Definition & Overview

A halo is a medical device that is designed to support the head and cervical spine of people with spine injuries. However, when the device was first developed in 1956, it was specifically for patients afflicted with poliomyelitis. Poliomyelitis is a disease that affects children. The disease attacks the nervous system and the spinal column causing paralysis and many other symptoms. One of the possible results is a significant reduction in the child’s mobility. In fact, children with this disease often end up bedridden for prolonged periods. A halo supports the spinal column and head allowing the child to be placed in a sitting position. Doing so will not only enable the child to be moved to different places, but also significantly reduces the time the child needs to stay in bed. Attaching a halo to an adult would have similar advantages. Adults who have an injury to the spinal column, or are undergoing treatment for spinal conditions, can also be bedridden for long periods. A halo will enable them to move around although such movement can be severely limited. A halo is a circular device that is attached to the head via metal pins that are connected directly to the skull. The device also has rods that are connected to the shoulders and upper back. The method of application is more difficult with children than adults. Children usually have thin skulls making it difficult to attach the halo. The pins that are used to connect the device to the skull are not supposed to penetrate the bone. Doctors look for thicker portions of the skull by having the patient undergo a three-dimensional computed tomography (3D CT) scan. It is important to note that even with the assistance of an imaging device, there is still a possibility of complications, such as bleeding or the pins loosening.

Who Should Undergo & Expected Results

There have been concerns regarding the use of a halo device on children, particularly those under three years old due to the thinness of their skulls. However, studies have shown that the procedure is relatively safe and that the device is reliable. Nevertheless, all risks have to be considered not only by the attending doctors and surgeons but also by the parents or guardians of the child. Children that require a halo device are usually those with a disease that affects the cervical column or have experienced significant trauma to the spine. Children who are born with an abnormality to the spine will also need the device. The length of time that the halo needs to be attached to the child will depend on the child’s condition and/or treatment programme. This can be anywhere from a month to a couple of years. It is also important to note that a halo is not in itself used to cure the condition. The device only helps improve a patient’s stability while undergoing treatment to cure or resolve a particular medical condition.

How Does the Procedure Work?

Prior to attaching a halo, the patient is first carefully assessed to confirm the requirement of such a device. The patient typically undergoes a CT scan with 3D reconstruction to assess the thickness of the skull and condition of the child’s neck. The surgeons will then study the result of the CT scan to plan the locations of the pins. The patient may require 6 to 10 pins to ensure that the halo is fixed to the skull securely. After the planning stage, the patient will be transferred to the operating room and administered a general anaesthetic. The halo will then be position on the child’s head and the pins tightened using a torque wrench. Some surgeons may require assistance during this procedure to ensure that the pins are tightened with the right amount of pressure. Highly experienced surgeons may perform the procedure using a freehand tightening technique. Utmost care is taken while tightening the pins, especially in patients with a bone-weakening condition. On these patients, even the recommended pressure may exceed the strength of bone, thus resulting in further complications. After the procedure, the patient will need to be carefully monitored. Doctors will check the condition of the pins on a regular basis to ensure that they haven’t loosened and that the area does not show any signs of infection. The parents or guardians of the child will be given instructions on how to take care of the halo properly and how to spot signs that require immediate medical attention.

Possible Risks and Complications

Even though attaching a halo does not involve opening the skull or performing any type of surgery to the brain, the procedure is still prone to complications and there are a number of risks involved. A child’s skull is thin, so there is no standard area where pins should be attached. Doctors will have to study the results of a CT scan carefully to identify the best areas to attach the pins. Nevertheless, there is still a risk of one or more pins penetrating the skull, especially for patients who have weak bones. There is also a risk that the pins may loosen over time. If this happens, the doctor may need to tighten the loose pin/s. There is also a possibility of complications occurring. The most common complications are bleeding in the area where the pins are attached and infections developing in that area. If this happens, the infection must be treated promptly to prevent it from spreading and creating a life-threatening condition.

References: * Alexandre Arkader, Harish S. Hosalkar, Denis S. Drummond, John P. Dormans; “Analysis of Halo-orthoses application in children less than 3 years old”; http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2656751/ * M. Letts, D. Kaylor, G. Gouw;”A biomechanical analysis of halo fixation in children”; http://www.boneandjoint.org.uk/content/jbjsbr/70-B/2/277.full.pdf * S.Garfin MD, M. Botte MD, R.Waters MD, V.Nickel MD; “Complications of the use of a halo fixation device”; http://www.oandplibrary.org/op/pdf/198703060.pdf

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