The symptoms of axial symptoms after cervical spine surgery include soreness, swelling, weakness, pain, stiffness and limitation of movement in the neck and back of the shoulder, etc. When the pain and limitation of movement continue to worsen, the quality of life of patients after surgery is seriously reduced . Our study showed that not wearing a neck brace reduces the incidence of axial symptoms in the early postoperative period after anterior cervical spine surgery. But there is no significant difference in incidence of axial symptoms at 3 months. Maybe the restriction of neck movement is lifted after 1 month and stiffness and limitation of movement are better than before. Due to the degeneration and instability of the patient's operated segment and adjacent segments, the normal physiological curvature of the cervical spine is reduced, resulting in cervical kyphosis. Soft tissues such as neck muscles and ligaments as well as the deep joint capsule are subject to stress changes under tension in a strained state. If a patient wears a brace for a long time after ACDF surgery, it restricts the active movement of his neck and leads to atrophy and stiffness of the posterior cervical muscle groups, which in turn produces axial symptoms or aggravates them . One study has shown that axial symptoms after cervical fusion can be prevented or reduced by early postoperative static neck exercises, which increase neck mobility and promote the recovery of self-care ability . Therefore, for patients after single-segment ACDF, the incidence of axial symptoms can be reduced by not wearing a cervical brace and by performing early functional neck exercises while ensuring safety.
Cervical spine mobility can effectively evaluate the postoperative quality of life and cervical spine motor function in patients with cervical spine diseases . Our results showed that there was no significant difference in the cervical spine mobility between the two groups before surgery. The cervical spine mobility of the two groups gradually increased with time after surgery, but it was still lower than before. Patients in the no brace group had higher cervical mobility than those in the brace group at 1 and 3 months postoperatively, and the difference in mobility at 1 month postoperatively was statistically significant. Due to the removal of the diseased disc, implantation of the fusion device and placement of the plate anteriorly during ACDF, the cervical mobility of the fused segment was directly lost. Moreover, the cervical brace was fixed for 1 month after surgery in the brace group, which restricted the movement of the neck and caused stiffness of the neck muscles, thus affecting the recovery of cervical mobility. Another study reported that wearing a brace for a long time after surgery significantly reduced the motion of the cervical C3-6 vertebrae, resulting in a decrease in overall cervical mobility and an increase in compensatory motion of the cervical 2/3 and cervical 6/7 segments. Finally, the patient developed axial symptoms . Therefore, for patients after single-segment ACDF, it is recommended to not wear a brace, which not only facilitates the recovery of cervical mobility, but also reduces the occurrence of axial symptoms.
In the beginning, postoperative cervical spine patients often needed a cervical brace to limit excessive movement of the cervical spine, increase the stability and promote the fusion of the cervical spine vertebrae. With the development of internal fixation techniques and materials, titanium plates are routinely fixed anteriorly to the vertebral body in ACDF surgery. Internal fixation with titanium plates can prevent displacement and subsidence of the intervertebral fusion, maintain segmental stability and interbody height, promote implant fusion, and reduce the dependence on external fixation. Additionally, cervical braces may cause discomfort and related complications such as dysphagia, and muscle atrophy, and even lead to changes in gait, affecting the quality of life and safety of patients . Therefore, patients after single-segment ACDF can be recommended to improve their postoperative quality of life by not wearing a brace.
There are some limitations in the study. The follow-up time of this study was only 3 months, the sample size was small and the surgical modality was limited to ACDF. Multicenter, anterior cervical multi-surgical modalities with longer follow-up time in randomized controlled clinical trials should be conducted in the future.