History of Cranial Surgery in World War I: Experience on the Italian Front.

Since ancient history, men have been attempting to intervene when skull trauma occurs. The majority of traumas were always linked to war injuries, and in the modern era, the culprit was reached during World War I. Cranial traumas in wartime were very common, and consequently, physicians in wartime became particularly interested in the subject of cranial traumatology. In the following text, we want to bring to light the experience of some of the pioneers of cranial surgery in Italy during the First Great War. In fact before the war, very few medical officers had received training in central nervous system surgery. In addition, the surgical instruments for that clinical activity were inadequate and obsolete, but to deal with the medical emergency that had arisen on the front lines, the Italian government established Battlefield Medical Schools. And it is also from the reports and lectures of surgeons working on the front lines that the next generations of neurosurgeons were able to develop this surgical field into the complex and well-established surgical specialty that it is today.

Craniotomy Burr Hole Covers: A Comparative Study of Biomechanical, Radiological, and Aesthetic Outcomes Using 3 Different Plug Materials.

Burr holes in the cranial vault are usually made during trephination for craniotomy or drainage of chronic subdural hematomas. The resulting cranial defect might bring to unsatisfactory esthetic outcome. In the current study the authors report clinical data regarding a cohort of patients who were treated with 3 different types of burr hole covers; autologous bone dust from skull trephination, and 2 different types of cylindric plug made out of porous hydroxyapatite in order to evaluate medium and long-term esthetic and radiological outcomes. Twenty patients were consecutively enrolled in the study and in each patient all 3 types of materials were used to cover different holes. Clinical and radiological outcomes at 6 and 12 months, were analyzed for all 3 types of plugs in terms of thickness of the graft coaptation of margins, remodeling, fractures, mobilization, and contour irregularities. In all craniotomy holes filled with autologous bone dust the authors have observed partial or complete bone reabsorption at 1 year and in 60% of the cases a visible and palpable cranial vault contour irregularity was reported. Both types of bone substitutes gave satisfactory results, comparable to autologous bone dust at 6 months and superior at 12 months, especially in terms of thickness and esthetic appearance. Hydroxyapatite plugs have shown better esthetic and biomechanical results and higher patients' satisfaction compared to autologous bone dust while not giving any additional complications.

Ceramic bone graft substitute (Mg-HA) in spinal fusion: A prospective pilot study.

Background: Iliac crest bone graft (ICBG) is considered the gold standard for spine surgical procedures to achieve a successful fusion due to its known osteoinductive and osteoconductive properties. However, complications related to harvesting procedure and donor site morbidity have been largely reported in the literature, favoring the development of a wide range of alternative products to be used as bone graft extenders or substitutes for spine fusion. Among all, ceramic-based biomaterials have been widely studied and employed in the last years as bone graft substitutes. Methods: We report here the results of a prospective pilot study aimed to evaluating the grade of ossification obtained by the use of an Mg-doped hydroxyapatite (HA) product to achieve postero-lateral fusion in degenerative spine diseases. Results: Results show a successful degree of fusion of about 62% at the 12-month follow-up and an improvement of quality of life and health status following surgery, as evaluated by clinical scores (ODI, VAS, and EQ-5L). No adverse events related to the material were reported. Conclusion: The present pilot study shows the effectiveness and the safety profile of an Mg-doped HA bone graft substitute used to achieve postero-lateral fusion in the treatment of degenerative spine diseases, laying down the basis for further larger clinical investigations.

The Antibiotic Immersion of Custom-Made Porous Hydroxyapatite Cranioplasty: A Multicentric Cohort Study.

ABSTRACT: Cranioplasty is a common neurosurgical procedure performed to reconstruct cranial defects. The most common cranioplasty materials used today can be divided into 2 types: autologous bone and bone substitutes, such as polyetheretherketone, titanium mesh, poly-methyl methacrylate, and Hydroxyapatite (HA). Infection represents one of the most feared complications, ranging from 2.3% to 20%. Early implant infections occur within 30 days from the operation and are mostly due to pathogens from the skin and the paranasal cavity. The authors aim to demonstrate the efficacy of our preoperative antibiotic immersion protocol of custom-made HA prosthesis, to prevent early implant infections. The authors compare this population to cranioplasties without preoperative antibiotic elution and those with anonstandardized antibiotic elution. The authors retrospectively analyzed data from patients referred to 6 different hospitals in northern Italy, in the period 2000 to 2020. Inclusion criteria were patients requiring reconstruction of thecal bone with HA prosthesis after post-traumatic decompressive surgery; age more than 18 years; detailed patient history and clinical data; and follow-up of minimum 6 months. A total of 77 cranioplasties were included in the study, along with 120 retrospective cases in comparison. Infections occurred in 2.6% of cranioplasties with antibiotic immersion compared to 7.8% of cranioplasties without. Even if nonsignificant, these results support our hypothesis that pretreatment of HA implants with antibiotic appears to prevent cranioplasty infections and could be a viable option to improve cranioplasty outcomes in the future.

Hydroxyapatite ceramic implants for cranioplasty in children: a retrospective evaluation of clinical outcome and osteointegration.

INTRODUCTION: Cranioplasty in children is a controversial and challenging issue, since there is still no consensus on the ideal material. Main problems in paediatric age are represented by the child's growing skull, the lower bone thickness and the high incidence of cerebrospinal fluid (CSF) disorders or brain swelling. Autologous bone is still considered the "gold standard". When it is not available, a wide range of alloplastic materials have been proposed. Hydroxyapatite, a ceramic-based derivative, bears a chemical composition very similar to the human natural bone, making this material a valuable alternative to other cranioplasty solutions. METHODS: All patients implanted with a custom-made porous hydroxyapatite device at Santobono-Pausilipon Hospital in Naples were retrospectively reviewed. A follow-up CT scan of the skull was performed from 1 up to 48 months postoperatively to document the bone ingrowth as well as the osteointegration process. The bone density was measured as according to the Hounsfield scale at the bone-implant interface. RESULTS: Between 2014 and 2018, 11 patients (7 males, 4 females) underwent cranioplasty with hydroxyapatite ceramic implants (HAP). Patients' age ranged between 3 and 16 years old. Initial aetiology was trauma in most cases. Two subjects were implanted with HAP as primary cranioplasty, 9 as revision surgery following previous cranioplasty failure. Sites of the cranial defect were unilateral fronto-temporo-parietal (N = 8), unilateral frontal (N = 1) and bifrontal (N = 2). Two patients with large bilateral defects received two prostheses. In one of these, the two prostheses were explanted and replaced with two back-up implants (accounting for a total of 15 implants in 11 patients). Osteointegration was measurable for 12 out of 15 implanted devices. The mean percentage was about 51%. There were six asymptomatic prosthesis fractures (40%), all occurring within 6 months from implant. In one case, the bifrontal prostheses were explanted and replaced. This was the only patient who underwent revision surgery. CONCLUSION: Hydroxyapatite ceramic implants represent a valid alternative to other cranioplasty solutions. Where coaptation occurs correctly, with good osteointegration, implant mechanical resistance increases over time.

Custom-made hydroxyapatite for cranial repair in a specific pediatric age group (7-13 years old): a multicenter post-marketing surveillance study.

BACKGROUND: CustomBone Service (CBS) is a patient-specific, biocompatible, and osteoconductive device made of porous hydroxyapatite, indicated for cranial reconstruction in adults and children. Adult literature data report a failure rate of about 8%. The aim of this Post-Marketing Surveillance study is to verify the hypothesis that CBS in children aged 7-13 years old shows a failure rate not superior to adults. MATERIALS AND METHODS: Inclusion criteria were age at implantation ranging 7-13 years old, with at least 1 year elapsed from the date of surgery. The degree of satisfaction of surgeons and patients was assessed. RESULTS: Data about 76 implants in 67 patients (M:F = 41:26) were obtained from 28 centers across 7 European countries. The mean age at surgery was 10.03 ± 1.72 years, with age stratification almost equally distributed. Fifty-nine subjects received one CBS, 7 subjects two and one subject received three CBS. Main etiologies were trauma (60.5%), malformation (11.8%), bone tumor (10.5%), and cerebral tumor (7.9%). Main indications to CBS were decompression (47.4%), autologous bone resorption (18.4%), tumor resection (11.8%), malformation (9.2%), comminuted fracture (5.3%), and other materials rejection (5.3%). Main implantation sites were fronto-parieto-temporal (26.3%), parietal (23.7%), frontal (11.8%), fronto-temporal (10.5%), and parieto-temporal (7.9%). CBS was chosen as first line of treatment in 63.1% of the cases. Mean follow-up was about 36 months. Eleven adverse events (14.5%) were reported in nine devices. Five CBS required explantation (three cases of infection, one fracture, and one mobilization). Failure rate was 6.58%, which is statistically not superior to the explantation rate recorded in adults (two-sided 95%, CI 2.2-14.7%). Satisfaction of surgeons and patients was of about 95%. CONCLUSION: CBS is a safe and effective solution for cranial repair in pediatric patients. In particular, over the age of 7, CBS shows a rate of failure as low as in adults.

A new bioinspired collagen-hydroxyapatite bone graft substitute in adult scoliosis surgery: results at 3-year follow-up.

BACKGROUND: Spinal fusion is a common procedure used for surgical treatment of spinal deformity. In recent years, many bone graft substitutes (BGS) have been developed to provide good arthrodesis when the available autologous bone harvested from the patient is not enough. The aim of this study was to analyze the use of a new-generation composite material (RegenOss) made of Mg-hydroxyapatite nanoparticles nucleated on type I collagen to obtain long posterolateral fusion in adult scoliosis surgery. METHODS: A total of 41 patients who underwent spinal fusion for the treatment of adult scoliosis were retrospectively analyzed. According to Lenke classification, visual analog scale (VAS) score and Oswestry Disability Index (ODI) score, radiographic rates of bone union were evaluated before surgery and at 6, 12 and 36 months of follow-up. Fusion was considered to be successful when criteria for Lenke grade A or B were satisfied. Patient-related risk factors were considered for the evaluation of the final outcome. RESULTS: At 36-month follow-up, radiographic evidence of spinal fusion was present in the majority of patients (95.1%). A time-dependent statistically significant improvement was evidenced after surgery for all clinical outcomes evaluated. Based on the demographic data collected, there were no statistically significant factors determining fusion. The correction of deformity was maintained at different time points. No intraoperative or postoperative complications were recorded. CONCLUSIONS: The present study demonstrated that RegenOss can safely be used to achieve good arthrodesis when associated with autologous bone graft to obtain long spinal fusion in the treatment of adult scoliosis.

Osteointegration in cranial bone reconstruction: a goal to achieve.

BACKGROUND: The number of cranioplasty procedures is steadily increasing, mainly due to growing indications for decompressive procedures following trauma, tumor or malformations. Although autologous bone is still considered the gold standard for bone replacement in skull, there is an urgent need for synthetic porous implants able to guide bone regeneration and stable reconstruction of the defect. In this respect, hydroxyapatite scaffolds with highly porous architecture are very promising materials, due to the excellent biocompatibility and intrinsic osteogenic and osteoconductive properties that enable deep bone penetration in the scaffold and excellent osteointegration. Osteointegration is here highlighted as a key aspect for the early recovery of bone-like biomechanical performance, for which custom-made porous hydroxyapatite scaffolds play a major role. There are still very few cases documenting the clinical performance of porous scaffolds following cranioplasty. METHODS: This paper reports 2 clinical cases where large cranial defects were repaired by the aid of porous hydroxyapatite scaffolds with customized shapes and 3D profiles (Fin-Ceramica, Faenza, Italy). RESULTS: In the long term (i.e., after 2 years), these scaffolds yielded extensive osteointegration through formation and penetration of new organized bone. CONCLUSIONS: These results confirm that porous hydroxyapatite scaffolds, uniquely possessing chemico-physical and morphological/mechanical properties very close to those of bone, can be considered as a tool to provide effective bone regeneration in large cranial bone defects. Moreover, they may potentially prevent most of the postsurgical drawbacks related to the use of metal or plastic implants.

The efficacy of custom-made porous hydroxyapatite prostheses for cranioplasty: evaluation of postmarketing data on 2697 patients.

PURPOSE: Cranioplasty is a surgical intervention aimed at reestablishing the integrity of skull defects. Autologous bone is still considered the treatment of choice for cranioplasty. The aims of this study were to characterize and evaluate the efficacy of porous hydroxyapatite (HA) to fill skull defects based on its biomimetic characteristics. METHODS: The authors analyzed the postmarketing data of all patients treated with custom-made porous HA prostheses (CustomBone Service). Characterization data in terms of physicochemical analysis and mechanical performance of the porous HA prostheses were also reported. RESULTS: The low incidence of adverse events (5.72%) due to the use of HA porous custom-made prostheses for cranioplasty is related to the biomimetic performance of the prostheses. The composition and morphology of the porosity enable it to be a useful biomimetic prosthesis for the reconstruction of large and complex skull defects, also able to promote osteointegration. CONCLUSIONS: These collected and analyzed data demonstrate that porous HA is a suitable material to produce custom-made prostheses to repair craniolacunia. It is a biomimetic implant well-tolerated in both adult and pediatric patients and has been shown to be an effective and good alternative for cranial reconstruction.

Post-marketing surveillance of CustomBone Service implanted in children under 7 years old.

BACKGROUND: The CustomBone Service is a bioceramic implant suitable for cranial repair in both adults and children, although there are no clinical data about its use in children under 7 years of age. This surveillance study investigates the outcome in this age group. METHOD: Twenty-eight children under 7 years old (range, 2.5-6 years) received CustomBone Service from July 2006 to May 2013 in 16 international hospitals. Data of 23 children (12 males and 11 females), harboring 24 prosthesis, were available with a minimum follow-up of 1 year. FINDINGS: Sites of the cranial defect were frontal or parietal (20.8 % each), parieto-temporal (16.7 %), fronto-parietal or occipital (12.5 % each), fronto-parieto-temporal or fronto-temporal (8.3 % each). Initial diseases were trauma (54.2 %), malformation (37.5 %), or tumor of the bone/skin (8.3 %). Rupture of the implant occurred in a single case during the implant (1/26 surgeries, 3.8 %) and the cranial repair was achieved by means of the back-up prosthesis. Five adverse events were registered during the follow-up period consisting of three cases of fracture and two of exposure/infection of the prosthesis. All cases required the removal of the device (20.8 %). CONCLUSIONS: The failure rate of CustomBone Service under 7 years of age was higher than reported in adults and children over 7 years old (20.8 vs. 3.8 %), However, CustomBone Service may be considered a valid option under 7 years old since other materials are burdened by more significant rates of complications in the long-term period. Due to specific properties of this material, indication to CustomBone Service in toddlers should be carefully evaluated by the surgeon on a case-by-case basis.