This retrospective study tried to assess the impact of percutaneous vertebroplasty on patients with thoracolumbar osteoporotic vertebral compression fracture (OVCF) who experienced pain in either the lumbosacral region (LS group) or the thoracolumbar region (TL group). The findings revealed that the LS group had lower preoperative anterior and middle vertebral heights compared to the TL group (P = 0.039 and 0.043, respectively). Following the surgery, significant improvements were observed in the VAS and CMODI scores, as well as in the anterior and middle vertebral heights and Cobb angle(P < 0.05). The LS group exhibited significantly higher VAS scores at both the 2-day and 1-month postoperative periods (both P < 0.0001) compared to the TL group. These findings suggest that percutaneous vertebroplasty may provide benefits for patients with thoracolumbar OVCF who experience pain in the lumbosacral or thoracolumbar regions. The presence of vertebral height loss may pose a risk for lumbosacral pain in patients with thoracolumbar OVCF. Additionally, short-term postoperative pain relief may be relatively poor in patients reporting pain in the lumbosacral region compared to those in the thoracolumbar region.
Thoracolumbar OVCFs typically manifest with intense pain in the corresponding region. However, a minority of patients, who have confirmed thoracolumbar OVCF through magnetic resonance imaging (MRI), have reported experiencing distal lumbosacral pain (DLP) instead of localized back pain at the level of the fractured vertebra.[3, 6] It is commonly observed that lumbosacral pain in older patients is primarily attributed to degenerative changes in the lumbosacral region,[11–13] whereas the association between thoracolumbar OVCF and lumbosacral pain is less frequently documented.[6, 14] Li et al.[5] found that 33.9% of patients suffering from thoracolumbar OVCF experienced pain solely in the distant lumbosacral region, rather than in the immediate vicinity of the fractured vertebra. Given the prevalence of lumbar degenerative changes in the elderly population, these OVCF patients are susceptible to being misdiagnosed with lumbar degenerative diseases.[3] Therefore, when an older individual presents with lumbosacral pain, particularly if there is a history of low-energy trauma, it is imperative to consider the possibility of a thoracolumbar fracture.[5] Nonetheless, it is crucial to also rule out any acute damage to the lumbosacral soft tissue and lumbar facet syndrome in these patients.
The etiology of DLP in thoracolumbar OVCF patients remains unclear.[3, 5, 6] Some scholars propose that this lumbosacral pain may be attributed to vertebrogenic referred pain, which can be explained by the convergence-projection mechanism.[5, 15, 16] According to this hypothesis, primary afferent nerve fibers originating from distinct anatomical regions converge onto the same secondary neuron within the spinal cord, leading to misidentification of the pain source by the central nervous system.[17, 18] Maigne et al.[19, 20] proposed that lumbosacral pain could originate in the thoracolumbar joint, mediated by the superior cluneal nerves, which was derived from the cutaneous branches of the dorsal rami of T11–L2.[19, 21, 22] Each of the rami supplied the areas of the lower back, around the sacroiliac joint and the iliac crest. Niu et al.[3] considered that thoracolumbar vertebral fractures with surrounding soft tissue and facet joint injury may stimulate the sympathetic ganglion or dorsal ramus of T11–L2, which leading to the referred DLP. Doo et al.[23] posited that the reduction in vertebral height resulted in the constriction of the intervertebral foramen, thereby causing irritation to the posterior branches of the spinal nerves at T12, L1, and L2. The present study observed that the preoperative anterior and middle vertebral heights were significantly lower in the LS group compared to the TL group (P = 0.039 and 0.043, respectively). This finding implies that an excessive collapse of vertebral height may potentially contribute to lumbosacral pain in patients with thoracolumbar OVCF.
There were few studies reported that percutaneous kyphoplasty could alleviate the DLP.[3–6] The results of this study showed significant improvements in the Cobb angle, anterior vertebral heights, VAS and CMODI after surgery. These outcomes can be attributed to the ability of PVP to restore vertebral height, eliminate micro-motion within the fractured vertebra, and alleviate the mechanical load exerted on the facet joints. Consequently, these factors collectively contribute to the reduction of irritation or compression on the sympathetic ganglion or dorsal ramus.[3] The LS group had higher VAS scores at both the 2-day and 1-month postoperative periods compared to the TL group. These findings suggest that patients with lumbosacral pain may experience inferior short-term pain relief following surgery compared to those with thoracolumbar pain, and this information should be communicated to patients before surgery.
This retrospective study had several limitations. Firstly, it was conducted at single hospital with a limited number of patients, which may have introduced bias due to the limited number of patients included. Secondly, the measurement of intervertebral foramen height was not performed. Therefore, large-scale and well-designed RCTs are necessary to generate high-quality evidence in the future.