Titanium‑coated polyetheretherketone cages vs. polyetheretherketone cages in lumbar interbody fusion: A systematic review and meta‑analysis

Abstract

Fusion material is one of the key factors in the success of lumbar interbody fusion surgery. The present meta-analysis compared the safety and efficacy of titanium-coated (Ti) polyetheretherketone (PEEK) and PEEK cages. Published literature on the use of Ti-PEEK and PEEK cages in lumbar interbody fusion was systematically searched on Embase, PubMed, Central, Cochrane Library, China National Knowledge Infrastructure and Wanfang databases. A total of 84 studies were retrieved and seven were included in the present meta-analysis. Literature quality was assessed using the Cochrane systematic review methodology. After data extraction, meta-analysis was performed using the ReviewManager 5.4 software. Meta-analysis showed that, compared with that in the PEEK cage group, the Ti-PEEK cage group showed a higher interbody fusion rate at 6 months postoperatively (95% CI, 1.09-5.60; P=0.03) and improved Oswestry Disability Index (ODI) scores at 3 months postoperatively [95% CI, -7.80-(-0.62); P=0.02] and visual analog scale (VAS) scores of back pain at 6 months postoperatively [95% CI, -0.8-(-0.23); P=0.0008]. However, there were no significant differences in intervertebral bone fusion rate (12 months after surgery), cage subsidence rate, ODI score (6 and 12 months after surgery) or VAS score (3 and 12 months after surgery) between the two groups. The results of the meta-analysis showed that the Ti-PEEK group had an improved interbody fusion rate and higher postoperative ODI score in the early postoperative period (≤6 months).

Keywords: lumbar interbody fusion; meta-analysis; titanium-coated polyetheretherketone.

Figure 1

Flow diagram of study identification and selection.

Figure 2

Forest plots of studies evaluating bone fusion rates in the Ti-PEEK vs. the PEEK group at 6 and 12 months postoperatively. Odds ratio values are shown as boxes, 95% CIs are shown as horizontal lines and the combined effect size results are shown as black diamonds. Positive effects represent higher rates of bone fusion in patients with Ti-PEEK cages placed after lumbar fusion and negative effects represent higher rates of bone fusion in patients with PEEK cages placed after lumbar fusion. Ti-PEEK, titanium coated polyetheretherketone; M-H, Mantel-Haenszel.

Figure 3

Forest plot of cage sedimentation rates in the Ti-PEEK group vs. PEEK group from 6-12 months postoperatively. Odds ratio values are shown as boxes, 95% CIs are shown as horizontal lines and the combined effect size results are shown as black diamonds. Positive effects represent lower cage sedimentation rates in patients with Ti-PEEK cages placed after lumbar fusion; negative effects represent lower cage sedimentation rates in patients with PEEK cages placed after lumbar fusion. Ti-PEEK, titanium coated polyetheretherketone; M-H, Mantel-Haenszel.

Figure 4

Forest plot of Oswestry Disability Index scores in the Ti-PEEK vs. PEEK group postoperatively (3, 6 and 12 months). Odds ratio values are shown as boxes, 95% CIs are shown as horizontal lines and the combined effect size results are shown as black diamonds. Positive effects represent better postoperative functional recovery in patients with Ti-PEEK cages placed after lumbar fusion, and negative effects represent better postoperative functional recovery in patients with PEEK cages placed after lumbar fusion. ODI, Oswestry Disability Index; Ti-PEEK, titanium coated polyetheretherketone; M-H, Mantel-Haenszel.

Figure 5

Forest plots of visual analog scale scores for lower back pain in the Ti-PEEK group versus the PEEK group postoperatively (3, 6 and 12 months). Odds ratio values are shown as boxes, 95% CIs are shown as horizontal lines and the combined effect size results are shown as black diamonds. Positive effects represent better postoperative lower back pain symptom relief in patients with Ti-PEEK cages placed after lumbar fusion and negative effects represent better postoperative lower back pain symptom relief in patients with PEEK cages placed after lumbar fusion. VAS, visual analog scale; Ti-PEEK, titanium coated polyetheretherketone.

Figure 6

Funnel plot of outcome indicators. The horizontal axis is the effect size, the vertical axis is the SE and the vertical midline indicates the combined OR. Each sample is represented by a graph in the figure and the basic symmetry and concentrated distribution of samples on both sides of the vertical midline in the figure indicates the absence of significant publication bias. (A) Bone fusion rate (6 and 12 months postoperatively). (B) Cage sedimentation rate (6-12 months postoperatively). (C) Postoperative Oswestry Disability Index score (3, 6 and 12 months postoperatively). (D) Postoperative lower back pain visual analog scale scores (3, 6 and 12 months postoperatively). OR, odds ratio; MD, mean difference.