Non-Contiguous OVCF Patients Had a Higher Risk of AVF After PVP Operation Related to Poor Bone Mineral Density Rather...

Biomechanical deterioration and low bone mineral density (BMD) are two primary triggers for adjacent vertebral fracture (AVF) after percutaneous vertebroplasty (PVP) operation. Sandwich vertebral body (SVB) refers to a vertebral body situated between two osteoporotic vertebral compressive fractures (OVCF) segments. There exists a contradiction regarding whether the SVB are at a heightened risk of AVF, and the underlying mechanism has yet to be elucidated.

Clinical data of PVP treated OVCF patients were included in this study. Patients were divided into two groups: those with single-level OVCF and those with SVB resulting from non-contiguous two-level OVCF. Statistical comparisons and logistic regression analyses were performed to investigate whether patients with two-level non-contiguous OVCFs constitute a risk factor for AVF. Furthermore, PVP procedures involving single-level and non-contiguous two-level OVCFs were simulated in models with identical bony density. Biomechanical indicators associated with AVF were computed under physiological loading conditions.

This study enrolled 173 patients with PVP-treated OVCF, including 134 with single-segment fractures and 39 with non-contiguous two-level fractures. Among these patients, the overall incidence of AVF was 22.39% (30/134) in the single-segment group and 38.46% (15/39) in the non-contiguous two-level group. The incidence of AVF was significantly higher in patients with non-contiguous two-level OVCF (P = 0.044). Correspondingly, HU values were significantly lower in those with two-level OVCF. However, only a lower HU value was judged to be an independent risk factor for AVF. Furthermore, the maximum difference between the two models with identical BMD was found to be less than 5%. The only exception observed was the cortical stress value in the L3 vertebral body under extension loading conditions. In this case, the stress value of the SVB increased by 10.41% compared to the control group (i.e. single-level OVCF at L2), and the difference in stress between groups was not influenced by the presence or absence of compressive load.

Patients with two-level non-contiguous OVCF experiences a higher incidence of AVF primarily due to poor BMD, rather than the exacerbation of stress concentration caused by two adjacent segmental cement augmentations.