High viscosity bone cement vertebroplasty versus low viscosity bone cement vertebroplasty in the treatment of mid-high thoracic vertebral compression fractures

BACKGROUND CONTEXT: As science and technology have advanced, novel bone cements with numerous formulated ingredients have greatly evolved and been commercialized for vertebroplasty. Recently, viscosity has been a focus to achieve better clinical outcomes and fewer complications. Meanwhile, the experience in the treatment of mid (T7–9) to high (T4–6) thoracic vertebral compression fractures is limited. PURPOSE: The objective of this study was to identify the different outcomes between high-viscosity bone cement (HVBC) and low-viscosity bone cement (LVBC) used to repair mid (T7–9)- and high (T4–6)- thoracic vertebral compression fractures. STUDY DESIGN/SETTING: This study was a single-center, retrospective cohort study PATIENT SAMPLE: A consecutive series of 107 patients with a total of 144 vertebrae was included. OUTCOME MEASURES: The anterior vertebral height (AVH), middle vertebral height (MVH), posterior vertebral height (PVH), local kyphotic angle (KA), Cobb angle (CA), and other associated parameters were evaluated radiologically at several time points—preoperative, surgery day 0, postoperative day 1, and 6-month follow-up. Pain evaluation was assessed by using a visual analog scale (VAS) before and 6 months after the procedure. METHODS: The patients were divided into two groups according to the viscosity of the bone cement used, and plain film and magnetic resonance imaging (MRI) of the vertebrae were used to calculate parameters. The patient characteristics; bone cement brand; changes in AVH, MVH, PVH, KA, CA, and VAS; and complications of each patient were recorded and then analyzed. RESULTS: Both groups showed increased vertebral body height, corrected KA, and CA after vertebroplasty. There were no significant differences between the HVBC and LVBC groups (ΔAVH: 2.19±2.60 vs. 2.48±3.09, p=.555; ΔMVH: 1.25±3.15 vs. 1.89±2.58, p=.192; ΔKA: -5.46±4.58 vs -5.37±4.47, p=.908; and ΔCA: -4.22±4.23 vs. -4.56±5.17, p=.679). There were significant preoperative to postoperative and preoperative to follow-up changes in AVH (HVBC, p=.012 and .046, respectively; LVBC, p=.001 and .015, respectively); a significant preoperative to postoperative change in MVH (HVBC, p=.045; LVBC, p=.001); and significant preoperative to postoperative and preoperative to follow-up changes in KA and CA (KA: HVBC, p=0.000 and .003, respectively; LVBC, p=.000 and .000, respectively; CA: HVBC, p=.017 and .047, respectively; LVBC, p=.006 and .034, respectively). The volume of cement injected was significantly higher with HVBC (3.66±1.36 vs. 3.11±1.53, p=.024), and the use of HVBC was associated fewer cases with cement leakage (26 vs. 45, p=.002). Furthermore, there was no difference between the groups in the incidence of adjacent fracture. Both groups showed an improved VAS score at follow-up, with statistically greater improvement in the HVBC group (2.40±1.53 vs. 3.07±1.69, p=.014). Moreover, significantly fewer patients with a VAS score ≥ 3 were found in the HVBC group (22 vs. 39, p=.004) CONCLUSIONS: HVBC and LVBC are safe and effective to treat mid-to-high level thoracic vertebral compression fractures. Compared with LVBC, HVBC shows less cement leakage, a greater injection volume, and better postoperative pain relief.