Rates of Adjacent Segment Disease in Polyetheretherketone Versus Titanium Rods After Posterior Lumbar Fusion: A Systematic Review and Meta-Analysis.

Adjacent segment disease (ASD) is a common complication and cause of reoperation following lumbar spinal fusion. Although most commonly performed with titanium or other metal rods, the use of polyetheretherketone (PEEK) rods in spinal fusion has increased. It has been hypothesized that the material properties of PEEK, compared to titanium, allow for less strain on, and therefore less degeneration of, segments adjacent to the fused segments.