The purpose of this study was to evaluate the efficacy of anterior debridement and BFIF combined with anti-TB chemotherapy in the treatment of SCS-TB and analyze the changes in vertebral radiographic sagittal parameters. In this cohort, the affected area was mostly concentrated in the C3-C6, where patients with more than two vertebrae involved were usually associated with local kyphotic deformity. The longer the duration of TB, the higher incidence of spine sagittal imbalance. The standardized anti-TB chemotherapy was always necessary for the management of SCS-TB. The purpose of the surgery was to decompress the spinal cord compression, restore the stability of the vertebral body to achieve the spine sagittal balance. The spinal cord compression and spine sagittal imbalance were remarkably improved in all patients after surgery combined with anti-TB chemotherapy, with effective control of TB poisoning symptoms.
SCS-TB was a severe type of osteoarticular tuberculosis, which cannot be ignored in animal husbandry areas and developing regions since the increasing incidence recently [1, 3]. In the view of anatomy, the compression symptoms caused by cervical TB may be concealed by the wide cervical spinal canal. The joints of the lower cervical spine were flexible, which led to rapid progress once infection took place here. If the treatment was not timely, symptoms of spinal cord compression (paresthesia, paralysis) or kyphotic deformity might be caused by the lesions. Hence, the patients with SCS-TB mostly were not treated until the disease developed at the mid or advanced stage. Via previous studies [4, 9, 11, 15–18], surgical treatment combined with standard anti-TB chemotherapy was recommended to be managed the patients with the above symptoms. The purpose was to remove the lesion completely, relieve the compression of the spinal cord, correct kyphotic deformity, and reconstruct the height and physiological curvature of the cervical spine [1, 11]. Cervical tuberculosis lesions were usually located in the anterior and middle column of the vertebra. Although there were several surgical approaches (anterior, anterior combined with posterior, and endoscopy-assisted anterior), the anterior approach was still a practical method for surgery, since the simple structure of incision, convenient procedure of internal fixation, sufficient exposure of lesion, and less recurrence of infection [1, 2]. In this cohort, all patients with cervical tuberculosis had lesions concentrated in the lower cervical spine (C3 ~ C7), 23 patients with lesions involving more than two vertebral bodies, and 12 patients with typical symptoms of spinal cord compression. And all patients were successfully treated by the anterior debridement, BFIF combined with anti-TB chemotherapy.
SCS-TB accounted for 3–5% of all spinal tuberculosis [3, 14]. The lesions here adjacent to the trachea and esophagus were brought out the high incidence of symptoms such as hoarseness of inspiration, anorexia, and cervical lymphadenopathy. At present, atlanto-pivotal lesions were mostly treated by the posterior approach of surgery to rebuild the vertebral stability [4, 13, 19], while the SCS-TB was managed by the anterior approach of surgery since the high rate of kyphotic deformity[11, 20–22]. In addition, the importance of cervical sagittal balance in surgical decision-making and postoperative evaluation had been gradually emphasized. A higher incidence of kyphotic deformity may occur in patients with C2–C7 cobb angle > 0° or C2–C7 SVA > 4 cm, and it was recommended to provide the anterior approach of debridement and reconstruction surgery for the above patients to acquire clearance of infection. In this study, 23 patients with a mean C2–C7 Cobb angle and C2-C7 SVA of 14.26 ± 9.93° and 36.48 ± 10.35 mm returned to -14.81 ± 7.37° and 8.44 ± 3.01 mm (P < 0.001), respectively. In our experience, the abscess and lesions of the intervertebral disc area should be resolved first, and then the diseased vertebral body. The range of debridement should be performed until the fresh blood was scraped from the upper and lower vertebral bodies to avoid excessive destruction of the vertebral body resulting in spinal instability. Appropriate trimming of the bone defect facilitated the placement of the bone graft. The Caspar retractor screws were placed parallel to the middle of the upper and lower vertebral bodies adjacent to the diseased vertebral body, which was helpful for the exposure and removal of the lesions, correcting the cervical kyphosis, and restoring the physiological curvature.
The use of internal fixation in the management of infectious diseases is still controversy [1, 2, 14]. Although previous theories had suggested that biofilms form on the surface of internal fixation, which may be not conducive to the control of infection . However, the current view is that surgical procedures combined with anti-TB chemotherapy can effectively eradicate the Mycobacterium tuberculosis on the surface of internal fixation . Restoration surgery using internal fixation in the treatment of spinal infection diseases was recommended, such as titanium plate and titanium mesh cage. Koptan et al. reported a prospective, nonrandomized multicenter study of 30 patients with cervical tuberculous spondylodiscitis was successfully treated by radical debridement and decompression using a titanium mesh cage. Besides, Mao et al. presented a series of 21 patients with SCS-TB effectively managed by anterior debridement and bone grafting using internal plate fixation. As far as we were considering, the significance of bone graft was to form a bridge between the upper and lower vertebral bodies, and satisfactory fusion depended on the osteogenesis process with stable fixation. Immediate stabilization of the vertebral body could be provided by the titanium plate, which was able to restore cervical curvature and allow early rehabilitation. However, it is not necessary to pursue a large amount of autogenous bone with bone graft when applied to the titanium mesh cage, which might reduce the incidence of donor site complications (pain and poor wound healing). And the sharp dentate structure of the titanium mesh cage strengthened the shear resistance, which enhanced the torsional strength of the bone graft. Though, the application of titanium mesh cage was limited by the extent of vertebral lesions, which was suitable for involving more than three vertebral bodies. Although the previous studies illustrated the practical efficacy of titanium mesh cage, its application of it still needed to be decided on the extent of the lesion. In this study, there were nine patients managed by the titanium mesh cage and fourteen patients with a titanium plate. None of displacement, nonunion, or pseudoarthrosis formation took place.
It was also necessary to recognize that anti-TB chemotherapy was the fundamental part, surgical treatment was only an auxiliary tool [1–3, 8, 12]. The satisfactory result of surgery depended on the standardization and rational utilization of anti-TB drugs (early, combined, adequate, regular, and consistent) . The recurrence of infection may be caused by ignorance of the role of anti-TB chemotherapy, which failed the entire treatment regimen. In our cohort, the 2HRZE/4HR regimen was conducted for patients and no recurrence of the infection. However, the side effects of anti-TB chemotherapy should be carefully observed during follow-up, and intervention should be applied timely, such as detection of liver and kidney function, psychological consult, etc.
The limitations of this study should also not be ignored. First of all, there was no mature treatment algorithm for the resolution of the SCS-TB. In addition, there was a lack of large case series with the complete postoperative of SCS-TB treated with anterior or combined anterior and posterior approach surgery (debridement and BGIF). Hence, a prospective study of more samples and multi-center is of more clinical significance.