Application field of auxiliary external fixation support

External fixator was used before operation. When craniocervical junction deformity is accompanied by atlantoaxial dislocation, atlantoaxial instability, odontoid dislocation moves backward, and the medullary junction of the neck is compressed. In this state, the patient's improper head movement or minor trauma may lead to the rapid deterioration of the disease and even lose the opportunity to recuperate. It is necessary to stabilize the craniocervical junction area by external fixation brace. Some severe patients even need skull traction to achieve partial reduction and maintain stability.

The structure of the neck circumference is simple, convenient and flexible, and the patient can master the wearing method through simple guidance.

The interval between two operations in most patients is 2-3 weeks, except for a few patients who complete two operations under one anesthesia. During this period, the stability change of the craniocervical junction area is: after the odontoid process is removed, the compression of the medulla oblongata is relieved, but the functions of the ligaments that play a major role in stabilizing the atlantoaxial joints, such as the apical ligaments, pterygoid ligaments and cruciate ligaments, are destroyed, and the stability between the atlantoaxial joints is even worse. Reducing head movement, especially avoiding vertical gravity acting on the atlantoaxial joint, is a necessary measure to prevent atlantoaxial spondylolisthesis. Although the stability of neck circumference is worse than that of soMi and head ring bra, it is mainly due to the poor inhibition of rotation movement, while the inhibition of head flexion and extension movement and vertical support are relatively good.

After posterior craniocervical fusion, the stability of craniocervical junction was different according to different internal fixation methods. The selection of auxiliary external fixation supports shall depend on the internal fixation method adopted and the reliability of internal fixation. The choice of brace is mainly based on the firmness of titanium cable binding during operation. The firmness experience is determined based on the hardness of bone graft (from iliac bone) and the tightness of binding.

In addition to the stability requirements of external fixation at different times according to the surgical treatment of craniocervical junction deformity, the selection of auxiliary external fixation brace also needs to consider other comprehensive factors of surgery and the characteristics of brace itself. In the cases of neck circumference and soMi after posterior surgery, there were patients with occipitocervical incision infection. The reason is that both neck circumference and soMi need to fix the head with a support plate placed on the occipital neck, resulting in skin compression, poor ventilation and local sweating at the incision of occipital neck surgery, which increases the risk of infection. The head ring bra not only has the advantage of stability, but also its head ring device can avoid the compression of occipital and neck surgical incision and is conducive to healing. The use of head ring bra after posterior surgery is worth advocating.

However, the head ring bra also has some disadvantages, such as skull nail penetration, skull nail loosening, local infection, etc., and its unique feeling and appearance after placement may also have a great psychological impact on patients.