146. Structural allograft vs polyetheretherketone (PEEK) implants in patients undergoing spinal fusion surgery: a systematic review and meta-analysis

BACKGROUND CONTEXT Interbody spacers have been successfully used in spinal fusion procedures with the aim to restore disc height, provide stability and promote the bone fusion. PURPOSE The authors aimed to evaluate the efficacy of structural body allograft vs polyetheretherketone (PEEK) implants in patients undergoing spinal fusion surgery. STUDY DESIGN/SETTING We conducted a systematic review of the electronic databases using different MeSH terms from January 1970 to August 2019. PATIENT SAMPLE A total of 6,640 patients (structural allograft: 64% and PEEK cage: 36%) from 7 comparative studies were included in our analysis. OUTCOME MEASURES Outcome parameters included subsidence rate, mean change in lordotic angle, pseudarthrosis, reoperation, fusion rates and patient reported outcome measures. METHODS Pooled and sub-group analysis were performed using the random and fixed effect model based upon the I2 heterogeneity. RESULTS There was no statistically significant difference in terms of age (p=0.27), gender (p=0.31), body mass index (p=0.82) and smoking status (p=0.27) between the two groups. Overall, the mean follow-up was 12.9 ±1.5 months. Pooled meta-analysis revealed that patients with structural allograft had a 2.59-fold higher likelihood of fusion rates compared to patients with PEEK cages (OR: 2.59, 95% CI:1.02-6.57, p=0.05) at the last follow-up evaluation. Furthermore, patients with structural allograft had 61% less likelihood of pseudarthroses (OR: 0.39, 95%CI: 0.15-0.98, p=0.05) and 74% lower incidence of reoperation compared to patients with PEEK implants (OR:0.26, 95% CI:0.09-0.79, p=0.02). Although our results suggest that patients with structural allografts had a higher subsidence rate compared to PEEK implants, but it was statistically insignificant (OR:1.07, 95% CI: 0.45-2.53, p=0.89). CONCLUSIONS Our results corroborate that structural allografts are highly effective in promoting bony fusion compared to PEEK implants in patients undergoing spinal fusion surgery. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.