Analysis of Cranioplasty Using Frozen Autologous Bone Following Post-Traumatic Decompressive Craniectomy

Objective: We conducted this study to evaluate outcome of delayed cranioplasty using frozen autologous bone flap following decompressive craniectomy in patients with traumatic brain injury. Methods: In 27 patients, 30 sites have undergone cranioplasty using frozen autologous bone flaps in the past 3 years. After decompressive craniectomy, bone flaps were stored at -40°C for 3 to 316 days (mean, 55.6 days). Bone flaps were thawed at room temperature before cranioplasty and repositioned. Serial follow-up of skull x-ray and/or computed tomography was performed to monitor bony resorption and other complications. Follow-up periods ranged from 9 to 46 months (mean, 20 months). Results: There was no surgically related complications. In 9 sites (30%), potoperative bone resorption was noted. Among them 3 sites underwent ventriculoperitoneal shunt (VPS) with multiple skull fractures and 2 sites underwent VPS without multiple skull fractures and 2 sites was with multiple bone fracture alone. In 7 sites with multiple skull fractures, resorption developed in 4 sites (57.1%) and 5 sites (83.3%) had resorption out of 6 sites with VPS. However, the aesthetic results were not dissatisfactory and a second cranioplasty was not indicated. Conclusion: Cranioplasty using frozen autologous bone following post-traumatic decompressive craniectomy is associated with a high incidence of bone resorption, especially in patients with multiple skull fracture or VPS, even though the aesthetic results were not dissatisfactory. The most important factor for successful bone union was manipulation of bone flap in cranioplasty to facilitate bone resorption followed by accretion. Further improvements are required to perform cranioplasty in patients with VPS. (J Kor Neurotraumatol Soc 2010;6:13-17)