Halo Brace

Excerpt

The halo brace, also known as the halo vest immobilizer, is a device that restrains the cranium to the torso, offering the most rigid form of external immobilization for the upper cervical spine, particularly the occipitocervical and atlantoaxial junctions, for both adult and pediatric patients. Compared to conventional cervical orthoses, the halo brace stands out as the superior option for immobilizing the upper cervical spine. This is because it can restrict atlantoaxial joint flexion and extension by 75%, as opposed to only 45% with conventional orthoses. Notably, intercalated paradoxical motion occurs upon application, with lateral bending being the least controlled within the subaxial cervical spine (at/below C3). Hence, conventional cervical orthoses are generally more effective in immobilizing this specific region.

Originally introduced in 1959 by Perry and Nickel to offer cervical immobilization for occipitocervical fusion in poliomyelitis patients, the application protocol and design of the halo brace have undergone significant evolution. Today, halo braces are utilized for various purposes, including as a definitive treatment for specific upper cervical spine trauma or injuries, preoperative correction of spinal deformities, and postoperative adjuvant stabilization. A halo brace application is usually performed in an operating room under the supervision of a physician-led clinical team. This method involves specific procedural steps, differentiating it from other cervical spine immobilization methods.

Examples of definitive treatment are occipital condyle fractures, occipitocervical dislocation, C1 fractures (most common), and C2 fractures, with an anticipated average healing time of 3 to 4 months. Although this technique demonstrates an approximate success rate of 85%, the effectiveness of the halo brace hinges on appropriate indication, application, and management. Risks are associated with the use of halo braces as a definitive treatment, especially among older patients, necessitating caution in specific populations. In addition, this device can be used in the pediatric population for cervical spine trauma (definitive or conjunction with surgical management), severe scoliosis, and arthrodesis, although this entails adjustments like utilizing more pins and applying reduced insertion torque force to accommodate differences in skull thickness.

Halo vest immobilization is considered safe for toddlers (aged 4 or younger); nevertheless, ambulation should be restricted within this age group. Pediatric and toddler populations typically have reduced skull thickness, necessitating specific modifications in halo brace application. This includes utilizing more pins (8 to 12) on the cranium and applying lower insertion torque force (1- to 5 in-lb). Despite these considerations, halo braces have been used to treat cervical spine injuries and deformities effectively.