Hardware Removal in Craniomaxillofacial Trauma: A Systematic Review of the Literature and Management Algorithm

Identification of temporal shifts of oral bacteria in bone regeneration following mandibular bone defect injury and therapeutic surgery in a porcine model

BACKGROUND

Considered the second largest and most diverse microbiome after the gut, the human oral ecosystem is complex with diverse and niche-specific microorganisms. Although evidence is growing for the importance of oral microbiome in supporting a healthy immune system and preventing local and systemic infections, the influence of craniomaxillofacial (CMF) trauma and routine reconstructive surgical treatments on community structure and function of oral resident microbes remains unknown. CMF injuries affect a large number of people, needing extensive rehabilitation with lasting morbidity and loss of human productivity. Treatment efficacy can be complicated by the overgrowth of opportunistic commensals or multidrug-resistant pathogens in the oral ecosystem due to weakened host immune function and reduced colonization resistance in a dysbiotic oral microbiome.

AIMS

To understand the dynamics of microbiota's community structure during CMF injury and subsequent treatments, we induced supra-alveolar mandibular defect in Hanford miniature swine (n = 3) and compared therapeutic approaches of immediate mandibullar reconstructive (IMR) versus delayed mandibullar reconstructive (DMR) surgeries.

METHODS

Using bacterial 16S ribosomal RNA gene marker sequencing, the composition and abundance of the bacterial community of the uninjured maxilla (control) and the injured left mandibula (lingual and buccal) treated by DMR were surveyed up to 70-day post-wounding. For the injured right mandibula receiving IMR treatment, the microbial composition and abundance were surveyed up to 14-day post-wounding. Moreover, we measured sera level of biochemical markers (e.g., osteocalcin) associated with bone regeneration and healing. Computed tomography was used to measure and compare mandibular bone characteristics such as trabecular thickness between sites receiving DMR and IMR therapeutic approaches until day 140, the end of study period.

RESULTS

Independent of IMR versus DMR therapy, we observed similar dysbiosis and shifts of the mucosal bacteria residents after CMF injury and/or following treatment. There was an enrichment of Fusobacterium, Porphyromonadaceae, and Bacteroidales accompanied by a decline in Pasteurellaceae, Moraxella, and Neisseria relative abundance in days allotted for healing. We also observed a decline in species richness and abundance driven by reduction in temporal instability and inter-animal heterogeneity on days 0 and 56, with day 0 corresponding to injury in DMR group and day 56 corresponding to delayed treatment for DMR or injury and immediate treatment for the IMR group. Analysis of bone healing features showed comparable bone-healing profiles for IMR vs. DMR therapeutic approach.

Reasons for Removal of Rigid Internal Fixation Devices in Craniofacial Surgery: A 20-year Update

The hardware utilized for rigid internal fixation of the craniofacial skeleton has evolved over time. Thus, the reasons for the unplanned removal of hardware continue to change. The purpose of this study is to compare past (1989-1995) and present (2000-2020) patient cohorts to establish trends related to unplanned removal of craniofacial hardware. A retrospective review study was designed. Data from our institution's original publication describing the unplanned removal of craniofacial hardware (1989-1995) was obtained. Data related to patients who underwent unplanned removal of hardware from 2000 to 2020 was collected from the electronic medical record. A descriptive statistical analysis was performed to compare demographics, reasons for hardware placement, and reasons for unplanned hardware removal between cohorts. This study includes 55 patients treated from 1989 to 1995 and 184 patients treated from 2000 to 2020. The average age at hardware placement decreased from 32 years (1989-1995) to 28 years (2000-2020). The most common reason for hardware placement changed from motor vehicle accident (1989-1995) to congenital deformity (2000-2020). The length of time with hardware in situ increased from 13 months (1989-1995) to 25 months (2000-2020). The most common reason for hardware removal changed from prominent hardware (1989-1995) to hardware exposure (2000-2020). In summary, patients who underwent rigid internal fixation of the craniofacial skeleton from 2000 to 2020 retained their hardware 2 times longer than patients treated from 1989 to 1995. Factors potentially contributing to increased retention include improved surgical technique, decreased profile of hardware, and increased surgeon experience. Further studies are warranted to define preoperative risk factors for unplanned hardware removal.

Osteosynthesis-associated infection in maxillofacial surgery by bacterial biofilms: a retrospective cohort study of 11 years

OBJECTIVES

The aim of this retrospective cohort study was to determine risk factors for osteosynthesis-associated infections (OAI) with subsequent necessity of implant removal in oral and maxillofacial surgery.

MATERIALS AND METHODS

A total of 3937 records of patients who received either orthognathic, trauma, or reconstructive jaw surgery from 2009 to 2021 were screened for osteosynthetic material removal due to infection. Treatment-intervals, volume of applied osteosynthetic material, and respective surgical procedures were also assessed. Moreover, intraoperatively harvested microbial flora was cultured and subsequently identified by MALDI TOF. Bacteria were then screened for antibiotic resistance via VITEK system or, if necessary, via agar diffusion or epsilometer test. Data was analyzed utilizing SPSS statistical software. For statistical analysis of categorical variables, chi-square tests or Fisher exact tests were used. Continuous variables were compared via non-parametric tests. The level of significance for p-values was set at < 0.05. Descriptive analysis was also performed.

RESULTS

The lower jaw was more prone to OAI than the mid face region. Larger volumes of osteosynthetic material led to significantly more OAI, resulting in reconstruction plates bearing the highest risk for OAI especially when compared to small-volume mini-plates frequently applied in trauma surgery. Among OAI associated with implant volumes smaller than 1500 mm3, the detection of Streptococcus spp., Prevotella spp., Staphylococcus spp., and Veillonella spp. was significantly elevated, whereas implant volumes larger than 1500 mm3 showed a significant increase of Enterococcus faecalis, Proteus mirabilis and Pseudomonas aeruginosa. High susceptibility rates (87.7-95.7%) were documented for 2nd- and 3rd-generation cephalosporines and piperacillin/tazobactam.

CONCLUSION

High material load and lower jaw reconstruction bear the greatest risks for OAI. When working with large volume osteosynthetic implants, gram-negative pathogens must be considered when choosing an appropriate antibiotic regime. Suitable antibiotics include, e.g., piperacillin/tazobactam and 3rd-generation cephalosporines.

CLINICAL RELEVANCE

Osteosynthetic material utilized in reconstructive procedures of the lower jaw may be colonized with drug-resistant biofilms.

Periodontal disease as a primary cause of surgical site infection in fractures of the mandible: is smoking a confounding variable?

Fractures of the mandible are common in contemporary oral and maxillofacial practice. Wound infection is the most common complication after open reduction and internal fixation, and the management of these is complex and costly in terms of morbidity to the patient, and in fiscal terms. Whilst numerous epidemiological studies implicate smoking, alcohol, drug use, and adverse behaviour, as well as fracture complexity and diabetes, as important risk factors, the role of periodontal disease is only occasionally mentioned and not formally investigated. The aim of this study therefore was to assess the presence of periodontal disease and its severity according to the 2018 EFP/AAP periodontitis case classification in patients with fractured mandibles who presented to a single level 1 trauma centre, and to look for a possible association with surgical site infection. A total of 305 patients were assessed retrospectively following open reduction and internal fixation via transoral incisions with load-sharing osteosynthesis. The postoperative infection rate was 22.95%. Multivariate and multiple logistic regression revealed that there was a strong association between periodontal staging and postoperative surgical site infection. Crucially, the study predicts that patients with severe periodontal disease (periodontal stage III and IV) are over seven times more likely to develop a wound infection than disease-negative individuals. This has implications for risk adjustment, prognostication, treatment planning, and postoperative care. Surprisingly in this study, cigarette smoking, an established risk factor in the pathogenesis of periodontal disease, did not achieve statistical significance, potentially conflicting with the established literature.

Management of failed stainless steel implants in the oromaxillofacial region of dogs

Management of complications of fracture fixation in the oromaxillofacial (OMF) region may present a diagnostic and therapeutic challenge. While titanium and stainless steel implants have been utilized in successful fracture fixation in the OMF region, the use of titanium implants is preferred due to the superior intrinsic properties of titanium. Nonetheless, stainless steel materials are still used due to their availability and familiarity. In the present methods report, we describe our approach to the management of failed stainless steel plates and screws used to treat traumatic injuries in the OMF region. Furthermore, we exemplify our approach with five dogs that exhibited complications of stainless steel implants in the OMF region and their subsequent management. In those cases, all failed implants were removed. Reconstruction with a combination of recombinant human bone morphogenetic protein-2 (rhBMP-2) and titanium implants was utilized in two cases while a mandibulectomy was performed in one case. Three cases required removal of the stainless-steel implant with no additional surgical therapy. We conclude that the success of treatment of failed stainless steel implants depends on the use of advanced imaging findings, appropriate antimicrobial therapy, as well as potentially regenerative reconstructive surgery.

Application of a bilateral temporal fascia free graft in a dog with multifragmented frontal sinus and nasal bone fracture

OBJECTIVE

To describe the use of temporal fascia free grafts to treat dorsal open comminuted frontal sinus and nasal fractures.

ANIMAL

One Belgian shepherd dog.

STUDY DESIGN

Case report METHODS: A 5-year-old spayed female Belgian shepherd was admitted with severe facial deformation due to trauma. A deep, 3 cm wide wound was present between the nose and the frontal sinus. No abnormalities were detected on neurological examination. On computed tomographic examination, comminuted open fractures of the frontal and nasal bones were associated with a severe depression of the dorsal wall and presence of bone fragments in the sinus cavities. Bone fragments were apposed with polydioxanone monofilament suture. Bilateral temporal fascia grafts were placed over the bone fragments.

RESULTS

The integrity of the frontal and nasal cavities, and the facial profile of the dog were restored. No short-term or long-term complications were observed after 4 months follow up.

CONCLUSION

The innovative combination of suture apposition of bone fragments and a temporal fascia free graft resulted in very satisfying long-term outcomes in a dog with open sinus and nasal bone fractures.

Hardware Removal in Maxillofacial Trauma: A Retrospective Study

Background

Miniplates are commonly used for the fixation of maxillofacial fracture segments. Removal of the hardware is controversial. A retrospective study of medical records was performed to observe the reasons for plate removal.

Materials and Methods

A 10-year retrospective study of medical records was performed. Demographics, type of fracture, location, type of miniplate used, the time gap between the insertion and removal, and causes of hardware removal were assessed.

Results

About 1472 patients had undergone internal fixation for the facial fractures. Stainless steel miniplate was used in 489 patients, and titanium was used in 983 patients. Out of the 42 cases, 22 cases involved the removal of titanium hardware and 20 patients involved the removal of stainless steel hardware. Infection/osteomyelitis was the main cause of hardware removal. The maximum amount of hardware failure was in the mandible. 78.6% of hardware removal was performed in males.

Conclusion

Based on our study, routine removal of titanium miniplates can be performed in children to avoid growth disturbances, not indicated in adult patients unless symptomatic.

Significance of Microbial Analysis during Removal of Miniplates at Infected Sites in the Craniomaxillofacial Region - An Evaluative Study

Introduction:

Open reduction and internal fixation (ORIF) can be complicated by miniplate exposure, loosening, or infection. Infected miniplates lead to exposure, extrusion, fistula formation, bony nonunion, and osteomyelitis. Whenever any posttreated cases of ORIF become infected, it is treated blindly with a high dose of antibiotics and surgical removal of infected miniplates or screws. The aim and objectives of the study were to identify the frequency and site of infection in craniomaxillofacial implants and significance of microbes isolated from the infected region.

Materials and Methods:

Removal of miniplates was being performed on 19 patients. Among them, 14 had infection or sinus opening, 3 had plate exposure, and 2 were removed asymptomatically according to patient willingness. Aspirated fluid/pus was collected and sent for microbial culture and sensitivity test. Test of significance of individual microbes was done using Z-test and the value of P was calculated.

Results:

Among 14 patients associated with miniplate infection, 11 (78%) had infection in the mandible and 3 at zygoma. The bacteria isolated were mainly Staphylococcus aureus (7) along with coagulase-negative Staphylococcus (2), Pseudomonas aeruginosa (3), Escherichia coli (2), Streptococcus salivarius (2), and Acinetobacter genre (1). S. aureus was predominantly present in majority of the samples and statistically significant at P = 0.023.

Discussion:

The present study observed that in contrast to other sites in the body, there is versatility in microbial flora in the craniomaxillofacial region. It is essential for routine microbial analysis of samples and antibiotic susceptibility test for proper treatment of such cases.

Reoperation in Zygomatico-orbital Trauma: A Review of Patients With Suboptimal Outcomes Following Initial Repair

Introduction

Treatment to restore anatomy, function, and aesthetics after trauma should involve as little surgical insult as possible. As such, repeated procedures may suggest failed initial management. To date, no predictive factors for failure of primary surgery have been identified.

Objectives

The aim of this review was to identify factors affecting the requirement for reoperation following treatment of zygomatico-orbital injuries.

Study Design and Methods

A retrospective review of patients undergoing surgery for zygomatico-orbital fractures between 2011 and 2019 in a single UK major trauma center was undertaken. All operative notes and imaging were reviewed independently by 2 authors to classify the fracture patterns for both zygomatic and orbital components of the injury. For all cases, the mode of preoperative imaging the grade of operating surgeon, materials used for fixation, and the surgical approaches were recorded.

Results

Coding data identified 432 patients who underwent surgery for zygomatico-orbital fractures. In total, 116 cases were treated with closed reduction and 316 with open reduction and internal fixation; 20 cases required reoperation. There were no significant differences identified between cases requiring reoperation and those who did not.

Conclusions

A need for repeated surgery is rare. However, this review identified an increased risk of infection of fixation when an intraoral approach was used and highlights the potential benefits that can be achieved by open reduction and internal fixation when more conservative approaches fail to achieve the desired outcome.

Nonvascularized Iliac Bone Reconstruction for the Mandible Without Maxillofacial Skin Scarring

PURPOSE

There are many methods to reconstruct the mandible, but they are often accompanied by trauma, which can lead to scarring of the maxillofacial skin. The purpose of this study was to show the utility of a minimally invasive method for reconstruction of the mandible with nonvascularized iliac bone grafts without a skin scar, as well as to evaluate the success rate and complications.

PATIENTS AND METHODS

This was a retrospective case series. We retrospectively analyzed patients who underwent transoral resection of benign mandibular pathologies, followed by nonvascularized iliac bone graft reconstruction. The primary outcome variable was the success rate of the bone grafts. Secondary outcome variables were postoperative complications at the grafted bone recipient and donor sites, the long-term absorptivity of grafted bone, and the type of mandibular defect. We computed descriptive statistics or performed the χ² test for each variable.

RESULTS

Overall, 54 patients were included in the study, including 21 male and 33 female patients, with an age range of 10 to 65 years. The complete survival rate was 87.0% (47 of 54 patients), and the partial survival rate was 98.1% (53 of 54). The average bone absorption rate 3 years after surgery was 1.8 to 30.7%. We propose a new classification method for mandibular defects based on the extent of the tumor, location of the osteotomy, and degree of surgical difficulty.

CONCLUSIONS

Intraoral nonvascularized iliac bone grafting is a highly successful minimally invasive method for mandibular reconstruction. It is also one of the best methods for mandibular reconstruction in patients with benign mandibular tumors without soft tissue involvement.

Influence of surface modifications on the degradation of standard-sized magnesium plates and healing of mandibular osteotomies in miniature pigs

Biodegradable magnesium alloys are suitable osteosynthesis materials. Despite the alloy composition, surface modifications appear to have an influence on the degradation process and biocompatibility. The aim of this study was to investigate the impact of hydrogenation and fluoridation of the surface in a mandibular osteotomy model. Standard-sized plates and screws were implanted in an osteotomy at the mandibular angle in nine miniature pigs. The plates and screws were harvested together with the adjacent tissues at 8 weeks after surgery and were investigated by micro-computed tomography and histological analysis. The bone healing of the osteotomy was undisturbed, independent of the surface properties. The adjacent bone tissue showed new bone formation at the implant surface; however, formation of some lacunae could be observed. The corrosion was between 9.8% and 11.6% (fluoridated<hydrogenated<non-modified) in histological specimens, while radiologically neither the volume nor the density of the osteosynthesis material was reduced in any treatment group. The soft tissues exhibited full biocompatibility with every surface property. In summary, surface modification by hydrogenation and fluoridation did not significantly influence bone healing, biocompatibility, or corrosion kinetics of the magnesium osteosynthesis at the mandibular angle.

Investigation of zinc‑copper alloys as potential materials for craniomaxillofacial osteosynthesis implants

In this study, zinc‑copper (ZnCu) alloys were investigated regarding their feasibility as absorbable metals for osteosynthesis implants, especially in the craniomaxillofacial area. Mechanical properties and in vitro corrosion behavior of as-rolled Zn-xCu (x = 1, 2 and 4 wt%) alloys were systematically evaluated and screened. The as-rolled Zn4Cu alloy had mechanical properties that were superior to the most absorbable craniomaxillofacial osteosynthesis materials recently reported. The addition of Cu to Zn showed to have no apparent effect on the corrosion rates of the samples. The rolling process on Zn and Zn1Cu resulted in more uniform corrosion than on as-cast counterparts after 28 days immersion. Furthermore, the Zn4Cu alloys exhibited no apparent cytotoxic effect towards L929, TAg or Saos-2 cells. Proliferation rates of TAg and Saos-2 cells were shown to be activated by specific Zn ion concentrations in the as-rolled Zn4Cu alloy extracts. Analysis of in vitro antibacterial properties revealed that the as-rolled Zn4Cu alloy possessed the potential to inhibit biofilm formation of mixed oral bacteria. We conclude that the as-rolled Zn4Cu alloy might be a promising material for fabrication of craniomaxillofacial osteosynthesis implants.

No Need to Routinely Remove Titanium Implants for Maxillofacial Fractures

PURPOSE

Titanium implants are typically used to fix maxillofacial fractures and their routine removal is a controversial topic in maxillofacial surgery. This study aimed to estimate the removal rate and risk factors associated with removal.

MATERIALS AND METHODS

The authors designed and implemented a retrospective study. Adult patients who underwent open reduction and internal fixation with titanium implants for maxillofacial fractures were included and those who returned for implant removal were identified from January 2007 to December 2016. The predictor variables were gender, age, preoperative infection, injury time, trauma cause, and fracture site. The primary outcome variable was removal of titanium implants. Descriptive and bivariate statistics were computed. Kaplan-Meier survival methods were used to estimate rate of removal. Univariate and multivariate Cox proportional hazards models were used to identify risk factors associated with removal.

RESULTS

Of 2,325 patients (1,890 men and 435 women; average age, ∼35.49 yr) registered in this study, 163 (7.01%) had their titanium implants removed and 1-, 2-, and 10-year removal rates were 3, 7, and 8%, respectively. The risk factors most closely associated with removal were preoperative infection, injury by a blow from an object, obsolete fracture, and female gender.

CONCLUSIONS

Routinely removing titanium implants in patients with maxillofacial fracture is not necessary. When the risk factors listed earlier are present in these patients, follow-up should be scheduled more frequently.

The correlation between periodontal health status and suspectibility to infections associated with craniomaxillofacial osteosynthesis plates

AIM

The aim of the present study was to demonstrate the possible relation between periodontal health status and infections associated with osteosynthesis materials (OMs) used in the oral and maxillofacial reconstruction.

MATERIAL AND METHODS

The study group consisted of 32 individuals which were subdivided into two groups regarding their PSI scores. After the removal of the osteosynthesis plates, microbial colonization was assessed via microbiological cultivation, fluorescence microscopy and scanning electron microscopy. In addition, samples obtained from gingival crevicular fluids were investigated by fluorescence microscopy.

RESULTS

A total of 118 osteosynthesis plates were examined. 8.5% (n = 10) of the plates were associated at least one of the clinical signs of infection. There was a positive correlation between periodontal disease and clinical signs of infection (p = 0.022). Patients with infection signs also had a higher number of smoking history (pack years, p = 0.010). Intraorally placed osteosynthesis plates showed wide range of bacterial colonizations compared to extraorally inserted osteosynthesis materials (p = 0.004).

CONCLUSION

Patients with poor periodontal health might be potential candidates for OM related infections. Early removal of OMs in patients with poor periodontal health status and/or heavy smokers would have clinical benefits. In addition, preferation of extraoral access to the fracture line might decrease the possibility of plate related infections.

Microflora of Retained Intracochlear Electrodes from Infected Cochlear Implants

Objectives Cochlear implant infections may be refractory to medical management and require device removal with subsequent reimplantation. During device removal, the intracochlear electrode array is commonly left in place to prevent obliteration of the cochlear lumen. If the electrode is colonized with pathogens, this risks contaminating the replacement implant. In this study, we compare the microorganisms detected on infected cochlear implants against those on the retained electrode using culture and microbial gene-sequencing techniques. Study Design Prospective single-cohort study. Setting Tertiary medical center. Subjects and Methods Six patients with refractory cochlear implant infections had the receiver-stimulator and extracochlear electrode removed to facilitate treatment of the infection. The intracochlear electrode was removed at (delayed) reimplantation. Implant specimens were analyzed by microbial culture and 16S DNA gene sequencing. Results Staphylococcus aureus was the organism most commonly identified. None of the 6 patients' intracochlear electrodes yielded microbes by culture. Two intracochlear electrodes revealed bacterial species, and 1 revealed fungal species by gene sequencing. There was no correlation between the microbes on the infected extracochlear implants and the retained intracochlear electrodes. All subjects underwent reimplantation after resolution of their infections. One of 6 subjects developed a second infection after reimplantation, with S aureus in the primary and secondary infections. Conclusions The intracochlear electrodes of infected cochlear implants carry a low microbial burden. Preserving intracochlear electrodes upon removal of infected cochlear implants appears to carry a low risk of contaminating a replacement cochlear implant.