Extensive skull ossification after decompressive craniectomy in an elderly patient: A case report and literature review

RATIONALE: After severe traumatic brain injury, patients often present with signs of increased intracranial hypertension and partially require decompressive craniectomies. Artificial materials are usually required to repair skull defects and spontaneous skull ossification is rarely observed in adults. PATIENT CONCERNS: This study reported a 64-year-old man was admitted to the hospital with a coma due to a traffic accident. DIAGNOSIS: Emergency computed tomography (CT) examination upon admission showed a left temporo-occipital epidural hematoma with a cerebral hernia and skull fracture. INTERVENTIONS: The patient underwent urgent craniotomy for hematoma removal and decompression under general anesthesia. The patient was discharged after 1 month of treatment. OUTCOMES: The patient returned to the hospital for skull repair 145 days after the craniotomy. Pre-operative CT showed island skull regeneration in the skull defect area; therefore, skull repair was postponed after clinical evaluation. Regular follow-up is required. Twenty-three months after surgery, head CT showed that the new skull had completely covered the defect area. LESSON: We collected other 11 similar cases of spontaneous human skull regeneration in a literature search to analyze the possible factors impacting skull regeneration. The analysis of the cases indicated that maintaining the integrity of the periosteum, dura, and blood vessels during craniotomy may play an important role in skull regeneration. Skull regeneration predominantly occurs in young patients with rapid growth and development; therefore, an appropriate postponement of the cranioplasty time under close monitoring could be considered for young patients with skull defects.