Stability of cranial defect size following decompressive craniectomy for traumatic brain injury in the pediatric population: A retrospective study.

Cranial defects are common sequelae of decompressive craniectomy (DC) for traumatic brain injury (TBI) in pediatric patients, and their long-term growth dynamics remain poorly understood. This study aims to evaluate cranial defect size and its pattern of change with age following DC for TBI in the pediatric population. This single-center retrospective study included pediatric patients who underwent DC for TBI and later returned for cranioplasty (CP). Cranial defect size was evaluated at three time points-DC, CP, and follow-up-using multiple morphological measurements, including circumference, sectional area, and volume. Additionally, a control group of 208 individuals under 22 years of age was used to establish an intact skull growth curve. Cranial defect measurements, assessed through circumference, sectional area, and volume at three time points, showed no statistically significant changes (p = 0.54, 0.19, and 0.59), indicating stability with age. Subgroup analysis by implant material (autologous bone, titanium, and PEEK) also revealed no significant differences in defect morphology. The defective skull, defined as the cranial bones excluding the defect area, exhibited significant growth over time. Additionally, the intact skull growth curve, derived from the control group, exhibited a segmented pattern with three distinct growth phases: rapid growth during the first 5 years, followed by slower growth in the next 5 years, and a period of accelerated growth from age 11 onwards, with stabilization of skull volume at approximately 430 cm³ after age 17. This study provides novel insights into the stability of cranial defect size following DC for TBI in the pediatric population. The results suggest that, despite ongoing skull growth, cranial defect size remains stable with age, regardless of implant material. Furthermore, the study contributes a growth curve for the intact skull, offering valuable reference data for clinical decision-making in pediatric cranioplasty.