The use of hydroxyapatite cranioplasties has grown progressively over the past few decades. The peculiar biological properties of this material make it particularly suitable for patients with decompressive craniectomy where bone reintegration is a primary objective. However, hydroxyapatite infection rates are similar to those of other reconstructive materials. We investigated if infected hydroxyapatite implants could be saved or not. We present a consecutive series over a 10-year period of nine patients treated for hydroxyapatite cranioplasty infection. Clinical and radiological data from admission and follow-up, photo and video material documenting the different phases of infection assessment and treatment, and final outcomes were retrospectively reviewed in an attempt to identify the best options and possible pitfalls in a case-by-case decision-making process. Five unilateral and four bifrontal implants became infected. Wound rupture with cranioplasty exposure was the most common presentation. At revision, all implants were ossified, requiring a new craniotomy to clean the purulent epidural collections. The cranioplasty was fully saved in one hemispheric and 2 bifrontal implants and partially saved in the remaining 2 bifrontal implants. A complete cranioplasty removal was needed in the other 4 cases, but immediate cranial reconstruction was possible in 2. Skin defects were covered by free flaps in 3 cases. Four patients underwent adjunctive hyperbaric therapy, which was effective in one case. In our experience, infected hydroxyapatite cranioplasty management is complex and requires a multidisciplinary approach. Salvage of a hydroxyapatite implant is possible under specific circumstances.

Background: Decompressive craniectomy (DC) is still controversial in neurosurgery. According to the most recent trials, DC seems to increase survival in case of refractory intracranial pressure. On the other hand, the risk of postsurgical poor outcomes remain high. The present study aimed to evaluate a series of preoperative factors potentially impacting on long-term follow-up of traumatic brain injury (TBI) patients treated with DC. Methods: We analyzed the first follow-up year of a series of 75 TBI patients treated with DC at our department in five years (2015–2019). Demographic, clinical, and radiological parameters were retrospectively collected from clinical records. Blood examinations were analyzed to calculate the preoperative neutrophil-to-lymphocyte ratio (NLR). Disability rating scale (DRS) was used to classify patients’ outcomes (good outcome [G.O.] if DRS ≤11 and poor outcome [P.O.] if DRS ≥12) at 6 and 12 months. Results: At six months follow-up, 25 out of 75 patients had DRS ≤11, while at 12 months, 30 out of 75 patients were included in the G.O. group . Admission Glasgow Coma Scale (GCS) >8 was significantly associated with six months G.O. Increased NLR values and the interval between DC and cranioplasty >3 months were significantly correlated to a P.O. at 6- and 12-month follow-up. Conclusion: Since DC still represents a controversial therapeutic strategy, selecting parameters to help stratify TBI patients’ potential outcomes is paramount. GCS at admission, the interval between DC and cranioplasty, and preoperative NLR values seem to correlate with the long-term outcome.