Complications and Failures of Autologous Heterotopic Cranial Bone versus Alloplastic Cranioplasties

Abstract

Background: Fresh autologous cranial bone graft has traditionally been regarded as the ideal cranioplasty material; however, long-term comparisons of outcomes with modern alloplastic materials are absent in the literature. The authors evaluated complications and failures among cranioplasties performed with fresh, heterotopic, cranial bone graft versus 3 common alloplastic materials.

Methods: Random-effects meta-analyses of logit-transformed proportions were performed on studies published between 1971 and 2021 to evaluate complications and failures of cranioplasties performed with fresh, autologous, heterotopic cranial bone; polyetheretherketone (PEEK); polymethylmethacrylate (PMMA); or titanium with a mean follow-up of 12 months or more. Generalized mixed model meta-regressions were performed to account for heterogeneity and to evaluate the contributions of moderators to outcomes variables.

Results: A total of 1490 patients (mean age, 33.9 ± 10.8 years) were included. Pooled, all-cause complications were 6.2% for fresh, heterotopic, autologous cranial bone (95% CI, 2.1% to 17.0%; I2 = 55.0; P = 0.02), 18.5% for PEEK (95% CI, 14.0% to 24.0%; I2 = 0.0%; P = 0.58), 26.1% for titanium (95% CI, 18.7% to 35.1%; I2 = 60.6%; P < 0.01), and 28.4% for PMMA (95% CI, 12.9% to 51.5%; I2 = 88.5%; P < 0.01). Pooled all-cause failures were 2.2% for fresh autologous cranial bone (95% CI, 0.4% to 10.6%; I2 = 0.0%; P = 0.45), 6.3% for PEEK (95% CI, 3.2% to 12.3%; I2 = 15.5%; P = 0.31), 11.4% for titanium (95% CI, 6.7% to 18.8%; I2 = 60.8%; P < 0.01), and 12.7% for PMMA (95% CI, 6.9% to 22.0%; I2 = 64.8%; P < 0.01). Meta-regression models indicated that each alloplastic subtype significantly and independently predicted higher complications, whereas titanium and PMMA were significant predictors for all-cause failures compared with autologous bone. All 3 subtypes were predictive of higher cranioplasty failures secondary to infection compared with autologous bone.

Conclusion: Cranioplasties performed with fresh, autologous, heterotopic cranial bone grafts resulted in lower complication and failure rates compared with alloplastic materials.