What is Frontal Sinus Fractures?
Skull fractures are often seen with injuries that result from both blunt and sharp force. One part of the skull, called the frontal sinuses, is located in the forehead area, above and inward of the eyes. These frontal sinuses start to develop when a person is about 5 to 6 years old and are fully grown by the time a person is between 12 and 20. Sensation in these sinuses is provided by nerves branching from a larger nerve called the trigeminal nerve. Blood supply comes from two arteries.
The frontal sinuses are structured with bone on the front and back with a drainage system. Depending on the connection of a bone called the uncinate process of the ethmoid bone, these sinuses can drain into one of two regions. If it connects to a bone called the lamina papyracea, it drains into the middle part of the sinus. If it connects to the skull base or the middle part of the nose, it drains into another area before emptying into the middle part of the sinus. The size of the frontal sinuses can vary greatly, but on average, they are about 10 mL. In a small amount of people (0.8-7.4%), the sinus may be completely missing on one or both sides.
The frontal part of the skull, which includes the frontal sinuses, is thicker than other parts of the skull. Because of this, it requires greater force to break these bones, and not surprisingly, fractures are less common in this area than other parts of the skull. It is also common for these fractures to occur along with other injuries. Other injuries can include damage to the eyes, nasal passages, fractures in the neck, and more serious cases like leaking brain fluid or internal brain bleeding. The possibility of these serious injuries makes it very important to evaluate patients with frontal sinus fractures thoroughly. Though, there are disagreements about how and when to surgically treat these fractures, leading to different treatment strategies being adopted.
What Causes Frontal Sinus Fractures?
Frontal bone fractures, or breaks in the bone at the front of the skull, in adults often result from car crashes, falling, being assaulted, having something fall on them, or some sort of penetrating trauma like a gunshot. According to a study of 164 patients, it found that car crashes were the most common cause (31.7%), followed by sports accidents (28.0%), workplace accidents (20.1%), violent attacks (3.7%), and accidents at home (3.1%). The severity of the injury can vary and it depends on how the injury happened, the fracture type, and if other parts of the body are involved.
For children, car crashes were also the most common cause of frontal bone fractures (25.7%), followed by sports-related injuries (16.1%), assault (14.7%), and falling over (10.1%). When looking at different age groups, the top cause of these fractures varied. For kids aged 0 to almost 7, the top reason was falling (28.6%). For those aged 7 to nearly 13, it was car crashes (31.9%), and for teenagers aged 13 to 18, it was assault (13 to 18 years).
Risk Factors and Frequency for Frontal Sinus Fractures
Frontal sinus fractures, which are injuries to the front of the skull, make up about 5% to 15% of all facial bone injuries. These fractures are mostly seen in young men (92%) within the age group of 20 to 31 years. For children, a report has indicated that fractures are more common in boys (65%) and typically occur around the age of 11.5 years, mostly among teenagers. Parietal bone fractures, or injuries to the side of the skull, are the most prevalent types of skull injuries. These fractures often follow a straight line, but they could also be concave or involve the base of the skull.
- Frontal sinus fractures make up about 5% to 15% of all facial bone injuries.
- These injuries mainly occur in young men (92%) aged 20 to 31 years.
- In children, fractures are more frequent in boys (65%), typically around 11.5 years, mainly teenagers.
- The most common skull injuries are parietal bone fractures.
- These fractures are usually linear, but they can also be concave or involve the base of the skull.
- In the United States every year, around 2.8 million people suffer from head injuries, and slightly over 2.1% of these are fatal.
Signs and Symptoms of Frontal Sinus Fractures
When looking after patients with facial injuries, it’s very important to gather as much information as possible. Sometimes, the patients might not be able to share this information due to their injuries, meaning doctors need to talk to family members, friends, or anyone who saw what happened. According to the Advanced Trauma Life Support protocol, doctors start by checking the patient’s ability to breathe, the functioning of their lungs, and their blood flow.
It’s necessary to evaluate the patient’s level of disabilities and do a detailed neurological test, using the Glasgow Coma Scale Score to assess brain function. Doctors will also look for other specific impairments and inspect the head and neck for any wounds, bruises, or bleeding. They will make sure any cuts located over fractures in the sinus are not infected, since this indicates that intravenous antibiotics might be needed.
The head examination will also include feeling the frontal sinus to check if there’s any abnormal feeling or indentation in the bone, cleaning any open wounds, and examining them closely. Different signs can be found from checking the ears, such as a Battle sign or blood leaking from the ear, which can show that the base of the skull is fractured.
The doctor will also need to examine the patient’s nose to test the movement of the nasal bones and check for a nosebleed, fluid leakage, and the formation of blood clots. An examination of the eye area is important to check the function of certain cranial nerves and to look for signs like raccoon eyes or a build-up of blood behind the eyes.
Testing for Frontal Sinus Fractures
After a thorough history and physical exam, the most vital test to identify any structural damage and plan subsequent management is a non-contrast computed tomography scan (commonly known as a CT scan) of the head and facial bones. This imaging uses various “windows” (osseous, soft tissue, heme windows) making it fast and reliable in assessing these injuries. Regular X-rays don’t usually offer any extra advantage if a CT scan is done. If there are worries about potential vascular injury, angiography (an imaging technique to visualize the inside of blood vessels) can be considered. An ultrasound may aid in identifying fractures when performed in a specific mode. However, it’s mostly complementary to the other methods mentioned.
As of now, there’s no widely agreed-upon classification for frontal sinus fractures. About one-third of all frontal sinus fractures include both the front and back plates of the frontal sinus. Two-thirds involve only the front plate, and less than 1% involve just the back plate. To broadly classify, below are few classification systems:
In 1997, a classification was introduced by Gonty et al., which listed fractures into categories like only front plate involvement (61.4%), both front and back plate involvement (33%), only back plate involvement (0.6%), comminuted fractures with the involvement of the orbit, ethmoids, and nasal base (2.5%), or fractures involving the nasofrontal duct (2.5%).
In 2014, Torre et al. proposed a classification based on the max displacement and surrounding structure involvement. In their study, Type A was the most common (38.4%) followed by Type D (25%), Type B (22.6%), and Type C (14%). Each type, based on displacement and other injuries, guides as to whether observation or surgical repair is needed.
Treatment Options for Frontal Sinus Fractures
Treatment plans for patients with fractures of the front part of the skull can vary greatly, depending on their accompanying injuries. For fractures that haven’t moved out of place, close monitoring and follow-up are typically adequate.
In the case of a front bone fracture with a cut on the surface (called an open fracture), it’s crucial to give suitable antibiotics and a tetanus shot or immunoglobulin as needed. If the front part of the fracture isn’t communicating with the brain, an antibiotic like IV amoxicillin-sulbactam will do the job. However, if the back part of the fracture is displaced or dislocated, a type of decedent generation antibiotic, like cefotaxime, can be added.
Different surgical options include operations to eliminate or fill up the sinus (frontal sinus obliteration), moving the broken parts back into place (closed fracture reductions or ORIF), and simply observing the patient’s condition over time. You might note that there isn’t a universal guide to figuring out the classification and optimal treatment for this condition, leading to different approaches by various surgeons.
In recent years, a significant number of surgeons have preferred less invasive treatments, sometimes even opting to monitor fractures that have moved out of place, as long as it doesn’t involve the sinus outflow tract or the back part of the fracture. If the bone doesn’t fix itself, fillers or fat grafts could be added later to improve the aesthetic result. Despite the differing opinions, it’s a generally accepted rule to perform surgery if the back part of the fracture has moved more than 5mm. It’s common for most procedures to happen within 12-48 hours of the patient first being seen, unless there are more severe, life-threatening injuries.
Sometimes, close monitoring and follow-up may be all that’s needed, especially for minimal fractures of the front part that have moved less than 1-2 mm without any damage to the nasofrontal recess. There are also various minimally invasive techniques for repairing these fractures, which often result in good-looking results. Two common methods include using screws and inflating a small balloon-like device (Foley catheter) within the sinus to push the broken parts back into place.
Open Reduction with Internal Fixation (ORIF) is a surgical procedure typically required for fractures that have moved more than 2mm without any involvement of the nasofrontal recess, or for patients with a noticeable cosmetic deformity in the forehead. The surgeon must ensure a clear view and access to the sinus for a successful repair while considering the patient’s aesthetic outcomes. This procedure uses small metal plates or a titanium mesh and screws to secure the broken pieces. In some cases, screws might be used to support the bone without fixation.
In the case of severely shattered fractures of the front part or other specific scenarios, an operation to fill up the sinus may be recommended. This procedure involves entirely removing all sinus mucosa, closing off the nasofrontal duct, and then filling up the sinus cavity with bone grafts or other materials. One downside to this procedure is the potential risk of mucocele development, which, if left untreated, could destroy more bone by expanding.
For more complicated fractures involving the back part, an operation called ‘cranialization’ may be necessary. This major surgery involves removing all the contents of the frontal sinus, including debris and fractured bone parts. Any defects in the front part should also be fixed properly to protect the brain and the dura that may have slipped into the sinus.
What else can Frontal Sinus Fractures be?
When discussing different types of skull and facial fractures, these are some of the possibilities:
- Naso-orbito-ethmoid fracture (a type of facial fracture)
- Nasal bone fracture (a broken nose)
- Temporal bone fracture (a fracture in the area near the ears)
- Parietal bone fracture (a fracture in the area at the top of the skull)
- Pott puffy tumor (a serious complication from a fracture, causing a swelling in the forehead)
What to expect with Frontal Sinus Fractures
The outcome of a patient largely depends on the severity of their injuries and their overall health. When a patient has multiple injuries, several specialists may be needed for treatment. On a positive note, individuals with only a frontal sinus fracture generally have a good outcome, regardless of whether specific areas like the nasofrontal outflow tract or posterior table are affected.
Thanks to advancements in surgical procedures and technology, we now have a better chance to preserve the frontal sinuses. This progress also enhances the expected quality of life for patients after treatment.
Possible Complications When Diagnosed with Frontal Sinus Fractures
Complications related to frontal sinus fractures can occur either within the first 6 weeks after the injury (acute complications) or last for more than 6 weeks (chronic complications). However, it’s possible for some complications to occur across both these time frames. The list of potential complications includes:
- Frontal sinusitis (infection or inflammation of the frontal sinus)
- Meningitis (inflammation of the protective membranes covering the brain and spinal cord)
- Cerebrospinal fluid leak (fluid that surrounds the brain and spinal cord leaking out)
- Mucocele (mucus-filled swelling)
- Mucopyocele (infected mucocele)
- Osteomyelitis (bone infection)
- Pneumocephalus (air or gas in the cranial cavity)
- Poor cosmetic outcome
- Brain abscess (a pocket of pus in the brain)
- Chronic headaches in the frontal region
- Extrusion of graft material (implanted material moving out of place)
- Intracranial hemorrhage (bleeding inside the skull)
- Diplopia (double vision)
- Ophthalmoplegia (eye muscle weakness or paralysis)
- Blindness
- Paresthesia (a sensation of tingling, pricking, or numbness) of the supraorbital, infraorbital, and/or supratrochlear nerves
- Hypoesthesia (reduced sense of touch) or paresthesia of the ophthalmic or maxillary nerves
- Facial deformity
Preventing Frontal Sinus Fractures
The best way to prevent or lessen the damage from fractures to the front part of your skull is to always wear a helmet during sports that involve fast movement or contact. These include sports like cycling, driving, skiing, and skateboarding. This also applies to sports where things are thrown fast such as baseball, cricket, or softball, and for sports with a lot of person-to-person contact like American football, ice hockey, and lacrosse.
When doing work that involves heavy machinery or if you’re in a risky environment, like a construction site, industrial factory, or a battlefield, wearing a helmet is vital for safety. Other than wearing a helmet, it’s also necessary to avoid places or activities that can lead to head injuries, especially if you don’t have a helmet available.
