Long-term outcomes following custom-made porous hydroxyapatite cranioplasty: a single-center experience of 234 consecutive cranioplasty procedures.

Custom-made porous hydroxyapatite cranioplasty is widely used for reconstruction of cranial defects after decompressive craniectomy and in other clinical settings, such as postoperative surgical site infection or perioperative brain oedema, but its long-term complications remain poorly characterized. Understanding the durability of custom-made porous hydroxyapatite cranioplasty will help refine surgical decision-making and postoperative follow-up. Retrospective analysis of 234 consecutive custom-made porous hydroxyapatite cranioplasty procedures performed in 217 patients at a single tertiary neurosurgical center between 2008 and 2025. Surgery-related complications including epidural hematoma, infection, implant fracture, and cranioplasty removal were assessed with Kaplan-Meier survival analysis at one, two, five, 10, and 15 years. Mean follow-up was 7.3 years (range, 0.2-16.8). Cranioplasty removal for any reason occurred in 15.8% of procedures, primarily during the first postoperative year (removal-free survival, 85.7% at one year, 83.8% at 15 years). An epidural hematoma requiring surgical evacuation occurred in 4.7% of procedures, primarily during the first postoperative year (hematoma-free survival, 94.6% at one year, 94.1% at 15 years). A bacterial surgical site infection occurred in 10.7% of procedures, primarily during the first postoperative year (infection-free survival, 89.5% at one year, 88.5% at 15 years). Implant fracture occurred in 2.5% of procedures, primarily during the first three postoperative years and never led to implant removal (fracture-free survival was 98.3% at one year, 97.3% at 15 years). No new complications were observed beyond three postoperative years. Custom-made porous hydroxyapatite cranioplasty demonstrates durable long-term safety. These findings emphasize the importance of close early follow-up, while suggesting minimal risk of late complications.