Hydroxyapatite Cement in Craniofacial Reconstruction

Safety and efficacy of hydroset cranioplasty as an adjunct to gasket-seal and nasoseptal flap closure of the skull base. A case-controlled study

BACKGROUND

Cerebrospinal fluid leak after endoscopic skull base surgery remains a significant complication. Several investigators have suggested Hydroset cranioplasty to reduce leak rates. We investigated our early experience with Hydroset and compared the rate of nasal complications and CSF leak rates with case-controlled historic controls.

METHODS

We queried a prospective database of patients undergoing first time endoscopic, endonasal resection of suprasellar meningiomas and craniopharyngiomas from 2015 to 2023. We compared cases closed with a gasket seal, Hydroset, and a nasoseptal flap with those closed with only a gasket seal and nasoseptal flap. Demographics, technical considerations and postoperative outcomes (SNOT-22) were compared.

RESULTS

Seventy patients met inclusion criteria, twenty patients in the Hydroset group (meningioma n = 12; craniopharyngioma n = 8) and 50 control patients (meningioma n = 25; craniopharyngioma n = 25). CSF diversion was used in fewer Hydroset patients (75%, 15/20) compared with control group (94%, 47/50; p = 0.02). CSF leak was less frequent in the Hydroset than the control group (5% versus 12%, p = 0.38). One Hydroset patient required delayed nasal debridement. SNOT-22 responses demonstrated no significant difference in sinonasal complaints between groups (Hydroset average SNOT-22 score 22.45, control average SNOT-22 score 25.90; p = 0.58).

CONCLUSIONS

We demonstrate that hydroxyapatite reconstruction leads to improved CSF leak control above that provided by the gasket-seal and nasoseptal flap, without significant associated morbidity as long as the cement is fully covered with vascularized tissue.

Management of Complications and Secondary Deformity After Fractures of the Midface, Orbit, and Upper Third of the Maxillofacial Skeleton

Craniomaxillofacial trauma is a challenging entity to manage effectively and often necessitates serial evaluation and treatment. A multidisciplinary team is best served to evaluate and treat these complex injury patterns with the use of necessary adjuncts, such as neuronavigation, intraoperative imaging, custom implant use, and virtual surgical planning. Complications of facial trauma can present at a spectrum of time points and manifest in a variety of manners and as such patients should be observed closely and longitudinally. Although not all complications and secondary deformities can be avoided, this article highlights some common pitfalls and our unique management strategies.

Frontiers of Cranial Base Surgery: Integrating Technique, Technology, and Teamwork for the Future of Neurosurgery

The landscape of cranial base surgery has undergone monumental transformations over the past several decades. This article serves as a comprehensive survey, detailing both the historical and current techniques and technologies that have propelled this field into an era of unprecedented capabilities and sophistication. In the prologue, we traverse the historical evolution from rudimentary interventions to the state-of-the-art neurosurgical methodologies that define today's practice. Subsequent sections delve into the anatomical complexities of the anterior, middle, and posterior cranial fossa, shedding light on the intricacies that dictate surgical approaches. In a section dedicated to advanced techniques and modalities, we explore cutting-edge evolutions in minimally invasive procedures, pituitary surgery, and cranial base reconstruction. Here, we highlight the seamless integration of endocrinology, biomaterial science, and engineering into neurosurgical craftsmanship. The article emphasizes the paradigm shift towards "Functionally" Guided Surgery facilitated by intraoperative neuromonitoring. We explore its historical origins, current technologies, and its invaluable role in tailoring surgical interventions across diverse pathologies. Additionally, the digital era's contributions to cranial base surgery are examined. This includes breakthroughs in endoscopic technology, robotics, augmented reality, and the potential of machine learning and AI-assisted diagnostic and surgical planning. The discussion extends to radiosurgery and radiotherapy, focusing on the harmonization of precision and efficacy through advanced modalities such as Gamma Knife and CyberKnife. The article also evaluates newer protocols that optimize tumor control while preserving neural structures. In acknowledging the holistic nature of cranial base surgery, we advocate for an interdisciplinary approach. The ecosystem of this surgical field is presented as an amalgamation of various medical disciplines, including neurology, radiology, oncology, and rehabilitation, and is further enriched by insights from patient narratives and quality-of-life metrics. The epilogue contemplates future challenges and opportunities, pinpointing potential breakthroughs in stem cell research, regenerative medicine, and genomic tailoring. Ultimately, the article reaffirms the ethos of continuous learning, global collaboration, and patient-first principles, projecting an optimistic trajectory for the field of cranial base surgery in the coming decade.

Autologous Fat Versus Hydroxyapatite Cement for Use in Frontal Sinus Obliteration: Systematic Review and Meta-Analysis

BACKGROUND

Frontal sinus obliteration is a possible terminus for the management of chronic sinusitis, frontal bone trauma, cancer extirpation, or mucocele. The mucosa of the sinus is stripped and space obliterated with either autogenic, allopathic, or synthetic materials. This study aimed to compare the outcomes of autologous fat and hydroxyapatite cement (HAC) for frontal sinus obliteration.

METHODS

A multidatabase systematic review was conducted to collect outcomes on frontal sinus obliterations with either autologous fat or HAC. Outcomes collected included infection of the frontal sinus or obliteration material, mucocele formation, skin infection at the operative site, hematoma or seroma, cosmetic defect, donor site infection, and need for revision procedure. Prevalence of outcomes was analyzed through meta-analysis of proportions.

RESULTS

Twenty studies were ultimately included in the meta-analysis. Sixteen studies reported outcomes for 667 patients obliterated with autologous fat, and 7 studies reported outcomes for 100 patients obliterated with HAC. Prevalence of infection of the frontal sinus or obliteration material, mucocele formation, skin infection at the operative site, hematoma or seroma, and cosmetic defect did not differ statistically between the cohorts. Donor site infection secondary to fat harvesting for fat obliteration had a prevalence of <0.01. Revision rate was 0.04 (95% confidence interval, 0.01-0.8) for fat obliteration and 0.10 (95% confidence interval, 0.00-0.33) for HAC obliteration.

CONCLUSIONS

No statistically significant differences in the studied outcomes were detected between obliterations with autologous fat and HAC, suggesting that either is equally suitable and may be up to the surgeon's preference.

Bone Graft Substitutes and Enhancement in Craniomaxillofacial Surgery

Critical-sized bone defects are a reconstructive challenge, particularly in the craniomaxillofacial (CMF) skeleton. The "gold standard" of autologous bone grafting has been the work horse of reconstruction in both congenital and acquired defects of CMF skeleton. Autologous bone has the proper balance of the protein (or organic) matrix and mineral components with no immune response. Organic and mineral adjuncts exist that offer varying degrees of osteogenic, osteoconductive, osteoinductive, and osteostimulative properties needed for treatment of critical-sized defects. In this review, we discuss the various mostly organic and mostly mineral bone graft substitutes available for autologous bone grafting. Primarily organic bone graft substitutes/enhancers, including bone morphogenic protein, platelet-rich plasma, and other growth factors, have been utilized to support de novo bone growth in setting of critical-sized bone defects. Primarily mineral options, including various calcium salt formulation (calcium sulfate/phosphate/apatite) and bioactive glasses have been long utilized for their similar composition to bone. Yet, a bone graft substitute that can supplant autologous bone grafting is still elusive. However, case-specific utilization of bone graft substitutes offers a wider array of reconstructive options.

Enhancement of physicochemical characterization of nanocomposites on Ag+/Fe2+ codoped hydroxyapatite for antibacterial and anticancer properties

The synthesis of nanosized Ag+/Fe2+ codoped hydroxyapatite (HAp) nanocomposite materials with antibacterial and anticancer characteristics is highly attractive for advancing the development of biological applications. The objective of this study was to evaluate the antibacterial and anticancer characteristics of Ag+/Fe2+ codoped hydroxyapatite materials. We developed a facile chemical precipitation method for the fabrication of Ag+/Fe2+:HAp nanocomposites. The developed Ag+/Fe2+:HAp nanocomposite materials were characterized with Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM). For measuring the size of Ag+/Fe2+:HAp nanocomposites, dynamic light scattering (DLS) is an advantageous method. The chemical states and chemical composition of Ag+/Fe2+:HAp were observed by X-ray photoelectron spectroscopy (XPS) analysis. In addition, the antibacterial efficacy of Ag+/Fe2+:HAps against Gram-positive (S.aureus), and Gram-negative (S.typhi, and E.Coli) microorganisms is examined in this current study. Ag+/Fe2+:HAp nanocomposite materials have been evaluated for biological toxicity in vitro, and the results showed that the particles were excellent at identifying and killing cancer cells. In this respect, Ag+/Fe2+:HAp nanocomposites significantly impact human colon cancer cells (HT29) while have no effect on normal fibroblast cells (L929).

Biocompatible Materials for Orbital Wall Reconstruction-An Overview

The reconstruction of an orbit after complex craniofacial fractures can be extremely demanding. For satisfactory functional and aesthetic results, it is necessary to restore the orbital walls and the craniofacial skeleton using various types of materials. The reconstruction materials can be divided into autografts (bone or cartilage tissue) or allografts (metals, ceramics, or plastic materials, and combinations of these materials). Over time, different types of materials have been used, considering characteristics such as their stability, biocompatibility, cost, safety, and intraoperative flexibility. Although the ideal material for orbital reconstruction could not be unanimously identified, much progress has been achieved in recent years. In this article, we summarise the advantages and disadvantages of each category of reconstruction materials. We also provide an update on improvements in material properties through various modern processing techniques. Good results in reconstructive surgery of the orbit require both material and technological innovations.

Graded Reconstruction Strategy Using a Multilayer Technique Without Lumbar Drainage After Endoscopic Endonasal Surgery

OBJECTIVE

Sellar reconstruction following endoscopic endonasal surgery (EES) requires modification based on the degree of cerebrospinal fluid (CSF) leak. For high-flow (grade II or III according to Esposito et al. 2007) intraoperative CSF leak, lumbar drainage (LD), in addition to the multilayer closing technique, is generally recommended. However, LD occasionally has complications including postpuncture headache, overdrainage symptoms, and increased length of stay. We retrospectively evaluated the outcome of our graded reconstruction strategy using a multilayer technique with a novel material, without LD, after EES.

METHODS

Ninety-seven patients who underwent EES with grade II or III intraoperative CSF leak between June 2020 and March 2021 were retrospectively reviewed. For grade II CSF leak, fibrin sealant and a nasoseptal flap were placed; for grade III CSF leak, a multilayer technique was used in combination with collagen matrix, an acellular dermal graft, injectable hydroxyapatite (HXA), and a nasoseptal flap. Postoperatively, routine LD was not performed.

RESULTS

This study included 48 (49.5%) grade II and 49 (50.5%) grade III CSF leaks. At follow-up (mean, 8.7 months), no patient showed postoperative CSF leak in either group. No HXA-associated complications occurred.

CONCLUSIONS

A graded surgical repair strategy after EES could avoid postoperative CSF leak. Combined use of injectable HXA and acellular dermal grafts for high-flow CSF leak can limit LD requirement without significant risks.

Craniofacial Bone Tissue Engineering: Current Approaches and Potential Therapy

Craniofacial bone defects can result from various disorders, including congenital malformations, tumor resection, infection, severe trauma, and accidents. Successfully regenerating cranial defects is an integral step to restore craniofacial function. However, challenges managing and controlling new bone tissue formation remain. Current advances in tissue engineering and regenerative medicine use innovative techniques to address these challenges. The use of biomaterials, stromal cells, and growth factors have demonstrated promising outcomes in vitro and in vivo. Natural and synthetic bone grafts combined with Mesenchymal Stromal Cells (MSCs) and growth factors have shown encouraging results in regenerating critical-size cranial defects. One of prevalent growth factors is Bone Morphogenetic Protein-2 (BMP-2). BMP-2 is defined as a gold standard growth factor that enhances new bone formation in vitro and in vivo. Recently, emerging evidence suggested that Megakaryocytes (MKs), induced by Thrombopoietin (TPO), show an increase in osteoblast proliferation in vitro and bone mass in vivo. Furthermore, a co-culture study shows mature MKs enhance MSC survival rate while maintaining their phenotype. Therefore, MKs can provide an insight as a potential therapy offering a safe and effective approach to regenerating critical-size cranial defects.

Nanoparticles and Nanostructured Surface Fabrication for Innovative Cranial and Maxillofacial Surgery

A novel strategy to improve the success of soft and hard tissue integration of titanium implants is the use of nanoparticles coatings made from basically any type of biocompatible substance, which can advantageously enhance the properties of the material, as compared to its similar bulk material. So, most of the physical methods approaches involve the compaction of nanoparticles versus micron-level particles to yield surfaces with nanoscale grain boundaries, simultaneously preserving the chemistry of the surface among different topographies. At the same time, nanoparticles have been known as one of the most effective antibacterial agents and can be used as effective growth inhibitors of various microorganisms as an alternative to antibiotics. In this paper, based on literature research, we present a comprehensive review of the mechanical, physical, and chemical methods for creating nano-structured titanium surfaces along with the main nanoparticles used for the surface modification of titanium implants, the fabrication methods, their main features, and the purpose of use. We also present two patented solutions which involve nanoparticles to be used in cranioplasty, i.e., a cranial endoprosthesis with a sliding system to repair the traumatic defects of the skull, and a cranial implant based on titanium mesh with osteointegrating structures and functional nanoparticles. The main outcomes of the patented solutions are: (a) a novel geometry of the implant that allow both flexible adaptation of the implant to the specific anatomy of the patient and the promotion of regeneration of the bone tissue; (b) porous structure and favorable geometry for the absorption of impregnated active substances and cells proliferation; (c) the new implant model fit 100% on the structure of the cranial defect without inducing mechanical stress; (d) allows all kinds of radiological examinations and rapid osteointegration, along with the patient recover in a shorter time.

A systematic review of cranioplasty material toxicity in human subjects

PURPOSE

Local and systemic toxic reactions to implanted materials can result in morbidities. However, little is reported about cranioplasty implants. Therefore, we performed a systematic review on the toxicity of different materials used for cranioplasty implants.

MATERIALS AND METHODS

A systematic search was conducted by browsing the Pubmed, Embase, and Cochrane Library databases. All human studies that identified toxic (aseptic) reactions to any types of material used as cranioplasty implants or onplants, published up to January 1, 2019, were included in the review.

RESULTS

Nineteen studies were identified. Collectively, 36 patients endured some type of toxic reaction to an implanted material. Eleven studies presented several types of toxicity for PMMA cranioplasties in several tissue types. One article highlighted the risk of neurotoxicity for PMMA cranioplasty. Three articles presented toxic reactions to calcium phosphate and titanium implants. Three additional articles presented toxic reactions to PEEK, polypropylene-polyester, and polyethylene.

CONCLUSION

All materials currently used for cranioplasty showed occasional toxicity and morbidities. Therefore, none can be considered completely biologically inert. We found that aseptic inflammatory reactions have been underreported in the literature due to a high incidence of infections with questionable evidence.

Clinical impact of high-profile animal-based research reported in the UK national press

OBJECTIVES

We evaluated animal-based biomedical 'breakthroughs' reported in the UK national press in 1995 (25 years prior to the conclusion of this study). Based on evidence of overspeculative reporting of biomedical research in other areas (eg, press releases and scientific papers), we specifically examined animal research in the media, asking, 'In a given year, what proportion of animal research "breakthroughs"' published in the UK national press had translated, more than 20 years later, to approved interventions?'

METHODS

We searched the Nexis media database (LexisNexis.com) for animal-based biomedical reports in the UK national press. The only restrictions were that the intervention should be specific, such as a named drug, gene, biomedical pathway, to facilitate follow-up, and that there should be claims of some clinical promise.

MAIN OUTCOME MEASURES

Were any interventions approved for human use? If so, when and by which agency? If not, why, and how far did development proceed? Were any other, directly related interventions approved? Did any of the reports overstate human relevance?

RESULTS

Overspeculation and exaggeration of human relevance was evident in all the articles examined. Of 27 unique published 'breakthroughs', only one had clearly resulted in human benefit. Twenty were classified as failures, three were inconclusive and three were partially successful.

CONCLUSIONS

The results of animal-based preclinical research studies are commonly overstated in media reports, to prematurely imply often-imminent 'breakthroughs' relevant to human medicine.

A Simple Bedside Technique for Quantifying Volumetric Defects Prior to Hydroxyapatite Cranioplasty

Contour irregularities following pediatric craniofacial surgery are common. Hydroxyapatite cranioplasty is a successful technique for optimizing the aesthetic outcome in these patients. We describe a simple technique that can be carried out at the bedside to calculate the volume of hydroxyapatite needed and therefore optimize the preoperative planning for hydroxyapatite cranioplasty.

Use of Onlay Hydroxyapatite Cement for Secondary Cranioplasty

BACKGROUND

Children who undergo bi-fronto-orbital advancement (BFOA) frequently develop a contour deformity on the temporal and supra-orbital region, with an incidence reported as high as 55% and 75%, respectively. Up to 20% of patients may require correction. Hydroxyapatite cement (HAC) is a good alternative to autogenous tissue. The available literature on its use focusses on the reconstruction of bone defects, but little has been published on its efficacy and safety as an onlay graft over intact cranium.

OBJECTIVES

To describe our institution's experience with HAC in the pediatric population.

METHODS

Retrospective chart review from 1998 to 2018 on all patients from the Craniofacial Unit at the Sydney Children's Hospital who had either coronal or metopic craniosynostosis and underwent BFOA and later in life required cranioplasty with HAC for contour repair.

FINDINGS

We have performed 166 BFOA and nineteen secondary cranioplasties for contour repair using onlay HAC. The mean age at the time of operation was 14 years. Bi-coronal craniosynostosis was most frequently associated with secondary cranioplasty and 37% had an associated syndrome. The mean volume of HAC used was 37 mL. There was only 1 patient who had a complication (5.3%) and required partial removal of allograft. The mean length of admission was 2 days. Mean follow up time of 22.4 months.

CONCLUSIONS

HAC represents a safe option when used correctly, with low rates of complication and satisfactory cosmetic outcomes.

Recovery period of sinonasal quality of life and its associated factors after endoscopic endonasal approach for anterior skull base tumors

BACKGROUND

Although endoscopic endonasal approach (EEA) for skull base tumors showed a good prognosis in sinonasal quality of life (QOL), what factors have influence on QOL is still in question. Aim/Objectives: To investigate the recovery of sinonasal QOL after EEA for anterior skull base tumors and find its prognostic factors.

MATERIAL AND METHODS

The study enrolled 250 patients undergoing EEA for anterior skull base tumors over 3 years. Sinonasal QOL was evaluated via sinonasal outcome test (SNOT-22) during 6 months. Age, gender, previous surgery, surgical extent, tumor pathology, combined surgical procedures, and surgical complications were analyzed.

RESULTS

There were 101 male and 149 female with average 48.6 ± 16.1 years old. SNOT-22 increased from baseline (median 17.0; Q₁-Q₃ 8.25-30.0) to postoperative 1 and 3 months (27.0; 15.0-36.0; p   <   .001 and 20.5; 11.0-32.0; p = .021, respectively) and it returned to the baseline within 6 months. Reconstruction with calcium hydroxyapatite and postoperative mucosal edema had a negative impact on the recovery (p  = .016 and .010, respectively), after adjustment for the baseline scores and postoperative months.

CONCLUSIONS AND SIGNIFICANCE

Sinonasal QOL was recovered within 6 months. Avoidance of calcium hydroxyapatite could prevent delayed recovery. Surgeons should carefully manipulate nasal mucosa to minimize postoperative mucosal edema.

Frontal Sinus Fractures: Evolving Clinical Considerations and Surgical Approaches

Frontal sinus fractures are an uncommon injury of the maxillofacial skeleton, and account for 5-15% of all maxillofacial fractures. As the force of impact increases, fractures may extend beyond the anterior table to involve adjacent skull, posterior table and frontal sinus outflow tract (FSOT). Fractures at these subsites should be evaluated independently to assess the need for and type of operative intervention. Historically, these fractures were managed aggressively with open techniques resulting in obliteration or cranialization. With significant injuries, these approaches are still indispensable. However, the treatment of frontal sinus fractures has changed dramatically over the past half-century, and recent case series have demonstrated favorable outcomes with conservative management. Concurrently, there has been an increasing role of minimally invasive endoscopic techniques, both for primary and expectant management, with a focus on sinus preservation. Here, we review the diagnosis and management of frontal sinus fractures, with an emphasis on subsite evaluation. Following a detailed assessment, an appropriate treatment strategy is selected from a variety of open and minimally invasive approaches available in the surgeon's armamentarium.

Complications after craniofacial reconstruction with calcium phosphate cements: a case report and review of the literature

Among different graft materials for craniofacial reconstruction, calcium phosphate cements have the advantages of alloplastic grafts and wide use. The authors report a case of foreign body reaction following frontal reconstruction with JectOS (an injectable calcium orthophosphate cement; Kasios) and reviewed the literature on complications of this material after craniofacial reconstruction from 2002 to 2017. Complications were categorized into two groups: immunologic reactions (consisting of seroma collection, chronic sinus mucosa swelling, and foreign body reaction) and non-immune events (infection, fragmentation, and ejection). It is wise to use calcium phosphate-based material only in selected cases with small defects, and long-term follow-up is needed to observe their consequences.

Synthesizing selenium- and silver-substituted hydroxyapatite-based bone grafts and their effects on antibacterial efficiency and cell viability

Hydroxyapatite (HA)-based biografts with selenium (Se) and silver (Ag) substitutions were synthesized using the sol-gel method. The synthesized HA-based biografts at various Se and Ag quantity ratios (wt%) were characterized via Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-Ray spectroscopy (EDX). Escherichia coli (JM103) and Gram-positive Staphylococcus aureus (ATCC29293) bacteria were used for the cell viability tests by performing the MTT assay. During antibacterial tests, it was determined that the synthesized biografts showed significant antimicrobial activity on E. coli and S. aureus; however, some materials were effective on Gram-negative E. coli, but had no effect on Gram-positive S. aureus. In vitro cell viability tests revealed that some of the synthesized biografts such as H30Ag10Se15 and H40Ag20Se10 provided the highest cell viability rates compared to those in the control group.

Antiviral activity of multifunctional composite based on TiO2-modified hydroxyapatite

An antiviral activity of TiO₂-modified hydroxyapatite composite (HA/TiO₂) had been investigated. The HA/TiO₂ composite (HA50:Ti50) was prepared by a solid state reaction method followed by calcination at 650 °C for 2 h. Phase formations and morphologies of the obtained HA/TiO₂ composite powders were determined using XRD and SEM. XRD result confirmed that HA/TiO₂ composite was successfully prepared. SEM revealed small crystals of anatase TiO₂ embedded in larger HA crystals. A strong antiviral activity against H1N1 Influenza A Virus was observed at 0.5 mg/ml concentration of the composite under the UV irradiation for 60 min. It showed the highest rate of reducing virus titer approximately more than 2 log/h. Results obtained from this study indicated that HA/TiO₂ composite could be a promising material to be used as antimicrobial filtration applications such as in face masks.

Calvarial Reconstruction

Calvarial reconstruction is a challenge to reconstructive surgeons, especially considering protection of intracranial contents. In recent years, the advent of multiple reconstructive materials adds tools to the surgical armamentarium. Options include autologous split calvarial and rib grafts and alloplastic materials such as titanium mesh, methyl methacrylate, calcium hydroxyapatite, and polyetheretherketone. The most important aspect of cranial reconstruction still lies in finding the most aesthetic, safe, and reliable means of filling a defect.

Open Anterior Skull Base Reconstruction: A Contemporary Review

Skull base extirpative and reconstructive surgery has undergone significant changes due to technological and operative advances. While endoscopic resection and reconstruction will continue to advance skull base surgery for the foreseeable future, traditional open surgical approaches and reconstructive techniques are still contemporarily employed as best practices in certain tumors or patient-specific anatomical cases. Skull base surgeons should strive to maintain a working knowledge and technical skill set to manage these challenging cases where endoscopic techniques have previously failed, are insufficient from anatomical constraints, or tumor biology with margin control supersedes the more minimally invasive approach. This review focuses on the reconstructive techniques available to the open skull base surgeon as an adjunct to the endoscopic reconstructive options. Anatomic considerations, factors relating to the defect or patient, reconstructive options of nonvascular grafts, local and regional flaps, and free tissue transfer are outlined using the literature and author's experience. Future directions in virtual surgical planning and emerging technologies will continue to enhance open and endoscopic skull base surgeon's preparation, performance, and outcomes in this continually developing interdisciplinary field.

Cranioplasty of Large Cranial Defects With Porous Polyethylene Implants

BACKGROUND

Reconstruction of cranial defects due to trauma or other causes has been carried out since ages with a wide variety of materials. The aim of reconstruction was mainly to restore cosmesis and protect the brain from further injury. However, recent studies have shown that cranioplasty not only improves the cerebral blood flow but also leads to improvement of cognitive functions. The materials used include autologous bone, allogeneic bone, xenografts, and alloplasts. The search for an ideal material continues. The authors present their experience with cranioplasty using prefabricated porous polyethylene implants.

MATERIALS AND METHODS

Patients requiring cranioplasty for reconstruction of large sized (more than 15 cm in any 1 dimension) cranial defects were selected. Three patients were men and 2 were women. The age group of the patient ranged from 18 to 58 years. Preformed Biopore Hemisphere was used in every patient for cranial reconstruction.

RESULTS

No complications were seen in our patients. One patient who had undergone titanium cranioplasty previously showed remarkable improvement in cognitive functions.

CONCLUSION

Porous polyethylene prefabricated implants are a good restorative material for reconstruction of large cranial defects.

Secondary Reconstruction of Frontal Sinus Fracture

Fractures of frontal sinus account for 5%-12% of all fractures of facial skeleton. Inadequately treated frontal sinus injuries may result in malposition of sinus structures, as well as subsequent distortion of the overlying soft tissue. Such inappropriate treatment can result in aesthetic complaints (contour deformity) as well as medical complications (recurrent sinusitis, mucocele or mucopyocele, osteomyelitis of the frontal bone, meningitis, encephalitis, brain abscess or thrombosis of the cavernous sinus) with potentially fatal outcomes. Frontal contour deformity warrants surgical intervention. Although deformities should be corrected by the deficiency in tissue type, skin and soft tissue correction is considered better choice than bone surgery because of minimal invasiveness. Development of infection in the postoperative period requires all secondary operations to be delayed, pending the resolution of infectious symptoms. The anterior cranial fossa must be isolated from the nasal cavity to prevent infectious complications. Because most of the complications are related to infection, frontal sinus fractures require extensive surgical debridement and adequate restructuring of the anatomy. The authors suggest surgeons to be familiar with various methods of treatment available in the prevention and management of complications following frontal sinus fractures, which is helpful in making the proper decision for secondary frontal sinus fracture surgery.

Infectious Complication Following Midface Reconstruction With Calcified Triglyceride

This case report describes an infectious complication related to the use of calcified triglyceride (Kryptonite Bone Cement) in post-traumatic midface reconstruction. Ultimately, the infected material required removal, and the facial deformity was repaired with subsequent procedures. The literature suggests that bone cement products should be used with caution when in contact with the paranasal sinuses.

Extending the traditional resection limits of squamous cell carcinoma of the anterior skull base

Objective

Preliminary report to evaluate the efficacy of resection of squamous cell carcinomas that demonstrate intracra-nial invasion.

Methods

A retrospective review of all cases of extracranial squamous cell carcinomas that extend intracranially treated by a single surgeon.

Results

A total of 21 cases were reviewed. In 6 cases, there was noted to be overt brain invasion. Complete resection of the intracranial disease was achieved in each of the remaining 15 cases. There were no instances of CSF leak, meningitis, brain abscess, stroke, or other intracranial complication noted either acutely or secondarily. In follow-ups that ranged from 10 months (single patient died of disease at 10 months) to 6 years (average, 3.8 years), there were no instances of intracranial recurrence. There was a disease-free control rate of 67.7% at an average follow-up of 4.1 years.

Conclusions

Extending the resection of squamous cell carcinoma into the intracranial vault judiciously as outlined appears to be associated with acceptable outcomes in the treatment of advanced squamous cell carcinoma of the skull base.

Exposure of Titanium Mesh after Cranioplasty for Microvascular Decompression Surgery: Two Case Reports

Two cases of exposed titanium mesh occurred after implantation for cranioplasty after repeated procedures for microvascular decompression (MVD). Case 1 was a 62-year-old female who underwent MVD for left hemifacial spasm followed by repair of cerebrospinal fluid leak after the surgery, and Case 2 was a 75-year-old female who underwent MVD twice for right trigeminal neuralgia. Both patients visited our hospital again with complaints of postauricular lesion. Titanium mesh was visible through the operative scar and was successfully removed with no complication in both cases. Both patients were underweight females, and combined with multistep surgery may have contributed to the pathology. The present cases suggest that use of titanium mesh should be avoided for cranioplasty of posterior fossa surgery, especially for repeated procedures.

Bioactive-glass in Oral and Maxillofacial Surgery

The use of synthetic materials to repair craniofacial defects is increasing today and will increase further in the future. Because of the complexity of the anatomy in the head and neck region, reconstruction and augmentation of this area pose a challenge to the surgeon. This review discusses key facts and applications of traditional reconstruction bone substitutes, also offering comparative information. It then describes the properties and clinical applications of bioactive-glass (B-G) and its variants in oral and maxillofacial surgery, and provides clinical findings. The discussion of each compound includes a description of its composition and structure, the advantages and shortcomings of the material, and its current uses in the field of osteoplastic and reconstructive surgery. With a better understanding of the available alloplastic implants, the surgeon can make a more informed decision as to which implant would be most suitable in a particular patient.

Preparation of Porous Chitosan-Siloxane Hybrids Coated with Hydroxyapatite Particles

This paper describes the apatite deposition of chitosan-silicate porous hybrids derived from chitosan and γ-glycidoxypropyltrimethoxysilane (GPTMS) in alkaline phosphate solution. The preparation of porous hybrids with needle-like apatite on their surfaces is described. Following apatite deposition the porous hybrids maintained high porosity. The enzymatic degradation rate was low even after 6 months and the porous hybrids were very flexible and cut easily using surgical scissors.

Cranioplasty of Hemispherical Defects Using Calcium Phosphate Cements Along with Titanium Mesh: Our Experience

INTRODUCTION

Cranial defects may arise due to trauma, infection, surgical ablation or errors in development. Restoration of such defects is important for esthetics, function and morale of the patient. Several materials are available. Each has its advantages and disadvantages. Search is on for an ideal material. Autogenous grafts remain the gold standard in reconstruction of such defects. However, the morbidity associated with their harvest, additional time required, the need for a second surgical site and the limited supply has led to the search for newer substitutes. Although many materials are available today including biologic and non biologic substitutes, there is still no consensus about the best material. In this article we describe our use of calcium phosphate cements for reconstruction of hemispherical cranial defects.

MATERIALS AND METHODS

Cases requiring reconstruction of hemispherical cranial defects (more than 15 cm in any dimension) were selected for study. After exposing the defect under GA, titanium mesh was adapted to the defect for support. Then the calcium phosphate cement was prepared and injected on the mesh to establish good contour. The alloplastic insert in each patient was evaluated for: (a) Immediate post-operative complications (b) Restoration of contour and soft tissue support (c) New bone formation ascertained on HRCT at the end of 2 years. Patients were examined on postoperative first week, at 3 and at 6 months. High resolution computed tomography scans were taken at 2 years postop. There were two female and three male patients.

RESULTS

There were no complications in the post operative period. The general condition of the patients improved post operatively. Even though the cements maintained their contour at 2 years, there were no signs of bone formation within the cement.

CONCLUSION

Calcium phosphate cement is a good bone substitute for use in cranioplasty. In defects requiring mechanical strength, it should be supported by a titanium mesh. It retains the contour but is not replaced by bone even after 2 years.

Assessment of injectable and cohesive nanohydroxyapatite composites for biological functions

Pressing need for utilization of injectables/fillers in various forms of orthopaedic treatments/surgeries commands an equal demand for better graft material. Injectable bone graft material based on biomimetically synthesized nanohydroxyapatite was developed and subjected to ball milling for different times; three materials thus produced were evaluated for their biological properties. The three composites tested were found to have some difference in proliferation and differentiation on mesenchymal stem cells in cultures. In vivo studies were performed by implanting the graft materials with or without cells in the bone drill hole injury created in the femur of Wistar rats. Our studies show that the composites lead to well-healed injury site with normal histology without inflammation or fibrous tissue formation and bone deformity. This material needs to be tested on large animals for further ascertaining its applicability in clinical use.

Lid cranioplasty: an elegant method of calvarial reconstruction

The reconstruction of calvarial defect is a challenging treat for any craniofacial surgeon. The split calvarial bone graft reconstruction is a well-described method of reconstruction and gives very good results. Here, we present a 14-year-old girl who presented with a frontal cranial bone defect with a size of 5 × 3 cm for which the reconstruction was done with a split calvarial bone graft taken from the parietal bone. The method of reconstruction resembled keeping a lid of a jar, and we named this procedure lid cranioplasty. We were able to come out with very good cosmetic and functional outcome.

Cranioplasty with custom-made titanium plates--14 years experience

BACKGROUND

There is no consensus on which material is best suited for repair of cranial defects.

OBJECTIVE

To investigate the outcomes following custom-made titanium cranioplasty.

METHODS

The medical records for all patients who had titanium cranioplasty at 2 major neurosurgical centers in Western Australia were retrieved and analyzed for this retrospective cohort study.

RESULTS

Altogether, 127 custom-made titanium cranioplasties on 113 patients were included. Two patients had 3 titanium cranioplasties and 10 patients had 2. Infected bone flap (n = 61, 54%), either from previous craniotomy or autologous cranioplasty, and contaminated bone flap (n = 16, 14%) from the initial injury were the main reasons for requiring titanium cranioplasty. Complications attributed to titanium cranioplasty were common (n = 33, 29%), with infection being the most frequent complication (n = 18 patients, 16%). Complications were, on average, associated with an extra 7 days of hospital stay (interquartile range 2-17). The use of titanium as the material for the initial cranioplasty (P = .58), the presence of skull fracture(s) (P > .99) or scalp laceration(s) (P = .32) at the original surgery, and proven local infection before titanium cranioplasty (P = .78) were not significantly associated with an increased risk of infection. Infection was significantly more common after titanium cranioplasty for large defects (hemicraniectomy [39%] and bifrontal craniectomy [28%]) than after cranioplasty for small defects (P = .04).

CONCLUSION

Complications after using titanium plate for primary or secondary cranioplasty were common (29%) and associated with an increased length of hospital stay. Infection was a major complication (16%), and this suggested that more vigorous perioperative infection prophylaxis is needed for titanium plate cranioplasty.

Prevention of postoperative cerebrospinal fluid leaks with multilayered reconstruction using titanium mesh-hydroxyapatite cement cranioplasty after translabyrinthine resection of acoustic neuroma

OBJECT

Several prophylactic surgical methods have been tried to prevent CSF leakage after translabyrinthine resection of acoustic neuroma (TLAN). The authors report an improvised technique for multilayer watertight closure using titanium mesh-hydroxyapatite cement (HAC) cranioplasty in addition to dural substitute and abdominal fat graft after TLAN.

METHODS

The study was limited to 42 patients who underwent TLAN at University Hospitals Case Medical Center using this new technique from 2006 to 2012. Systematic closure of the surgical wound in layers using temporalis fascia, dural substitute, dural sealant, adipose graft, titanium mesh, and then HAC was performed in each case. Temporalis muscle and eustachian tube obliteration were not used. The main variables studied were patient age, tumor size, tumor location, cosmetic outcome, length of hospitalization, and the incidence of CSF leak, pseudomeningocele, and infection.

RESULTS

Excellent cosmetic outcome was achieved in all patients. There were no cases of postoperative CSF rhinorrhea, incisional CSF leak, or meningitis. Cosmetic results were comparable to those achieved using HAC alone. This cost-effective technique used only a third of the HAC required for traditional closure in which the entire mastoid defect is filled with cement, predisposing to infection. Postoperative CT and MRI showed excellent bony contouring and dural reconstitution, respectively.

CONCLUSIONS

The authors report on successful use of titanium mesh-HAC cranioplasty in preventing postoperative CSF leak after TLAN in all cases in their series. The titanium mesh provides a well-defined anatomical dissection plane that would make reoperation easier than working through scarred soft tissue. The mesh bolsters the fat graft and keeps HAC out of direct contact with mastoid air cells, thereby reducing the risk of infection. The cement cranioplasty does not preclude subsequent implantation of a bone-anchored hearing aid.

Bone morphogenetic proteins in craniofacial surgery: current techniques, clinical experiences, and the future of personalized stem cell therapy

Critical-size osseous defects cannot heal without surgical intervention and can pose a significant challenge to craniofacial reconstruction. Autologous bone grafting is the gold standard for repair but is limited by a donor site morbidity and a potentially inadequate supply of autologous bone. Alternatives to autologous bone grafting include the use of alloplastic and allogenic materials, mesenchymal stem cells, and bone morphogenetic proteins. Bone morphogenetic proteins (BMPs) are essential mediators of bone formation involved in the regulation of differentiation of osteoprogenitor cells into osteoblasts. Here we focus on the use of BMPs in experimental models of craniofacial surgery and clinical applications of BMPs in the reconstruction of the cranial vault, palate, and mandible and suggest a model for the use of BMPs in personalized stem cell therapies.

A review of reconstructive materials for use in craniofacial surgery bone fixation materials, bone substitutes, and distractors

Over the last 40 years, craniofacial surgery, in general, and surgery for craniosynostosis, in particular, has witnessed the introduction of a number of new materials for use in operations involving the cranial vault. Some of these materials have proven quite useful over time, while others have failed to meet their stated objectives. In this review, the more popular implant materials are analyzed, and their relative merits and drawbacks are discussed. Craniofacial surgery in the pediatric population has its own unique limitations, quite different from the adult population and those issues are reviewed as well.

Calcium orthophosphate-based bone cements (CPCs): Applications, antibiotic release and alternatives to antibiotics

Calcium orthophosphate bone cements (CPCs) are widely used in orthopedic surgery. Implants are highly susceptible to infection and often lead to the formation of microbial biofilms. Antibiotics are often incorporated into bone cement to prevent infection. The increase in the number of microorganisms acquiring or developing resistance to antibiotics, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), is a major concern. Bacteriocins (antimicrobial peptides) offer an alternative to antibiotics. Their mode of activity involves permanent destabilization of the plasma membrane of target cells. A number of broad-spectrum bacteriocins produced by lactic acid bacteria and Bacillus spp. have recently been reported. In this REVIEW the major characteristics of calcium phosphate bone cements, prosthetic joint-associated infections, and treatment of these infections is discussed. The role of antimicrobial agents in CPCs is discussed and the possibility of incorporating bacteriocins in prosthetic devices is investigated.

Biocompatibility and resorption of a radiopaque premixed calcium phosphate cement

Calcium phosphate cements (CPC) are used as bone void filler in various orthopedic indications; however, there are some major drawbacks regarding mixing, transfer, and injection of traditional CPC. By using glycerol as mixing liquid, a premixed calcium phosphate cement (pCPC), some of these difficulties can be overcome. In the treatment of vertebral fractures the handling characteristics need to be excellent including a high radio-opacity for optimal control during injection. The aim of this study is to evaluate a radiopaque pCPC regarding its resorption behavior and biocompatibility in vivo. pCPC and a water-based CPC were injected into a Ø 4-mm drilled femur defect in rabbits. The rabbits were sacrificed after 2 and 12 weeks. Cross sections of the defects were evaluated using histology, electron microscopy, and immunohistochemical analysis. Signs of inflammation were evaluated both locally and systemically. The results showed a higher bone formation in the pCPC compared to the water-based CPC after 2 weeks by expression of RUNX-2. After 12 weeks most of the cement had been resorbed in both groups. Both materials were considered to have a high biocompatibility since no marked immunological response was induced and extensive bone ingrowth was observed. The conclusion from the study was that pCPC with ZrO(2) radiopacifier is a promising alternative regarding bone replacement material and may be suggested for treatment of, for example, vertebral fractures based on its high biocompatibility, fast bone ingrowth, and good handling properties.