Successful use of rib grafts for cranioplasty in children

Clinical and imaging characteristics of growing skull fractures in children

Growing skull fracture (GSF) is an uncommon form of head trauma among young children. In prior research, the majority of GSFs were typically classified based on pathophysiological mechanisms or the duration following injury. However, considering the varying severity of initial trauma and the disparities in the time elapsed between injury and hospital admission among patients, our objective was to devise a clinically useful classification system for GSFs among children, grounded in both clinical presentations and imaging findings, in order to guide clinical diagnosis and treatment decisions. The clinical and imaging data of 23 patients less than 12 years who underwent GSF were retrospectively collected and classified into four types. The clinical and imaging characteristics of the different types were reviewed in detail and statistically analyzed. In all 23 patients, 5 in type I, 7 in type II, 8 in type III, and 3 in type IV. 21/23 (91.3%) were younger than 3 years. Age ≤ 3 years and subscalp fluctuating mass were common in type I-III (P = 0.026, P = 0.005). Fracture width ≥ 4 mm was more common in type II-IV (P = 0.003), while neurological dysfunction mostly occurred in type III and IV (P < 0.001).Skull "crater-like" changes were existed in all type IV. 10/12 (83.3%) patients with neurological dysfunction had improved in motor or linguistic function. There was not improved in patients with type IV. GCS in different stage has its unique clinical and imaging characteristics. This classification could help early diagnosis and treatment for GCS, also could improve the prognosis significantly.

Pediatric Cases of Recurrent Skull Giant Osteoma Misdiagnosed as Fibrous Dysplasia

ABSTRACT

Osteomas are benign mature bone tumors that typically arise in the skull. Osteomas larger than 3 cm in diameter are considered giant osteomas. Giant osteomas of the skull vault are very rare, especially in children; therefore, only a few cases have been reported in the literature. Although osteomas are usually asymptomatic, a large skull mass can cause headache, as well as esthetic disfigurement of the forehead. it can be misdiagnosed as other conditions, such as fibrous dysplasia, ossifying cephalhematoma, or other malignant bone tumors. Herein, the authors report 2 rare pediatric cases of giant osteomas mimicking fibrous dysplasia and their successful surgical excision. These cases showed good results without recurrence or complications on long-term follow-up after complete excision.

A murine model of large-scale bone regeneration reveals a selective requirement for Sonic Hedgehog

Building and maintaining skeletal tissue requires the activity of skeletal stem and progenitor cells (SSPCs). Following injury, local pools of these SSPCs become active and coordinate to build new cartilage and bone tissues. While recent studies have identified specific markers for these SSPCs, how they become activated in different injury contexts is not well-understood. Here, using a model of large-scale rib bone regeneration in mice, we demonstrate that the growth factor, Sonic Hedgehog (SHH), is an early and essential driver of large-scale bone healing. Shh expression is broadly upregulated in the first few days following rib bone resection, and conditional knockout of Shh at early but not late post-injury stages severely inhibits cartilage callus formation and later bone regeneration. Whereas Smoothened (Smo), a key transmembrane component of the Hh pathway, is required in Sox9+ lineage cells for rib regeneration, we find that Shh is required in a Prrx1-expressing, Sox9-negative mesenchymal population. Intriguingly, upregulation of Shh expression and requirements for Shh and Smo may be unique to large-scale injuries, as they are dispensable for both complete rib and femur fracture repair. In addition, single-cell RNA sequencing of callus tissue from animals with deficient Hedgehog signaling reveals a depletion of Cxcl12-expressing cells, which may indicate failed recruitment of Cxcl12-expressing SSPCs during the regenerative response. These results reveal a mechanism by which Shh expression in the local injury environment unleashes large-scale regenerative abilities in the murine rib.

Contemporary Review on Craniectomy and Cranioplasty; Part 2: Material Selection and Plate Manufacture

ABSTRACT

Cranioplasty materials include metals (ie, titanium); ceramics (ie, hydroxyapatite); polymers (ie, poly-methyl-metha-acrylate [PMMA]); and plastics (ie, polyether ether ketone). This paper aims to review their advantages and drawbacks. No ideal material currently exist, however, titanium implants are universally agreed to have lower infection rates than those reported for hydroxyapatite and PMMA implants; thus justifying their current wide use. These implants can be manufactured conventionally from medical grade titanium alloy Ti64 (titanium-aluminum-vanadium) in the form of plates ranging in thickness from 0.5 to 0.7 mm thick, or following the computer-aided design/manufacture principle. Surface finish of these implants is best achieved by electroplating.

Cranioplasty: A Comprehensive Review of the History, Materials, Surgical Aspects, and Complications

Cranioplasty is a common neurosurgical procedure performed to reconstruct cranial defects. The materials used to replace bone defects have evolved throughout history. Cranioplasty materials can be broadly divided into biological and synthetic materials. Biological materials can be further subdivided into autologous grafts, allografts, and xenografts. Allografts (bony materials and cartilage from cadavers) and xenografts (bony materials from animals) are out of favor for use in cranioplasty because of their high rates of infection, resorption, and rejection. In autologous cranioplasty, either the cranial bone itself or bones from other parts of the body of the patient are used. Synthetic bone grafts have reduced the operation time and led to better cosmetic results because of the advancement of computer-based customization and three-dimensional printing. Aluminum was the first synthetic bone graft material used, but it was found to irritate neural tissue, induce seizures, and dissolve over time. Acrylic, in the form of methyl methacrylate, is the most widely used material in cranioplasty. Hydroxyapatite is a natural component of bone and is believed to enhance bone repair, resulting in decreased tissue reactions and promoting good osteointegration. Polyetheretherketones are light and nonconductive and do not interfere with imaging modalities. The complication rates of cranioplasty are high, and surgical site infection is the most common complication. The effect of cranioplasty timing on cognitive function remains debatable. However, the timing of cranioplasty is independent of neurologic outcomes. In this article, the history, materials, complications, and evolution of current practices used in cranioplasty are comprehensively reviewed.

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.

Cranioplasty after craniectomy in pediatric patients-a systematic review

INTRODUCTION

Complications following cranioplasty with either autografts or cranial implants are commonly reported in pediatric patients. However, data regarding cranioplasty strategies, complications and long-term outcomes are not well described. This study systematically reviews the literature for an overview of current cranioplasty practice in children.

METHODS

A systematic review of articles published from inception to July 2018 was performed. Studies were included if they reported the specific use of cranioplasty materials following craniectomy in patients younger than 18 years of age, and had a minimum follow-up of at least 1 year.

RESULTS

Twenty-four manuscripts, describing a total of 864 cranioplasty procedures, met the inclusion criteria. The age of patients in this aggregate ranged from 1 month to 20 years and the weighted average was 8.0 years. The follow-up ranged from 0.4 months to 18 years and had a weighted average of 40.4 months. Autologous bone grafts were used in 484 cases (56.0%). Resorption, infection and/or hydrocephalus were the most frequently mentioned complications. In this aggregate group, 61 patients needed a revision cranioplasty. However, in 6/13 (46%) papers studying autologous cranioplasties, no data was provided on resorption, infection and revision cranioplasty rates. Cranial implants were used in 380 cases (44.0%), with custom-made porous hydroxyapatite being the most commonly used material (100/380, 26.3%). Infection and migration/fracturing/loosening were the most frequently documented complications. Eleven revision cranioplasties were reported. Again, no data was reported on infection and revision cranioplasty rates, in 7/16 (44%) and 9/16 (56%) of papers, respectively.

CONCLUSION

Our systematic review illuminates that whether autografts or cranial implants are used, postcranioplasty complications are quite common. Beyond this, the existing literature does not contain well documented and comparable outcome parameters, suggesting that prospective, long-term multicenter cohort studies are needed to be able to optimize cranioplasty strategies in children who will undergo cranioplasty following craniectomy.

Cranioplasties following craniectomies in children-a multicenter, retrospective cohort study

OBJECTIVE

Complications following pediatric cranioplasty after craniectomy with either autologous bone flaps or cranial implants are reported to be common, particularly bone flap resorption. However, only sparse data are available regarding cranioplasty strategies, complications, and outcomes. This manuscript describes a Canadian-Dutch multicenter pediatric cohort study with autografts and cranial implant cranioplasties following craniectomies for a variety of indications.

METHODS

The study included all children (< 18 years) who underwent craniectomy and subsequent cranioplasty surgeries from 2008 to 2014 (with a minimum of 1-year follow-up) at four academic hospitals with a dedicated pediatric neurosurgical service. Data were collected regarding initial diagnosis, age, time interval between craniectomy and cranioplasty, bone flap storage method, type of cranioplasty for initial procedure (and redo if applicable), and the postoperative outcome including surgical site infection, wound breakdowns, bone flap resorption, and inadequate fit/disfigurement.

RESULTS

Sixty-four patients (46 males, average age 9.7 ± 5.5 years) were eligible for inclusion, with mean follow-up of 82.3 ± 31.2 months after craniectomy. Forty cranioplasties (62.5%) used autologous bone re-implant, 23 (57.5%) of which showed resorption. On average, resorption was documented at 434 days (range 62-2796 days) after reimplantation. In 20 cases, a revision cranioplasty was needed. In 24 of the post-craniectomy cases (37.5%), a cranial implant was used with one of ten different implant types. Implant loosening prompted a complete revision cranioplasty in 2 cases (8.3%). Cranial implants were associated with low morbidity and lower reoperation dates compared to the autologous cranioplasties.

CONCLUSION

The most prominent finding in this multicenter cohort study was that bone flap resorption in children remains a common and widespread problem following craniectomy. Cranioplasty strategies varied between centers and evolved over time within centers. Cranial implants were associated with low morbidity and low reoperation rates. Still, longer term and prospective multicenter cohort studies are needed to optimize cranioplasty strategies in children after craniectomies.

Complications following pediatric cranioplasty after decompressive craniectomy: a multicenter retrospective study

OBJECTIVE In children, the repair of skull defects arising from decompressive craniectomy presents a unique set of challenges. Single-center studies have identified different risk factors for the common complications of cranioplasty resorption and infection. The goal of the present study was to determine the risk factors for bone resorption and infection after pediatric cranioplasty. METHODS The authors conducted a multicenter retrospective case study that included all patients who underwent cranioplasty to correct a skull defect arising from a decompressive craniectomy at 13 centers between 2000 and 2011 and were less than 19 years old at the time of cranioplasty. Prior systematic review of the literature along with expert opinion guided the selection of variables to be collected. These included: indication for craniectomy; history of abusive head trauma; method of bone storage; method of bone fixation; use of drains; size of bone graft; presence of other implants, including ventriculoperitoneal (VP) shunt; presence of fluid collections; age at craniectomy; and time between craniectomy and cranioplasty. RESULTS A total of 359 patients met the inclusion criteria. The patients' mean age was 8.4 years, and 51.5% were female. Thirty-eight cases (10.5%) were complicated by infection. In multivariate analysis, presence of a cranial implant (primarily VP shunt) (OR 2.41, 95% CI 1.17-4.98), presence of gastrostomy (OR 2.44, 95% CI 1.03-5.79), and ventilator dependence (OR 8.45, 95% CI 1.10-65.08) were significant risk factors for cranioplasty infection. No other variable was associated with infection. Of the 240 patients who underwent a cranioplasty with bone graft, 21.7% showed bone resorption significant enough to warrant repeat surgical intervention. The most important predictor of cranioplasty bone resorption was age at the time of cranioplasty. For every month of increased age the risk of bone flap resorption decreased by 1% (OR 0.99, 95% CI 0.98-0.99, p < 0.001). Other risk factors for resorption in multivariate models were the use of external ventricular drains and lumbar shunts. CONCLUSIONS This is the largest study of pediatric cranioplasty outcomes performed to date. Analysis included variables found to be significant in previous retrospective reports. Presence of a cranial implant such as VP shunt is the most significant risk factor for cranioplasty infection, whereas younger age at cranioplasty is the dominant risk factor for bone resorption.

Autogenous Bone Reconstruction of Large Secondary Skull Defects

BACKGROUND

The authors sought to ascertain the upper limits of secondary skull defect size amenable to autogenous reconstructions and to examine outcomes of a surgical series. Published data for autogenous and alloplastic skull reconstructions were also examined to explore associations that might guide treatment.

METHODS

A retrospective review of autogenously reconstructed secondary skull defects was undertaken. A structured literature review was also performed to assess potential differences in reported outcomes between autogenous bone and synthetic alloplastic skull reconstructions. Weighted risks were calculated for statistical testing.

RESULTS

Ninety-six patients underwent autogenous skull reconstruction for an average defect size of 93 cm (range, 4 to 506 cm) at a mean age of 12.9 years. The mean operative time was 3.4 hours, 2 percent required allogeneic blood transfusions, and the average length of stay was less than 3 days. The mean length of follow-up was 28 months. There were no postoperative infections requiring surgery, but one patient underwent secondary grafting for partial bone resorption. An analysis of 34 studies revealed that complications, infections, and reoperations were more commonly reported with alloplastic than with autogenous reconstructions (relative risk, 1.57, 4.8, and 1.48, respectively).

CONCLUSIONS

Autogenous reconstructions are feasible, with minimal associated morbidity, for patients with skull defect sizes as large as 500 cm. A structured literature review suggests that autogenous bone reconstructions are associated with lower reported infection, complication, and reoperation rates compared with synthetic alloplasts. Based on these findings, surgeons might consider using autogenous reconstructions even for larger skull defects.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

An Outcomes Comparison Between Autologous and Alloplastic Cranioplasty in the Pediatric Population

BACKGROUND

The use of alloplastic material in cranial reconstruction has been well described in the adult population, especially when a paucity of autologous tissue exists. In children it is unknown how long-term growth, however, may be affected by the implantation of nonexpansible alloplastic material. Therefore, the authors sought to compare the outcomes of pediatric patients undergoing alloplastic versus autologous cranial reconstruction.

METHODS

To assess the safety and long-term outcomes of alloplastic cranioplasty in children, an institutional review board-approved, retrospective, single institution review of pediatric patients undergoing cranioplasty was performed from 2000 to 2014. The age at surgery, cause of the cranial defect, defect size, time since initial surgery to reconstruction, implant type, and complications were assessed. Postreconstruction imaging was reviewed if available.

RESULTS

A reconstructive cranioplasty was performed in 41 pediatric patients (ages 1-19 years, average 7.35 years). Thirty patients underwent alloplastic reconstruction (age 4.37 ± 5.57 years), and 11 underwent autologous reconstruction (age 2.00 ± 3.74 years). The size of the cranial defects was 144.01 ± 393.04 cm for autologous and 405.31 ± 572.96 cm for alloplastic reconstructions. Follow-up for all patients was an average of 2.33 ± 2.76 years (0.1-9 years). No patients in either group showed evidence of elevated intracranial pressure after cranioplasty. In long-term follow-up, none of the implants were exposed or lost because of infection. Computed tomography and physical examination demonstrated that there was no skull growth restriction in either group.

CONCLUSIONS

Our data show that alloplastic cranioplasty in the pediatric population is a safe alternative, when autologous cranial bone is not available.

Titanium cranioplasty in children and adolescents

Full thickness calvarial defects present considerable challenges to reconstructive surgeons. In paediatric cases, the use of biomaterials as a substrate for cranioplasty rather than autologous bone is controversial. Alloplastic cranioplasty in adults is supported by several large case series however long term outcome of biomaterial use in paediatric cases is limited. Retrospective seven year analysis of departmental database and clinical records identified 22 patients aged under 18 who had undergone 23 custom made titanium cranioplasties by a single surgeon using the same technique. Data including patient demographics, reason for craniectomy and complications experienced following surgery was obtained. The mean age at operation was 12 years 9 months. The mean defect size was 44.3 cm(2). No significant complications related to the cranioplasty were recorded in the early post operative period or during long term review (average follow up 4 years 6 months). No cranioplasty implant required removal. This retrospective case series shows that custom made patient specific titanium cranioplasty is a viable alternative to autologous bone as a reconstructive material in paediatric patients under specific circumstances.

Split Rib Cranioplasty for Frontal Osteoma: A Case Report and Review of the Literature

INTRODUCTION

Osteomas are benign bone tumors. They generally lead to a local thickness on the frontal bone in calvarium. When they occur on the forehead, they often cause a cosmetic disorder without any neurological symptoms. The significant problem is the repair method of the cranium defect.

CASE PRESENTATION

The rib of a 34-year-old female was split and used for a small cranium defect of 3 × 3.5 cm. The preferred method and the obtained results were presented under the guidance of the literature.

CONCLUSIONS

Along with the technological advancement, different materials are employed according to the size of the cranium defect and the age of the case. The application of split costa cranioplasty for the small cranium defects in the region of patient's face is the method with the least possibility of complications, and its cosmetic and functional results are quite promising.

Rare giant frontal sinus osteoma mimicking fibrous dysplasia

OBJECTIVE

To present the first report of a giant frontal sinus osteoma treated by excision and single-stage reconstruction with custom-made titanium cranioplasty and left orbital roof prostheses.

CASE REPORT

A 31-year-old man with a history of chronic frontal sinusitis presented with a deforming, painless, midline forehead swelling of 11 years' duration, which had been treated unsuccessfully in Nigeria. Differential diagnosis included both benign and malignant bony tumours. Computerised tomography revealed a giant bony frontal sinus tumour extending beyond the sinus roof and breaching the left orbit, consistent with fibrous dysplasia. Given the extent of the tumour, open craniectomy was performed for surgical extirpation. Histological analysis identified multiple osteomas. This surgical approach achieved excellent cosmesis, with no evidence of recurrence at 12-month follow up.

CONCLUSION

Forehead swelling may pose diagnostic and management dilemmas for the ENT surgeon; however, effective management is facilitated by a multidisciplinary approach.

Costochondral Graft as Interpositional material for TMJ Ankylosis in Children: A Clinical Study

ABSTRACT

TMJ ankylosis is one of the most disruptive anomaly that affects the masticatory system. The inability to move the mandible has significant functional ramification, such as the inability to eat a normal diet. Additionally, speech is affected, making it difficult for some individuals to communicate and express themselves to others. As there are several biologic and anatomic similarities to the mandibular condyles, autogenous costochondral grafts have been considered to be the most acceptable tissue for temporomandibular joint reconstruction. In addition donor site complications are infrequent and regeneration of the rib usually occurs within a year post operatively in children.

AIM

The aim of this study was to evaluate the function of costochondral grafts to replace the mandibular condyles and to assess the position, growth, overgrowth, function, success, failure and resorption of costochondral grafts.

MATERIALS AND METHODS

Ten TMJ ankylosis patients were operated in the Department of Oral and Maxillofacial Surgery at Institute of Dental Sciences, Bareilly. Out of the 10 cases 6 were male patients and 4 female patients in age group of ≤14 years; of which 8 patients were of unilateral TMJ ankylosis and 2 were of bilateral TMJ ankylosis. All ten patients underwent interpositional gap arthroplasty with reconstruction of the condyle by costochondral graft.

RESULTS

All patients with costochondral grafts had improved mandibular symmetry and growth with adequate mouth opening.

CONCLUSION

This study indicates that using costochondral grafts to reconstruct TMJ ankylosis in children provides a good result.

Evolution of cranioplasty techniques in neurosurgery: historical review, pediatric considerations, and current trends

Cranial bone repair is one of the oldest neurosurgical practices. Reconstructing the natural contours of the skull has challenged the ingenuity of surgeons from antiquity to the present day. Given the continuous improvement of neurosurgical and emergency care over the past century, more patients survive such head injuries, thus necessitating more than ever before a simple, safe, and durable means of correcting skull defects. In response, numerous techniques and materials have been devised as the art of cranioplasty has progressed. Although the goals of cranioplasty remain the same, the evolution of techniques and diversity of materials used serves as testimony to the complexity of this task. This paper highlights the evolution of these materials and techniques, with a particular focus on the implications for managing pediatric calvarial repair and emerging trends within the field.

A surgical procedure for resecting the mouse rib: a model for large-scale long bone repair

This protocol introduces researchers to a new model for large-scale bone repair utilizing the mouse rib. The procedure details the following: preparation of the animal for surgery, opening the thoracic body wall, exposing the desired rib from the surrounding intercostal muscles, excising the desired section of rib without inducing a pneumothorax, and closing the incisions. Compared to the bones of the appendicular skeleton, the ribs are highly accessible. In addition, no internal or external fixator is necessary since the adjacent ribs provide a natural fixation. The surgery uses commercially available supplies, is straightforward to learn, and well-tolerated by the animal. The procedure can be carried out with or without removing the surrounding periosteum, and therefore the contribution of the periosteum to repair can be assessed. Results indicate that if the periosteum is retained, robust repair occurs in 1 - 2 months. We expect that use of this protocol will stimulate research into rib repair and that the findings will facilitate the development of new ways to stimulate bone repair in other locations around the body.

Outcomes of cranioplasty following decompressive craniectomy in the pediatric population

Cranioplasty is routinely performed following decompressive craniectomy in both adult and pediatric populations. In adults, this procedure is associated with higher rates of complications than is elective cranial surgery. This study is a review of the literature describing risk factors for complications after cranioplasty surgery in pediatric patients. A systematic search of PubMed, Cochrane, and SCOPUS databases was undertaken. Articles were selected based on their titles and abstracts. Only studies that focused on a pediatric population were included; case reports were excluded. Studies in which the authors assessed bone flap storage method, timing of cranioplasty, material used (synthetic vs autogenous), skull defect size, and/or complication rates (bone resorption and surgical site infection) were selected for further analysis. Eleven studies that included a total of 441 cranioplasties performed in the pediatric population are included in this review. The findings are as follows: 1) Based on analysis of pooled data, using cryopreserved bone flaps during cranioplasty may lead to a higher rate of bone resorption and lower rate of infection than using bone flaps stored at room temperature. 2) In 3 of 4 articles describing the effect of time between craniectomy and cranioplasty on complication rate, the authors found no significant effect, while in 1 the authors found that the incidence of bone resorption was significantly lower in children who had undergone early cranioplasty. Pooling of data was not possible for this analysis. 3) There are insufficient data to assess the effect of cranioplasty material on complication rate when considering only cranioplasties performed to repair decompressive craniectomy defects. However, when considering cranioplasties performed for any indication, those in which freshly harvested autograft is used may have a lower rate of resorption than those in which stored autograft is used. 4) There is no appreciable effect of craniectomy defect size or patient age on complication rate. There is a paucity of articles describing outcomes and complications following cranioplasty in children and adolescents. However, based on the studies examined in this systematic review, there are reasons to suspect that method of flap preservation, timing of surgery, and material used may be significant. Larger prospective and retrospective studies are needed to shed more light on this important issue.

Cranioplasty: Review of materials and techniques

Cranioplasty is the surgical intervention to repair cranial defects. The aim of cranioplasty is not only a cosmetic issue; also, the repair of cranial defects gives relief to psychological drawbacks and increases the social performances. Many different types of materials were used throughout the history of cranioplasty. With the evolving biomedical technology, new materials are available to be used by the surgeons. Although many different materials and techniques had been described, there is still no consensus about the best material, and ongoing researches on both biologic and nonbiologic substitutions continue aiming to develop the ideal reconstruction materials. In this article, the principle materials and techniques of cranioplasty are reviewed.

Cranioplasty prosthesis manufacturing based on reverse engineering technology

Background

Most patients with large focal skull bone loss after craniectomy are referred for cranioplasty. Reverse engineering is a technology which creates a computer-aided design (CAD) model of a real structure. Rapid prototyping is a technology which produces physical objects from virtual CAD models. The aim of this study was to assess the clinical usefulness of these technologies in cranioplasty prosthesis manufacturing.

Material/Methods

CT was performed on 19 patients with focal skull bone loss after craniectomy, using a dedicated protocol. A material model of skull deficit was produced using computer numerical control (CNC) milling, and individually pre-operatively adjusted polypropylene-polyester prosthesis was prepared. In a control group of 20 patients a prosthesis was manually adjusted to each patient by a neurosurgeon during surgery, without using CT-based reverse engineering/rapid prototyping. In each case, the prosthesis was implanted into the patient. The mean operating times in both groups were compared.

Results

In the group of patients with reverse engineering/rapid prototyping-based cranioplasty, the mean operating time was shorter (120.3 min) compared to that in the control group (136.5 min). The neurosurgeons found the new technology particularly useful in more complicated bone deficits with different curvatures in various planes.

Conclusions

Reverse engineering and rapid prototyping may reduce the time needed for cranioplasty neurosurgery and improve the prosthesis fitting. Such technologies may utilize data obtained by commonly used spiral CT scanners. The manufacturing of individually adjusted prostheses should be commonly used in patients planned for cranioplasty with synthetic material.

Split-rib reconstruction of the frontal sinus: two cases and literature review

BACKGROUND

Large defects of the anterior wall of the frontal sinus require closure using either autologous or foreign material. In cases of osteomyelitis, the reconstruction must be resistant to bacterial infection. Split-rib osteoplasty can be used in different sites.

METHODS

Two patients with malignant sinonasal tumours underwent repeated treatment, and subsequently developed osteomyelitis of the frontal bone. After adequate therapy, a large defect of the anterior wall persisted. Reconstruction was performed using the split-rib method. The literature on this topic was reviewed.

RESULTS

Both patients' treatment were successful. No complications occurred. A PubMed search on the topic of rib reconstruction of the frontal sinus and skull was performed; 18 publications matched the inclusion criteria. From these sources, we noted that 182 reconstructions yielded good results with few complications.

CONCLUSION

Large defects of the anterior wall of the frontal sinus can be closed successfully using autologous split-rib grafting. Aesthetic outcome is good and donor site morbidity is minimal.

Principles of Skull Base Reconstruction After Ablative Head and Neck Cancer Surgery

“Resection of malignancies of the skull base can result in significant functional and cosmetic morbidity as well as mortality. Reconstructive efforts provide not only functional and cosmetic rehabilitation, but also allow for the avoidance of potentially disastrous complications such as cerebrospinal fluid leak or meningitis. The optimal reconstruction is determined both by a patient based approach and a defect based approach. Skull base defects can be addressed by the separate components of the craniofacial skeleton in which they involve, and therefore the individual reconstructive issues which must be addressed. In this article, we describe an approach to skull base reconstruction and the technical aspects of the available reconstructive options.

Bioengineering of calvaria with adult stem cells

BACKGROUND

Defects of the adult skull do not heal spontaneously, producing challenging problems for the craniofacial surgeon. Reconstruction of such defects requires either the placement of alloplastic material or the harvest of autogenous bone. A technique is described for the reconstruction of critical-sized, full-thickness calvarial defects in the adult rat model using specific adult stem cells, namely, multipotent adult stem cells.

METHODS

The cells were harvested from adult skeletal muscle and cultured in an undifferentiated state within a matrix of polyglycolic acid mesh. An 8-mm critical-sized defect was created in the calvaria of adult rats and either left empty, filled with polyglycolic acid mesh alone, or filled with multipotent adult stem cells seeded into the polyglycolic acid mesh. After 12 weeks, the calvariae were harvested, stained, and blind graded by light microscopy on the presence or absence of reconstituted bone.

RESULTS

A total of 22 animals were available for study: seven from the empty defect group, eight from the polymer group, and seven from the polymer plus stem cell group. The mean scores for the three groups were 1.9, 2.3, and 5.3, respectively. Statistical analysis showed statistical significance among the groups as a whole (p < 0.01) and between the polymer plus stem cell group and the empty defect and polymer-alone group.

CONCLUSIONS

The results demonstrate that regeneration of calvarial bone is possible using stem cells harvested from adult skeletal muscle and seeded into a polyglycolic matrix. The technique may ultimately be used in clinical practice to reconstruct calvarial defects.

Cranioplasty using polymethyl methacrylate prostheses

In this retrospective study we attempted to assess the clinical performance of prefabricated polymethyl methacrylate (PMMA) prostheses and to determine whether they outperform intra-operatively moulded PMMA prostheses in reducing operating time, blood loss and surgical complications in elective delayed cranioplasty operations, after decompressive craniectomy, to repair large (> 100 cm2) cranial defects. Patients (n=131) were divided into three groups according to the cranioplasty technique used. Group 1 patients received fresh frozen autograft bone that had been removed at the craniectomy and refrigerated at -80 degrees C. Group 2 included patients whose PMMA prosthesis was moulded intra-operatively. Group 3 patients received a custom-made prefabricated PMMA prosthesis manufactured using computer-aided design/computer-aided manufacturing (CAD/CAM). Group 2 patients required significantly more operating time than both group 1 (p<0.001) and group 3 (p<0.001) patients, but operating time did not differ significantly between groups 1 and 3 (p>0.05). Mean intra-operative blood loss was significantly higher in group 2 than in group 1 (p=0.015) but did not differ significantly between group 1 and group 3 (p>0.05). The infection rate associated with prefabricated PMMA prostheses was lower than that for intra-operatively moulded PMMA prostheses and was comparable to that for autograft bone flaps. A CAD/CAM PMMA prosthesis is an excellent alternative when no autogenous bone graft harvested during craniectomy is available.

RECURRING OSTEOMA WITHIN A CALCIUM PHOSPHATE BONE CEMENT CRANIOPLASTY

OBJECTIVE

We present a unique case of a recurrent osteoma within a cranioplasty performed with calcium phosphate bone cement.

CLINICAL PRESENTATION

The patient is a 7-year-old boy who had initially undergone a craniotomy for resection of a frontal cranial tumor followed by a cranioplasty with artificial bone matrix. On routine follow-up evaluation 2 years later, the patient had a mass expanding from the cranioplasty.

INTERVENTION

At the time of reoperation, the patient was found to have a histopathologically confirmed recurrent osteoma within the artificial bone matrix. The patient later underwent repair of the frontal cranial defect using a patient-specific implant.

CONCLUSION

We discuss this unusual case, treatment, and possible causes. We believe that a safety margin and curettage of the resection border as well as resection of the overlying periosteum might prevent recurrence.

Management of postneurosurgical bone flap loss caused by infection

LEARNING OBJECTIVES

After studying this article, the participant should: 1. Be able to define indications and timing for secondary cranioplasty. 2. Understand the surgical options for reconstructing the cranium and overlying soft-tissue defect including their advantages and disadvantages. 3. Be able to apply this knowledge to the clinical setting of an infectious bone flap loss.

BACKGROUND

Infection after craniotomy occurs in approximately 1.1 to 8.1 percent of cases and often necessitates bone flap removal. For a secondary cranioplasty, there is an increased risk of recurrent infection, which influences the reconstructive plan. The soft tissue/scalp is frequently compromised by infection, sequelae of prior surgery, and/or adjuvant radiation therapy.

METHODS

A literature review was conducted to compile and summarize the indications for secondary cranioplasty after infectious bone flap loss, the timing of the procedure, and the surgical options for bone and soft-tissue reconstruction. In coordination with soft-tissue coverage, cranioplasty options include alloplastic reconstruction, allogeneic or autogenous bone grafts, and free tissue transfer.

RESULTS

The literature review identified the following factors that must be considered in the treatment plan for secondary cranioplasty after postneurosurgical bone flap loss: indications, timing of reconstruction, soft-tissue status and the need for soft-tissue reconstruction, and method of cranioplasty.

CONCLUSIONS

Treatment recommendations for cranioplasty in the clinical setting of infectious postneurosurgical bone flap loss are presented. These guidelines consider the risk factors for a recurrent infection, the condition of the soft-tissue coverage, and the concavity of the preoperative cranial deformity.

Catcher's mask cranioplasty for extensive cranial defects in children with an open head trauma: a novel application of partial cranioplasty

OBJECTIVE

In children who have suffered a severe, extensive head trauma, cranioplasty is complicated because allografting is not advisable in pediatric patients and the amount of available autologous materials is limited. To overcome these problems, we employed a combination of autologous rib grafts and calvarial grafts for partial cranioplasty.

MATERIALS AND METHODS

We named this partial cranioplasty technique 'catcher's mask cranioplasty'. Rib grafts were placed mimicking a baseball catcher's mask to obtain maximum strong coverage of the defect. Calvarial grafts were used to achieve a smooth forehead contour. Islands of osteoanagenesis were also used.

CONCLUSIONS

These autografts were of sufficient strength, esthetically satisfactory, and no patient developed sinking skin flap syndrome. Catcher's mask cranioplasty is a useful technique to successfully reconstruct the skull in pediatric patients with extensive cranial defects and an insufficient amount of autologous graft material.

Reconstruction of a large complex skull defect in a child: a case report and literature review

BACKGROUND

Major skull defects, especially in the anterior region, can present as a most disturbing deformity. Reconstructive cranioplasty can restore cerebral protection and improve craniofacial aesthetics. Complex and large skull defects in children often present reconstructive difficulties.

MATERIALS AND METHODS

In this paper, an unusual case of a very large post-traumatic defect (318 cm(2)) in a child managed by a multidisciplinary team is described. The literature is reviewed.

CONCLUSION

The management of a large complex skull defect in children is still controversial. Each case should be extensively debated in craniofacial units. In our case, bioceramics proved to be an effective and good alternative for final skull reconstruction.

Prevention of Temporal Depression That Follows Fronto-orbital Advancement for Craniosynostosis

Contour abnormalities presenting after fronto-orbital advancement for craniosynostosis are common. Often there is bilateral temporal depression, the result of leaving a coronal bony gap posterior to the advanced segments. The authors present techniques to prevent this temporal depression by utilizing full-thickness bone grafts for structural support in the inferior coronal defects, and cortico-cancellous graft in the remaining superior coronal and parietal donor defects. Prior to contouring and repositioning the frontal elements, a hand-driven Hudson brace and D'Ericco bit is used to harvest cortico-cancellous bone "mush" from the endo- and ectocortical surfaces. The bandeau and frontal elements are advanced and secured, and the resultant coronal gap is measured. Full-thickness cranial bone grafts are harvested from the parietal regions (near the vertex) and secured in the coronal defect behind the frontal elements. The temporalis muscle is rotated, advanced, and secured to the bandeau. Bone mush is used to fill the remaining superior coronal and donor site defects. Representative case examples are presented.

Expansile cranioplasty for massive occipital encephalocele

OBJECTIVE

This report highlights the management of infrequently encountered massive occipital encephaloceles with herniation of large amount of apparently functional cortex into the encephalocele sac.

MATERIALS AND METHODS

Two children with giant occipital encephaloceles with herniation of significant brain parenchyma into the encephalocele sac were managed with expansile cranioplasty and reconstruction of the calvarial defect with autologus bone graft harvested from the adjacent parietal region.

CONCLUSIONS

Giant occipital encephaloceles with significant brain parenchyma in the encephalocele sac can be considered for preservation of the herniated parenchyma and expansile cranioplasty.

Simple and safe method of cranial reconstruction after posterior fossa craniectomy

BACKGROUND

Reconstructing the posterior fossa after surgical intervention in this region is important both for prevention of postoperative complication such as headache and for cosmetic purposes. Several methods have been reported that use either synthetic or natural graft, the latter being either autograft or allograft. The previously described methods require either surgical intervention on a second setting or an additional procedure that prolongs the time of the surgery and may contribute to morbidity. The present report describes a simple modified method of reconstructing the postcraniectomy defect by using the patients' own bone dust, tissue glue, and gel foam sheets.

METHODS

The method of reconstruction requires collection of as much as possible of the produced bone dust at the time of craniectomy, adding tissue glue, placing in between 2 sheets of gel foam, and shaping it to match the surgical defect.

RESULTS

Ten cases of various posterior fossa pathologies managed at King Faisal hospital of the university between January 2000 and September 2004 had reconstruction of the posterior fossa after craniectomy during the same operative setting using the described method of cranial reconstruction. No complication was noted. Patients did not have any delayed postcraniectomy pain at reconstruction site. Postoperative plane x-ray of the skull and computed tomography showed good healing and shaping of the suboccipital bone at the surgical defect.

CONCLUSIONS

Reconstructive cranioplasty is an important part of any posterior fossa exposure. The present report describes a safe and simple method that gives acceptable results both clinically and radiologically.

Scalp and Forehead Reconstruction

The reconstruction of defects that involve the scalp and forehead presents unique aesthetic and functional challenges. This article reviews the surgical anatomy of these regions and presents an algorithm for decision making in reconstructive surgery. Nonmicrosurgical techniques are briefly reviewed. The microsurgical reconstruction of scalp and forehead defects differs from the more common oropharyngeal reconstructions in several ways, including flap choices, choices for recipient vessels, and the opportunity to use conventional and microsurgical techniques simultaneously to improve outcomes. Each of these considerations is reviewed and the authors' preferred techniques presented.

Cranioplasty in children

OBJECTIVE

The objective was to assess the outcome and complications associated with different cranioplasty implant materials in children.

MATERIALS AND METHODS

A retrospective review was conducted of 28 consecutive cranioplasties carried out on 24 children between 1994 and 2001 (age range, 9 months to 15 years; minimum follow-up 18 months). The indications were: defect from previous craniectomy for trauma, tumour, infection or evacuation of haematoma (n=21), intradiploic dermoid cysts (n=2), growing fractures (n=4) and residual bony defect following craniofacial reconstruction (n=1). The materials used were: patient's craniectomised bone flap (n=16), split calvarial graft (n=8), acrylic (n=3) and titanium (n=1). All patients were assessed for bony fixation, cosmesis, wound healing and flap infection.

RESULTS

There was no mortality and 18% morbidity (n=5: 3 infected flaps, 1 sterile wound dehiscence and 1 sterile wound discharge; overall infection rate 10%). Out of the 14 patients who had their own craniectomised bone flaps implanted initially, 3 became infected (2 in patients with bilateral defects) necessitating flap removal. Two of these were successfully re-implanted. No donor or recipient bone flap complications were seen in the 8 split calvarial grafts, wound discharge was seen in 1, requiring wound toilet. No complications were seen with acrylic or titanium cranioplasties.

CONCLUSION

In this series, the use of the patients' own craniectomised flap had a low infection rate, and was mainly seen in patients who had bilateral flaps re-implanted soon after removal. There were no complications arising from the use of split calvarial and allograft material. Use of autologous implant material should be preferred whenever possible due to obvious resource and biological advantages, and can even be re-implanted if infected.

New method of pediatric cranioplasty for skull defect utilizing polylactic acid absorbable plates and carbonated apatite bone cement

Cranial defect repair in the pediatric population requires a variety of special considerations. The pediatric skull has a dynamic nature that prohibits the use of rigid fixation, which is commonly applied in the adult population. A technique using a combination of polylactic acid plates and carbonated apatite bone cement has been devised by our group. Skull defects of varying sizes were repaired in 34 pediatric patients. Patients were examined on postoperative day 3 and at 3 months via three-dimensional computed tomography scans. Patients have been followed up to 60 months after surgery without complications or failures to date. This method benefits the pediatric patients undergoing cranioplasty by minimizing the insertion of long-term foreign bodies and allows the possibility for transformation of this construct into viable tissue.

Bone autografting of the calvaria and craniofacial skeleton: historical background, surgical results in a series of 15 patients, and review of the literature

BACKGROUND

Although the use of autologous bone for reconstruction of the cranial and facial skeleton underwent a partial reappraisal following the introduction of a vast range of alloplastic materials for this purpose, it has demonstrated definite advantages over the last century and, particularly, during the last decade.

METHODS

Fifteen patients underwent cranial and/or cranio-facial reconstruction using autologous bone grafting in the Department of Neurologic Sciences-Neurosurgery and the Division of Maxillo-Facial Surgery of the Rome "La Sapienza" University between 1987 and 1995. This group of patients consisted of 8 females and 7 males whose average age was 29.5 years (range 7.5 to 59 years, mean age 30). In all these patients cranioplasty and/or cranio-facial reconstruction had been performed to repair bone defects secondary to benign tumors or tumor-like lesions (12 cases), trauma (2 cases), or, in the remaining case, to wound infection after craniotomy for a neurosurgical operation.

RESULTS

The results obtained in a series of 15 patients treated using this method are described with reference to the abundant data published on this topic.

CONCLUSION

The mechanical, immunologic, and technical-grafting properties of autologous bone, together with its superior esthetic and psychological effects, probably make it the best material for cranioplasty.