Existing STB treatment mainly includes anti-TB drugs and surgical intervention. Anti-TB drug therapy plays an essential role in treating STB and provides a basis for surgical treatment. The goals of surgical treatment are to eradicate the lesion(s), relieve spinal cord compression, correct kyphosis deformity, and restabilize the spine [8]. Surgery alone, without regular anti-TB treatment, is extremely dangerous and ineffective. Effective surgical treatment is only possible in combination with effective anti-TB drug therapy. It is difficult to relieve spinal cord compression, improve nerve dysfunction and prevent progressive spinal deformity using conservative treatment alone. In contrast, surgery is an effective solution to this problem [14].
It remains a controversial issue which surgical approach to use when accessing the lesion sites. Single-stage anterior debridement, bone grafting, and instrumentation has been widely accepted as the “gold standard” for STB treatment [15] because it allows for thorough removal of lesions, decompression of the anterior structure of the spine, easy bone grafting, kyphosis correction, and reconstruction of spinal stability under direct vision, with the lesions being fully exposed [16]. However, it shows inadequate fixation rigidity and orthopedic strength [8, 9] and imposes a high risk of vascular injury because of poor access to the lesion site [17]. Considering the high exposure, the large wound, and a great risk of hemopneumothorax, this method is not a good choice for patients with multisegmental TSTB [18]. In the present study, the patients who underwent single anterior debridement, bone grafting, and instrumentation in combination with regular anti-TB drug therapy pre- and postoperatively experienced significant improvement in the VAS scores, ESR, and CRP levels as compared to the preoperative levels. Moreover, no serious complications were caused by this approach. Therefore, the anterior approach is a safe and effective option for TSTB treatment under specific circumstances. Despite its benefits, this study found the anterior approach associated with postoperative kyphosis angle loss, which has been agreed upon by other authors [17, 18].
As STB surgical techniques develop, single posterior debridement, bone grafting, and instrumentation have achieved satisfactory outcomes of kyphosis correction and reconstruction of spinal stability, as well as long-segment fixation without creating a serious wound [10,11]. Zhang et al. [19] reported favorable clinical outcomes of TSTB treatment using the single posterior approach. Liu et al. [20] performed posterior debridement, bone grafting, and instrumentation on patients with monosegmental TSTB and achieved satisfactory curative effect, with favorable bone graft fusion and significant improvement in the patients’ Cobb angles. Hassan et al. [21] treated TSTB patients with the anterior and posterior approaches, respectively, and found that the posterior approach outperformed the anterior one in mean operation time, intraoperative blood loss, and blood transfusion; in addition, the single posterior approach produced favorable surgical outcomes by creating a small wound to access the lesion site when treating TSTB. In this study, single posterior debridement, bone grafting, and instrumentation were performed on the 17 patients in group B. Through analysis, these patients experienced significant improvement in their ASIA impairment scale scores and a sharp decrease in their Cobb angles, and ESR levels after the operation. The pre- and postoperative parameters were significantly different (P < 0.05), indicating the favorable surgical outcomes of the posterior approach. Besides, there was no statistically significant difference between the two groups in the VAS scores and changes in ESR and ASIA impairment scale scores. However, the single posterior approach also has its own limitations. To be specific, it is difficult to remove TB lesions radically using the posterior approach; TB bacteria may invade the normal tissue in the posterior structure of the spine; the surgery may bring damage to the normal posterior spine, compromise the spinal stability, interfere the spinal cord and increase postoperative intraspinal scar adhesion. Beyond that, this approach only gives limited exposure of the anterior structure of the spine, and thus it is not an option when there is a large paraspinal abscess. It was stated in our previous study that the single posterior approach had shorter operation time and a smaller volume of intraoperative blood loss compared to the anterior approach [8], and these findings were proved by this study. Through analysis, it is believed that these advantages of the posterior approach are associated with the development of the pedicle screw insertion technique and the posterior approach itself through day-to-day applications, as well as the use of the approach in a large number of short-segment fixation (no more than three segments) cases. Also, it was found that the posterior approach had an angle loss rate smaller than the anterior approach in terms of kyphosis correction, which was reported in another relevant study [21]. The rationale for the use of the posterior approach lies in the removal of the lesion and the sclerotic bone surrounding the lesion to clear the path for anti-TB drugs. As to the residual TB-like lesion and purulent fluid, long-term, standard anti-TB chemotherapy is an effective postoperative solution. This study has some limitations, including the small sample size and the short follow-up. A prospective multicenter randomized comparative study having a larger sample size is needed to investigate the long-term efficacy of the two approaches.