Tacks: a new technique for craniofacial fixation

Evaluation of neurosurgical implant infection rates and associated pathogens: evidence from 1118 postoperative infections

OBJECTIVE

Various implanted materials are used in neurosurgery; however, there remains a lack of pooled data on infection rates (IRs) and infective bacteria over past decades. The goal of this study was to investigate implant infections in neurosurgical procedures in a longitudinal retrospective study and to evaluate the IRs of neurosurgically implanted materials and the distribution of pathogenic microorganisms.

METHODS

A systematic literature search was conducted using PubMed and Web of Science databases for the time period between 1968 and 2018. Neurosurgical implant infections were studied in 5 subgroups, including operations or diseases, implanted materials, bacteria, distribution by country, and time periods, which were obtained from the literature and statistically analyzed. In this meta-analysis, statistical heterogeneity across studies was tested by using p values and I2 values between studies of associated pathogens. Egger’s test was used for assessing symmetries of funnel plots with Stata 11.0 software. Methodological quality was assessed to judge the risk of bias according to the Cochrane Handbook.

RESULTS

A total of 22,971 patients from 227 articles satisfied the study’s eligibility criteria. Of these, 1118 cases of infection were reported, and the overall IR was 4.87%. In this study, the neurosurgical procedures or disorders with the top 3 IRs included craniotomy (IR 6.58%), cranioplasty (IR 5.89%), and motor movement disorders (IR 5.43%). Among 13 implanted materials, the implants with the top 3 IRs included polypropylene-polyester, titanium, and polyetheretherketone (PEEK), which were 8.11%, 8.15%, and 7.31%, respectively. Furthermore, the main causative pathogen was Staphylococcus aureus and the countries with the top 3 IRs were Denmark (IR 11.90%), Korea (IR 10.98%), and Mexico (IR 9.26%). Except for the low IR from 1998 to 2007, the overall implant IR after neurosurgical procedures was on the rise.

CONCLUSIONS

In this study, the main pathogen in neurosurgery was S. aureus, which can provide a certain reference for the clinic. In addition, the IRs of polypropylene-polyester, titanium, and PEEK were higher than other materials, which means that more attention should be paid to them. In short, the total IR was high in neurosurgical implants and should be taken seriously.

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.

Use of Absorbable Poly (D,L) Lactic Acid Plates in Cranial-Vault Remodeling: Presentation of the First Case and Lessons Learned about Its Use

Objective

To present the first clinical use of a new bioabsorbable material, poly (D,L) lactic acid (PDLLA), in pediatric cranial-vault remodeling procedures. This discussion will highlight the benefits and detriments of PDLLA in comparison with currently used absorbable plating systems.

Design

This was a case study documenting the first North American case in which PDLLA was used to treat craniosynostosis.

Materials and Methods

Evaluation of pure PDLLA, a copolymer product of the mixture of poly L-lactic acid and its D-isomer, was used in an 8-month-old boy with a severe phenotypic expression of sagittal craniosynostosis. No signs of elevated intracranial pressure were present, and the neurological examination did not show impairments. Total cranial-vault remodeling with the “hung-span” technique was performed. The Resorb X system, containing 2.2-mm screws and 0.6- to 1-mm-thick plates, was used to stabilize the reconstructed cranial vault.

Results

No surgical complications occurred. The preoperative cranial index measured 62. The scaphocephalic appearance of the skull was eliminated, and the cranial index was normalized to 77. The screws and plates were less palpable than other plating systems. Twelve months postoperatively, none of the plates and screws were identifiable by external palpation.

Conclusion

Resorb X has been successfully used in the treatment of sagittal craniosynostosis. Its rapid rate of resorption and lower profile make it an advantageous system for pediatric skull reconstruction. This represents the first use of this product in the United States for any pathology.

[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.

Management of pediatric mandibular fractures using bioresorbable plating system - Efficacy, stability, and clinical outcomes: Our experiences and literature review

AIMS

The purpose of this study was to determine the efficacy and stability of the biodegradable fixation system for treatment of mandible fractures in pediatric patients by measuring the bite force.

METHODS

Sixty pediatric patients with mandibular fractures (36 males, 24 females) were included in this study. The 2.5-mm resorbable plates were adapted along Champy's line of ideal osteosynthesis and secured with four 2.5 mm diameter monocortical resorbable screws, 8 mm in length. All patients were followed for 10 months. Clinical parameters, such as soft tissue infection, nonunion, malunion, implant exposure, malocclusion, nerve injury, and bite force for stability, were prospectively assessed.

RESULTS

Adequate fixation and primary bone healing was achieved in 100% of the cases. Six minor complications (10%) were observed: 2 soft tissue infections (3%), 1 plate dehiscence (2%), 1 malocclusion (2%), and 2 paresthesia (3%).

CONCLUSION

2.5-mm resorbable plating system along Champy's line of ideal osteosynthesis is a good treatment modality for mandible fractures in pediatric patients.

One-piece frontoorbital advancement with distraction but without a supraorbital bar for coronal craniosynostosis

Traditional frontoorbital advancement with a supraorbital bar is the standard technique for correcting coronal craniosynostosis. However, several recent reports indicate that cranioplasty using distraction osteogenesis may be an alternative. To maximize the advantages of distraction, preservation of the dura attachment to the frontal bone appears to be important. Therefore, we designed a novel procedure for coronal craniosynostosis involving a one-piece frontoorbital advancement with distraction but without a supraorbital bar using only a small temporal burr hole. The novel one-piece frontoorbital advancement technique was used in 10 coronal craniosynostotic patients. Follow-up ranged from 8-28 months (mean 16.2 months). Osteotomy on the fronto-parietal area was performed using a saw, and a burr hole of <1.5 cm was made at the 'pterion'. While referring to a rapid prototype model, osteotomies in the orbital roof, zygomatico-frontal, nasion areas and pterion were performed using a guarded osteotome to protect the dura mater. Distraction devices were applied without detachment of the bone flap from the dura (standard cranial distraction protocols were used). The present technique resulted in minimal bleeding, shorter surgery time and minimization of the bony defect with preservation of the dural attachment. The 1.5 cm burr hole allowed visualization of the greater and lesser sphenoid bone wings, which is necessary for a safe osteotomy. The average length of distractions was 17 mm. This approach was less invasive than the traditional approach and resulted in satisfactory correction. Transfusions were not required for six patients, while the remaining four patients received a mean 37.3 ml packed red cells. The average cephalic index decreased from 96 to 86. There were no complications other than a case of meningitis which resolved following intravenous antibiotic administration. The present novel technique appears to be a good alternative surgical approach for treating non-complex forms of single suture coronal craniosyntosis.

Síntese e caracterização do copolímero poli (L-co-D,L Ácido Láctico)

A aplicação de polímeros biorreabsorvíveis em próteses temporárias é constante nos procedimentos médicos relacionados a fraturas ósseas. Dentre os polímeros bioreabsorvíveis, o poli(L-co-D, L ácido láctico), PLDLA, na relação 70:30, tem sido estudado visando à obtenção de placas e parafusos para a recuperação de traumas nas regiões buco e crâniomaxilofacial. Nessa relação de monômeros obtém-se um polímero amorfo, o que permite uma adaptação do dispositivo ao local do implante durante a cirurgia. Um fator limitante para o uso desse polímero é seu alto custo em função da importação. Neste trabalho o PLDLA foi sintetizado através da polimerização em massa dos monômeros cíclicos do L-ácido láctico e do D, L ácido láctico, utilizando como catalisador o Sn(Oct)2. Obteve-se material de alta massa molar (Mw = 10(5) g/mol), o qual foi caracterizado por ¹H RMN, 13C RMN, GPC, FTIR e DSC.

Long-term magnetic resonance imaging evaluation of bioresorbable anterior cervical plate resorption following fusion for degenerative and traumatic disk disruption

STUDY DESIGN

A retrospective magnetic resonance imaging (MRI) review of a series of patients who underwent a single-level anterior cervical discectomy and fusion followed by anterior plate stabilization using an anterior cervical resorbable mesh plate and screw system.

OBJECTIVE

MRI evaluation of the long-term implant resorption properties of a bioresorbable anterior cervical plate and the adjacent peri-implant soft tissue environment.

SUMMARY OF BACKGROUND DATA

The use of bioresorbable anterior cervical plates for immediate cervical stabilization following an anterior cervical discectomy and fusion presents several distinct advantages over metallic instrumentation. Bioresorbable polymers may diminish, by their resorbability, implant-related complications such as loosening, migration, and failure of instrumentation, as well as stress shielding of the underlying fusion. Information on the intermediate and long-term bony and soft tissue reaction to the resorption byproducts of these biomaterials is limited.

METHODS

There were 9 consecutive patients who underwent single-level anterior cervical decompression and fusion using allograft cortical bone, followed by bioresorbable polylactide anterior mesh plate and screw fixation. Following institutional review board approval, 5 of the 9 patients agreed to postoperative MRI assessment of the peri-implant area. An independent radiologist then characterized implant degradation, and the presence of soft tissue inflammation and swelling during the resorption phase of the bioresorbable plate.

RESULTS

At an average follow-up of 32 months, MRI assessment showed no evidence of soft tissue swelling or inflammation related to the resorption of a bioresorbable anterior plate in any of the 5 patients. In addition, none of the patients complained of any dysphagia or phonation difficulties.

CONCLUSIONS

Based on MRI assessment, these devices, at more than 2-year follow-up, did not indicate any local chronic inflammation or swelling resulting from their degradation. Clinical symptoms of dysphagia or dysarthria, a common reported problem following anterior cervical spine procedures, were not observed in any patient.

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.

A Resorbable Rivet System for Pediatric Craniofacial Surgery: Biomechanical Testing and Clinical Experience

The use of a new method of bone fixation for pediatric craniofacial surgery was evaluated by both biomechanical tests and clinical use. A "pull-back" rivet composed of 82% poly-L-lactic acid and 18% polyglycolic acid (LactoSorb) for use with resorbable plates was developed to obviate the traditional hand-tapping technique used for the placement of resorbable screws. In in vitro testing, the average failure load of the rivets in uniaxial pullout was nearly 50 kg and approximately 75 kg in shear. Approximately two thirds of their initial strength was retained by 6 weeks. In clinical testing, 10 patients undergoing cranial vault reconstruction were treated by 1.5-mm resorbable plates secured by rivets. Although postoperative clinical outcomes were unaffected, good engagement of the devices with secure plate fixation was obtained in only about 70% of the rivets fired. Although the novel approach of a pull-back rivet was encouraging in both design and in vitro testing, its clinical use is impaired by the sensitivity of the device to the thickness of the bone into which it is placed, as well as its larger diameter compared with resorbable screws.

MacroPore resorbable devices in craniofacial surgery

Resorbable polymer implants have become a compelling option in the treatment of acquired and congenital craniofacial deformities. The resorbable polylactide (PLa) and polyglycolide (PGa) polymers in particular have demonstrated excellent safety profile sin multiple in vitro, animal, and clinical studies and are currently being used in a wide variety of craniofacial applications. In this article, the authors discuss the biomaterial properties of PLa and PGa resorbable implants and provide an overview of the use of these polymers in craniofacial surgery. They conclude by relating their experience with an ongoing clinical series using MacroPore PLDLa and FRP implants for various applications,including Le Fort osteotomies, midface/monobloc internal distraction, and craniosynostosis reconstruction.

Seprafilm superior to Gore-Tex in the prevention of peridural fibrosis

OBJECT

This is an investigation into the effects of two barrier membranes in the prevention of peridural fibrosis in an animal model.

METHODS

Seprafilm or Gore-Tex was applied to a laminectomy defect overlying the dura mater in rats separated into treatment groups. A third group of rats underwent laminectomy only and served as controls. Two months postoperatively a histological study was performed to compare the amount of scar tissue in each group. The gross dissection demonstrated that both membranes created a controlled dissection plane, facilitated access to the epidural space, and provided a reduction in the amount of tissue adhering to the dura mater. Statistically, Seprafilm was superior to Gore-Tex in preventing peridural fibrosis (p < 0.05).

CONCLUSIONS

Seprafilm can prevent peridural fibrosis better than Gore-Tex and can be used in humans in spinal surgery.

Craniofacial reconstruction with a fast resorbing polymer: a 6- to 12-month clinical follow-up review

OBJECT

Resorbable polymer implants have become a compelling option in the treatment of acquired and congenital craniofacial deformities. In particular, the resorbable polylactide and polyglycolide polymers have demonstrated excellent safety profiles in multiple in vitro, animal, and clinical studies and are currently being used in a wide variety of craniofacial applications. In pediatric craniofacial reconstruction a desirable attribute of fixation is early resorption, which may limit the duration of any effect on cranial growth. In this paper the authors discuss the biomaterial properties of a fast resorbing polymer (FRP) and the clinical results in a series of patients who participated in a 6- to 12-month study.

METHODS

The authors performed craniofacial reconstruction by using FRP implants in 29 patients beginning in August 2002. All patients experienced maintenance of stable bone fixation followed by bone healing. Cosmetic results were rated satisfactory or excellent, except for one unsatisfactory cosmetic result caused by disease progression.

CONCLUSIONS

Results of this study support the effectiveness of an FRP implant in a variety of craniofacial surgical procedures including craniosynostoses, fibrous dysplasia, cranial defects, and encephaloceles.

Lumbar interbody fusion after treatment with recombinant human bone morphogenetic protein–2 added to 70:30 poly(L-lactide-co-D,L-lactide) bioresorbable implants

Object

To evaluate the effectiveness of recombinant human bone morphogenetic protein–2 (rhBMP-2) combined with a bioresorbable implant, the authors conducted a prospective study of 43 patients with degenerative lumbar disc disease who underwent transforaminal lumbar interbody fusion.

Methods

The authors used Infuse bone graft, which consisted of rhBMP-2 applied to an absorbable collagen sponge and contained within a HYDROSORB Telamon bioresorbable implant to perform the fusion. Multilevel fusions were performed in 30% of the 43 patients, for a total of 57 levels. At 6 months postoperatively, x-ray films and computerized tomography (CT) scans demonstrated solid fusion in 98% of 41 patients. Improvement from the baseline Oswestry Disability Rating was demonstrated at 6 months postoperatively in 68% of the patients, based on the Oswestry Disability Questionnaire. At 12 months all 11 patients in whom CT scans were obtained showed complete bridging of bone; there were no device-related complications.

Conclusions

Results in this series provide evidence of the feasibility of using HYDROSORB Telamon biore-sorbable spacers in combination with Infuse bone graft for lumbar spine fusion.

Use of polylactide resorbable film as an adhesion barrier

OBJECT

The present investigation evaluates two thicknesses of a resorbable polylactic acid (PLA) barrier film as an adhesion barrier to posterior spinal scar formation.

METHODS

A readily contourable, thin film was placed directly over the dura. The thick film was placed above the lamina defect to act as a physical barrier inhibiting the prolapse of soft tissue into the epidural space. Through a combination of gross dissection with and without scar scores, quantitative analysis of collagen adjacent to the scar site, and histological evaluation, the resorbable adhesion barrier membranes were found to be effective treatment for reduction of posterior adhesions.

CONCLUSIONS

The gross dissection demonstrated that both thicknesses of resorbable PLA barrier films created a controlled dissection plane, facilitated access to the epidural space, and provided a reduction in the tissue adherent to the dura.

Use of a resorbable sheet in iliac crest reconstruction in a sheep model

OBJECT

Iliac crest bone graft harvesting can result in major complications, the rates of which range from approximately 6 to 8%. The objective of this study was to evaluate the postoperative regeneration of iliac crest donor defects in an animal model after harvesting a full-thickness tricortical graft.

METHODS

In skeletally mature sheep, a tricortical iliac crest graft was harvested. The graft sites were allowed to heal unprotected or protected with the resorbable polylactic acid sheet material, MacroPore OS Protective Sheeting. After 6 months of healing, the sites were assessed by examination of undecalcified histological sections. Histomorphometric measurements of the original defect area, the area of new bone within the defect site, and the percentage of defect filled with new bone were quantified for both control and protected groups. In all histological sections, new bone growth within the defect sites appeared normal, with no observed excessive inflammatory cells. The developing bone tissue appeared to be remodeling normally. For the unprotected sites, the area of new bone averaged 16.3 mm2 (+/- 7.2 mm2), and the percentage of the defect area filled with bone averaged 10.7% (+/- 6.5%). In the protected sites, the area of new bone averaged 64.8 mm2 (+/- 11.6 mm2) and the percentage of the defect area filled with bone averaged 25.9% (+/- 1.6%). Both differences in area of new bone growth and percentage of defect area filled were statistically significant. Literature review has indicated that regeneration of donor site defects is desirable.

CONCLUSIONS

Based on the results of the present study, MacroPore resorbable Protective Sheeting can improve bone regeneration significantly within the donor site following tricortical iliac crest graft harvesting.

Use of polylactide resorbable film as an adhesion barrier

The present investigation evaluates two thicknesses of a resorbable polylactide barrier film as an adhesion barrier to posterior spine scar formation. A readily contourable, thin film was placed directly over the dura. The thick film was placed above the lamina defect to act as a physical barrier inhibiting the prolapse of soft tissue into the epidural space. Through a combination of gross dissection with and without scar scores, quantitative analysis of collagen adjacent to the scar site, and histologic evaluation, the resorbable adhesion barrier membranes were found to be effective treatment for reduction of posterior adhesions. The gross dissection demonstrated that both thicknesses of resorbable polymer barrier films created a controlled dissection plane, facilitated access to the epidural space, and provided a reduction in the tissue adhered to the dura.

Use of a resorbable sheet in iliac crest reconstruction in a sheep model

Iliac crest bone graft harvesting can result in major complications that occur at rates of approximately 6%-8%. The objective of this study was to evaluate the postoperative regeneration of iliac crest donor defects in an animal model after harvesting a full-thickness tricortical graft. In skeletally mature sheep, a tricortical iliac crest graft was harvested. The graft sites were allowed to heal nonprotected or protected with the resorbable polylactic acid sheet material, MacroPore OS Protective Sheeting, (MacroPore Biosurgery, San Diego, Calif). After 6 months of healing, the sites were assessed by examination of undecalcified histologic sections. Histomorphometric measurements of the original defect area, the area of new bone within the defect site, and the percentage of defect filled with new bone were quantified for both control and protected groups. In all histologic sections, new bone growth within the defect sites appeared normal, with no excessive inflammatory cells observed. The developing bone tissue appeared to be remodeling normally. For the nonprotected sites, the area of new bone averaged 16.3 mm2 (+/-7.2 mm2), and the percentage of the defect area filled with bone averaged 10.7% (+/-6.5%). In the protected sites, the area of new bone averaged 64.8 mm2 (+/-11.6 mm2) and the percentage of the defect area filled with bone averaged 25.9% (+/-1.6%). Both differences in area of new bone growth and percentage of defect area filled were statistically significant. Literature review has indicated that regeneration of donor site defects is desirable. Based upon the results of the present study, MacroPore resorbable protective sheeting can improve bone regeneration significantly within the donor site following tricortical iliac crest graft harvesting.