Polyetheretherketone (PEEK) Rods for Lumbar Fusion: A Systematic Review and Meta-Analysis

The purpose of this systematic review is to evaluate the safety and effectiveness of polyetheretherketone (PEEK) rod systems in patients receiving lumbar interbody fusion treatment. Meta-analyses of relevant clinical data were also conducted when possible.

Relevant studies were identified by searching the PubMed, EMBASE, and Cochrane Library databases. Clinical studies evaluating the safety and/or effectiveness of the PEEK rod spinal stabilization system in patients receiving lumbar spinal fusion procedure were included. Studies regarding dynamic stabilization and hybrid stabilization (fixed and dynamic; eg, topping-off technique) were not included in this analysis. The analyses included patients who had a lumbar fusion procedure with PEEK rods or titanium rods as a control reference (only for controlled studies). Fusion success, functional and pain improvement, and safety data were evaluated, if reported.

The search yielded 5 studies (1 prospective and 4 retrospectives) that included 177 participants (156 received PEEK rods, and 21 received titanium rods). Meta-analysis of interbody fusion success rate in PEEK rod patients yields the estimate of 95.6% (confidence interval: 91.6% to 98.4%). Functional outcomes in PEEK rod patients demonstrated clinically significant improvement when comparing postoperative to preoperative scores, with an average improvement of 67.4% ± 8.5%. Similarly, pain improvement was clinically significant with an average visual analog scores-back pain and visual analog scores-leg pain improvement percentages of 68.9% ± 8.6% and 76.6% ± 1.5%, respectively. Rod fracture was not reported in any of the studies. The rates of screw fracture and loosening were 3/114 (2.6%) and 1/50 (2.0%), respectively. In the controlled study, no statistically significant difference was reported in the fusion success rate, function improvement, pain improvement, or device-related events between subjects treated with PEEK rods and the subjects treated with titanium rods.

Experience with PEEK rod systems has shown satisfactory clinical outcomes. Therefore, these results support the use of PEEK rod systems as supplemental fixation during lumbar fusion procedures.