Infection rates following custom-made cranioplasty using heterologous materials: insights from a systematic review on 3260 patients with a focus on follow-up length.

introductionCustom-made cranioplasty can be performed using various heterologous materials, each associated with a distinct complication profile. This systematic review focuses on infections, the most common complication following cranioplasty. MATERIALS AND

methodsA systematic review of the available literature was conducted to identify infection and explantation rates associated with materials used in custom-made heterologous cranioplasty. A comprehensive search of PubMed/MEDLINE, Scopus, and Embase databases yielded 3437 articles. After screening, 43 articles met the inclusion criteria and data on study parameters, patient populations, and infection characteristics were extracted.

resultsForty-three articles were selected and included in this review, analyzing a total of 3260 implanted cranioplasties, divided by material as follows: 931 titanium, 1227 hydroxyapatite, 680 PMMA, 379 PEEK, and 143 composites. The cumulative infection and explantation rates were: 8.2% and 3.7% for titanium, 6.7% and 5.3% for hydroxyapatite, 14.9% and 6.1% for PMMA, 11.1% and 3.8% for PEEK, and 4.2% and 6.2% for composites. Importantly, the follow-up duration varied significantly among materials. Studies involving titanium and composites had the shortest follow-up, potentially underestimating infection rates, while studies on PMMA and hydroxyapatite had the longest follow-up, providing more robust estimates.

conclusionsThis review confirms general trends in infection rates among cranioplasty materials and emphasizes the critical role of follow-up duration in interpreting complication rate. Differences in study design and reporting standards limit direct comparison between materials. Future research should adopt standardized follow-up thresholds and uniform outcome definitions to enable reliable cross-material comparisons.