Three-dimensional patient-specific implants for cranioplasty: a systematic review of clinical outcomes, complications, workflow, and cost

BACKGROUND: Three-dimensional (3D) imaging, computer-aided design, and additive manufacturing have enabled patient-specific implants for individualized cranial reconstruction. However, evidence remains heterogeneous regarding materials, indications, study designs, and comparators. This study aimed to systematically evaluate clinical outcomes, complications, anatomical and cosmetic results, operative characteristics, and economic considerations associated with 3D-manufactured patient-specific cranioplasty implants. METHODS: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in PROSPERO (CRD42023486538). MEDLINE (PubMed), Scopus, and Web of Science were searched from inception to May 31, 2026. Eligible studies evaluated 3D-prototyped or 3D-manufactured patient-specific implants for cranial defect reconstruction. Two reviewers independently performed study selection and data extraction. Risk of bias was assessed using Joanna Briggs Institute critical appraisal tools. Due to substantial heterogeneity, findings were synthesized narratively. RESULTS: Of 128 records identified, 48 articles underwent full-text assessment and 36 studies were included. Evidence comprised retrospective comparative studies, case series, technical reports, and clinical reports involving titanium, polyetheretherketone, polymethylmethacrylate, calcium-phosphate-based materials, and other constructs. Patient-specific implants generally demonstrated favorable anatomical conformity and cosmetic outcomes, with some studies reporting reduced intraoperative modification and operative time. However, complication outcomes were inconsistent and influenced by patient, surgical, material, and follow-up characteristics. Economic findings were heterogeneous. CONCLUSION: 3D patient-specific implants are a feasible option for complex cranial reconstruction and precise contour restoration. However, current evidence does not establish universal superiority over autologous bone or other alloplastic materials. Larger prospective comparative studies with standardized clinical and economic outcomes are warranted.