VP14: Long-Term Explantations and Complications of Autologous Heterotopic Bone Graft Versus Alloplastic Cranioplasties: A Systematic Review and Metaanalysis

Abstract

INTRODUCTION: When immediate autologous bone replacement is not possible following cranioplasty, autologous reconstruction may occur via delayed replacement with banked or grafted fresh heterotopic autologous bone, or alloplastic implants composed of polyetheretherketone (PEEK), polymethylmethacrylate (PMMA), or titanium. In this work, we performed a systematic review and meta-analysis evaluating long-term cranioplasty outcomes of fresh, heterotopic autologous bone versus alloplastic materials. MATERIALS AND METHODS: A systematic review was conducted on PubMed for studies published between March 1971 and December 2020. Inclusion criteria consisted of a mean follow-up ≥12 months. Exclusion criteria included reporting craniosynostosis, and cranial vault remodeling. Extracted variables included patient demographics, operative details, and proportions of explantations and complications. We performed a random effects meta-analysis model and a mixed effects meta-regression model to compare pooled proportions of explantations and complications for each material. RESULTS: Thirty articles met the inclusion criteria totaling 109 autologous and 1130 alloplastic patients, averaging a 31.49±20.70 month follow-up, 37.33±13.50 years of age, and 61.26±33.25 cm2 defect size. Compared to bone, there were greater proportions of explantations for PMMA (Point Estimate (PE)=1.56, 95%C.I.=0.24–2.88, p=0.02) and of complications for PMMA (PE=2.04, 95%C.I.=0.62–3.47, p<0.01) and titanium (PE=1.64, 95%C.I.=0.25–3.03, p=0.02). When follow-up was included as an independent variable (PE=-0.02, 95%C.I=-0.04–-0.01, p=0.01), PEEK exhibited greater proportions of complications compared to bone (PE=1.78, 95%C.I.=0.27–3.29, p=0.02). CONCLUSION: Our findings suggest that compared to bone, PMMA and titanium exhibited greater proportions of explantations meanwhile all included alloplastic materials exhibited greater proportions of complications, decreasing by 2% with every month of follow-up.