Continuing Education Activity

Fractures of the orbital floor and the medial orbital wall (blowout fractures) are common midface injuries. Orbital fractures have a distinct trauma mechanism and are complex due to the complex anatomy of the bony and soft tissue structures involved. Knowledge of anatomy is mandatory when dealing with patients presenting with trauma to the orbit. The frontal, ethmoidal, sphenoid, zygomatic, and lacrimal bones form the bony structures of the orbit. This activity reviews the etiology, presentation, evaluation, and management of fractures of the orbital floor and reviews the role of the interprofessional team in evaluating, diagnosing, and managing the condition.

Objectives:

• Outline the osseous anatomy of the orbit of the eye.
• Review the procedure for a proper history and physical examination to address a potential orbital floor fracture, including potential differentials.
• Describe the treatment and management of orbital floor fractures, including potential complications after initial treatment or surgery.
• Summarize the role of improving coordination among the interprofessional team to streamline diagnosis and treatment for patients with orbital floor fracture.

Introduction

Fractures of the orbital floor and the medial orbital wall (blowout fractures) are common midface injuries.

Orbital fractures have a distinct trauma mechanism and are complex due to the complex anatomy of the bony and soft tissue structures involved.

Knowledge of anatomy is mandatory when dealing with patients presenting with trauma to the orbit.

The frontal, ethmoidal, sphenoid, zygomatic, and lacrimal bones form the bony structures of the orbit. Medially, the maxillary and the lacrimal bone form the lacrimal fossa. Together with the lamina papyracea of the ethmoid bone, they form the medial wall. The sphenoid bone forms the posterior wall and houses the orbital canal. Lateral to the orbital canal lies the superior orbital fissure housing cranial nerves III, IV, V, and VI. The zygomatic bone forms the lateral wall. Superior and inferior borders are the frontal and maxillary bones. Located around the globe of the eye and attached to it are 6 extraocular muscles; the 4 rectus muscles and the superior and inferior oblique muscles. The fat and connective tissue around the globe help to reduce the pressure exerted by the extraocular muscles.[1][2]

The goal of treatment is to restore aesthetics and physiological function. The problem with orbital blowout fractures is that the volume of the orbit can be increased, resulting in enophthalmos and hypoglobus. In addition, the orbital tissue and inferior rectus muscle can become trapped by the bony fragments leading to diplopia, limitation of gaze, and tethering. Finally, the orbital injury can lead to retinal edema, hyphema, and significant loss of vision.

While some cases may be managed with conservative care, others may require some type of surgical intervention.

Etiology

A blowout fracture is an isolated fracture of the orbital walls without compromise of the orbital rims.[3] The common mechanisms are falls, high-velocity ball-related sports, traffic accidents, and interpersonal violence.

The trauma mechanism is a blunt, directed force that may be aimed at the eye without a pressure component toward the eye rim, leading to an increase of pressure inside the orbit with a fracture of the bony structures (a hydraulic mechanism). Alternatively, the trauma may be directed towards the orbital rim, which then leads to a bending of the orbital walls with consequent fracturing (buckling mechanism).[4][5]

The mechanism of entrapment is more frequently referred to as a trapdoor in children, as opposed to the "blowout or punched-out" fracture present in adults.

Epidemiology

Orbital fractures are more common in males than in females and most often occur in men, ages 21  to 30.[6]

Fractures of the orbital floor and the medial orbital wall are the most common fractured site.[7]

Falls, motor vehicle accidents, and assaults account for most midfacial fractures.[8][9][10][6]

Pathophysiology

In most cases, orbital blowout fractures are secondary to an explosive increase in the intraorbital pressure. The kinetic energy from the impact is transmitted to all the adjacent structures within the bony socket. The majority of fractures tend to occur in the posterior medial area, where the bones are thin.

History and Physical

Modern imaging techniques do not replace history and physical examination. The physical examination is especially important to help distinguish between fractures that need acute surgical care and referral versus those for which simple observation is sufficient. Some patients present with extensive damage to other facial structures for which detailed assessment is mandatory. Some limitations may exist due to extensive soft tissue swelling or non-responsive patients.

Traumatized patients should be treated only after the initial assessment, according to advanced trauma life support criteria. Examination always has to include a full examination of the facial structures according to current guidelines published by the relevant authority.

The patient should be queried specifically about the trauma mechanism and if they have double vision, numbness to his face, and/or loss of visual acuity.

The following assessments are characteristic of orbital floor fractures and mandate further imaging:

1. Diplopia (on upward gaze)
2. Limitation of upward gaze
3. Trigeminal function assessment: The infraorbital nerve runs along the floor of the orbit. Decreased sensation over the inferior orbital rim, extending to the edge of the nose and ipsilateral upper lip can occur.
4. Tenderness, or step-offs at the infraorbital rim
5. Subcutaneous emphysema (indicates a fracture of the maxillary sinus)
6. Oculomotor function: Entrapment of the inferior rectus muscle; often occurs between fragments of the lower orbit and is the cause of diplopia
7. Pupillary light reflex: An absent reflex can show damage to the afferent or efferent nerve system
8. Gross visual acuity
9. Position of the globe: A dislocated fracture can lead to enophthalmos and swelling behind the globe, to exophthalmos
10. Chemosis and sub-conjunctival hemorrhage[7][11]
11. Edema and periorbital ecchymosis

Careful evaluation of the eye is important for visual acuity, hyphema, or retinal detachment, and of the nose for septal hematoma. In the presence of eye pain and decreased visual acuity, globe rupture should be suspected since it is associated with a high rate of concomitant orbital floor fracture.

Evaluation

Preoperative blood work should include CBC, electrolytes, coagulation profile, and a pregnancy test.

Imaging should provide useful information to differentiate orbital floor fractures from any of the following:

1. Medial or lateral wall fractures
2. Orbito-zygomatic fractures
3. LeFort I, II, and III fractures
4. Naso-orbital ethmoidal fractures (Markowitz fractures)

Clinical examination has to eliminate the need for acute intervention under the following conditions:

1. Large fractures with a high risk of enophthalmos
2. Entrapment of infra-orbital structures
3. Optical neuropathy

Computed Tomography Scan

Computed tomography (CT) is the imaging modality of choice if a blowout fracture is suspected after blunt orbital trauma. Some symptoms include double vision, pain with eye movements, and restriction of extraocular muscle movements. A CT scan often reveals herniation of orbital fat or the inferior rectus muscle into the maxillary sinus. Such a scan can also detect occult tears and retained foreign bodies, if any are present.

Plain Radiograph

Can help suspect an orbital floor fracture in the presence of the following:

• Subcutaneous emphysema
• Soft-tissue teardrop along the roof of the maxillary sinus
• Air-fluid level in the maxillary sinus

Treatment / Management

The choice of orbital fracture treatment depends on findings following a clinical examination. Indications for surgery vary among different countries; but, there is a consensus about several indications for surgery.

However, considerable differences in opinion may exist regarding the management of blowout fracture due to a lack of a reliable consensus. Nonetheless, early surgical intervention (preferably within 24 hours)  is necessary when other injuries threaten the eye, such as nerve incarceration, acute enophthalmos or hypoglobus, and limitation of gaze caused by extraocular muscle or periorbital tissue entrapment. Many clinicians have recommended that orbital volume increases be treated as an indication for early reconstructive surgery. However, the increased post-traumatic orbital volume is not particularly useful in predicting late enophthalmos or diplopia.

1. Entrapment of muscle or periorbital fat leads to diplopia and/or the initiation of the oculocardiac reflex with bradycardia, nausea, and vomiting. These can be life-threatening and indicate a need for immediate surgery.[12]
2. Retrobulbar hematoma with a progressive loss in visual acuity
3. Enophthalmos (more than 2 mm) on first clinical examination

In general, surgery should be undertaken within 14 days to prevent fibrosis. Most surgeons wait 24-72 hours to allow the edema to subside before undertaking surgery. If the patient's only complaint is infraorbital nerve dysfunction, then the decision to repair requires judgment and experience. Some surgeons report good results with an early repair.  Children with orbital fracture and oculomotor dysfunction tend to have a more favorable outcome if the repair is done within the first 7 days.

Relative indications for surgery are high-risk fractures for enophthalmos, which involve over one-half of the orbital floor or lateral orbital wall.[13]

Use an observation with possible intervention within 1 to 2 weeks in all other cases of confirmed orbital floor fractures.[14]

Patients with fractures where the orbital floor fragments are not displaced, and the orbital volume remains unchanged can be addressed without any surgical intervention.

The goal of surgery is to restore herniated structures into the orbital cavity. The surgery may be done via a transconjunctival or transmaxillary approach. Today there are endoscopic techniques to manage orbital fracture. Several types of implants are also available for reconstruction of the orbit, but these should be avoided in the presence of an obvious infection. Prior to any procedure, the patient's visual acuity, extraocular motor function, diplopia, degree of enophthalmos, and dysesthesia should be documented. During surgery, the function of the pupil must be serially assessed. The anesthesiologist should be told to avoid medications that cause pupillary constriction or dilatation. When manipulating the extraocular muscles, the anesthesiologist should be warned about bradycardia secondary to the oculocardiac reflex.

Relative contraindications for surgery, according to Kim et al., include the following conditions:

1. Hyphema
2. Retinal tears
3. Globe perforation
4. Medical instability[15]

Begin prophylactic antibiotic treatment for oral organisms in all types of fractures of the orbit.

Corticosteroids may help reduce the edema in some cases. At the same time, the patient should be discouraged from blowing the nose or performing a Valsalva maneuver because this may worsen the orbital emphysema. 

Differential Diagnosis

• Soft tissue edema secondary to trauma
• Abducens nerve palsy 
• Traumatic diplopia
• Compressive optic neuropathy
• Oculomotor nerve palsy
• Trochlear nerve palsy

Prognosis

Following the repair of a blowout fracture, the outcomes are not always guaranteed, and the recovery is often prolonged. Some patients may have neuralgia of the infraorbital nerve for 6-9 months. Others may have diplopia, which may require REDO surgery. Finally, enophthalmos may worsen with time.

Complications

Acute surgical complications include loss of vision due to retrobulbar hematoma or impingement of the orbital apex.

Delayed surgical complications depend on the surgical procedure used and include entropion, ectropion, diplopia, infraorbital paresthesia, enophthalmos, and blindness.

Postoperative and Rehabilitation Care

During postoperative care, the examiner should watch out for postoperative complications such as infection, visual, or central nervous system (CNS) symptoms. The patient's head should be elevated to reduce the edema, and cool compresses can be placed over the closed eyelid to reduce pain and swelling. The patient's visual acuity ad pupillary function should be periodically assessed; if any changes are noticed, the surgeon should be immediately notified.

Deterrence and Patient Education

Patients need to be counselled on the importance of follow up to determine long-term sequelae, especially in patients treated with conservative management. 

Pearls and Other Issues

1. Diplopia with upward gaze, limited upward gaze, infraorbital anesthesia, and enophthalmos are hallmarks of blow-out fractures and need a referral for surgical evaluation. However, the initial clinical presentation is not always able to predict long-term sequelae, such as late enophthalmos and diplopia.
2. Early ophthalmologic consultation is mandatory.
3. Observation of uncomplicated fractures is recommended for up to 2 weeks; then, a decision can be made whether the patient needs surgery.
4. Loss of vision, exophthalmos, and absent pupillary light reflex are important criteria for ruling out optic neuropathy.

Enhancing Healthcare Team Outcomes

An interprofessional approach to blow-out fracture is recommended.

Management is relevant from a number of surgical specialties, such as otolaryngological (ENT) surgery, plastic surgery, facial plastic surgery, ocular plastic surgery, and oral maxillofacial surgery.

1. Ophthalmologist: All patients suspected of orbital fractures must see an ophthalmologist on presentation to the emergency department and before surgery
2. Otolaryngologist and/or facial plastic surgeon and/or maxillofacial surgeon depending on the institutional practice.
3. Nursing care is critical both during and after surgery. The patient should be pain-free and should be told to avoid blowing the nose. Nurses should monitor the patients in the ICU or the surgical floor, depending on the extent of the injury. At all times, the nurse should closely monitor the vitals, pupillary function, visual acuity, Glasgow coma score (GCS) score, and assess the patient for mental status changes. Any change in visual or mental status should be immediately reported to the surgeon.

Close communication with all the staff is vital to improve patient outcomes. The outcomes of most blow-out fractures are reasonable, but some patients may have altered eye function and cosmetic changes of the face.[6][16]