Overview of Halo Brace
The halo brace or halo vest immobilizer is a tool that attaches the head to the upper body. It provides the best external hold for the upper neck, especially the back neck and first two vertebral joints, which is used for adults and children. It limits the movement of the first neck joint by 75%, while other neck supports only do so by 45%. There is some unusual movement in the lower neck when wearing this brace, where typical neck supports work better.
First used in 1959 to immobilize the neck for polio patients undergoing surgery, the halo brace design and uses have evolved over time. Today, it is used to treat specific upper neck injuries, correct neck deformities before surgery, and provide extra support after surgery. Applying a halo brace usually takes place in a hospital operating room with a team of medical professionals.
It can definitively treat conditions like fractures at the base of the skull, dislocation between the skull and spine, and fractures of the first and second neck vertebrae. These conditions generally heal in 3 to4 months. The success rate of the procedure is about 85%. However, its effectiveness strongly depends on the right patient selection, correct application, and careful management. It carries some risks, especially for older adults, so its use in these groups should be done with caution.
The halo brace is also used for children for specific neck injuries, serving as extra support after surgery, treating severe curvature of the spine (scoliosis), and joint fusion procedures. Because children’s skulls are not as thick as adults’, special adjustments like using more pins and using less force to insert them are required.
Although the halo vest immobilizer is considered safe for toddlers (ages four and under), walking should be limited as much as possible. Just as with children, the thickness of a toddler’s skull requires some changes in the application of the halo brace. More pins (8-12) are used on the head and less force (1-5 in-lb) is used to insert them. Despite these adjustments, the halo brace is a proven effective treatment for neck injuries and deformities in children.
Anatomy and Physiology of Halo Brace
Health professionals need to have a good understanding of how the head is structured to ensure pins are placed properly. The area where it’s safe to place these pins is about 1 cm above the outer two-thirds of the rim of the eye socket (basically where the eyebrow is). This area is found just under the spot where the head is widest, which is roughly 0.5 to 1 cm above the tops of the ears. In the front-to-back plane, the inner edge of this safe area is around 4.5 cm from the middle of the head, and pins should be avoided in areas closer to the middle of the face.
There are two important nerves within this region, the supraorbital and supratrochlear nerves (from outside to inside), which are the last branches of a big nerve called the trigeminal nerve. This nerve is in charge of sensation to the front and top part of the scalp and some areas of the bridge of the nose.
The frontal sinus, found towards the middle of the head from the safe zone, should not be used for pin placement. This area has thinner bone, making the risk of a pin going through it much higher. There are several structures to the outer side of this safe zone including the temporal bone (which is thinner), a muscle called the temporalis muscle, and a nerve called the zygomaticotemporal nerve. If pins are placed too far to the outside in the front, it could lead to problems like the pin going through, irritation when moving the jaw, and feelings of tingling or numbness along the side of the head.
Why do People Need Halo Brace
A halo brace is a special kind of brace that is used to stabilize and support the neck and upper spine during the recovery process from certain types of injuries and surgeries. It is essentially a ring that surrounds the head and is secured with pins, which is attached to a vest worn on the body. Here are the main situations in which a halo brace is definitely required for adults:
– For a fracture of the occipital condyle, which is a small bony protrusion at the base of the skull that helps it connect to the spine. A halo brace becomes crucial when this fracture is accompanied by damage to the ligaments around the area or signs of instability.
– If there are fractures on both occipital condyles, a halo brace can provide better immobilization.
– Atlantooccipital dislocation is a rare and often fatal neck injury that can be caused by severe trauma. This happens when the joint that connects the base of your skull and top of your spine becomes dislocated. Even when a CT scan does not show signs of instability, if moderately abnormal MRI reflects ligament damage, a halo brace might be needed.
– For a type II Jefferson fracture, a rare and serious injury to C1 (the first cervical vertebrae), when the ligament that connects C1 and C2 (the second cervical vertebrae) is torn.
– For type II odontoid fractures in young patients and for Levine types II and IIA Hangman fractures. Odontoid and Hangman fractures relate to injuries to C2, the second cervical vertebrae.
There are also situations where the use of a halo brace is temporary for adults. This can include as extra immobilization after cervical spine surgery.
For children, the reasons to use a halo brace may include dislocation of the atlantooccipital joint (the joint connecting the base of the skull and top of the spine), displacement or slipping of the joint between the first and second cervical vertebrae (atlantoaxial subluxation), Burst fracture of C1, fractures of the first cervical vertebra or the odontoid process (a tooth-like knob on C2), ongoing rotation of the atlantoaxial joint, idiopathic or congenital scoliosis, or for pre-surgical reduction in patients with deformity of the spine.
When a Person Should Avoid Halo Brace
There are two types of conditions that can mean a person shouldn’t wear a halo brace (a kind of neck brace), and these are known as absolute and relative contraindications.
Absolute contraindications are reasons a person definitely should not wear a halo brace. These include:
- Having a broken skull or very weak bones.
- Needing surgery on the skull (craniotomy).
- Having severe skin damage or infections on the scalp where the brace would be attached.
Relative contraindications are reasons a person might need to be careful when considering a halo brace. It doesn’t always mean they can’t use it, but they should discuss it carefully with their doctor. These include:
- Having multiple severe injuries (polytrauma).
- Having a collapsed lung (pneumothorax).
- Having a chest injury that has caused a hole in the chest.
- Having a lung contusion, which is a bruise or damage to the lung tissue.
- Being significantly overweight (obesity).
- Having a barrel-shaped chest, which means the chest is rounded and larger than usual.
- Being older than 65, as there are higher risks for complications and even death.
Equipment used for Halo Brace
Here’s a simple list of all the things your doctor would need to carry out this procedure:
- Anesthetic: Lidocaine with epinephrine 1%. It’s a painkiller that helps numb the area where the procedure would happen, about 10 to 20 mL of it is required.
- Needle: Size 22 to 25-gauge. This is needed to inject the anesthesia.
- Syringe: This is used to draw up the anesthetic agent, and it’s between 10 and 20 mL in size.
- Gloves: Both sterile and non-sterile examination gloves. These are used to keep everything clean and safe.
- Antiseptic solution: This could be Povidone-iodine solution or another type. This helps to clean the skin before the procedure.
- Emergency medical cart: This has equipment like a manual resuscitator and an endotracheal tube in case there’s a need to manage breathing or deal with heart and lung issues.
- Halo ring: This is sterile and already measured from the largest head circumference. It’s used to immobilize the head during the procedure.
- Halo pins: These are sterile pins specifically for the halo ring. There are 5 of them including 1 extra.
- Halo pin locknuts: There are also 5 of these, with one of them acting as a spare. They help to secure the halo pins in place.
- Halo torque screwdriver or wrenches: These are used to tighten the pins. If they’re using wrenches, they’ll need 4.
- Ratchet wrenches: These are used to adjust the halo ring.
- Halo vest: This is measured from the chest circumference at the xiphoid (lower part of the sternum). It helps to stabilize the halo ring.
- Halo upright post (4) and connecting rods (2): These are parts of the halo vest and are used for further stabilization.
Remember, your doctor will prepare all these materials before the procedure. You don’t have to worry about it. Your doctor’s goal is to ensure your safety and comfort during the procedure.
Who is needed to perform Halo Brace?
Putting on halo braces usually needs a team of 2 to 3 healthcare workers. This team often includes a doctor and an assistant. The assistant could be a nurse, a physician assistant or a doctor-in-training. These people work together to make sure your brace fits correctly and comfortably.
Preparing for Halo Brace
Before starting a medical procedure, doctors explain everything to the patient or to their family member or health care representative, in case the patient isn’t able to understand. They will discuss how the procedure will be done, what equipment will be used, and the risks and benefits of the operation. Once the patient or their representative gives permission, the medical team gets everything ready for the procedure. The procedure can take place in a special room that has all the necessary equipment, or in an operating room. Patients might feel somewhat sleepy or completely asleep, depending on the type of sedation used. No need to worry though, while the operation is on, even if you are not completely asleep, an anesthesiologist (a doctor who specializes in managing pain through medication) will be there to keep you comfortable.
How is Halo Brace performed
Adults undergoing this procedure will lay flat on a bed with their head propped up a bit. The appropriate size for the halo ring (a device that goes around your head) is determined by measuring around your head. There must be a small space between your scalp and the halo ring. Your chest size around the level of the lower part of your sternum (a long flat bone in the middle of your chest) will determine the size of your halo vest.
Once the ring is in the correct position, around 1/2 cm above your eyebrows and centered equally around your head, they will pick the places where the pins will go through. They will clean these spots and numb them so you don’t feel any pain when the pins go in. Four pins go through the skin and into your skull.
You will close your eyes so that the tension from the pins does not stop you from being able to close them properly later on. These pins will be tightened so they are at a 90-degree angle from your skull. They will tighten them slowly, going back and forth between the ones diagonally opposite each other. The screwdriver used to apply the torque will show how much torque is being applied, and it wll stop at 8 inch-pounds of torque.
Once this is done, they will put locknuts on the pins. Next, the vest will be put on which has a front and back part connected by straps. While the back part is held by an assistant, the halo ring is attached to it with the straight support bars on both sides. Then the front part of the vest is put on and attached to the back part with straps and to the halo ring with support bars on both sides. These bars must be parallel and at a right angle (90 degrees) to the crossbars for optimal stability. There will be equal bending at the halo ring to the supports. Once this is all done, all the parts will be checked again to ensure they are tight. All necessary tools should be affixed to the front shell of the vest for emergencies.
The places where the pins go through the skin should be cleaned every day or every other day with hydrogen peroxide or antiseptic solution. They will move the skin around each pin site to minimize the risk of infection.
Each pin will be retightened to 8 inch-pounds of torque 24 hours after it is first put in. Two days after it’s first put in, they will redo the whole check, and then repeat it every 3 to 4 weeks.
Pediatric patients (children) require several modifications to this procedure. The pins are not tightened as much so they don’t go through the bone in the skull. More pins are used to lessen the risk of the pins going through the bone. The locations for pin placement are the same as in adults.
The brace/vest must be fitted for the child if they are 2 or older. For kids who are 2 or younger, it’s recommended to use a Minerva cast, a type of cast specifically designed for children.
In some cases, a CT scan (a type of X-ray that provides detailed images) could be helpful to plan the pin placement by avoiding the thin areas of the skull. However, radiation from CT scans can harm children, so the risks and benefits should be carefully considered, a rule applied in all medical procedures.
Possible Complications of Halo Brace
There can be a number of complications from certain procedures, such as:
Nerve damage affecting areas at the back of the head (greater occipital nerve), above the eyebrow (supraorbital nerve), and above the eye socket (supratrochlear nerve).
Damage to the roof of the eye socket, that can potentially lead to an infection in the tissues around the eye (orbital cellulitis).
In some rare instances, particularly in children, an injury can occur to the sixth cranial nerve (abducens nerve) during brace placement. This can cause double vision, and limit the ability to move the eye sideways. Usually, doctors just watch over these symptoms and they often resolve on their own.
There may also be bouts of intense nerve root pain, issues with equipment used in the procedure such as penetration or loosening, along with neck stiffness or discomfort.
Infections can occur at the pin site, sometimes needing oral antibiotics or even the removal and replacement of the pin if an abscess (a swollen area filled with pus) forms. In severe cases, it could lead to a bone infection in the skull, and in very rare instances, a collection of pus in the brain or under the protective layers of the brain.
Other potential issues may include limited arm movement due to vest placement, potential risk of infection or injury at the fracture site post-procedure, and breathing issues – especially pneumonia or critical lung conditions particularly in older people over the age of 65.
There could also be irregular heart rhythms, difficulty swallowing, damage to the outer layer of the brain or skull, air trapped in the skull due to pin penetration into the frontal sinus (the area above your eyes), or development of pressure sores from the vest or cast.
Additionally, if the vest is not well-adjusted or loosens, it may fail to keep the injured/fractured site still. This may result in abnormal healing or movement in different directions in the neck spine while changing positions, which could hinder the healing process.
In older patients, they may become less active due to these complications. In a specific condition called osteogenesis imperfecta, a patient may even end up with a gap between the upper front teeth (incisor diastasis).
What Else Should I Know About Halo Brace?
Doctors have many ways to treat neck injuries and abnormalities in both children and adults. These range from non-surgical treatments that involve stabilizing the neck externally, to surgical methods. One of these methods is the use of a special brace known as the halo vest immobilizer. Although its use has declined due to better surgical options and the issues that arise from keeping the neck immobilized, it’s still a good choice for certain situations, such as patients who can’t undergo surgery or for young people.
Successful treatment using the halo vest immobilizer largely depends on correctly applying and maintaining it. It must be taken care of regularly during the period of immobilization, which generally lasts around 12 weeks. The screws that attach it need to be tightened 24 to 48 hours after it’s first put on, with regular checkups every 3 to 4 weeks thereafter. It’s also important to clean the screw sites each day, or every other day, to reduce the risk of infection. Doctors usually take X-rays during these checkups to confirm the neck is properly aligned.
In preparation for attaching the halo vest immobilizer, doctors may use special imaging techniques such as CT scans. This is particularly valuable for children who often have different anatomical features. This helps to avoid placing screws in areas of the head that are too thin or close to the sutures, which are the areas where the bones of the skull join. Doctors must understand the anatomy and technique involved to ensure the screws are safely placed and the halo vest is properly applied. Despite the potential for minor complications, this treatment method has been successful in up to 85% of cases. This shows that the halo vest immobilizer can be a reasonable choice for treating neck injuries when appropriate.
