Halo-Vesting in Preschool Aged Children with Synchondrosis Fracture: A Case Series which Explores the Current Techniques Associated with this Procedure

Abstract

Upper cervical spine injuries are the most common form of spinal cord trauma that occur in preschool children. Among such injuries, odontoid synchondrosis fractures are the most frequently 
observed, though relatively few cases have been reported in the medical literature. The most 
appropriate approach to describe such cases is physeal injuries of the basilar synchondrosis 
plate between the odontoid process and the body of the axis. Acute odontoid synchondrosis 
fractures are further classified into 3 subtypes based on the amount of dense displacement and 
the degree of fracture angulation. Type Ic, the most severe subtype, will require a posterior atlantoaxial fixation for an associated atlantoaxial subluxation. The majority of Type Ia and type 
Ib odontoid synchondrosis fractures that display only mild to moderate dense displacement 
and angulation, can be adequately addressed through proper fusion. Complete fusion may be 
achieved through external immobilization after careful alignment is reached by either Minerva 
Orthosis or the use of a Halo-vest. Regardless of the technique applied, prior to immobilization, 
acute synchondrosis fractures should be brought together through either neck hyperextension 
or by using the skull traction procedure. While Minerva orthosis has been effective in the treatment for two case series and a few case reports, the use of Halo-vesting in young children presents challenges due to decreased skull thickness and the presence of a certain amount of soft 
osseous tissue. For these reasons, a certain level of controversy exists in the medical literature 
as to whether the use of such a device is warranted. According to the opponents of this practice, 
Halo-vesting is often a frustrating and anxiety-provoking experience for young patients. They 
likewise draw attention to the concerns and hospitality anticipated from the caregivers of such 
children who have been vested. Furthermore, these authors document that Halo orthosis is associated with a higher percentage of complications such as pin site infections, pin loosening or 
dislodgement, the breakdown of skin, dysphagia, dural tears and even brain abscesses. Conversely, proponents believe that Halo-vesting is a well-tolerated procedure in a majority of children as well as in toddlers. In accordance with this belief, existing evidence demonstrates that 
with a modification in the pin number, pin design, location of insertion, and insertion torque, 
the incidence of pin dislodgement and pin loosening may be reduced. Moreover, pin-site infections can be prevented through periodic medical supervision of the child patient as well as 
educating caregivers on how to properly clean and monitor pin sites. Overall, the number of 
the children with odontoid synchondrosis fractures, who have been treated with Halo-vesting 
accounts for roughly 40 cases with a mean percentage of complication rate recorded at 40%. 
Herein, 3 young children with acute odontoid synchondrosis fractures are reported in whom 
solid fusion at the synchondrosis plate was achieved through the application of Halo orthosis. 
These children were placed in a Halo-vest for 8 to 10 weeks without demonstrating any noted 
complications.