Percutaneous Image-Guided Vertebral Fixation in Cancer-Related Vertebral Compression Fractures: A Case Series Study

Background and objectives: Cancer-related vertebral compression fractures (VCF) may cause debilitating back pain and instability, affecting the quality of life of cancer patients. To further drive cement deposition during vertebroplasty, the aims of this restrospective case series study were to report the feasibility, safety and short term efficacy (≤6 months) of percutaneous vertebral fixation in cancer-related vertebral compression fractures using various intravertebral implants. Methods: All consecutive cancer patients treated with percutaneous vertebral fixation for VCF were retrospectively included. Various devices were inserted percutaneously under image guidance and filled by cement. Descriptive statistics were used and a matched paired analysis of pain scores was performed to assess for changes following interventions. Results: A total of 18 consecutive patients (12 women (66.6%) and 6 men (33.3%); mean age 59.7 ± 15.5 years) were included. A total of 42 devices were inserted in 8 thoracic and 16 lumbar vertebrae. Visual analogue scale measurement significantly improved from 5.6 ± 1.8 preoperatively to 1.5 ± 1.7 at 1 week (p < 0.01) and to 1.5 ± 1.3 at 6 months (p < 0.01). No severe adverse events were observed, but three adjacent fractures occurred between 1 week and 5 months after implantation. Conclusions: Percutaneous vertebral fixation of cancer-related VCF is feasible and safe and allows pain relief.

A Retrospective Analysis in 1347 Patients Undergoing Cement Augmentation for Osteoporotic Vertebral Compression Fracture: Is the Sandwich Vertebra at a Higher Risk of Further Fracture?

BACKGROUND Multiple percutaneous vertebral cement augmentation may create sandwich vertebrae. Whether the sandwich vertebra is at higher risk of further fracture remains unknown. OBJECTIVE To compare the incidence of further fractures of sandwich vertebrae and adjacent vertebrae and to identify potential risk factors for sandwich vertebral fractures. METHODS Patients who underwent cement augmentation for osteoporotic vertebral compression fractures (OVCFs) in a single medical center between January 2012 and December 2015 were included. A sandwich vertebra was defined as an intact vertebra located between 2 previously cemented vertebrae. Demographic data and imaging findings were recorded. All patients were followed up for at least 24 mo postoperatively. During follow-up period, if the patient reported new-onset back pain with corresponding imaging findings, a diagnosis of sandwich vertebral fracture was made. RESULTS Among the 1347 patients who underwent vertebroplasty/kyphoplasty for OVCFs, 127 patients with 128 fracture levels met the criteria for sandwich vertebrae (females/males 100/27, mean age 77.8 ± 7.7 yr old). The fracture location was most common in the thoraco-lumbar junction (T10-L2), 68.5% (87/127). The incidence of sandwich vertebral fracture was 21.3%, whereas the incidence of adjacent level fracture of those with no sandwich vertebra was 16.4% (196/1194), P = .1879. CONCLUSION The incidence of sandwich vertebral fracture is not higher than that at the adjacent levels. The factor associated with further sandwich vertebral fracture was male gender. Once sandwich vertebral fracture occurred, patients may seek more surgical intervention than those with only adjacent fractures.

Earlier Vertebroplasty for Osteoporotic Thoracolumbar Compression Fracture May Minimize the Subsequent Development of Adjacent Fractures: A Retrospective Study

Background: Percutaneous vertebroplasty (PVP) is widely used to treat osteoporotic vertebral compression fractures (OVCFs). The influence of timing (early vs. late) of PVP on the development of adjacent vertebral fractures (AVF) has rarely been discussed. Objective: This study aimed to compare the incidence of AVF among patients who received early PVP (≤ 30 days after symptom onset, EPVP) or late PVP (> 30 days after symptom onset, LPVP) in the thoracolumbar region (T10 to L2) after a 1-year follow up. Study Design: A retrospective cohort study. Setting: Department of Orthopedic, an affiliated hospital of a medical university. Methods: Patients who had single-level, T-score ≤ -2.5 of lumbar bone mineral density (BMD), primary OVCF in the thoracolumbar region (T10 to L2) and who received PVP between July 2012 and June 2014 were included in the study. They were divided into early PVP and late PVP groups according to the interval between symptom onset and treatment. The risk factors associated with subsequent AVFs were analyzed. Results: Of the 225 patients reviewed, 124 met the criteria and were followed for a minimum of 1 year. Eleven patients (14.1%) in the EPVP group (n = 78) and 18 patients (39.1%) in the LPVP group (n = 46) experienced an AVF during the first year following vertebroplasty. Outcomes were significantly better in patients with higher bone mineral density, lower cement volume, and without cement leakage (P < 0.01). Cox regression indicated an increase risk for AVF for LPVP, with an adjusted hazard ratio of 6.08 (95% confidence interval: 2.50–14.81). Limitation: The incidence of AVFs could be over estimated due to this being a retrospective study with a small case number and lack of either biomechanical study of intra-vertebral cement distribution by times to support the result. Conclusions: Compared with later interventions, PVP performed within 30 days after fracture development may be associated with a lower risk of adjacent fractures in the thoracolumbar region. Key words: Percutaneous vertebroplasty, osteoporosis, osteoporotic vertebral compression fracture, adjacent vertebral fracture

A REVIEW ON BIOMECHANICAL ASPECTS OF VERTEBROPLASTY AND KYPHOPLASTY USING FINITE ELEMENT MODELING-BASED METHODS

The vertebroplasty (VP) and kyphoplasty (KP) are two minimally invasive surgeries using cement augmentation to treat the osteoporotic vertebrae in elderlies in order to relieve pain and prevent the continuation of microfractures. Biomechanists have always tried to assess the mechanical behavior of vertebrae after cement augmentation by using both the experimental and theoretical methods such as finite element modeling (FEM). In this study, 31 related articles using FEM in analyzing the VP and KP have been reviewed. This study included two main categories of spinal load distribution and tension in vertebrae after the VP and KP operations. This could be obtained by conducting FEM on the whole spine or other sectors of it such as intervertebral disc (IVD) or end plates (EPs). This study also referred to articles predicting the probability of adjacent fractures following VP and KP. The most common software employed in FEM was ABAQUS, applied for static and dynamic loads’ analyses. It was found that most of the reviewed articles adopted reverse engineering techniques by converting 2D computed tomography (CT) scan images into 3D reconstructed models. The material properties were generally taken from the literature. In more than 80% of studies, the model geometry was based on CT data of the spine. Almost 45% of the studies have attempted to compare the simulated vertebra after augmentation with experimental results taken from the literature (5% of the reviewed articles) or their own experimental tests (40% of the reviewed articles).

Prophylactic adjacent-segment vertebroplasty following kyphoplasty for a single osteoporotic vertebral fracture and the risk of adjacent fractures: a retrospective study and clinical experience

OBJECTIVE This study investigated the benefit of prophylactic vertebroplasty of the adjacent vertebrae in single-segment osteoporotic vertebral body fractures treated with kyphoplasty. METHODS All patients treated with kyphoplasty for osteoporotic single-segment fractures between January 2007 and August 2012 were included in this retrospective study. The patients received either kyphoplasty alone (kyphoplasty group) or kyphoplasty with additional vertebroplasty of the adjacent segment (vertebroplasty group). The segmental kyphosis with the rate of adjacent-segment fractures (ASFs) and remote fractures were studied on plain lateral radiographs preoperatively, postoperatively, at 3 months, and at final follow-up. RESULTS Thirty-seven (82%) of a possible 45 patients were included for the analysis, with a mean follow-up of 16 months (range 3–54 months). The study population included 31 women, and the mean age of the total patient population was 72 years old (range 53–86 years). In 21 patients (57%), the fracture was in the thoracolumbar junction. Eighteen patients were treated with additional vertebroplasty and 19 with kyphoplasty only. The segmental kyphosis increased in both groups at final follow-up. A fracture through the primary treated vertebra (kyphoplasty) was found in 4 (22%) of the vertebroplasty group and in 3 (16%) of the kyphoplasty group (p = 0.6). An ASF was found in 50% (n = 9) of the vertebroplasty group and in 16% (n = 3) of the kyphoplasty group (p = 0.03). Remote fractures occurred in 1 patient in each group (p = 1.0). CONCLUSIONS Prophylactic vertebroplasty of the adjacent vertebra in patients with single-segment osteoporotic fractures as performed in this study did not decrease the rate of adjacent fractures. Based on these retrospective data, the possible benefits of prophylactic vertebroplasty do not compensate for the possible risks of an additional cement augmentation.