and our own experience has convinced us that the overall longer-term clinical outcomes after anterior cervical discectomy and fusion (ACDF) and total disc replacement (TDR) in the general patient population are not significantly different in terms of symptomatic improvement, neurological improvement, and restoration to better quality of life. Age of the patients and number of affected levels may impact the outcomes and hence determine the choice of optimum procedure. To definitely compare the incidence of adjacent segment disease after these procedures, multi-institutional studies with predetermined and unanimously agreed upon clinical and radiological criteria should be undertaken and the results analyzed in an unbiased fashion. Until that time, it is reasonable to assume that ACDF as well as cervical TDR are both safe and effective procedures that may have outcome benefits in specific patient subgroups based upon demographics and clinical/radiological parameters at the time of surgery.