Traumatic spondylolisthesis of the lower cervical spine is a serious injury that affects spinal cord function and even endangers the lives of patients. Its characteristics are as follows: 1) abnormal cervical spine alignment affects stability; 2) most vertebral segments with spondylolisthesis also exhibit disc injury or herniation, resulting in spinal cord compression or injury; and 3) varying losses of cervical intervertebral height and physiological curvature [11, 12]. The basic principles of treatment are restoration of the normal cervical alignment, complete decompression, restoration of intervertebral height and physiological curvature and reconstruction of immediate stability of the cervical spine [13]. Operation is the gold standard to cure traumatic spondylolisthesis of the axis. It is crucial to reduce pressure and restore the normal sequence of spinal stability to create conditions facilitating the recovery of neural function [14]. Traumatic spondylolisthesis of the axis can be caused by anterior cervical discectomy and distraction between vertebral bodies [15, 16]. Anterior surgery with less trauma, less bleeding and simple exposure can restore the normal cervical spine sequence, intervertebral height and physiological curvature, and it is characterised by high fusion rates, few fusion segments and guaranteed spinal activities [17, 18]. At the same time, it avoids secondary spinal cord injury that may be caused by postural changes during anterior and posterior surgeries [17, 18]. According to the study results after surgery, all cases of spondylolisthesis were completely reset, intervertebral bone grafts were fused and no loss of cervical intervertebral height and physiological curvature with good stability of the cervical spine was observed, consistent with previous results.
It would be combined with intervertebral disc injuries or herniations when Traumatic spondylolisthesis of the lower cervical spine occurred with compression mainly in the front of the spinal cord. Therefore, the surgery successfully accomplished direct decompression of the spinal cord, fully relieving the compression of the spinal cord, restoring the effective capacity of the cervical spinal canal and providing conditions for the recovery of neurological function[19]. In prior research, all patients had a better ASIA score after surgery, which is consistent with our results. This indicates that single anterior decompression, fixation and fusion can provide conditions for spinal cord functional recovery and a curative effect.
Anterior surgery is highly effective for correcting spinal cord decompression and facilitating the immediate recovery of cervical curvature. In addition, anterior intervertebral bone graft fusion can avoid the dysplasia of cervical curvature caused by secondary collapse of the injured intervertebral disc [6]. This study indicated that the recovery of the cervical sequence and physiological curvature is achieved through anterior surgery, but it is difficult to reset the rear facet fracture dislocation using this strategy. This surgery is also prone to aggravate the spinal cord damage caused by excessive intervertebral distraction, especially in cases of severe damage joint disorder. The anterior-posterior approach failed to reset one facet dislocation in this study, and thus, anterior surgery had a certain failure rate (2.04%). However, there were no secondary complications of spinal cord injury. We might add posterior surgery to reset facet fracture dislocation for normal articular process correspondence when anterior surgery fails.
However, there was less impact on the clinical curative effect if the dislocation was not reset. Two patients experienced postoperative discomfort when swallowing eased, but both cases were resolved within 6 months after surgery. It has been reported that bone graft displacement, prosthesis formation, hoarseness, cerebrospinal fluid leakage and other complications are common after anterior cervical surgery, and adjacent segment degeneration is accelerated [19]. However, in this study, there were no cases of epidural haematoma, aggravation of spinal cord injury, recurrent laryngeal nerve injury and tracheoesophageal fistula. During the follow-up period, there were no implant-related complications, such as loosening, fracture and internal fixation displacement.
This study had a few limitations. First, this was a retrospective study with a small sample size. Large-sample, multi-centre and randomised prospective studies are needed to verify its conclusions. This study lacked an evaluation of quality of life. The follow-up time was relatively short, and the long-term effects were not discussed.