Thoracolumbar burst fractures without neurological symptoms are frequently seen in the clinic, and the ideal treatment of these fractures is still controversial, especially in patients with TLICS scores < 4.10, 13As an attempt to develop a grading system with prognostic significance that could also be used as an algorithm to guide the clinical decision of operative or nonoperative treatment, the TLICS system has been extensively investigated in terms of its reliability and validity since its introduction in 2005. The controversy of using it for guiding treatment decisions for thoracolumbar burst fractures has been reported previously and has been increasingly questioned, especially in terms of its recommendation of conservative treatment for patients with a score < 4. 4, 14, 15 A large retrospective analysis by Joaquimet al.16 that included a total of 458 patients showed that the recommendation matching rate of the TLICS system in the conservative group was as high as 99%; however, only 46.6% of patients matched TLICS recommendations in the surgical group, especially in the population with burst fractures but without neurological injury (TLICS score = 2); the mismatched rate was 100%. These data seem to suggest that, in those patients who had received conservative treatment based on the TLICS recommendation but in accordance with the judgment of the surgeon, more than half of them should be treated with surgical intervention. Another retrospective study conducted by Shen 17 confirmed that after evaluating 129 patients who had TLICS scores less than 4, 25 patients (up to 19.4%) who were neurologically intact still failed nonoperative treatment and ultimately required surgery. Therefore, the author suggested that the TLICS system was too conservative and that inconsistencies remained in the treatment of thoracolumbar burst fractures. A meta-analysis conducted by Gnanenthiran et al.18 indicated that, in patients with thoracolumbar burst fractures but without neurologic deficits, despite no between-group differences in pain relief or functional disorders found in operative versus nonoperative patients, there may have been a significant improvement in residual kyphosis in operative patients compared with nonoperative patients at the last follow-up(mean of 4 years). Taken together, these results show that the efficacy of conservative treatment has been questioned for this set of patients. Specifically, patients with a total TLICS score < 4 who did not receive surgery could experience further collapse of the vertebral body with marked local kyphosis, progressive loss of vertebral body height and deterioration in pain status after long-term follow-up19. For instance, Mattei et al. 20 presented a case of a patient with a total TLICS score of 2 who was managed conservatively; after 12 months, the patient presented with complaints of increased back pain and a major kyphotic deformity. Ultimately, the patient was submitted to a staged anterior-posterior procedure to assure definitive fixation and adequate reconstruction of spinal alignment. The author suggested that due to the high risk of late progressive deformities, patients displaying a TLICS score of less than 4 should be considered for upfront surgical stabilization.
Consistent with most previous studies, the results of the current study showed no significant difference in the VAS pain score and ODI value between the surgical group and conservative group at the last follow-up. However, we found that no improvement in the LSA (p = 0.09) and an even worse RSA (p=-0.03)were observed in the conservative group, while significant improvements in the LSA and RSA were observed in the surgical group(p < 0.01). Thus, compared with surgical patients, patients who received conservative treatment seemed to have similar pain relief and functional recovery, but in general, there was no improvement or even aggravation of segmental kyphosis during the follow-up.
As previously reported in the literature, compared with previous classifications, the TLICS system has deficiencies in terms of the evaluation of the morphology and stability of fractures. For example, Oxland et al.21 suggested that a vertebral height loss > 50% and kyphotic angulation > 20° may be indicative of instability. There is a possibility of progressive kyphotic deformity or even subsequent neurological deficits in such patients. Schnake et al.22 recommended that patients in this subgroup(TLICS score < 4)should be assessed in combination with the AO-Magerl classification, taking into account instability indicators such as the fracture level, degree of comminution (integrity of posterior vertebral wall, upper / lower endplate) and kyphotic angulation to determine the stability of the fracture. Thus, in cases that are considered to be "unstable" burst fractures, conservative treatment should be implemented with caution, especially in patients with osteoporosis. Nevertheless, none of these instability indicators described above are taken into account in the TLICS system. Therefore, it has been suggested that it is better to combine the TLICS system with the AO spine injury classification or the load-sharing score when making treatment decisions. In particular, the modified AO-Magerl system is a helpful supplement for the TLICS system to assess the deficiencies of anterior column fractures23. As our typical patient mentioned in Fig. 3, with a total TLICS score < 4, conservative treatment was recommended. However, taking into account the more than 50%vertebral height loss and 22° of kyphotic angulation or an AO-Magerl classification of A3, which indicated the instability of the fracture13, the patient was ultimately treated with surgery, resulting in a satisfactory prognosis after 2 years of follow-up. Furthermore, it has been proven that this strategy is reliable in a previous study by Wood et al.,2who indicated that while using both the TLICS classification and AO systems as a practical algorithm to orient the clinical decision-making between conservative and surgical management in the treatment of thoracolumbar burst fractures, the patients in the conservative treatment group had less pain and better function than the patients in the surgery group after long-term (16 ~ 22 years) follow-up. In addition, it is also worth mentioning another retrospective cohort trial conducted by Shen et al.17, who showed that the recommendation of nonoperative treatment for patients with a TLICS score < 4 has limitations in terms of patients having greater VAS scores or IPD (interpedicular distance). If conservative treatment is implemented, a close follow-up is necessary due to the high likelihood of long-term kyphotic deformities.