Bioabsorbable plates and screws in pediatric craniofacial surgery: a review of 22 cases

Posterior cranial vault distraction in children with syndromic craniosynostosis: the era of biodegradable materials-a comprehensive review of the literature and proposed novel global application

Distraction osteogenesis is utilized to increase intracranial volume in the treatment of restrictive pathologies, most commonly syndromic synostosis. Children too young for open calvarial vault expansion or other systemic or local contraindications to a direct reconstructive approach benefit greatly from distraction osteogenesis, typically addressing posterior vault expansion. Wound infection, cerebrospinal fluid (CSF) leak, device failure, need for a second surgery for removal, and cost, are issues that can limit the use of this approach. These challenges are more pronounced in low- and middle-income countries (LMICs) due to lack of access to the device, the financial burden of the need for a second surgery, and the severity of the implications of infection and CSF leak. Over the last five decades, there has been an increased acceptance of bioresorbable instrumentation in craniofacial surgery. Poly L-lactic acid, polyglycolic acid, and polydioxanone are the most commonly used polymers. New resorbable fixation tools such as ultrasound-activated pins and heat-activated pins are superior to conventional bioresorbable screws in allowing attachment to thinner bone plates. In this paper, we present a review of the literature on cranial vault distraction and the use of bioresorbable materials and propose a novel design of a fully absorbable cranial distractor system using external magnetic distraction control, eliminating the need for external activation ports and a second surgery to remove the hardware. The application of this technology in LMIC settings could advance access to care and treatment options for patients with syndromic synostosis.

A Rare Case of Metal Exposure After Internal Fixation of Facial Bone Fracture With Autogenous Bone Graft

Few studies have reported complications in metal fixation systems, such as infection or device exposure. Here, we report our experience with exposed metal screws after the reduction of facial bone fracture. This will be a useful guide to using a metal fixation system in situations in which metal fixation systems should not be used.

Resorbable Versus Titanium Rigid Fixation for Pediatric Mandibular Fractures: A Systematic Review, Institutional Experience and Comparative Analysis

Study Design

Pediatric mandible fractures mandate special consideration because of unerupted teeth, mixed dentition, facial growth and the inability to tolerate maxillomandibular fixation. No consensus exists as to whether resorbable or titanium plating systems are superior with regards to clinical outcomes.

Objective

This study aims to systematically review and compare the outcomes of both material types in the treatment of pediatric mandible fractures.

Methods

After PROSPERO registration, studies from 1990-2020 publishing on outcomes of ORIF of pediatric mandible fractures were systematically reviewed according to PRISMA guidelines. An additional retrospective review was conducted at a pediatric level 1 trauma center.

Results

1,144 patients met inclusion criteria (30.5% resorbable vs. 69.5% titanium). Total complication rate was 13%, and 10% required a second, unplanned operation. Complication rates in the titanium and resorbable groups were not significantly different (14% vs. 10%; P = 0.07), and titanium hardware was more frequently removed on an elective basis (P < 0.001). Condylar/sub-condylar fractures were more often treated with resorbable hardware (P = 0.01); whereas angle fractures were more often treated with titanium hardware (P < 0.001). Within both cohorts, fracture type did not increase the risk of complications, and comparison between groups by anatomic level did not demonstrate any significant difference in complications.

Conclusions

Pediatric mandible fractures requiring ORIF are rare, and hardware-specific outcomes data is scarce. This study suggests that titanium and resorbable plating systems are equally safe, but titanium hardware often requires surgical removal. Surgical approach should be tailored by fracture anatomy, age-related concerns and surgeon preference.

Resorbable Versus Titanium Hardware for Rigid Fixation of Pediatric Upper and Midfacial Fractures: Which Carries a Lower Risk Profile?

PURPOSE

Titanium associated risks have led to interest in resorbable hardware for open reduction and internal fixation (ORIF) of pediatric facial fractures. This study aims to systematically review and compare the outcomes of titanium/resorbable hardware used for ORIF of upper/midfacial fractures to determine which hardware carries a higher complication rate in the pediatric patient.

METHODS

Studies published between 1990 and 2020 on the ORIF of pediatric upper/midfacial fractures were systematically reviewed. A retrospective institutional review was also conducted, and both arms were compiled for final analysis. The primary predictor value was the type of hardware used and the primary outcome was the presence of a complication. Fisher's exact test and 2-proportion 2-tailed z-test calculations were used to determine statistical significance, which was defined as a P value < .05. The low quality of published evidence precluded meta-analysis.

RESULTS

Systematic review of 23 studies identified 659 patients, and 77 patients were identified in the institutional review. A total of 736 patients (299 resorbable, 437 titanium) were included in the final analysis. Total complication rate was 22.8%. The titanium group had a higher complication rate (27 vs 16.7%; P < .01), and more often underwent elective hardware removal (87.3 vs 0%, P < .01). In each hardware subgroup, the incidence of complications was analyzed by fracture site. In the titanium group, complication incidence was higher when treating maxillary fractures (32.8 vs 22.9%, P = .03). When comparing the 2 hardware groups by fracture site, maxillary fractures had a higher rate of complications when treated by titanium hardware compared with resorbable hardware (32.8 vs 18%, P < .01).

CONCLUSIONS

Upper/midfacial pediatric fractures requiring ORIF, especially maxillary fractures, may be best treated with resorbable hardware. Additional hardware-specific outcomes data is encouraged.

Resorbable Implants for Orbital Fractures: A Systematic Review

BACKGROUND

Orbital fractures are one of the most common sequelae of facial trauma.

OBJECTIVE

The objective of this study was to summarize published data for resorbable implants in orbital reconstruction, including polymer composition, degradation characteristics, osteoconductivity, and complications such as enophthalmos, diplopia, and peri-implant inflammation. A literature search of the National Library of Medicine was performed via PubMed using the keyword resorbable orbital implant. A total of 27 studies were reviewed. Strength of data was assessed according to the Oxford Centre criteria.

RESULTS

Most commercially available implants provide adequate tensile strength for up to 6 months (with the exception of polydioxanone, which loses strength within 1 month, and poly(D,L-lactide) within 3 months). This is sufficient for the isolated orbital floor or medial wall (tensile strength, ~300 MPa) but insufficient for reconstruction of load-bearing areas (eg, the inferior orbital rim with tensile strength of ~1.2 GPa). Thicker products (>1 mm) have increased risk for delayed inflammation than thinner products. Postoperative complications including delayed inflammation (0%-9%), eyelid malposition (0%-5%), enophthalmos (5%-16%), diplopia (0%-16%), infection (0%-2%), and infraorbital nerve hypesthesia (2%-18%) are variably distributed across implants with several notable exceptions: poly(L-lactide) has an increased risk of delayed inflammation, and polydioxanone has a risk of delayed enophthalmos and hematoma.

CONCLUSIONS

Resorbable implants are suitable for isolated medial wall or floor fractures with intact bony buttresses and function as a barrier rather than a load-bearing support.

Tissue repair in neonatal and paediatric surgery: Analysis of infection in surgical implantation of synthetic resorbable biomaterials

BACKGROUND

There has been increased interest in the use of biomaterials that resorb completely leaving only the patient's native tissue. Synthetic materials are advantageous for tissue repair because they are highly customisable. The infection rate of using resorbable natural materials in paediatric surgery has recently been outlined, but there has not yet been a review of the use of synthetic resorbable materials in paediatric surgery.

OBJECTIVES

This systematic review analyses the risk of infection after implantation of fully resorbable synthetic biomaterials in paediatric cases.

METHODS

The literature was searched from January 1970 to January 2018 (inclusive), specifically searching for paediatric cases (0-18 years old), use of synthetic resorbable materials and infection.

RESULTS

The infection rate in 3573 cases of synthetic resorbable material implantation was 1.1% (41 cases). A Chi-squared test for independence found infection rate to vary among materials. Of the many biomaterials identified in this review, the highest infection rates were seen in Suprathel's use in burns injuries (12.1%).

CONCLUSIONS

This review found a low infection rate in synthetic resorbable materials used in paediatric surgery, with particularly strong evidence for low infection risk in LactoSorb® use.

Comparison of Resorbable Mesh (Poly L-Lactide/Glycolic Acid) and Porous Polyethylene in Orbital Floor Fractures in an Experimental Model

BACKGROUND

Resorbable mesh and porous polyethylene are frequently used alloplastic materials for the treatment of the orbital blowout fractures. The literature lacks reports comparing their long-term effects on experimental models.

OBJECTIVE

Our aim was to radiologically and histologically evaluate the effectiveness and safety of porous polyethylene and resorbable mesh in a rabbit orbital blowout fracture model.

METHODS

Twelve New Zealand white rabbits (24 orbits) were randomized to 4 groups. In group 1, only orbital floor dissection was done. In group 2, following orbital floor dissection, a 10-mm defect was created without any extra procedure. In group 3, following a 10-mm defect creation, a 12-mm-round cut porous polyethylene was placed on the defect. In group 4, following a 10-mm defect creation, a 12-mm-round cut resorbable mesh was placed on the defect. Computed tomographic analysis was performed during follow-up period. Orbital floors were evaluated histologically at month 6.

RESULTS

No clinical complications were observed during follow-up period. In radiological evaluation, there was no statistically significant difference between groups regarding bone formation. In histological evaluation, the connective tissue was denser, and organized and better bone formation was observed in group 3 and 4 when compared with other groups.

CONCLUSION

Although no significant radiological changes were present, porous polyethylene and resorbable mesh performed better histologically. They were effective and well tolerated for reconstruction of the isolated orbital floor defects.

The Efficacy of Bioabsorbable Mesh in Craniofacial Trauma Surgery

Background

The ultimate goal of craniofacial reconstructive surgery is to achieve the most complete restoration of facial functions. A bioabsorbable fixation system which does not need secondary operation for implant removal has been developed in the last decade. The purpose of this study is to share the experience of authors and to demonstrate the efficacy of bioabsorbable mesh in a variety of craniofacial trauma operations.

Methods

Between October 2008 and February 2015, bioabsorbable meshes were used to reconstruct various types of craniofacial bone fractures in 611 patients. Any displaced bone fragments were detached from the fracture site and fixed to the mesh. The resulting bone-mesh complex was designed and molded into an appropriate shape by the immersion in warm saline. The mesh was molded once again under simultaneous warm saline irrigation and suction.

Results

In all patients, contour deformities were restored completely, and bone segments were fixed properly. The authors found that the bioabsorbable mesh provided rigid fixation without any evidence of integrity loss on postoperative computed tomography scans.

Conclusion

Because bioabsorbable meshes are more flexible than bioabsorbable plates, they can be molded and could easily reconstruct the facial bone in three dimensions. Additionally, it is easy to attach bone fragments to the mesh. Bioabsorbable mesh and screws is effective and can be easily applied for fixation in various craniofacial trauma reconstructive scenarios.

Application of Materials as Medical Devices with Localized Drug Delivery Capabilities for Enhanced Wound Repair

The plentiful assortment of natural and synthetic materials can be leveraged to accommodate diverse wound types, as well as different stages of the healing process. An ideal material is envisioned to promote tissue repair with minimal inconvenience for patients. Traditional materials employed in the clinical setting often invoke secondary complications, such as infection, pain, foreign body reaction, and chronic inflammation. This review surveys the repertoire of surgical sutures, wound dressings, surgical glues, orthopedic fixation devices and bone fillers with drug eluting capabilities. It highlights the various techniques developed to effectively incorporate drugs into the selected material or blend of materials for both soft and hard tissue repair. The mechanical and chemical attributes of the resultant materials are also discussed, along with their biological outcomes in vitro and/or in vivo. Perspectives and challenges regarding future research endeavors are also delineated for next-generation wound repair materials.

[Biodegradable fixation systems in pediatric craniofacial surgery: 10-year experience with 324 patients]

INTRODUCTION

Over the past 15 years, resorbable materials have been successfully used for osteosynthesis, but their high cost prevents widespread application. However, the use of resorbable systems could be a method of choice, especially in treatment of children in the active growth period. Obviously, biodegradable materials not only are highly competitive with known metal constructs in terms of fixation rigidity, biocompatibility, and a low risk of infection but also have an undeniable advantage, such as gradual resorption allowing quick return of damaged bones to the physiological conditions of functioning. A special feature of bioresorbable systems is that they can be assembled using ultrasonic welding, which greatly facilitates the fixation process and also provides necessary rigidity, even in cases of joining very thin bones when reliable fixation with screws is impossible.

MATERIAL AND METHODS

Over the past 10 years, we have used biodegradable systems in 324 patients. In 244 of them, we used traditional (plate/screw) systems; in 80 cases, an ultrasonic welding system was chosen for osteosynthesis.

RESULTS

In the present work, we discuss, based on clinical evidence, the advantages and disadvantages of both fixation systems for reconstructive craniofacial surgery in children.

Increased Osteoid Formation in BMP-2-Loaded Silk-Based Screws

BACKGROUND

Resorbable osteosynthesis systems are used to treat craniofacial fractures. However, conventional synthetic polyester materials are potentially associated with inflammatory reaction and negative host response and may result in incomplete bone remodeling. The authors have developed a resorbable silk fibroin-based osteosynthesis system and propose that silk screws loaded with bone morphogenetic protein-2 (BMP-2) may exhibit biocompatibility and promote bone remodeling.

METHODS

Resorbable silk screws were prepared and loaded with BMP-2. The BMP-2-loaded and nonloaded silk screws were inserted into the distal femora in 15 Sprague-Dawley rats by self-tapping, similar to conventional metal systems. Animals were euthanized after 1, 3, and 6 months. The femora were explanted at the designated time points, dissected for histologic evaluation, and compared regarding osteoid formation and inflammatory response.

RESULTS

Increasing organization of newly formed bone tissue was observed over time in both groups. No appreciable difference in inflammation was noted between the BMP-2-loaded and nonloaded silk screws. Notably, mineralized collagen around the periphery of the screw appears to be greatest and more organized in the BMP-2-loaded samples. There was greater recruitment of osteoclasts and osteoblasts around the perimeter of the BMP-2-loaded screws at 3 and 6 months.

CONCLUSIONS

The BMP-2-loaded silk-based fixation device in this study exhibited characteristics comparable to the current nonloaded silk screws with regard to integration and biocompatibility. However, functionalization of silk screws with BMP-2 appeared to allow for more organized collagen and osteoid deposition after 3 and 6 months and may increase the potential of successful remodeling.

Minimally Invasive Suturectomy and Postoperative Helmet Therapy : Advantages and Limitations

Various operative techniques are available for the treatment of craniosynostosis. The patient's age at presentation is one of the most important factors in the determination of the surgical modality. Minimally invasive suturectomy and postoperative helmet therapy may be performed for relatively young infants, whose age is younger than 6 months. It relies upon the potential for rapid brain growth in this age group. Its minimal invasiveness is also advantageous. In this article, we review the advantages and limitations of minimally invasive suturectomy followed by helmet therapy for the treatment of craniosynostosis.

Delayed Foreign Body Reaction Caused by Bioabsorbable Plates Used for Maxillofacial Fractures

BACKGROUND

Bioabsorbable plates and screws are commonly used to reduce maxillofacial bones, particularly in pediatric patients because they degrade completely without complications after bone healing. In this study, we encountered eight cases of a delayed foreign body reaction after surgical fixation with bioabsorbable plates and screws.

METHODS

A total of 234 patients with a maxillofacial fracture underwent surgical treatment from March 2006 to October 2013, in which rigid fixation was achieved with the Inion CPS (Inion, Tampere, Finland) plating system in 173 patients and Rapidsorb (Synthes, West Chester, PA, USA) in 61 patients. Their mean age was 35.2 years (range, 15-84 years). Most patients were stabilized with two- or three-point fixation at the frontozygomatic suture, infraorbital rim, and anterior wall of the maxilla.

RESULTS

Complications occurred in eight (3.4%) of 234 patients, including palpable, fixed masses in six patients and focal swelling in two patients. The period from surgical fixation to the onset of symptoms was 9-23 months. Six patients with a mass underwent secondary surgery for mass removal. The masses contained fibrous tissue with a yellow, grainy, cloudy fluid and remnants of an incompletely degraded bioabsorbable plate and screws. Their histological findings demonstrated a foreign body reaction.

CONCLUSIONS

Inadequate degradation of bioabsorbable plates caused a delayed inflammatory foreign body reaction requiring secondary surgery. Therefore, it is prudent to consider the possibility of delayed complications when using bioabsorbable plates and surgeons must conduct longer and closer follow-up observations.

[Our experience about the use of resorbable plates in the treatment of craniostenosis]

INTRODUCTION

The use of resorbable plates increases for craniosynostosis surgery. This material, based on polymere (PLA, PGA) can replace steel wire and non resorbable plates. A few studies present surgical results about the use of this material with a long follow-up. We present our ten years experience of using resorbable material for craniosynostosis treatment in children.

METHODS

Between 2002 and 2012, we operated 283 craniosynostosis (98 scaphocephalies, 55 trigonocephalies, 79 plagiocephalies et 51 craniofaciostenoses). Among these surgeries, 211 were realized with resorbable material (plates and screws). Different criteria were observed: the esthetic result, the infection rate, the re-intervention, the bone defects and the inflammatory granuloma.

RESULTS

Among the 211 craniosynostosis, we found 62 plagiocephalies, 66 scaphocephalies, 50 trigonocephalies, 33 craniofaciostenoses. All the reconstructions were realized with the same resorbable material (Macropore by Medtronic). The rate of complications was low: one scar infection without participation of material for two patients (0.9%), a pseudo-meningocele for two patients (0.9%), epilepsy for four children (1.8%) and bone defect for 15 (7%). We observed no granuloma for these patients.

CONCLUSION

Our experience of ten years using resorbable material is very satisfactory. This material permits to realize solid and esthetic reconstructions with a low rate of infection without dangerous reaction for children in young age.

Evidence-based medicine: Orbital floor fractures

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Explain the epidemiology, anatomy, and pathophysiology of orbital floor fractures. 2. Select the optimal timing of--and understand the indications for-operative repair of orbital floor fractures. 3. List advantages and disadvantages of the surgical approaches and materials available for orbital floor reconstruction. 4. Identify special considerations in treating pediatric patients presenting with orbital floor fractures.

SUMMARY

This maintenance of certification module reviews the anatomy, pathophysiology, diagnosis, and management of orbital floor fractures in addition to special considerations for pediatric patients. The shows the evidence rating scale used for the literature review in creating this maintenance of certification article.

The "in situ molding technique: " an accurate and simple way to fix resorbable plates to the facial skeleton

Bioabsorbable plates developed for use in the facial skeleton have become an integral part of the craniomaxillofacial surgeon's reconstructive armamentarium. They avoid the problems associated with the retention of metal plates and can be easily contoured when heated in a thermobath. The technical process of molding and securing these devices, often through small access incisions, to achieve rigid fixation of facial fractures can be difficult. In this article, we describe a simple, novel technique that we have developed, using hot water suction irrigation, to achieve in situ molding of resorbable plates during facial fracture fixation. We used this technique to fix 123 facial fractures in 110 patients over a 4-year period. No complications secondary to the use of hot water suction irrigation were encountered.

Effects of hydroxyapatite and PDGF concentrations on osteoblast growth in a nanohydroxyapatite-polylactic acid composite for guided tissue regeneration

The technique of guided tissue regeneration (GTR) has evolved over recent years in an attempt to achieve periodontal tissue regeneration by the use of a barrier membrane. However, there are significant limitations in the currently available membranes and overall outcomes may be limited. A degradable composite material was investigated as a potential GTR membrane material. Polylactic acid (PLA) and nanohydroxyapatite (nHA) composite was analysed, its bioactive potential and suitability as a carrier system for growth factors were assessed. The effect of nHA concentrations and the addition of platelet derived growth factor (PDGF) on osteoblast proliferation and differentiation was investigated. The bioactivity was dependent on the nHA concentration in the films, with more apatite deposited on films containing higher nHA content. Osteoblasts proliferated well on samples containing low nHA content and differentiated on films with higher nHA content. The composite films were able to deliver PDGF and cell proliferation increased on samples that were pre-absorbed with the growth factor. nHA-PLA composite films are able to deliver active PDGF. In addition the bioactivity and cell differentiation was higher on films containing more nHA. The use of a nHA-PLA composite material containing a high concentration of nHA may be a useful material for GTR membrane as it will not only act as a barrier, but may also be able to enhance bone regeneration by delivery of biologically active molecules.

Pediatric orbital fractures

It is wise to recall the dictum "children are not small adults" when managing pediatric orbital fractures. In a child, the craniofacial skeleton undergoes significant changes in size, shape, and proportion as it grows into maturity. Accordingly, the craniomaxillofacial surgeon must select an appropriate treatment strategy that considers both the nature of the injury and the child's stage of growth. The following review will discuss the management of pediatric orbital fractures, with an emphasis on clinically oriented anatomy and development.

Repair of a floating sternum with autologous rib grafts and polylactide bioabsorbable struts in an 18-year-old male

Failed regeneration of costal cartilage after open repair of pectus chest wall deformities can result in a floating sternum. A floating sternum can be repaired by insertion of a rib graft between the rib and sternum, and stabilization with a metal strut. The metal implant is usually removed with a second operation. We report use of bioabsorbable struts to stabilize rib grafts during repair of a floating sternum in an 18-year-old male with a failed open repair of pectus carinatum. He had an uncomplicated peri-operative course. One year later, the sternum had a normal appearance and was sturdy. A second operation for removal of hardware was not necessary.

Maxillofacial trauma in children

Pediatric trauma involving the bones of the face is associated with severe injury and disability. Although much is known about the epidemiology of facial fractures in adults, little is known about injury patterns and outcomes in children. The most common facial fractures were mandible, nasal and maxillary/zygoma. The most common mechanisms of injury are motor vehicle collisions, violence and falls. These fracture patterns and mechanisms of injury varies with age. Cranial and central facial injuries are more common among toddlers and infants, and mandible injuries are more common among adolescents. Although bony craniofacial trauma is relatively uncommon among the pediatric population, it remains a substantial source of mortality, morbidity and hospital admissions. Continued efforts toward injury prevention are warranted. An overview of various types of fractures and their management modalities is discussed, with case reports. How to cite this article: Mukherjee CG, Mukherjee U. Maxillofacial Trauma in Children. Int J Clin Pediatr Dent 2012;5(3):231-236.

Complications of rigid internal fixation

Over the past 20 years, there have been many advances in the development of bone fixation systems used in the practice of craniomaxillofacial surgery. As surgical practices have evolved, the complications of each technologic advance have changed accordingly. Interfragmentary instability of interosseous wiring has been replaced by the risk of exposure, infection, and palpability of plate and screw fixation systems. The improved rigidity of plate fixation requires anatomic alignment of fracture fragments. Failure to obtain proper alignment has led to the phenomenon known as "open internal fixation" of fracture fragments without proper reduction. The size of the plates has decreased to minimize palpability and exposure. However limitations in their application have been encountered due to the physiologic forces of the muscles of mastication and bone healing. In the pediatric population, the long-standing presence of plates in the cranial vault resulted in reports of transcranial migration and growth restriction. These findings led to the development of resorbable plating systems, which are associated with self-limited plate palpability and soft tissue inflammatory reactions. Any rigid system including these produces growth restriction in varying amounts. In this discussion, we review the reported complication rates of miniplating and microplating systems as well as absorptive plating systems in elective and traumatic craniofacial surgery.

Biomaterials for craniofacial reconstruction

Biomaterials for reconstruction of bony defects of the skull comprise of osteosynthetic materials applied after osteotomies or traumatic fractures and materials to fill bony defects which result from malformation, trauma or tumor resections. Other applications concern functional augmentations for dental implants or aesthetic augmentations in the facial region. For ostheosynthesis, mini- and microplates made from titanium alloys provide major advantages concerning biocompatibility, stability and individual fitting to the implant bed. The necessity of removing asymptomatic plates and screws after fracture healing is still a controversial issue. Risks and costs of secondary surgery for removal face a low rate of complications (due to corrosion products) when the material remains in situ. Resorbable osteosynthesis systems have similar mechanical stability and are especially useful in the growing skull. The huge variety of biomaterials for the reconstruction of bony defects makes it difficult to decide which material is adequate for which indication and for which site. The optimal biomaterial that meets every requirement (e.g. biocompatibility, stability, intraoperative fitting, product safety, low costs etc.) does not exist. The different material types are (autogenic) bone and many alloplastics such as metals (mainly titanium), ceramics, plastics and composites. Future developments aim to improve physical and biological properties, especially regarding surface interactions. To date, tissue engineered bone is far from routine clinical application.

Surgical treatment of trigonocephaly: technique and long-term results in 48 cases

OBJECT

The authors present their experience in the surgical treatment of metopic synostosis by orbital bandeau remodeling and frontal bone rotation. The pitfalls and advantages of the surgical technique are discussed, along with the long-term clinical results in 48 consecutive cases.

METHODS

Forty-eight consecutive patients in whom trigonocephaly was diagnosed between 1990 and 2009 were treated with frontal bone rotation and frontoorbital bandeau remodeling. Of these patients, 38 (79%) were boys and 10 (21%) were girls. The age at the time of surgical treatment ranged between 4 and 42 months (mean ± SD 11.4 ± 8.7 months). The average follow-up period was 5.5 ± 4.2 years (range 5 months-19 years). The preoperative and latest postoperative photographs of the patients were evaluated for the following features: 1) shape of the forehead; 2) hypotelorism; and 3) temporal depression. Scores of 0, 1, or 2 were assigned for each item: 0 was normal, 1 meant moderate deformity, and 2 denoted severe deformity.

RESULTS

In the early postoperative period, no complications were documented. The average hospitalization period was 4 days. Follow-up radiographs or 3D CT scans were obtained at regular intervals. The mean preoperative scores for the evaluated items were 1.38 ± 0.49 for the shape of the forehead, 1.33 ± 0.48 for hypotelorism, and 1.7 ± 0.46 for the temporal depression. The mean postoperative scores were 0.06 ± 0.24 for the shape of the forehead, 0.21 ± 0.4 for hypotelorism, and 0.67 ± 0.48 for the temporal depression. Overall, the total preoperative score dropped from 4.4 to 0.93 postoperatively (p < 0.05). All the patients were contented with the cosmetic results.

CONCLUSIONS

Early detection and treatment of metopic suture synostosis has a significant, favorable influence on the outcomes. Good understanding of the structural abnormality and the pathophysiological mechanisms of the possible complications is very important for performing proper surgical reconstruction.

Stability of maxillary position after Le Fort I osteotomy using self-reinforced biodegradable poly-70L/30DL-lactide miniplates and screws

PURPOSE

The purpose of this study was to evaluate the stability of Le Fort I osteotomy using self-reinforced biodegradable poly-70L/30DL-lactide miniplates and screws.

PATIENTS AND METHODS

Nineteen patients who had Le Fort I osteotomy and internal fixation using self-reinforced biodegradable poly-70L/30DL-lactide miniplates and screws were evaluated both radiographically and clinically. Changes in maxillary position after operation were documented 1 week, 1, 3, 6 mo, and/or 1-yr postoperatively with lateral cephalometric tracings. Complications of the self-reinforced biodegradable poly-70L/30DL-lactide miniplates and screws were evaluated by follow-up roentgenograms and clinical observation. A mixed model analysis for repeated measures was used for statistical analysis.

RESULTS

Maxillary position was stable after operation with no change between time points (P > .05). There were no complications with the self-reinforced biodegradable poly-70L/30DL-lactide miniplates and screws.

CONCLUSIONS

Internal fixation of the maxilla after Le Fort I osteotomy with self-reinforced biodegradable poly-70L/30DL-lactide miniplates and screws is a reliable method for maintaining the postoperative maxillary position after Le Fort I osteotomy.

Absorbable plate strength loss during molding

Bioabsorbable plating systems play an integral role in cranial vault remodeling. After experiencing a case of plate failure requiring emergent reexploration, we investigated the potential causes. We hypothesize that extended submersion in the molding bath during plate preparation might advance the rate of hydrolysis and compromise plate structural integrity. Using an absorbable poly-D/L-lactic acid plating system, we assessed the effect of extended submersion on plate strength and stiffness when loaded in a cantilever fashion and with pure tension. We assessed these differences with the Student t test and linear regression modeling. We also generated a computer model of the plates for finite element analysis. When left in the molding bath for extended periods, the plates changed color and lost strength. After 5 minutes, 30% of maximum plate load capacity was lost in a cantilever beam test (P < 0.001) consistent with use of a 15% thinner plate. Tensile testing revealed the initial elastic modulus of 6.42 +/- 0.13 GPa decreased 16% to 5.41 +/- 0.50 GPa after 5 minutes of submersion (P = 0.027). The changes in plate strength and elastic modulus both worsened with increased submersion times. Finite element analysis of the plates also predicted clinically significant increases in plate deviation under normal loading conditions. Our study demonstrates that extended submersion of absorbable plates during molding results in a significant loss of plate strength and stiffness. Further, our computer model predicts that these changes could result in an unacceptable plate deviation under normal loading conditions. Together, these data caution against overmolding of plates to avoid compromising their structural integrity.

Bioabsorbable osteofixation devices in craniosynostosis. Clinical experience in 216 cases

INTRODUCTION

The pursuit of bone fixation systems capable of affording appropriate stability for osteosynthesis has gone through several stages from the use of metal wires, plates, and screws to the current stage of bioabsorbable systems. In our Pediatric Neurosurgery Service and Craniofacial Surgery Unit we began employing these systems in June 1997. The object of this paper is to present a review of the bioabsorbable materials most commonly used in pediatric age, and more specifically in treating craniosynostosis, to describe the characteristics of each one of them and our experience.

PATIENTS AND METHODS

From June 1997 to May 2006 we implanted bioabsorbable fixation systems in 216 patients diagnosed with craniosynostosis. Age at treatment ranged between 4 and 24 months (mean age 6.38 months). Brain computed tomography (CT) scans, and three-dimensional (3-D) reconstruction of CT scans were performed before and after treatment. An 82: 18 L-lactic acid: glycolic acid copolymer was used in 92.2% of these cases, and a 70:30 L-lactic acid: D-lactic acid copolymer was used in the remaining 7.8% of cases. The follow-up of the patients ranged between six months and five years.

RESULTS

There was no displacement of bioabsorbable plates or screws in any case. In one case (0.46%), radiological imaging revealed osteolysis underneath the implant eight months after the surgical procedure. Prominences caused by the plates and screws employed were visible in two cases (0.93%). We found fractures in the osteosynthesis mesh in two patients (0.93%). Four patients (1.85%) presented local inflammation. No alterations of cranial morphology secondary to inadequate stability were observed.

CONCLUSIONS

1) Bioabsorbable fixation systems provide excellent stability during the bone "healing" period, without a higher complication rate than with other systems. 2) They help the bone grafts keep their remodeled shape. 3) They promote reossification by preventing the bone grafts from moving after osteosynthesis. 4) No interference with normal growth of the cranial vault has been observed.

Effective correction of frontal cranial deformities using biodegradable fixation on the inner surface of the cranial bones during infancy

PURPOSE

Fixation of cranial bones in pediatric craniofacial surgery with biodegradable materials has developed into an accepted method. However, placing the fixation material on the outer surface of the cranial bone at the frontal cranium in infants can result in suboptimal cosmetic outcomes, as the plates and screws can be palpable. The placement of resorbable fixation devices on the inner surface of the skull would allow for less obvious fixation beneath the skin with a potentially superior cosmetic result. The authors report the use of such resorbable fixation devices on the inner or endocranial aspect of the cranium which appears to be novel.

MATERIALS AND METHODS

Ten patients with the mean age of 14 months (range 7-35 months) were treated with cranial remodeling using poly(lactide-co-glycolide) (PLGA) biodegradable fixation on the inner surface of the cranial bones. Five patients had trigonocephaly, four plagiocephaly, and one brachycephaly. All patients had 3D computed tomography (CT) and clinical photographs done preoperatively and postoperatively at follow-up. The outcome was judged at follow-up by clinical evaluation, photographs, 3D CT, and interview of the parents. The mean follow-up time was 3.5 years (range 0.5-6 years).

RESULTS

The primary recovery was uneventful in all cases. No wound infection occurred, but one patient had a minor skin necrosis which required a single revision operation to correct. The cosmetic outcome was scored as excellent, good, fair, or poor. There was no case with delayed union. Seven out of ten cases were judged as excellent and three as good, none as fair or poor.

CONCLUSIONS

The use of resorbable PLGA fixation devices on the inner aspect of the skull appears to provide a satisfactory cosmetic result in this small preliminary group of pediatric patients. Further long-term study of these materials in this specific location in a larger patient group is needed.

Non-syndromic trigonocephaly: surgical decision making and long-term cosmetic results

BACKGROUND

Surgical correction is often required for cosmetic correction of trigonocephaly. The purpose of this paper was to report the long-term aesthetic outcome as appreciated by the parents/patients themselves. The self-evaluation of cosmetic outcome after trigonocephaly correction has not previously been reported. The management and different surgical techniques utilized over a 16-year period are discussed.

MATERIALS AND METHODS

An observational study was undertaken of the clinical outcome, operative data, complications and cosmetic satisfaction of these trigonocephaly patients. The parents/child were asked to rate their satisfaction with the cosmetic outcome both in terms of head shape and scar appearance, on a five-point scale (excellent-5, very good-4, good-3, fair-2 and poor-1).

RESULTS

Sixty-three patients presented with non-syndromic trigonocephaly over the 16 years. Nineteen of 63 had a mild form of trigonocephaly and were managed conservatively. The remainder underwent surgical correction. Forty-two of 44 (95%) underwent fronto-orbital advancement with either barrel staving (26/44) or frontal bone rotation/re-modelling (16/44), with 2 of 44 having burring of the metopic ridge. Head shape rating was regarded as excellent in 25 of 63 (40%), very good in 18 of 63 (28%), good in 18 of 63 (28%) and fair in 2 of 63 (4%). Of those that underwent surgery, the scar was zigzag in 32 of 44 and straight in 12 of 44. Scar was rated as being excellent in 21 of 44 (48%), very good in 12 of 44 (28%) good in 11 of 44 (24%).

CONCLUSIONS

Metopic synostosis can result in varying degrees of severity. Milder forms can be treated conservatively, with more severe forms requiring both frontal bone re-modelling and fronto-orbital advancement. Surgical correction results in a high level of patient/parent satisfaction.

Comparison of Tensile Strength of Resorbable Plating Systems Used in Monocortical Mandible Angle Osteotomy Repair

OBJECTIVE

To determine the usefulness of resorbable plating systems in load-bearing applications of the mandible and the location of critical failure.

METHODS

An osteotomy was created in 24 fresh cadaveric mandibles at the angle and fixated by the Champy technique with similar resorbable craniofacial plating systems from 4 manufacturers. Each mandible was held rigid as a material test system applied a downward force anteriorly. The critical tolerance was measured and the type of failure was noted.

RESULTS

Critical failure occurred at forces from 34.6 to 137.8 N. We found a statistically significant difference between the plating groups (P<.001 for all comparisons). The point of failure was almost uniformly at the plate.

CONCLUSIONS

Critical failure was overwhelmingly due to rupture of the plate rather than to stripping or shearing of the screws as had been strongly expected. We found differences in plate strengths for this particular application and did not evaluate their respective long-term resorptive properties. We do not advocate that single resorbable plate fixation be the sole means of mandible angle fracture fixation, regardless of the plating system used.

Morphometric analysis of the effects of LactoSorb bioabsorbable plates on the craniofacial growth of rabbits using computed tomography

This study investigated the effect of bioabsorbable plates and titanium microscrews on the growth of the craniofacial skeleton of rabbits (Oryctolagus cuniculus) in the neonatal period. All animals underwent surgery at seven weeks of age and were killed at twenty-four weeks. In the study group, LactoSorb plate and PROMM titanium microscrews were positioned across the coronal suture. In the control group, only PROMM titanium microscrews were attached to the cranium. Computed tomography was used to obtain morphometric measurements of volume. Results showed no significant intergroup (P < or = 0.05) or intragroup (control group P < or = 0.01; study group P < or = 0.05) differences in craniofacial volume. Under the experimental conditions of this study, bioabsorbable plates did not affect neonatal growth of craniofacial volume in rabbits.

One-year postoperative stability of LeFort I osteotomies with biodegradable fixation: A retrospective analysis of skeletal relapse

INTRODUCTION

The purpose of this retrospective analysis was to determine the magnitude of postoperative skeletal relapse of a maxillary LeFort I osteotomy procedure performed with fixation plates and screws composed of a biodegradable copolymer (poly-L lactic and poly-L glycolic acid).

METHODS

Twenty-three consecutively treated subjects, aged 19 to 39, were diagnosed with excess vertical maxillary height or anteroposterior maxillary deficiency and treated with LeFort I impaction or advancement osteotomies. Lateral cephalometric radiographs were measured and compared for the absolute magnitude of skeletal relapse from pretreatment to immediately postoperative to 1 year after surgery.

RESULTS

Correlation analysis determined that a positive relationship existed between the magnitude of the surgical movement and the magnitude of postoperative relapse. The greatest relapse for any subject in any direction was 0.940 mm (anterior nasal spine to nasion-perpendicular). The greatest average relapses were 0.249 mm horizontally (anterior nasal spine to Frankfort horizontal) and 0.141 mm vertically (M-point Frankfort horizontal).

CONCLUSIONS

The most significant contribution of this study to surgical stability literature is reporting the absolute magnitudes of postoperative relapse over a 1-year period of observation. Consistent with previously published reports on postoperative stability, greater magnitudes of relapse were noted for larger surgical movements, yet the absolute values of postoperative relapse with biodegradable copolymers was clinically negligible. Biodegradable copolymers can provide excellent postoperative stability for superior and anterior maxillary surgical repositioning that appears to rival published stability measurements for rigid internal metallic fixation.

Self-Reinforced Ciprofloxacin-Releasing Polylactide-Co-Glycolide 80/20 Inhibits Attachment and Biofilm Formation by Staphylococcus Epidermidis

We have observed the efficiency of antibiotic-releasing polylactide-co-glycolide (PLGA) 80/20 in preventing Staphylococcus epidermidis attachment and biofilm formation in vitro. The aim of the present study was to evaluate the effect of self-reinforced (SR) implants with enhanced antibiotic release on bacterial attachment and biofilm formation rates, and also on growth inhibition of Staphylococcus epidermidis. Cylindrical SR-PLGA+AB specimens (length 30 mm, diameter 3 mm) were examined by scanning electron microscopy (SEM) for attachment of S. epidermidis ATCC 35989 on biomaterial surface and formation of biofilm, after incubating with bacterial suspension of ca. 10 cfu/mL for 1, 3, 7, 14 and 21 days. SR-PLGA and SR-PLGA+AB implants were tested on agar plates by measuring the inhibition distance around implants. On the surface of SR-PLGA+AB, at days 1, 3, 7, 14 and 21, the percentage of areas with not a single bacteria attached, was 88.6%, 71.1%, 73.7%, 73.7%, and 68.4%, respectively. On the areas where bacteria were detected, the number of bacterial cells remained low during whole study period, and no significant increase by time was seen. There was no biofilm observed on 97-99% of the examined areas during the whole study period on SR-PLGA+AB. In agar plates, the SR-PLGA+AB showed inhibition of bacterial growth, with (mean) 53.2 mm diameter of inhibition area with peeled implants and 50.5 mm with non-peeled implants. There was no inhibition seen around implants without ciprofloxacin. Bioabsorbable ciprofloxacin-releasing self-reinforced PLGA (SR-PLGA+AB) was superior to plain SR-PLGA in preventing bacterial attachment, biofilm formation, and also the growth of Staphylococcus epidermidis.

Bone Grafting in Arthroscopy and Sports Medicine

Bone graft substitutes include autografts, allografts, xenografts, and synthetics. Although autograft is still the gold standard, limited supply and donor morbidity must be considered. Allograft can vary in its bone-inductive qualities and may be processed into various shapes and constructs. Although allografts provide an osteoconductive matrix with some osteoinductivity, only limited anatomic constructs can be provided. Xenografts are abundant in supply, yet their shape and construct dimensions are restricted and xenograft properties are less than ideal due to the processing required to render the material nonimmunogenic. To achieve optimal bone graft properties, researchers are developing new materials with the goal of designing synthetics as close to autograft as possible. The advantages and disadvantages of all of these bone graft materials will be reviewed with emphasis on their relevance and applicability for sports medicine procedures.

Effects of the LactoSorb bioabsorbable plates on the craniofacial development of rabbits: direct morphometric analysis using linear measurements

The use of plates for the treatment of fractures can affect craniofacial bone development. This study investigated the effect of bioabsorbable plates and titanium microscrews on the growth of the craniofacial skeleton of rabbits (Oryctolagus cuniculus), in the neonatal period. A LactoSorb plate and PROMM titanium microscrews were positioned across the coronal suture in animals in the study group. In the control group, only PROMM titanium microscrews were attached to the cranium. Anteroposterior linear measurements were obtained using 3 different gauging devices: digital precision caliper, EKG caliper and nylon string. Frontal-nasal (FN) distances were statistically different between the left and right side when the digital caliper (P<or=0.01), EKG caliper (P<or=0.01) and nylon string (P<or=0.05) were used. Mean right-side FN distances in the control and study groups were significantly different (P<or=0.05) when measured with the EKG caliper. Normal neonatal craniofacial growth of rabbits was affected by the use of bioabsorbable plates in this study. Further studies should be conducted to investigate whether these plates affect growth in human beings.

The use of biodegradable plates and screws to stabilize facial fractures

PURPOSE

The purpose of this preliminary retrospective study was to review the demographics and outcome of patients with a variety of facial fractures that were stabilized with PL bone plates and screws.

MATERIALS AND METHODS

The records of 295 consecutive patients with facial fractures treated by open reduction and internal fixation, performed by the author from 2001 through 2004, were retrospectively reviewed. Patients were selected to receive biodegradable fixation on the basis of mechanism of injury, the degree of bony displacement demonstrated on clinical and radiographic examination, patient age, and fracture pattern or location. Outcome measures such as infection, non-union, and mal-union were identified and subjectively assessed. Descriptive statistics were recorded and analyzed.

RESULTS

Two hundred eighty-one patients met the criteria for inclusion in the study with follow-up of 3 weeks to 3 years. Fifty-nine (21%) patients were identified as having received biodegradable plates and screws. All patients eventually went on to satisfactory healing with favorable restoration of form and function. Complications occurred in 16 patients overall (6%). Of these, 2 patients were treated with resorbable plates and screws; 1 patient with a zygomatico-maxillary complex fracture developed a sterile abscess that presented 1 year postoperatively and responded to local measures. Another patient with a Le Fort I fracture developed an anterior open bite necessitating Le Fort I osteotomy for correction.

CONCLUSIONS

Favorable healing can be observed through the use of biodegradable PL plates and screws to stabilize selected midface fractures in patients of all ages, as well as mandible fractures in early childhood.

Craniofacial muscle engineering using a 3-dimensional phosphate glass fibre construct

The current technique to replace missing craniofacial skeletal muscle is the surgical transfer of local or free flaps. This is associated with donor site morbidity, possible tissue rejection and limited supply. The alternative is to engineer autologous skeletal muscle in vitro, which can then be re-implanted into the patient. A variety of biomaterials have been used to engineer skeletal muscle with limited success. This study investigated the use of phosphate-based glass fibres as a potential scaffold material for the in vitro engineering of craniofacial skeletal muscle. Human masseter (one of the muscles of mastication)--derived cell cultures were used to seed the glass fibres, which were arranged into various configurations. Growth factors and matrix components were to used to manipulate the in vitro environment. Outcome was determined with the aid of microscopy, time-lapse footage, immunofluorescence imaging and CyQUANT proliferation, creatine kinase and protein assays. A 3-dimensional mesh arrangement of the glass fibres was the best at encouraging cell attachment and proliferation. In addition, increasing the density of the seeded cells and using Matrigel and insulin-like growth factor I enhanced the formation of prototypic muscle fibres. In conclusion, phosphate-based glass fibres can support the in vitro engineering of human craniofacial muscle.

Surgical Site Infections after Pediatric Intracranial Surgery for Craniofacial Malformations: Frequency and Risk Factors

OBJECTIVE:

Surgical site infections (SSIs) after pediatric intracranial surgery for craniofacial malformations are relatively common and potentially serious nosocomial infections. Despite this, few studies have been published on this topic. We performed a retrospective study to determine the incidence of and factors associated with SSIs after intracranial surgery for craniofacial malformations at a single multidisciplinary craniofacial center during a 6-year period.

METHODS:

Retrospective chart review was performed on 254 patients who underwent 281 intracranial procedures during a 6-year period. Patients with SSIs (cases) were compared with those without SSIs (controls). National Nosocomial Infection Surveillance System criteria were used to identify cases of SSI.

RESULTS:

SSIs occurred in 9 (3.2%) of 281 intracranial procedures that took place during the study period. Factors associated with an SSI included a complicated diagnosis comprising a diagnosis of syndromic craniosynostosis, frontonasal dysplasia, or oblique facial cleft (odds ratio [OR], 13.0; 95% confidence interval [CI], 2.6–64.4); duration of surgery longer than 426 minutes (OR, 12.1; 95% CI, 2.4–59.9); closure of skin under tension (OR, 12.5; 95% CI, 3.0–52.6); use of bovine pericardium (OR and 95% CI undefined); more than four surgeons present during surgery (OR, 6.3; 95% CI, 1.2–32); pediatric intensive care unit stay longer than 2 days (OR, 10.8; 95% CI, 2.2–53.3); and use of a ventilator after surgery (OR, 4.8; 95% CI, 1.2–18.6).

CONCLUSION:

In this study, the presence of a complicated diagnosis and a number of other factors were associated with an SSI after pediatric intracranial surgery for craniofacial malformations. We speculate that a complicated diagnosis may be a marker for other factors that contribute to the risk of an SSI. Future studies investigating SSIs after intracranial surgery should consider these factors.

Complications of bioresorbable fixation systems in pediatric neurosurgery

OBJECTIVE

Bioresorbable devices are an attractive alternative to metal instrumentation for internal fixation of bone, and have been used extensively in orthopedic and craniofacial surgery. In neurosurgery, the reported literature is predominantly confined to pediatric craniofacial procedures, with encouraging results and minimal complications. We have used bioreabsorbable plates and screws in cranial and spinal pediatric neurosurgery procedures. We report four complications related to their usage.

MATERIALS AND METHODS

Bioabsorbable instrumentation was used in pediatric patients for fixation of bone after cranial or spinal procedures.

RESULTS

Four patients developed complications related to the instrumentation: 2 following cranial surgery for epilepsy, 1 after correction of a growing skull fracture, and 1 after laminotomy for an intramedullary tumor. Two patients had fibrous encapsulation with granuloma formation and 2 patients had osteolysis following the fixation.

CONCLUSION

Bioabsorbable fixation devices for the stabilization of bone following craniotomy and laminotomy in pediatric patients may be associated with complications, including granuloma formation and osteolysis.

A randomized controlled trial of resorbable versus titanium fixation for orthognathic surgery

OBJECTIVES

To determine any differences in the intra- and postoperative morbidities and complications between resorbable and titanium plating systems for fixation in orthognathic surgery.

STUDY DESIGN

This prospective randomized clinical trial was conducted in the Oral and Maxillofacial Surgery unit of the University of Hong Kong. Patients with dentofacial deformities were randomly assigned into the titanium and resorbable fixation groups. Intraoperative data such as the surgical procedures, time for fixing each plate, and number of broken plates and screws were recorded. Subjective and objective parameters related to clinical morbidities were assessed postoperatively.

RESULTS

A total of 60 patients with 177 osteotomies were included in this study. Eighty-seven osteotomies fixated with 196 titanium plates and 784 titanium screws were performed in 30 patients, whereas 90 osteotomies fixated with 165 resorbable plates and 658 resorbable screws were done in another 30. The postoperative infection rate was 1.53% (3/196) and 1.82% (3/165) in the titanium and resorbable fixation groups, respectively. These infections were mainly due to loose screws and wound dehiscence. The plate exposure rate was 1.02% (2/196) for the titanium group and 1.21% (2/165) for the resorbable group. The plate removal rate in the titanium and resorbable groups was 1.53% (3/196) and 3.63% (6/165), respectively. Statistically significant difference was shown in the plating time of step (mandibular body) and Hofer (mandibular subapical) osteotomies. There was no significant difference in the subjective clinical parameters such as wound discomfort, clinical stability of the osteotomy segments, palpability of plate, and overall satisfaction of the results between the 2 fixation groups. Similarly, objective parameters including wound dehiscence, rate of infection, plate exposure, occurrence of sinus tract, and palpability assessed by surgeons in both groups also showed no significant difference.

CONCLUSION

Bioresorbable fixation devices offer similar function as titanium in fixation for orthognathic surgery and do not impose an increase in the clinical morbidities.