Critical computed tomographic diagnostic criteria for frontal sinus fractures

Frontal Sinus Fractures: A Review on Etiology and Management Emphasizing Minimally Invasive and Endoscopic Techniques

ABSTRACT

In spite of a long and tortuous history of the acute management of frontal sinus fractures, current optimal management remains steeped in controversy. These fractures are frequently produced by excessive forces and are often accompanied with other injuries. However, disruption of the nasofrontal duct persists as essential to maintain proper sinus function and should guide current management. Although there has never been any distinct procedure defining optimal outcomes, proper treatment is contingent on precise diagnosis culled from a complete history, physical examination, and imaging studies. This is further augmented by the surgeon's intraoperative findings. Reconstruction will ultimately rest on the degree of disruption of the anterior and posterior sinus walls, as well as the status and function of the nasofrontal ducts. For these reasons, current management continues to be challenging and evolving. Thus, this review will discuss the etiology and clinical presentation of frontal sinus fractures, the current complications arising in the subject, and the evolution of treatment options towards a more conservative and endoscopic approach to care.

Frontal sinus fracture management: a systematic review and meta-analysis

A systematic review of the frontal sinus fracture management literature was undertaken to document measurable outcomes, with emphasis on complications associated with the various treatment strategies. A comprehensive electronic search was undertaken in October 2018. Randomized controlled trials (RCT), controlled clinical trials, retrospective and prospective studies describing the management of frontal sinus fractures and complications were included. Twenty-four publications were included: one reporting a prospective RCT and 23 reporting consecutive case series studies (four prospective, 19 retrospective). These included 2388 patients (84.1% male, average age 23-43 years); 50.7% of cases were due to motor vehicle accidents and 61.8% had a concomitant intracranial injury. There were six categories for anterior table reconstruction, three endoscopic surgery categories, 11 for obliteration, and six for cranialization. Forest plots demonstrating complications based on the Clavien-Dindo classification of 1 ('low') and >3 ('high') were determined for total, early, and late complications, with heterogeneous effect sizes. Fractures with a nasofrontal outflow tract (NFOT) injury without obstruction can be treated with reconstruction if displaced, or managed conservatively if undisplaced. Obliteration and cranialization should be considered when there is obstruction of the NFOT. A computed tomography scan should be performed at 6 months to evaluate re-ventilation of the sinus. Endoscopic sinus surgery is a reasonable salvage re-ventilation procedure.

Frontal Sinus Fractures: Evolving Clinical Considerations and Surgical Approaches

Frontal sinus fractures are an uncommon injury of the maxillofacial skeleton, and account for 5-15% of all maxillofacial fractures. As the force of impact increases, fractures may extend beyond the anterior table to involve adjacent skull, posterior table and frontal sinus outflow tract (FSOT). Fractures at these subsites should be evaluated independently to assess the need for and type of operative intervention. Historically, these fractures were managed aggressively with open techniques resulting in obliteration or cranialization. With significant injuries, these approaches are still indispensable. However, the treatment of frontal sinus fractures has changed dramatically over the past half-century, and recent case series have demonstrated favorable outcomes with conservative management. Concurrently, there has been an increasing role of minimally invasive endoscopic techniques, both for primary and expectant management, with a focus on sinus preservation. Here, we review the diagnosis and management of frontal sinus fractures, with an emphasis on subsite evaluation. Following a detailed assessment, an appropriate treatment strategy is selected from a variety of open and minimally invasive approaches available in the surgeon's armamentarium.

Frontal Bone Fractures and Frontal Sinus Injuries: Treatment Paradigms

Background:

Timely, expeditious and appropriate management of Frontal bone fractures and associated Frontal Sinus (FS) injuries are both crucial as well as challenging. Treatment options vary considerably, depending upon the nature, extent and severity of these injuries as well as operator skill, expertise and experience. In cases of posterior table fractures of the Frontal Sinus, literature reports have in general, propounded direct visualization and exploration of the sinus via a bifrontal craniotomy, followed by sinus cranialization.

Aims and Objectives:

To review the standard protocols of management of Frontal bone fractures and Frontal Sinus injuries. To assess the efficacy of a more conservative approach in the management of outer and inner table fractures of the FS.

Materials and Methods:

Contemporary and evolving management protocols and changing treatment paradigms of different types and severities of frontal bone fractures and frontal sinus injuries, have been presented in this case series. A useful Treatment Algorithm has been proposed to efficiently and effectively manage these injuries.

Results:

In the present case series, effective and satisfactory results could be achieved in cases of significantly displaced inner and outer table fractures of the Frontal sinus by a more conservative protocol comprising of open reduction and internal fixation carried out via the existing scar of injury, without having to resort to the more radical intracranial approach and sinus cranialization. Nevertheless, presence of complicating factors such as cerebrospinal fluid rhinorrhea, evidence of meningitis or the development of encephalomeningocoeles necessitated the standard protocol of sinus exploration and its cranialization or obliteration.

Conclusion:

Management protocols of Frontal Sinus injuries vary, based on aspects such as the timing of presentation and intervention, degree of injury sustained, concomitant associated Craniomaxillofacial injuries present, presence of complicating factors or Secondary/Residual deformities & Functional debility, and need to be decided upon on a case to case basis.

Frontal Sinus Obliteration Utilizing Autogenous Abdominal Fat Graft

BACKGROUND:

Frontal sinus fractures have always been unique because of the controversy surrounding their ideal treatment protocol and the fatal complications that could follow if the wrong treatment opts.

AIM:

The purpose of this study was to assess clinically and radiographically frontal sinus obliteration technique utilising autogenous abdominal fat graft.

PATIENTS AND METHODS:

This study was carried out on 20 patients having anterior table fracture of their frontal sinuses indicated for sinus obliteration. All sinuses were obliterated using autogenous abdominal fat graft. Post-operatively, patients were clinically evaluated for any signs or symptoms of intracranial infections, wound dehiscence, sinus affections, or aesthetic deformity. Computerized tomography (CT) radiographic evaluations were carried out immediately and 12 months postoperatively to evaluate any uneventful healing of the graft.

RESULTS:

Clinical follow-up showed no cerebrospinal fluid leak, no postoperative infection or wound dehiscence in 18 cases. There were two cases however that showed infection. Radiographic follow-up revealed uneventful healing of the abdominal fat grafts with no abnormality detected in the sinus cavity throughout the whole postoperative period.

CONCLUSION:

Autogenous abdominal fat graft appears to be a successful obliteration material in the frontal sinus cavity and is beneficial in fractures of the anterior table.

Frontal Sinus Morphology: A Reliable Factor for Classification of Frontal Bone Fractures?

PURPOSE

The frontal sinus shows a wide range of morphologic variations. The aim of this study was to evaluate the influence of frontal sinus size on fracture characteristics in frontal bone trauma.

MATERIALS AND METHODS

In this cross-sectional study, data from patients with traumatic fractures of the frontal bone were retrospectively collected from the institution's database. Radiometric analysis of computed tomography and cone-beam computed tomography datasets was performed. Frontal sinus size was measured as variables of height, width, and depth. The secondary predictor was morphologic sinus type according to Guerram's classification: hyperplasia, medium size, hypoplasia, or aplasia of the frontal sinus. To determine outcomes, we classified fractures into the following categories: fracture isolated to the anterior table, combined fractures of the anterior and posterior tables, fracture isolated to the posterior table, and frontal bone fracture without sinus involvement. Further study variables were patients' demographic characteristics, combined midfacial fractures, orbital rim involvement, fracture displacement, and surgical approach. For statistical analysis, fracture types were assessed for frontal sinus metric size and morphologic type using bivariate tests with P < .05 defined as significant.

RESULTS

We enrolled 53 consecutive patients with a mean age of 35 years; male patients comprised 91%. Fracture types differed significantly in sinus width and height (both P < .001), as well as depth (P = .002). Frontal sinus morphology was hyperplastic in 66%, medium in 30.2%, and hypoplastic in 3.8%. Patients with a hyperplastic frontal sinus had an increased likelihood of isolated anterior table fractures (odds ratio, 6.0; P = .007) compared with medium-sized types. Fractures without sinus involvement were more likely in hypoplastic and medium types (P < .001).

CONCLUSIONS

The morphology of the frontal sinus determines the probability of fracture types from craniofacial trauma. Thus the frontal sinus size appears to be a major factor for frontal bone resistance to traumatic force impingement.

Treatment of frontal bone fracture sequelae through inversion of the bone fragment

Treatment of frontal sinus fractures depends on the structures involved: the anterior wall, the posterior wall and the nasofrontal duct. It may vary from the correction of the defect in the anterior wall to the cranialization with obliteration of the nasofrontal duct. The inversion of the frontal sinus's anterior wall to correct the defect in the fractured region is a good treatment option for sequelae, since this technique eliminates or reduces the use of biomaterial in the area, and allows direct assessment of the permeability of the nasofrontal duct. This work describes the technique of fractured segment inversion for the treatment of frontal sinus fracture sequelae in a motorcycle accident victim.

Changing the surgical dogma in frontal sinus trauma: transnasal endoscopic repair

BACKGROUND

Management of frontal sinus trauma includes coronal or direct open approaches through skin incisions to either ablate or obliterate the frontal sinus for posterior table fractures and openly reduce/internally fixate fractured anterior tables. The objective of this prospective case-series study was to evaluate outcomes of frontal sinus anterior and posterior table trauma using endoscopic techniques.

METHODS

Prospective evaluation of patients undergoing surgery for frontal sinus fractures was performed. Data were collected regarding demographics, etiology, technique, operative site, length involving the posterior table, size of skull base defects, complications, and clinical follow-up.

RESULTS

Forty-six patients (average age, 42 years) with frontal sinus fractures were treated using endoscopic techniques from 2008 to 2016. Mean follow-up was 26 (range, 0.5 to 79) months. Patients were treated primarily with a Draf IIb frontal sinusotomies. Draf III was used in 8 patients. Average fracture defect (length vs width) was 17.1 × 9.1 mm, and the average length involving the posterior table was 13.1 mm. Skull base defects were covered with either nasoseptal flaps or free tissue grafts. One individual required Draf IIb revision, but all sinuses were patent on final examination and all closed reductions of anterior table defects resulted in cosmetically acceptable outcomes.

CONCLUSION

Frontal sinus trauma has traditionally been treated using open approaches. Our findings show that endoscopic management should become part of the management algorithm for frontal sinus trauma, which challenges current surgical dogma regarding mandatory open approaches.

Survey of Current Practice Patterns in the Management of Frontal Sinus Fractures

The management of frontal sinus fractures has evolved in the endoscopic era. The development of functional endoscopic sinus surgery (FESS) has been incorporated into management algorithms proposed by otolaryngologists, but the extent of its influence on plastic surgeons and oral and maxillofacial surgeons is heretofore unknown. A cross-sectional survey was performed to assess the practice pattern variations in frontal sinus fracture management across multiple surgical disciplines. A total of 298 surveys were reviewed. 33.5% were facial plastic surgeons with otolaryngology training, 25.8% general otolaryngologists, 25.5% plastic surgeons, and 15.1% oral and maxillofacial surgeons. 74.8% of respondents practiced in an academic setting. 61.7% felt endoscopic sinus surgery changed their management of frontal sinus fractures. 91.8% of respondents favored observation for uncomplicated, nondisplaced frontal sinus outflow tract fractures. 36.4% favored observation and 35.9% favored endoscopic sinus surgery for uncomplicated, displaced frontal sinus outflow tract fractures. For complicated, displaced frontal sinus outflow tract fractures, obliteration was more frequently favored by plastic surgeons and oral and maxillofacial surgeons than those with otolaryngology training. The utility of FESS in managing frontal sinus fractures appears to be recognized across multiple surgical disciplines.

Facial Fractures

LEARNING OBJECTIVES

After reading this article, the participant should be able to: 1. Demonstrate an understanding of some of the changes in aspects of facial fracture management. 2. Assess a patient presenting with facial fractures. 3. Understand indications and timing of surgery. 4. Recognize exposures of the craniomaxillofacial skeleton. 5. Identify methods for repair of typical facial fracture patterns. 6. Discuss the common complications seen with facial fractures.

SUMMARY

Restoration of the facial skeleton and associated soft tissues after trauma involves accurate clinical and radiologic assessment to effectively plan a management approach for these injuries. When surgical intervention is necessary, timing, exposure, sequencing, and execution of repair are all integral to achieving the best long-term outcomes for these patients.

Computed tomography image guidance for more accurate repair of anterior table frontal sinus fractures

BACKGROUND

Anterior table frontal sinus fractures accompanied by nasofrontal duct injury require surgical correction. Extracranial approaches for anterior table osteotomies have traditionally used plain radiograph templates or a "cut-as-you-go" technique. We compared these methods with a newer technique utilizing computed tomography (CT)-guided imaging.

METHODS

Data of patients with acute, traumatic anterior table frontal sinus fractures and nasofrontal duct injury between 2009 and 2013 were reviewed (n = 29). Treatment groups compared were as follows: (1) CT image guidance, (2) plain radiograph template, and (3) cut-as-you-go. Frontal sinus obliteration was performed in all cases. Demographics, operative times, length of stay, complications, and osteotomy accuracy were recorded.

RESULTS

Similar demographics, concomitant injuries, operative times, and length of stay among groups were noted. No patients in the CT-guided group had perioperative complications including intraoperative injury of the dura, cerebrum, or orbital structures. In the plain radiograph template group, 25% of patients had inadvertent dural exposure, and 12.5% required take-back to the operating room for cranial bone graft donor site hematoma. In the cut-as-you-go group, 11% required hardware removal for exposure. There were no cases of cerebrospinal fluid leak, meningitis, or mucocele in any group (follow-up, 29.2 months). The CT image guidance group had the most accuracy of the osteotomies (95%) compared with plain radiograph template (85%) and the cut-as-you-go group (72.5%).

CONCLUSIONS

A new technique using CT image guidance for traumatic frontal sinus fractures repair offers more accurate osteotomy and elevation of the anterior table without increased operative times or untoward sequelae.

A novel classification of frontal bone fractures: The prognostic significance of vertical fracture trajectory and skull base extension

PURPOSE

The broad spectrum of frontal bone fractures, including those with orbital and skull base extension, is poorly understood. We propose a novel classification scheme for frontal bone fractures.

METHODS

Maxillofacial CT scans of trauma patients were reviewed over a five year period, and frontal bone fractures were classified: Type 1: Frontal sinus fracture without vertical extension. Type 2: Vertical fracture through the orbit without frontal sinus involvement. Type 3: Vertical fracture through the frontal sinus without orbit involvement. Type 4: Vertical fracture through the frontal sinus and ipsilateral orbit. Type 5: Vertical fracture through the frontal sinus and contralateral or bilateral orbits. We also identified the depth of skull base extension, and performed a chart review to identify associated complications.

RESULTS

149 frontal bone fractures, including 51 non-vertical frontal sinus (Type 1, 34.2%) and 98 vertical (Types 2-5, 65.8%) fractures were identified. Vertical fractures penetrated the middle or posterior cranial fossa significantly more often than non-vertical fractures (62.2 v. 15.7%, p = 0.0001) and had a significantly higher mortality rate (18.4 v. 0%, p < 0.05). Vertical fractures with frontal sinus and orbital extension, and fractures that penetrated the middle or posterior cranial fossa had the strongest association with intracranial injuries, optic neuropathy, disability, and death (p < 0.05).

CONCLUSIONS

Vertical frontal bone fractures carry a worse prognosis than frontal bone fractures without a vertical pattern. In addition, vertical fractures with extension into the frontal sinus and orbit, or with extension into the middle or posterior cranial fossa have the highest complication rate and mortality.

Management of frontal sinus fractures--treatment decision based on metric dislocation extent

The treatment of frontal sinus fractures is still a matter of research in neurosurgical and craniofacial surgery. The present study aimed to determine new criteria regarding surgical or observational treatment, especially concerning the fracture dislocation. Clinical information on 164 consecutive patients with fractures of the frontal sinus, treated at the Department of Craniomaxillofacial Surgery of the Medical University of Innsbruck from 2006 to 2010, have been evaluated. 23 female (14%) and 141 male (86%) patients suffered mainly from traffic (31.7%) and sports accidents (28.0%), followed by work accidents (20.1%), violence (3.7%) and accidents at home (3.1%). 51.8% presented an isolated fracture of the anterior wall, 47.6% both anterior and posterior wall fracture, 0.6% an isolated posterior wall fracture. Injury of the nasofrontal duct was found in 29.2%, CSF liquorrhoea in 15.9%. In total, 44.5% of the patients underwent surgical therapy, 55.5% were treated conservatively by observation. Treatment decision depended significantly on concomitant injuries of the nasofrontal duct and the presence of rhinoliquorrhoea as well as on the fracture dislocation. A new classification of frontal sinus fractures depending on their maximum dislocation is proposed. In addition, a treatment algorithm considering displacement, liquorrhoea and injury of the nasofrontal duct is presented.

Frontobasilar fractures: proposal for image reviewing algorithm

OBJECTIVE

The aim of this study was to develop and test the utility of a novel systematic protocol to analyze CT images of patients with trauma in the anterior cranial base and upper midface.

MATERIAL AND METHODS

The radiological data and primary reports of 27 consecutive patients with a frontal skull base fracture treated in two tertiary care hospitals from 2007 to 2011 were scrutinized. A novel algorithm for systematic image reviewing was used to assess the CT images and the findings were compared with the primary radiological reports.

RESULTS

The systematic review detected a substantial number of fractures and defects in anatomical structures that had not been systematically reported in the primary, on-call reports. Anterior skull base fracture was not initially reported in 32% of the patients; however, the algorithm detected this in 93% of them. The corresponding rates for fracture through cribriform plate were 28% and 72% and for fracture through the sella or hypophyseal area 22% and 78%. There were two fractures of the clivus and these were initially missed.

CONCLUSIONS

Despite the failure to identify these fractures radiologically in the primary setting, all patients were still considered to have received appropriate treatment, but, the use of an image-reviewing algorithm will enhance the specificity of CT in the diagnosis of frontobasilar fractures.

Nasofrontal outflow tract visibility in computed tomography imaging of frontal sinus fractures

The choice of frontal sinus fracture treatment is based on multiple factors, one of which is injury to the nasofrontal outflow tract (NFOT). Computed tomography (CT) imaging of the NFOT can play an important role in the decision process. We sought to assess the visibility of the NFOT on CT scans in frontal sinus fractures. Patients with frontal sinus fractures (including the posterior table) receiving a CT scan from April 1st 2001 to December 31st 2009 were included. Scans were retrospectively assessed for available views (axial, coronal, and sagittal), slice thickness, inclusion of the anatomical NFOT region in the scanned area, and visibility of the NFOT. A total of 170 patients were included. In majority (71%) of patients NFOT was visible on one or more views, whereas in 33% (N = 56) of patients had three complete views (complete anatomical NFOT region scanned in three views). In this subgroup, the ability to assess the NFOT increased to 89%. When selecting patients with three complete views of ≤ 2 mm slice thickness (N = 47), the ability to assess the NFOT increased to 96%. In conclusion, when assessing the NFOT using CT imaging, having three complete views (axial, coronal, and sagittal) and a ≤ 2 mm slice thickness greatly increases the NFOT visibility.

Relation between preoperative computed tomographic criteria of injury to the nasofrontal outflow tract and operative findings in fractures of the frontal sinus

Injury to the nasofrontal outflow tract is important in the treatment of fractures of the frontal sinus. In 2008 preoperative computed tomographic (CT) criteria or signs of such injuries were proposed and stated to be reliable. The aim of this study was to evaluate the validity of these criteria by comparing the radiological evidence with the operative findings. Thirty-nine patients for whom the data from preoperative CT could be compared with operative findings were eligible for the study, all but 4 of whom had at least one indicator of injury to the outflow tract. Patients whose tracts were found to be obstructed at operation had at least 2 preoperative CT signs of obstruction of the tract. If the outflow tract was obstructed all 3 criteria were significantly more likely to be present than if it was intact (p=0.02). Two criteria or fewer did not correlate significantly with obstruction. Fractures were managed by reconstruction (n=18), obliteration (n=11), or cranialisation (n=10). This study is the first to our knowledge to examine the correlation between preoperative CT criteria and operative findings, and there was a significant difference in the number of criteria present depending on whether the outflow tract was intact or injured. Our findings allow for more accurate planning of management of fractures of the frontal sinus.

Management of midface maxillofacial trauma

The management of midface trauma continues to challenge maxillofacial surgeons. The complex local anatomy and functional and cosmetic importance of the region make precise surgical correction and reconstruction essential to success.

Multidetector computed tomography of maxillofacial fractures: the key to high-impact radiological reporting

Maxillofacial fractures are very common. Recognizing patterns of facial fractures is helpful in assessing maxillofacial injury and accurately characterizing all fractures that may be present. Facial fractures are grouped into the following categories: nasal bone, naso-orbito-ethmoid, orbital, zygomatic, maxillary (including Le Fort-type fractures), mandibular, and frontal sinus fractures. Within each subgroup of facial fractures, there are key findings, whether of the fracture itself or of potential associated injuries, that are important factors in determining whether the patient is managed conservatively or with surgery. This article highlights the features of facial fractures that are the most important to the surgeons and provides a framework for effective radiological reporting.

Management of frontal sinus fractures

The traditional treatment of frontal sinus fractures is undergoing a review by many clinicians. This review will undoubtedly contribute to the existing controversy surrounding the management of patients with this condition. This article seeks to further the review and suggest the authors' perspective on a more appropriate approach to the care of patients with frontal sinus injuries.