Orbital "blow-in" fracture: MRI

Globe Compression by Bone Fragments in Orbital Blow-in Fractures: A Case Series and Systematic Review

PURPOSE

The purpose of this study was to describe the clinical characteristics, management, and outcomes of orbital blow-in fractures involving compression of the globe by bone fragments.

METHODS

A retrospective case series and systematic literature review were performed.

RESULTS

Three male patients (mean age 29 years) with orbital blow-in fractures causing globe indentation presented with extraocular movement restriction, choroidal folds, and B-scan ultrasonography demonstrating deformation of the globe contour by a hyperechoic bone fragment. All underwent surgical repair within 1 day of presentation resulting in improved visual outcomes. An additional 10 cases were identified in the literature review. The majority of patients were male (80%) with a mean age of 29 years. Fractures originated primarily from the lateral orbital wall (50%) or the orbital roof (40%). Globe compression was evident on CT of the orbit (100%) and ultrasonography (30%). Common presenting signs included decreased visual acuity (70%), restriction of supraduction (40%) or abduction (40%), choroidal folds (30%), brow laceration (40%), periorbital edema (40%), and hypoglobus (40%). Most patients underwent surgical intervention (80%) involving fracture reduction (50%) or fragment removal (38%). Reported postsurgical outcomes were excellent with resolution of diplopia, motility, and visual acuity.

CONCLUSION

Globe indentation from blow-in fractures are rare. Clinicians should be suspicious in cases of high-velocity trauma to the superolateral orbit with hypoglobus, motility limitation, and indentation of the globe upon dilated exam. Prompt diagnosis and early surgical removal of the compressive orbital bone fragments in a multidisciplinary fashion can lead to good visual, functional, and cosmetic outcomes.

Post-traumatic intra-orbital meningoencephalocele in adults: technical note on a rare entity and review of the literature

Post-traumatic orbital meningoencephaloceles related to orbital roof fractures are a challenging clinical entity because of their rarity and difficult differential diagnosis. We report a case of post-traumatic intra-orbital meningoencephalocele in a 69-year-old man, secondary to a likely trapdoor mechanism, treated with a modified one-piece orbitozygomatic craniotomy. We also performed an extensive literature review of traumatic Intra-Orbital Encephalocele related to Orbital Roof Fracture focused on adult patients on electronic databases including Scopus, MEDLINE/PubMed, and Google Scholar. Patient well recovered after surgery with immediate exophthalmos resolution and discharged without visual or neurological deficits. The literature review included 22 papers with a total of 28 patients: 22 males (78.6%) and 6 females (21.4%), with a median age of 34.7 years. Twenty-six patients (92.9%) reported ocular injuries, with associated intracranial complications in 16 cases (61.5%). Twenty-seven patients (96.4%) were surgically treated, 18 of those underwent unilateral or bilateral frontal approach. Most orbital roof fractures can be managed nanoperatively if asymptomatic. Indeed, when the intra-orbital volume decreases, for example due to an encephalocele, the intra-orbital pressure could increase and determine an orbital compartment syndrome. In our case, we performed a one-piece modified orbitozygomatic approach, which has several advantages in comparison to the frequent unilateral or bilateral frontal craniotomy like the better exposure of the brain and orbit and a minimum brain retraction.

Long-Term Results of Orbital Roof Repair with Titanium Mesh in a Case of Traumatic Intraorbital Encephalocele: A Case Report and Review of Literature

Orbital roof fractures associated with cranial and maxillofacial trauma are rarely encountered. Traumatic intraorbital encephaloceles due to orbital roof fractures developing in the early posttraumatic period are even rarer. A variety of materials, such as alloplastic implants or autogenous materials, have been used for the reconstruction of orbital roof, but data regarding the long-term results of these materials are very limited. We report a case of intraorbital encephalocele developing in the early posttraumatic period (2 days) in a child patient and the long-term results of titanium mesh used for the reconstruction of the orbital roof. The case is presented with a pertinent review of literature.

Traumatic orbital encephalocele: Presentation and imaging

OBJECTIVE

Traumatic orbital encephalocele is a rare but severe complication of orbital roof fractures. We describe 3 cases of orbital encephalocele due to trauma in children.

METHODS

Retrospective case series from the University of Wisconsin - Madison and Medical College of Wisconsin.

RESULTS

Three cases of traumatic orbital encephalocele in pediatric patients were found. The mechanism of injury was motor vehicle accident in 2 patients and accidental self-inflicted gunshot wound in 1 patient. All 3 patients sustained orbital roof fractures (4 mm to 19 mm in width) and frontal lobe contusions with high intracranial pressure. A key finding in all 3 cases was progression of proptosis and globe displacement 4 to 11 days after initial injury. On initial CT, all were diagnosed with extraconal hemorrhage adjacent to the roof fractures, with subsequent enlargement of the mass and eventual diagnosis of encephalocele.

CONCLUSION

Orbital encephalocele is a severe and sight-threatening complication of orbital roof fractures. Post-traumatic orbital encephalocele can be challenging to diagnose on CT as patients with this condition often have associated orbital and intracranial hematoma, which can be difficult to distinguish from herniated brain tissue. When there is a high index of suspicion for encephalocele, an MRI of the orbits and brain with contrast should be obtained for additional characterization. Imaging signs that should raise suspicion for traumatic orbital encephalocele include an enlarging heterogeneous orbital mass in conjunction with a roof fracture and/or widening fracture segments.

Supraorbital blowin fracture presenting as an ocular dystopia in a nine-year-old girl

A 9-year-old girl was referred to a trauma centre with severe head injury. 3D CT scan revealed depressed fracture involving the frontal bone on the right side, right parietal bone, and right superior orbital margin, right lamina papyracea. The frontal table was managed conservatively and open reduction and internal fixation was done for the supraorbital blow in to correct the ocular dystopia. The clinical course, possible mechanism, and management of the patient are discussed.

A Comparative Study of 2 Implants Used to Repair Inferior Orbital Wall Bony Defects: Autogenous Bone Graft Versus Bioresorbable Poly-L/DL-Lactide [P(L/DL)LA 70/30] Plate

PURPOSE

The purpose of this study was to compare our clinical findings on the use of autogenous bone grafts and bioresorbable poly-L/DL-Lactide [P(L/DL)LA 70/30] implants to repair inferior orbital wall defects.

PATIENTS AND METHODS

Thirty-nine patients who suffered orbital blow-out fractures with >or=2 cm2 bony defect in the inferior orbital wall took part in the study. Each inferior orbital wall was reconstructed using either an autogenous bone graft or a triangle form plate of P(L/DL)LA 70/30. Computed tomography scans were taken before the operation and at 2 and 36 weeks postoperatively. To describe the distribution of complications and facilitate statistical analysis, we categorized our findings into diplopia, enophthalmos, numbness, gaze restrictions, size of bony defect after treatment, bone growth, and implant resorption. A comparative study was carried out using chi2 test and the Fisher exact test. We considered P < .05 to be statistically significant.

RESULTS

The clinical outcome was excellent in 19 of the 24 (79%) cases treated with autogenous bone grafts and in 13 of the 15 (87%) cases treated with P(L/DL)LA 70/30. No statistically significant differences were found between the 2 groups in overall type or number of complications. The most frequent type of complication found in both groups was enophthalmos, with 5 cases (bone graft, 3; P(L/DL)LA plates, 2). Diplopia was the second most frequent type of complication; however, both complications caused no need for the removal of the implants in either group.

CONCLUSION

Autogenous bone grafts and P(L/DL)LA 70/30 implant plates do not present statistically significant differences in the parameters studied. Taking into account the availability and the advantages of P(L/DL)LA 70/30 implants when compared with autogenous bone grafts, our results allow us to conclude that there is no compromise regarding successful bridging of orbital floor defects using biodegradable P(L/DL)LA 70/30 osteosyntheses.

Bioresorbable poly-L/DL-lactide (P[L/DL]LA 70/30) plates are reliable for repairing large inferior orbital wall bony defects: a pilot study

PURPOSE

The purpose of this study was to share our clinical experience on the use of bioresorbable poly-L/DL-lactide implants (P[L/DL]LA) 70/30 (PolyMax; Synthes, Oberdorf, Switzerland) to repair, large (> or =2 cm2), inferior orbital wall defects and to evaluate whether P(L/DL)LA 70/30 implants adequately support the orbital soft tissue contents.

PATIENTS AND METHODS

Thirteen patients who suffered orbital blowout fractures, with > or =2 cm2 bony defects in the inferior orbital wall, took part in the study. The inferior orbital wall was explored via subconjunctival approach. After repositioning of orbital content, each inferior orbital wall was reconstructed using a round plate of P(L/DL)LA 70/30. Computed tomography and magnetic resonance imaging coronal sections were undertaken before the operation and 2 and 36 weeks postoperatively.

RESULTS

The magnetic resonance imaging studies showed no abnormal tissue foreign body reactions in the orbital region. The material showed adequate strength to stabilize bone segments during the critical period of bone healing. The bone healing seems to take place along the bone fragments. The clinical outcome was excellent in 11 of the 13 cases (85%). At the end of the study, only one patient had mild enophthalmos.

CONCLUSIONS

Bioresorbable P(L/DL)LA 70/30 implants are safe and reliable for the repair of large defects (> or =2 cm2) in the inferior orbital wall. It seems that this is the first reported biodegradable material, in the literature, to promote bone healing along the bone fragments of the inferior orbital wall.

A novel high-resolution magnetic resonance imaging microscopy coil as an alternative to the multislice computed tomography in postoperative imaging of orbital fractures and computer-based volume measurement

BACKGROUND

Multislice computed tomography (MSCT) has been the modality of choice for postoperative detailed imaging of orbital trauma. Unfortunately, it involves extensive exposition of the lens to radiation, especially when taking multiple readings. Also, it holds beam hardening effects and limited imaging (delineation) of the reconstruction material. Alternative conventional magnetic resonance imaging (MRI) head coils (MRIhc) present reduced differentiation of anatomic structures caused by low signal and artifact appearance. A substantially improved depiction is made possible by a newly introduced MRI microscopy coil (MRImc), used for the first time in this field.

PATIENTS AND METHODS

In this prospective study, 32 patients with extended orbital wall fractures (n = 36) were treated surgically using a polydioxanonsulfate (PDS) foil after reconstruction. Postoperatively, imaging was performed using MRImc, conventional MRI, and MSCT to evaluate the different imaging techniques.

RESULTS

The position of the PDS foil could precisely be depicted in 29 of 36 fractures by MRImc, whereas by conventional MRI and MSCT the reconstruction material could only be detected in 25 and 24 of 36 fractures, respectively. In contrast to MRIhc, the new microscopy coil allows fast and high resolution imaging and therefore a clear differentiation of eventual postoperative complications (eg, dislocation of the PDS foil with secondary soft tissue entrapment resulting in limitation of ocular movements or enophthalmos). In 13 long lasting symptomatic cases, revision surgery could be avoided because of regular MRImc findings, apart from muscle swelling and hematoma. In 11 cases of inadequate PDS foil position resulting in revision, the mean volume of displaced tissue (VDT) of 0.62 cm3 correlated significantly to an enophthalmos of more than 2 mm.

CONCLUSION

In this pilot study, MRImc proved to be highly superior to MRIhc and MSCT in postsurgical orbital imaging, especially for decision making regarding revision surgery.

Evaluation of reconstructed orbital wall fractures: high-resolution MRI using a microscopy surface coil versus 16-slice MSCT

We evaluated high-resolution magnetic resonance imaging (MR) using a 47-mm microscopy surface coil in comparison to 16-slice multislice CT (MSCT) for postsurgical imaging of reconstructed orbital walls. Twenty-five patients with 27 internal orbital wall fractures were imaged prospectively after reconstruction with resorbable polydioxanone sulfate (PDS) sheets. Coronal high-quality T1- and T2-weighted MR images were obtained with an in-plane resolution of 350 microm within a measure time of 6-7 min for each sequence. Nineteen symptomatic patients underwent MSCT as the current gold standard. In MRI the PDS foil appears in T1- and T2-weighted images as a thin, low-signal-intensity linear structure. In CT it appears hyperdense in comparison to soft tissue and slightly hypodense in comparison to cortical bone. PDS foils could be clearly depicted in 20 out of 25 patients (80%) with MRI and in 13 out of 19 patients (68%) with MSCT. An inadequate foil position or size could be diagnosed in eight patients with MRI and in only three patients with MSCT. In ten symptomatic patients secondary surgery could be avoided because of regular MRI findings except mild hematoma and muscle edema. High-resolution MRI of the orbit using a 47-mm microscopy coil is a promising method to accurately demonstrate normal and pathologic conditions in symptomatic patients after orbital wall reconstruction with PDS foils.

Demographics and treatment options for orbital roof fractures

OBJECTIVE

The purpose of this article was to review the frequency, germane anatomy, management modalities, and complications associated with the treatment of orbital roof fractures in the pediatric and the adult population.

STUDY DESIGN

A review of the past 30 years of the English-language maxillofacial surgical literature was undertaken. Important concepts were coupled with the authors' experience to provide a synopsis of contemporary thought on this topic.

RESULTS

More than 235 articles in the oral and maxillofacial, plastic and reconstructive, otolaryngology-head and neck, ophthalmologic, oculoplastic, neurologic, and pediatric surgical literature were reviewed and assessed. From this group, 50 articles were found to contain useful information.

CONCLUSIONS

It has been estimated that 1% to 9% of all facial fractures involve the orbital roof. The typical adult with an orbital roof fracture is a man (89%-93%) who has been involved in a high-energy impact and who has sustained concomitant multisystem injuries (57%-77%). Orbital roof fractures most commonly coexist with other craniofacial injuries. In contrast, in pediatric patients with an orbital roof injury, we see nearly equal sex distribution; the typical patient in this case has a frontobasal fracture that is minimally displaced or nondisplaced (53%-93%) and has sustained concomitant multisystem injuries. The pediatric patient is usually managed by means of observation alone (53%-86%). For the adult patient, a subcranial approach to the orbital roof by means of a bitemporal flap or superior blepharoplasty incision offers wide access with minimal morbidity. Currently available titanium microscrew and miniscrew and mesh systems offer a near-ideal modality for orbital roof reconstruction. The coexisting neurocranial, frontal sinus, and supraorbital rim fractures take priority over the management of orbital roof fractures. Complications associated with orbital roof injuries can be categorized as those attributed to the following: concomitant injury, surgical access, postreconstruction volume discrepancy, muscle entrapment, hemorrhage, and/or infection.

Traumatic encephalocele related to orbital roof fractures: report of six cases and literature review

BACKGROUND

Orbital roof fractures after blunt injury are rare. Traumatic encephaloceles in the orbital cavity are even rarer, with only 15 cases published to date.

METHODS

The clinical, radiological, and surgical findings of 6 cases of traumatic encephalocele treated at our institution from June 1998 to January 2000 are presented. They are also compared with previously published series.

RESULTS

In contrast to other published cases, 5 out of 6 patients in our series were adults. The most common cause of trauma was road traffic accident. Ecchymosis and preoperative exophthalmos/proptosis were frequent. In all of our patients a coronal CT scan (3 mm increments with bone windows) was obtained. It demonstrated the extension of the orbital roof fractures and a possible encephalocele in 4 cases. Associated frontal brain contusions were seen in 5 cases. An MRI was performed in 3 patients (and only in 2 previously published cases); it showed the extension of the brain herniation into the orbital cavity. Surgical treatment via a fronto-basal approach with evacuation of the contused herniated brain tissue and orbital roof reconstruction was performed. The outcome at 6 months was good recovery in five patients with one patient still in a persistent vegetative state. Postoperatively the ocular disturbances improved in 5 cases. A review of the other published cases confirmed recovery of normal ocular function in the vast majority of the cases.

CONCLUSIONS

Whenever orbital roof fractures associated with frontal contusions are identified in an acute brain injured patient, an orbital encephalocele should be suspected. In our opinion MRI is the investigation of choice in such patients. If the encephalocele is confirmed, a surgical approach via the subfrontal route is indicated with resection of herniated contused brain tissue, dural closure, and orbital roof reconstruction. Good results in regard to the orbital symptoms (mainly exophthalmos) can be expected.

Effectiveness of operative treatment of internal orbital wall fracture with polydioxanone implant

Many implants, some made from teflon or silicone, have been used for internal orbital wall reconstruction. Late complications relating to use of such implants have been reported. In this prospective study a polydioxanone (PDS) implant absorbable in vivo was used for internal orbital wall reconstruction. Follow-up involved clinical examination, magnetic resonance imaging (MRI) and computerized tomography (CT). Clinical examinations were undertaken before operation and up to 36 weeks postoperatively. Sixteen consecutive patients (10 pure blow-out fractures, six with associated zygomatic fracture) took part in the study. Prevalences of diplopia, proptosis and enophthalmus were recorded during each follow-up examination. This study revealed no muscle entrapment within the fracture line. Although CT results confirmed bone growth in the internal orbital wall, shape was unsatisfactory, and orbital volume was not reduced. MRI revealed thick scar formations in six cases (37.5%), fibrotic sinuses filled with air or gas in three cases (19%) and a fibrotic sinus with fluid around the PDS in one case (6%). Our results suggest that use of PDS in reconstructing the internal orbital wall is inadvisable.