Clinical factors that may affect outcome in lumbar total disc replacement. what is the evidence?

Abstract

The role of artificial disc replacement in the treatment of disorders of the lumbar spine remains unclear. The strength of the available evidence concerning a variety of factors that might affect outcomes needs to be assessed when evaluating the scientific merit of the new technology. Only lower level studies with conflicting results assess the effect on outcomes of single vs. multilevel surgery, L4-L5 vs. L5-S1 implantations, patient's age and history of previous surgery. The extent of pre-operative facet degeneration that can be accepted remains unclear, as level IV studies report degradation of facet degeneration after implantation. Higher level studies support the importance of surgical precision upon clinical outcome and lower level studies give mixed results on the same issue. A level III prognostic study suggests that higher ROM of the implanted segment may be associated with better outcomes, while two level IV therapeutic studies provide conflicting results. Two level IV studies suggest that preservation of motion may have a prophylactic effect on adjacent discs. In conclusion, existing evidence does not provide definite conclusions in the majority of the clinical questions regarding indications and factors that may affect outcomes. Highest quality data are short term while longer term data are of lower quality and in many instances conflicting. More high-level studies with long-term follow-up are necessary to shed light into important clinical issues. © 2010 Springer-Verlag Berlin Heidelberg.