Autogenous Bone Reconstruction of Large Secondary Skull Defects

High-Density Porous Polyethylene Implant Cranioplasty: A Systematic Review of Outcomes

Porous polyethylene has been widely used in craniofacial reconstruction due to its biomechanical properties and ease of handling. The objective of this study was to perform a systematic review of the literature to summarize outcomes utilizing high-density porous polyethylene (HDPP) implants in cranioplasty. A literature search of PubMed, Cochrane Library, and Scopus databases was conducted to identify original studies with HDPP cranioplasty from inception to March 2023. Non-English articles, commentaries, absent indications or outcomes, and nonclinical studies were excluded. Data on patient demographics, indications, defect size and location, outcomes, and patient satisfaction were extracted. Summary statistics were calculated using weighted averages based on the available reported data. A total of 1089 patients involving 1104 cranioplasty procedures with HDPP were identified. Patients' mean age was 44.0 years (range 2 to 83 y). The mean follow-up duration was 32.0 months (range 2 wk to 8 y). Two studies comprising 17 patients (1.6%) included only pediatric patients. Alloplastic cranioplasty was required after treatment of cerebrovascular diseases (50.9%), tumor excision (32.0%), trauma (11.4%), trigeminal neuralgia/epilepsy (3.4%), and others such as abscesses/cysts (1.4%). The size of the defect ranged from 3 to 340 cm 2 . An overall postoperative complication rate of 2.3% was identified, especially in patients who had previously undergone surgery at the same site. When data were available, contour improvement and high patient satisfaction were reported in 98.8% and 98.3% of the patients. HDPP implants exhibit favorable outcomes for reconstruction of skull defects. Higher complication rates may be anticipated in secondary cranioplasty cases.

Leite T, Gustafson J, Wilk K, Yozgatian J, Garakani S, Bassir SH, Cunningham ML, Lin CP, Intini G. Expansion of the sagittal suture induces proliferation of skeletal stem cells and sustains endogenous calvarial bone regeneration

In newborn humans, and up to approximately 2 y of age, calvarial bone defects can naturally regenerate. This remarkable regeneration potential is also found in newborn mice and is absent in adult mice. Since previous studies showed that the mouse calvarial sutures are reservoirs of calvarial skeletal stem cells (cSSCs), which are the cells responsible for calvarial bone regeneration, here we hypothesized that the regenerative potential of the newborn mouse calvaria is due to a significant amount of cSSCs present in the newborn expanding sutures. Thus, we tested whether such regenerative potential can be reverse engineered in adult mice by artificially inducing an increase of the cSSCs resident within the adult calvarial sutures. First, we analyzed the cellular composition of the calvarial sutures in newborn and in older mice, up to 14-mo-old mice, showing that the sutures of the younger mice are enriched in cSSCs. Then, we demonstrated that a controlled mechanical expansion of the functionally closed sagittal sutures of adult mice induces a significant increase of the cSSCs. Finally, we showed that if a calvarial critical size bone defect is created simultaneously to the mechanical expansion of the sagittal suture, it fully regenerates without the need for additional therapeutic aids. Using a genetic blockade system, we further demonstrate that this endogenous regeneration is mediated by the canonical Wnt signaling. This study shows that controlled mechanical forces can harness the cSSCs and induce calvarial bone regeneration. Similar harnessing strategies may be used to develop novel and more effective bone regeneration autotherapies.

Exosomal Lnc NEAT1 from endothelial cells promote bone regeneration by regulating macrophage polarization via DDX3X/NLRP3 axis

BACKGROUND

Bone regeneration is a complex procedure that involves an interaction between osteogenesis and inflammation. Macrophages in the microenvironment are instrumental in bone metabolism. Amount evidence have revealed that exosomes transmitting lncRNA is crucial nanocarriers for cellular interactions in various biotic procedures, especially, osteogenesis. However, the underlying mechanisms of the regulatory relationship between the exosomes and macrophages are awaiting clarification. In the present time study, we aimed to explore the roles of human umbilical vein endothelial cells (HUVECs)-derived exosomes carrying nuclear enrichment enriched transcript 1 (NEAT1) in the osteogenesis mediated by M2 polarized macrophages and elucidate the underlying mechanisms.

RESULTS

We demonstrated HUVECs-derived exosomes expressing NEAT1 significantly enhanced M2 polarization and attenuated LPS-induced inflammation in vitro. Besides, the conditioned medium from macrophages induced by the exosomes indirectly facilitated the migration and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Mechanically, Exos carrying NEAT1 decreased remarkably both expression of dead-box helicase 3X-linked (DDX3X) and nod-like receptor protein 3 (NLRP3). The level of NLRP3 protein increased significantly after RAW264.7 cells transfected with DDX3X overexpression plasmid. Additionally, the knockdown of NEAT1 in exosomes partially counteracted the aforementioned effect of Exos. The results of air pouch rat model demonstrated that HUVECs-derived exosomes increased anti-inflammatory cytokines (IL-10) and decreased pro-inflammatory cytokines (IL-1β and IL-6) significantly in vivo, contributing to amelioration of LPS-induced inflammation. Afterwards, we further confirmed that the HUVECs-derived exosomes encapsulated in alginate/gelatin methacrylate (GelMA) interpenetrating polymer network (IPN) hydrogels could promote the bone regeneration, facilitate the angiogenesis, increase the infiltration of M2 polarized macrophages as well as decrease NLRP3 expression in the rat calvarial defect model.

CONCLUSIONS

HUVECs-derived exosomes enable transmitting NEAT1 to alleviate inflammation by inducing M2 polarization of macrophages through DDX3X/NLRP3 regulatory axis, which finally contributes to osteogenesis with the aid of alginate/GelMA IPN hydrogels in vivo. Thus, our study provides insights in bone healing with the aid of HUVECs-derived exosomes-encapsulated composite hydrogels, which exhibited potential towards the use of bone tissue engineering in the foreseeable future.

An Algorithm for Reconstruction of Electrical Injuries of the Scalp

BACKGROUND

Electrical injuries of the scalp are a frequent occurrence in developing countries. Burns can be contact or conductive and result in extensive tissue damage. The authors present their experience with treatment of scalp and calvarial electrical injuries and propose a management algorithm.

METHODS

This was a retrospective cohort study comprising all patients with electrical injuries of the scalp treated at the authors' center between January of 2010 and December of 2016. Noncontrast computed tomography scans were obtained to assess viability of the calvarium in patients who presented more than 2 weeks after injury. Single-stage débridement and reconstruction were performed. All nonviable soft tissue and bone was removed. Soft-tissue reconstruction was performed with skin grafts, local scalp flaps, pedicled trapezius flaps, and free flaps (anterolateral thigh, latissimus dorsi, and scapular). Cranioplasty was performed in a delayed manner with autologous bone grafts.

RESULTS

Over a 7-year period, a total of 52 patients underwent scalp reconstruction for high-voltage (44 patients) and low-voltage (eight patients) electrical injury. All patients underwent successful soft-tissue reconstruction. Osteomyelitis with draining sinuses developed in three patients; these patients underwent flap re-elevation and bone débridement, which resulted in a healed wound and stable reconstruction. Cranioplasty was performed with split calvarial grafts in two patients and split rib grafts in four patients. One patient underwent scalp tissue expansion for hair restoration.

CONCLUSION

The authors propose an algorithm for reconstruction of electrical injuries of the scalp. Thorough débridement of the calvarium is the most important determinant of a successful outcome.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Current Concepts in Cranial Reconstruction: Review of Alloplastic Materials

Cranioplasty for acquired cranial defects can be complex and challenging. Benefits include improved cosmesis, protection of intracranial structures, and restoration of neurocognitive function. These defects can be reconstructed with preserved craniectomy bone flaps, split autografts, or alloplastic materials. When alloplastic cranioplasty is planned, the material should be carefully selected. There is confusion on which material should be used in certain scenarios, particularly in composite defects.

Stereophotogrammetric Method for Fabrication of Cranioplast Using Digital Facial Scan Technology - A Case Report

Rationale

Traumatic brain injury is the most common cause of cranial defects. Cranioplasty is the surgical intervention performed to repair cranial defects. The purpose of a cranioplast is to protect the underlying brain tissues, reduce pain, and improve calvarial contour and symmetry.

Patient Concerns

This case report describes the management of an ambulatory aided patient who met with a road traffic accident and had undergone decompressive craniectomy.

Diagnosis

Noncontrast computed tomography confirmed the frontal cranial defect and was planned for decompressive craniectomy.

Treatment Plan

An innovative multi-camera three-dimensional (3D) face-scanning software (Bellus 3D) was used for facial scanning to obtain a 3D face model and fabrication of 3D model using rich presence technology.

Outcomes

The wax pattern was then fabricated on a 3D-prototyped model and a customised polymethylmethacrylate cranioplast was fabricated.

Take-Away Lessons

his method with the added advantage of rapid prototyping technology resulted in prosthesis with good aesthetics and better fit.

Co-Culture of Bone Marrow Mesenchymal Stem Cell (BMSC) and Osteoclasts Regulates Cell Differentiation and Alleviates Osteoporosis by Up-Regulating miR-211

Bone marrow mesenchymal stem cells (BMSCs) can release a large amount of exosomes (EXO) during bone remodeling by osteoclasts. EXO contains miRNA-211, which has a variety of biological effects. However, little is known about whether miR-211 from BMSC-EXO affects the surrounding cells. Therefore, we aim to study the role of miRNA-211 derived from BMSC-EXO in regulating osteoclasts differentiation. Macrophage colony stimulating factor (M-CSF) and nuclear factor kappa B receptor activator (RANKL) were used to stimulate bone marrow macrophages (BMM) to obtain osteoclasts, which were treated with BMSC-EXO or LPS followed by analysis of osteoclast-related genes expression by PCR, ROS release by flow cytometry, actin ring formation by immunofluorescence, and osteoclast differentiation by anti-tartrate acid phosphatase (TRAP) staining. Finally, an in vivo experiment was conducted to verify BMSC-EXO’s effect on osteoporosis. BMSC-EXO significantly inhibited RNAKL-induced osteoclast differentiation of BMMs. During osteoclasts formation, BMSC-EXO inhibited ROS production induced by RANKL and the subsequent activation of NF-κB signaling pathway induced by ROS. In addition, BMSC-EXO significantly down-regulated the osteoclast genes including nuclear factor, cytoplasmic 1 (NFATc1), C-fos, tartrate-resistant acid phosphatase (TRAP) and osteoclast-associated immunoglobulin-like receptor (OSCAR) in activated T cells. BMSC-EXO inhibited ROS release by promoting miR-211 expression, thereby inhibiting the NF-κB signaling and ultimately participating in osteoclasts differentiation. In LPS-induced mouse osteoporosis models, BMSC-EXO inhibited LPS-induced bone loss and exerted a protective effect. In conclusion, microRNA-211 derived from BMSC-EXO can regulate osteoclasts differentiation, suggesting that it might be used as a potential approach for treating osteoporosis.

Pediatric Cranial Defects: What Size Warrants Repair?

PURPOSE

Identifying which cranial defects among children warrant surgical repair is integral to providing adequate protection of the skull whereas minimizing exposure to surgical complications. This review examines the available evidence regarding the role of defect size in determining the appropriateness of nonsurgical versus surgical management.

METHODS

An electronic literature review was performed using PubMed and Google Scholar to identify publications that provided rationales for nonsurgical management of cranial defects in the pediatric population based on size. Titles and abstracts were reviewed by the authors to determine eligibility for full-text analysis. Ineligible studies were categorized and relevant data from fully analyzed texts were recorded.

RESULTS

Of the 523 articles that were reviewed, 500 were ineligible for full-text analysis due to the following most common reasons: no cranial defect described (227, 45%), did not discuss management of cranial defects (68, 14%), or surgery was performed on all defects in evaluation of a technique or protocol (86, 17%). Ten publications provided relevant data. The suggested size below which surgery was not recommended varied widely between articles. Beyond the age of 1 to 2 years, no general agreement on recommended management in children was found. Craniofacial surgeons had divergent views on the minimum diameter for a "critical" defect and the size for which surgical repair is necessary.

CONCLUSIONS

Little guidance or consensus exists regarding the indications for surgical correction of cranial defects based on the size of the defect. Objective data is needed to classify "clinically critical defects" in the pediatric population.

Decision-Making in Adult Cranial Vault Reconstruction

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Define and classify different types of cranial defects 2. Compare both autologous and alloplastic options for reconstruction 3. Develop an optimal approach for cranial vault reconstruction in various clinical scenarios.

SUMMARY

Defects of the cranium result from various causes, including traumatic loss, neurosurgical intervention, skull tumors, and infection. Cranial vault reconstruction aims to restore both the structural integrity and surface morphology of the skull. To ensure a successful outcome, the choice of appropriate cranioplasty reconstruction will vary primarily based on the cause, location, and size of the defect. Other relevant factors that must be considered include adequacy of soft-tissue coverage, presence of infection, and previous or planned radiation therapy. This article presents an algorithm for the reconstruction of various cranial defects using both autologous and alloplastic techniques, with a comparison of their advantages and disadvantages.

Urine-derived stem cells loaded onto a chitosan-optimized biphasic calcium-phosphate scaffold for repairing large segmental bone defects in rabbits

The treatment of large segmental bone defects can be challenging for orthopedic surgeons. The development of bone tissue engineering technology, including the selection of seeding cells and the construction of scaffolds, provides a promising solution. In this study, we investigated osteogenic differentiation of human urine-derived stem cells (hUSCs, a newly identified class of stem cells), and developed a novel porous hybrid scaffold using biphasic calcium phosphate (BCP) bioceramic ornamented with chitosan sponges (CS). We combined hUSCs with a CS/BCP hybrid scaffold to construct tissue-engineered bone and evaluated whether the combination promotes bone regeneration in large segmental bone defects in rabbits. The study showed that hUSCs can differentiate into osteoblasts, and the hUSCs adhered, proliferated, and differentiated on CS/BCP hybrid scaffolds. Micro-computed tomography measurements, biomechanical detection, and histological analyses revealed that the combination of hUSCs and the CS/BCP hybrid scaffold enhanced bone regeneration more effectively compared with conventional pure BCP scaffolds, indicating that hUSCs can be used as a cell source for bone tissue engineering and that cell-scaffold-based biomimetic bone may be a promising approach to the repair of bone defects.

A New Type of Three-Dimensional Customized Composite Implant in Reconstruction of Large Skull Defects

ABSTRACT

Large skull defects can result in chronic injury to intracranial tissues as well as psychological trauma for patients, and their repair presents a challenge to surgeons. Hydroxyapatite has been used in reconstructing skull defects for many years, but it is difficult to adjust the shape and size of the material intraoperatively, especially for large defects. With three-dimensional digital technology, a new type of customized composite implant made of epoxide acrylate maleic and hydroxyapatite has been applied in clinical practice. In this retrospective review, 15 patients with large skull defects (4 female and 11 male, at a mean age of 36.4 years, range from 24-65 years) were treated with the novel customized composite implant, reconstructing the large skull defects successfully. During the average 2.2 years follow-up period (range 0.5-4 years), complications including infection, cerebrospinal fluid leakage, intracranial hemorrhage, or implant exposurea were not occured, only 1 patient (6.7%) with a seroma managed non-operatively. The customized implants, which required no intraoperative adjustments and are about a third of the cost of titanium implants, are an excellent alternative for large skull defect repair.

Photobiomodulation combined with adipose-derived stem cells encapsulated in methacrylated gelatin hydrogels enhances in vivo bone regeneration

Reconstruction of bone defects is still a significant challenge. The aim of this study was to evaluate the effect of application of photobiomodulation (PBM) to enhance in vivo bone regeneration and osteogenic differentiation potential of adipose-derived stem cells (ADSCs) encapsulated in methacrylated gelatin (GEL-MA) hydrogels. Thirty-six Sprague-Dawley rats were randomly separated into 3 experimental groups (n = 12 each). The groups were control/blank defect (I), GEL-MA hydrogel (II), and ADSC-loaded GEL-MA (GEL-MA+ADSC) hydrogel (III). Biparietal critical sized bone defects (6 mm in size) are created in each animal. Half of the animals from each group (n = 6 each) were randomly selected for PBM application using polychromatic light in the near infrared region, 600-1200 nm. PBM was administered from 10 cm distance cranially in 48 h interval. The calvaria were harvested at the 20th week, and macroscopic, microtomographic, and histologic evaluation were performed for further analysis. Microtomographic evaluation demonstrated the highest result for mineralized matrix formation (MMF) in group III. PBM receiving samples of group III showed mean MMF of 79.93±3.41%, whereas the non-PBM receiving samples revealed mean MMF of 60.62±6.34 % (p=0.002). In terms of histologic evaluation of bone defect repair, the higher scores were obtained in the groups II and III when compared to the control group (2.0 for both PBM receiving and non-receiving specimens; p<0.001). ADSC-loaded microwave-induced GEL-MA hydrogels and periodic application of photobiomodulation with polychromatic light appear to have beneficial effect on bone regeneration and can stimulate ADSCs for osteogenic differentiation.

Mesenchymal stem cells and three-dimensional-osteoconductive scaffold regenerate calvarial bone in critical size defects in swine

Craniofacial bones protect vital organs, perform important physiological functions, and shape facial identity. Critical‐size defects (CSDs) in calvarial bones, which will not heal spontaneously, are caused by trauma, congenital defects, or tumor resections. They pose a great challenge for patients and physicians, and significantly compromise quality of life. Currently, calvarial CSDs are treated either by allogenic or autologous grafts, metal or other synthetic plates that are associated with considerable complications. While previous studies have explored tissue regeneration for calvarial defects, most have been done in small animal models with limited translational value. Here we define a swine calvarial CSD model and show a novel approach to regenerate high‐quality bone in these defects by combining mesenchymal stem cells (MSCs) with a three‐dimensional (3D)‐printed osteoconductive HA/TCP scaffold. Specifically, we have compared the performance of dental pulp neural crest MSCs (DPNCCs) to bone marrow aspirate (BMA) combined with a 3D‐printed HA/TCP scaffold to regenerate bone in a calvarial CSD (>7.0 cm²). Both DPNCCs and BMA loaded onto the 3D‐printed osteoconductive scaffold support the regeneration of calvarial bone with density, compression strength, and trabecular structures similar to native bone. Our study demonstrates a novel application of an original scaffold design combined with DPNCCs or BMA to support regeneration of high‐quality bone in a newly defined and clinically relevant swine calvarial CSD model. This discovery may have important impact on bone regeneration beyond the craniofacial region and will ultimately benefit patients who suffer from debilitating CSDs.

In situ bone regeneration of large cranial defects using synthetic ceramic implants with a tailored composition and design

Large cranial reconstructions are increasingly performed worldwide and still represent a substantial clinical challenge. The gold standard, autologous bone, has limited availability and high donor-site morbidity. Current alloplastic materials are associated with high complication and failure rates. This study shows the capacity of a customized, purely synthetic, 3D-manufactured bioceramic implant to regenerate and restore large cranial defects with mature, well-vascularized bone, with a morphology, ultrastructure, and composition similar to those of native skull bone. This approach triggers the regenerative potential of host tissue by tailoring the implant composition and design. The regeneration of large defects using purely synthetic material without adjunct cell therapy or growth factors represents a major advancement for rehabilitating patients in need of large cranial reconstructions.

The repair of large cranial defects with bone is a major clinical challenge that necessitates novel materials and engineering solutions. Three-dimensionally (3D) printed bioceramic (BioCer) implants consisting of additively manufactured titanium frames enveloped with CaP BioCer or titanium control implants with similar designs were implanted in the ovine skull and at s.c. sites and retrieved after 12 and 3 mo, respectively. Samples were collected for morphological, ultrastructural, and compositional analyses using histology, electron microscopy, and Raman spectroscopy. Here, we show that BioCer implants provide osteoinductive and microarchitectural cues that promote in situ bone regeneration at locations distant from existing host bone, whereas bone regeneration with inert titanium implants was confined to ingrowth from the defect boundaries. The BioCer implant promoted bone regeneration at nonosseous sites, and bone bonding to the implant was demonstrated at the ultrastructural level. BioCer transformed to carbonated apatite in vivo, and the regenerated bone displayed a molecular composition indistinguishable from that of native bone. Proof-of-principle that this approach may represent a shift from mere reconstruction to in situ regeneration was provided by a retrieved human specimen, showing that the BioCer was transformed into well-vascularized osteonal bone, with a morphology, ultrastructure, and composition similar to those of native human skull bone.

Spatial Distributions, Characteristics, and Applications of Craniofacial Stem Cells

Stem cells play an irreplaceable role in the development, homeostasis, and regeneration of the craniofacial bone. Multiple populations of tissue-resident craniofacial skeletal stem cells have been identified in different stem cell niches, including the cranial periosteum, jawbone marrow, temporomandibular joint, cranial sutures, and periodontium. These cells exhibit self-renewal and multidirectional differentiation abilities. Here, we summarized the properties of craniofacial skeletal stem cells, based on their spatial distribution. Specifically, we focused on the in vivo genetic fate mapping of stem cells, by exploring specific stem cell markers and observing their lineage commitment in both the homeostatic and regenerative states. Finally, we discussed their application in regenerative medicine.

Hyberbaric oxygen and bone reconstruction

INTRODUCTION

The aim of this literature review was to determine the benefits of hyperbaric oxygen therapy after bone reconstruction procedures in humans and identify information that may be useful for the development of optimal protocols for hyperbaric oxygen therapy to stimulate bone healing.

EVIDENCE ACQUISITION

We searched the electronic database PubMed/Medline for studies published between January 1999 and December 2018, using the key words: "bone" or "bone graft" and "mandible reconstruction" or "jaw reconstruction" and "hyperbaric oxygen" or "HBO." First, the titles and abstracts of the studies found were evaluated and those that corresponded to the aims of this review were pre-selected for analysis of the full text. Subsequently, the full texts were analyzed, and those that met the eligibility criteria were pre-selected for the review. The full texts of studies whose abstracts did not provide enough data for decision were also evaluated. Two examiners independently assessed eligibility, risk of bias and extracted data.

EVIDENCE SYNTHESIS

A total of 2237 studies were found according to pre-established criteria for data collection, of which only 5 studies were included in this systematic review. Although we observed positive results in the included studies, there are still few standardized clinical studies in the literature, assessing hyperbaric oxygen therapy after extensive bone reconstructive procedures.

CONCLUSIONS

It is difficult to compare results found in different studies due to the variety of methodological and clinical conditions assessed.

Calvarial Reconstruction With Autologous Sagittal Split Rib Bone Graft and Latissimus Dorsi Rib Myoosseocutaneous Free Flap

OBJECTIVE

Cranioplasty is essential because cranial defects cause cosmetic and functional problems, and neurologic sequalae in patients. However, reconstruction options are limited in patients with unfavorable conditions. This study aimed to review our experience with skull defect reconstruction using autogenous bone with sagittal split rib bone grafts or latissimus dorsi rib myoosseocutaneous free flaps.

METHODS

Patients who underwent autogenous bone graft for cranial defect coverage from December 2011 to November 2015 at our institution were reviewed. Rib bone graft or latissimus dorsi rib myoosseocutaneous free flaps were done to cover the defect. The patient follow-up period ranged from 3 months to 7 years.

RESULTS

There were 6 patients, with 9 surgeries. Two cases of latissimus dorsi rib myoosseocutaneous free flap procedures were performed in 2 patients and 7 sagittal split rib bone grafts were performed in 6 patients. There were no postoperative infections in any patients, despite 4 patients had previous surgical site infection histories. Two patients with neurologic sequalae showed improvement after the surgeries.

CONCLUSION

Sagittal split rib bone graft and latissimus dorsi rib myoosseocutaneous free flap procedures could be fine options for calvarial reconstruction of defects under the unfavorable conditions of bilateral cranial defects or previous infection history.

Donor Site Changes in Bone Thickness, Volume, and Density Following Split Cranial Bone Graft Harvest

The calvarium can provide large amount of good quality corticocancellous autogenous bone graft. Although many studies have highlighted the advantages of the split cranial bone graft, there is no published work available in the literature about the fate of donor site of the split cranial bone graft. The present study was undertaken to assess the donor site as regards to the thickness, volume, and the density of the residual bone over a period of 12 months in the postoperative period. A total of 30 patients in the age group of 15 to 43 years were studied from January 2015 to January 2016. Postoperative computer tomography scans were taken at 2 weeks, 6 months, and 1 year postoperative to measure the bone thickness, volume, and density at the donor site of the split cranial bone graft harvest. The bone thickness at the donor site showed progressive increase in the thickness over the period of study and the average increase in thickness was about 12.4% at the end of 1 year. The average increase in volume at the donor site was of 2.65% after 12 months. Similarly, the average bone density increased by 3.7% at the end of 1 year. This prospective study conclusively proves that the residual bone at the donor site of the split cranial bone graft harvest site continues to grow in thickness and density over a period of 1 year.

Autogenous Bone Cranioplasty: Review of a 42-Year Experience by a Single Surgeon

BACKGROUND

Autogenous bone is frequently espoused as the gold standard material for cranioplasty procedures, yet alloplastic cranioplasty continues to persist in the search, presumably, for a simpler technique. Although short-term outcomes can be successful using foreign materials, long-term follow-up in these patients often demonstrates increased rates of failure because of exposure or late infection. Autogenous bone grafts, however, integrate and revascularize, and are thus more resistant to infection than alloplastic materials.

METHODS

This is a retrospective review of all patients that underwent reconstructive cranioplasty for full-thickness defects, as performed by the senior author (S.A.W.) between 1975 and 2018. All procedures were performed with autogenous bone.

RESULTS

One hundred fifty-four patients met criteria for inclusion in the report. Cranioplasties were performed for both congenital and secondary indications. Split calvaria was used in 115 patients (74.7 percent), rib graft was used in 12 patients (7.8 percent), iliac crest graft was used in 10 patients (6.5 percent), and combinations of donor-site grafts were used in 17 patients (11.0 percent). In the entire series, none of the patients suffered from complications related to infection of either the donor site or transferred bone graft. None of the patients required secondary operations to fill in defects created by the postoperative resorption.

CONCLUSIONS

Although autologous bone is widely considered the gold standard material for cranioplasty procedures, some argue against its use, mainly citing unpredictable resorption as the purported disadvantage. However, it is less susceptible to infection, and results in fewer long-term complications than alloplastic materials. There is no alloplastic material that has matched these outcomes, and thus autogenous bone should be considered as the primary option for cranioplasty procedures.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Ten-Year Outcomes After Catcher's Mask Cranioplasty for Large Cranial Bone Defects in Children: A Report of Two Cases

Cranioplasty is complicated in children with severe, extensive head trauma because allografting is not advisable in pediatric patients and the amount of available autologous materials is limited. To overcome these problems, Takumi reported a novel procedure called "catcher's mask cranioplasty" in 2008, in which split-rib grafts are placed perpendicularly over each other while calvarial grafts are placed in the hairless forehead region. Despite the small amount of grafts used, this method can yield esthetically satisfactory results and provides excellent structural integrity. Here, we report 2 cases of catcher's mask cranioplasty and their long-term outcomes. After more than 10 years, the transplanted bone grafts have not resorbed and have maintained their esthetically pleasing contours. In conclusion, catcher's mask cranioplasty is an effective option for traumatic cranial defects in children.

[Modern aspects of reconstructive surgery of skull defects]

The aim of this study is to systematize the modern methods used for reconstruction of extensive and complex skull defects. Special attention is paid to computer technologies, including 3D imaging and CAD/CAM. Laser-based stereolithography is thoroughly reviewed among other additive technologies. We present our view of the problem associated with proper timing of cranioplasty and choice of materials for it. Complications of skull defect reconstruction are also discussed.

Venous Thromboembolism Incidence After Craniofacial Surgery

INTRODUCTION

Current protocols for venous thromboembolism (VTE) prophylaxis after craniofacial surgery (CFS) vary widely with substantial disagreements in both indications and managements. An evidence-based approach to this issue requires the following: the incidence of postoperative VTE, comorbidities associated with coagulopathy, risk reduction after VTE prophylaxis, and complications attributable to prophylaxis. This study addresses the first two.

DESIGN

Retrospective cross-sectional study.

METHODS

Discharge data from 64,170 patients undergoing CFS between 2008 and 2013 extracted from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample were analyzed. The outcome measures extracted were: deep venous thrombosis, pulmonary embolism, demographic data, common comorbidities, length of stay, total cost, and discharge outcome.

RESULTS

Diagnoses of deep venous thrombosis or pulmonary embolism, collectively classified as VTE, were observed in 355 (0.55%) of 64,170 patients discharged after CFS. Other surgeries exhibited a VTE rate of 1.17%. Men exhibited nearly double the incidence of VTE relative to women (0.69% compared with 0.37% respectively, P < 0.001), and the risk factors of adulthood, advanced age, cardiovascular disease, obesity, and malignancy were associated with increased VTE incidence with odds ratios of 9.93, 3.66, 1.80, 2.02, and 2.02, respectively (P < 0.005). Tobacco use did not exhibit any significant association (odds ratio, 0.94; P = 0.679). Afflicted patients experienced 4.60 times longer hospital stays averaging 23.8 days (95% confidence interval, 21.4-26.2; P < 0.001) compared the average of 5.2 days experienced by CFS patients without VTE. They incurred an average cost of US $298,228 (95% confidence interval, 262,726 to 333,731; P < 0.001) which was 4.17 times the US $72,376 expense of treating other CFS patients. The likelihood for a CFS patient to experience a poor outcome at the time of discharge was 54.6% higher after VTE.

CONCLUSIONS

The risk of postoperative VTE after CFS is significantly increased in adults, patients with advanced age, cardiovascular disease, obesity, and malignancy. However even in those high-risk cases, postoperative VTE incidence remains relatively low after CFS. These findings in conjunction with further study regarding the risk associated with the addition of VTE chemoprophylaxis compared against mechanical VTE prophylaxis, such as sequential pneumatic compression stockings, may determine whether routine use of VTE chemoprophylaxis is appropriate.

Syndromic Craniosynostosis

Management strategies for syndromic craniosynostosis patients require multidisciplinary subspecialty teams to provide optimal care for complex reconstructive approaches. The most common craniosynostosis syndromes include Apert (FGFR2), Crouzon (FGFR2), Muenke (FGFR3), Pfeiffer (FGFR1 and FGFR2), and Saethre-Chotzen (TWIST). Bicoronal craniosynostosis (turribrachycephaly) is most commonly associated with syndromic craniosynostosis. Disease presentation varies from mild sutural involvement to severe pansynostoses, with a spectrum of extracraniofacial dysmorphic manifestations. Understanding the multifaceted syndromic presentations while appreciating the panoply of variable presentations is central to delivering necessary individualized care. Cranial vault remodeling aims to relieve restriction of cranial development and elevated intracranial pressure and restore normal morphology.