Correlation analysis of the puncture-side bone cement/vertebral body volume ratio and bone cement leakage in the paravertebral vein in vertebroplasty

Analysis of Prognostic Factors in Osteoporotic Patients Who Were Treated with Percutaneous Vertebroplasty for Refracture After Vertebral Augmentation

OBJECTIVE

To retrospectively analyze prognostic factors in osteoporotic patients who treated with percutaneous vertebroplasty for refracture after vertebral augmentation.

METHODS

A retrospective analysis was performed of 61 patients with refractures after vertebral augmentation who received percutaneous vertebroplasty treatment again from January 2019 to December 2021. Based on the presence of back pain at the last follow-up, 17 patients were placed in the pain group, and 44 patients were placed in the pain-free group. The following covariates were reviewed: age; bone mineral density; bone cement dosage; bone cement leakage; body mass index; and rate of anterior vertebral height (AVH) loss in the target before surgery, 1 week after surgery, and at last follow-up. Patients were assessed using visual analogue scale score and Oswestry Disability Index.

RESULTS

Binary logistic regression analysis revealed that the rate of AVH loss after surgery was associated with postoperative back pain. According to the receiver operating characteristic curve analysis, the area under the curve of AVH loss rate at 1 week after surgery was 0.6845, and the cutoff value was 0.18; the area under the curve of AVH loss rate at the last follow-up was 0.7306, and the cutoff value was 0.2815. Kaplan-Meier survival analysis showed that patients with lower AVH loss rates had lower incidence of postoperative back pain and better prognosis.

CONCLUSIONS

Occurrence of postoperative back pain was strongly associated with AVH loss after surgery. Patients with a lower rate of AVH loss had a lower incidence of postoperative back pain and a better prognosis.

Implementation of a Specific Set of Intraoperative C-Arm Fluoroscopy Terminologies in Percutaneous Vertebroplasty

OBJECTIVE

Percutaneous vertebroplasty (PVP) is currently the primary minimally invasive surgical approach for treating vertebral compression fractures caused by senile osteoporosis. The current existing problem is the lack of research on the application of a specific set of intraoperative C-arm fluoroscopy terminologies in PVP. Therefore, the purpose of this study is to explore the use of a specific set of intraoperative C-arm fluoroscopic terminologies in PVP in order to increase fluoroscopy accuracy, decrease fluoroscopy frequencies and ray protection, and minimize operation times through rapid preoperative training of surgeons and radiographers.

METHODS

Spine surgeons and radiographers with at least 5 years of experience from nine different hospitals were randomly selected for a series of specialized intraoperative C-arm fluoroscopy terminology training between October 2018 and December 2021. Before and after the training, they were surveyed using a five-point Likert scale to statistically compare their knowledge of the terminology. Simultaneously, 190 PVP cases completed by these surgeons and radiographers before and after the training were chosen for comparison and analysis of fluoroscopy times, effective fluoroscopy rate, fluoroscopy time, repeated puncture rate, and other indicators before and after receiving specialized terminology training. Two-sample tests were mainly used to investigate differences in answers between surgeons and radiographers.

RESULTS

After the training, there was a notable improvement in the fluency of intraoperative communication between professional spine surgeons and radiographers. By comparing the indicators of pre-training with post-training, the effective anteroposterior fluoroscopy rate increased from 46.5% to 75.7%; the effective lateral fluoroscopy rate increased from 59.8% to 76.9%. Moreover, a notable decrease in communication barriers, fluoroscopy frequencies, fluoroscopy time, and the rate of repeated punctures, and a notable increase in the effective fluoroscopy rate was observed.

CONCLUSION

Smooth intraoperative communication between professional spine surgeons and radiographers can significantly lower the communication barrier, reduce the fluoroscopy frequencies and time, the rate of repeated puncture, and increase the effective fluoroscopy rate, all of which are important in improving the fluoroscopy in PVP.

Analysis of Potential Risk Factors for Cement Leakage into Paraspinal Veins after Vertebroplasty for Acute Osteoporotic Vertebral Fractures Based on a 3D Reconstruction Technique: A Retrospective Matched Case-Control Study

OBJECTIVE

Pulmonary embolism, cardiac embolism, and even cerebral embolism due to paraspinal vein leakage (PVL) are increasingly reported, and their risk factors need to be adequately investigated for prevention. To this end, this study investigated the correlation of the distribution and morphological characteristics of fracture lines with the occurrence of PVL after percutaneous vertebroplasty (PVP), which has not been previously reported.

METHODS

Patients with acute single-segment thoracolumbar osteoporotic vertebral compression fractures (OVCFs) treated with PVP at our institution from January 2019 to July 2022 were selected for a matched case-control study. The case and control groups included those with and without PVL, respectively, matched at a 1:1 ratio based on general clinical characteristics. Additionally, fracture map and heatmap analysis was performed in both groups. In addition to the general clinical characteristics, the vertebral height ratio, puncture angle, delivery rate, and indexes were assessed via the three-dimensional CT reconstruction fracture line mapping technique, namely, the distribution of fracture lines, fracture line length, main fracture line shape, location of fracture line involvement, and number of fracture line branches, were compared between the two groups. The Wilcoxon rank-sum test, t tests, analysis of variance, and conditional logistic regression were used for statistical analysis.

RESULTS

Among 658 patients with OVCFs, 54 who did and 54 who did not develop PVL were included in this study. Significant differences in the puncture angle, fracture line distribution (MR-1, ML-2, MM-2, MR-2, ML-3, MM-3, LL-1, LM-1, LL-2, LM-2), fracture line involvement of the posterior wall, total fracture line length, and main fracture line length were found between the two groups (p < 0.05). Logistic univariate analysis showed significant differences in the puncture angle, fracture line distribution (MR-1, ML-2, MM-2, MR-2, ML-3, MM-3, LL-1, LL-2, LM-2, LL-3), total fracture line length, main fracture line length, and fracture line involvement of the posterior wall between the two groups (p < 0.05). Logistic multifactorial analysis showed that the fracture line distribution (UR-3, ML-3, LM-2, LR-2) and main fracture line length were independent risk factors for the development of PVL in both groups. In addition, the fracture maps and heatmaps showed a greater degree of fracture line encapsulation and more extensive involvement in the middle and lower regions of the vertebral body in the PVL group than in the control group.

CONCLUSIONS

Through a three-dimensional computed tomography reconstruction-based fracture line mapping technique, this study revealed for the first time that the distribution of fracture lines (UR-3, ML-3, LM-2, LR-2) and main fracture line length were independent risk factors for PVL after PVP in patients with acute single-segment thoracolumbar OVCFs. In addition, we hypothesized that the fracture line-vein traffic branch that may appear within 2 weeks after injury in acute OVCF patients may be one of the mechanisms influencing the above potential independent risk factors associated with PVL.

Case report: Inspiration from a rare fatal heart perforation after percutaneous vertebroplasty

The principal benefit of employing percutaneous vertebroplasty (PVP) for managing osteoporotic vertebral compression fractures lies in its capacity to facilitate early mobilization in elderly patients, thereby effectively avoiding the potential catastrophic complications associated with prolonged bedridden states. However, bone cement leakage, as the most common complication of PVP, may have fatal consequences. Here, we report a case involving an 85-year-old male patient with L1 vertebral compression fracture who underwent PVP at our hospital and was discharged on the same day of the surgical intervention. Subsequently, the patient experienced symptoms of chest tightness and palpitations. Cardiac ultrasound examination revealed pericardial effusion, while pulmonary computed tomographic angiography (CTA) demonstrated a strip high-density shadow in the right ventricular area. Finally, it was determined that the perforation of the right ventricular wall was caused by bone cement embolism. Through this comprehensive case report, we aim to deepen the understanding of orthopedic doctors on the importance of preventing bone cement leakage.

The significance of the best puncture side bone cement/vertebral volume ratio to prevent paravertebral vein leakage of bone cement during vertebroplasty: a retrospective study

OBJECTIVES

To verify the clinical significance of the best puncture-side bone cement/vertebral volume ratio (PSBCV/VV%) and bone cement leakage in paravertebral veins during vertebroplasty.

METHODS

This was a retrospective analysis of a total of 210 patients from September 2021 to December 2022, who were divided into an observation group (110 patients) and a control group (100 patients). In the observation group, patients' preoperative computed tomography (CT) data were imported into Mimics software, and the VV was calculated using the three-dimensional (3D) reconstruction function. Then, based on the best PSBCV/VV% of 13.68% determined in a previous study, the optimal PSBCV to be injected during vertebroplasty was calculated. In the control group, vertebroplasty was performed directly using the conventional method. The incidence of cement leakage into paravertebral veins was observed postoperatively in both groups.

RESULTS

There were no statistically significant differences (P > 0.05) in the evaluated indicators between the two groups pre- or postoperatively, including the anterior vertebral margin height, mid-vertebral height, injured vertebral Cobb angle, visual analogue scale (VAS) score, and Oswestry Disability Index (ODI). Intragroup comparisons showed improvements in the anterior vertebral height, mid-vertebral height, injured vertebral Cobb angle, VAS score, and ODI after surgery compared with before surgery (P < 0.05). In the observation group, there were 3 cases of cement leakage into the paravertebral veins, for a leakage rate of 2.7%. In the control group, there were 11 cases of cement leakage into the paravertebral veins, for a leakage rate of 11%. The difference in the leakage rate between the two groups was statistically significant (P = 0.016).

CONCLUSION

In vertebroplasty, preoperative VV calculations using Mimics software, combined with calculation of the PSBCV according to the best PSBCV/VV% (13.68%), can effectively prevent leakage of bone cement into paravertebral veins and further prevent serious life-threatening complications such as pulmonary embolism.

[Translated article] Relation between the volume of injected cement and the vertebral volume in the clinical outcome and in the appearance of leakage after a percutaneous vertebroplasty

OBJECTIVES

To assess the connection between the volume of injected cement and the vertebral volume measured through a volumetric analysis with a computed tomography (CT scan) in relation to the clinical result and the appearance of a leakage in patients who underwent a percutaneous vertebroplasty after an osteoporotic fracture.

MATERIALS AND METHODS

A prospective study of 27 patients (18 female-9 male) with an average age of 69 years old (50-81), and with a one-year follow-up. The study group presented 41 vertebrae with osteoporotic fractures that were treated with a percutaneous vertebroplasty with a bilateral transpedicular approach. The volume of injected cement was registered in each procedure and it was assessed together with the spinal volume measured through a volumetric analysis with CT scans. The percentage of the spinal filler was calculated. The appearance of cement leakage was proved by means of a simple radiography and a postoperative CT scan in all the cases. The leaks were classified according to the location in relation to the vertebral body (posterior, lateral, anterior and in the disc), and the significance (minor: smaller than the largest diameter of the pedicle; moderate: larger than the pedicle but smaller than the height of the vertebra; major: larger than the height of the vertebra).

RESULTS

The average vertebra volume was 26.1cm3, the average volume of the injected cement was 2.0cm3 and the percentage of the average filler was 9%. A total of 15 leaks in 41 vertebrae appeared (37%). The leaks were posterior in 2 vertebrae, vascular in 8 and into the disc in 5 vertebrae. They were deemed as minor in 12 cases, moderate in 1 and major in 2 cases. The preoperative assessment of the pain was as it follows: VAS (8) and Oswestry (67%). The cessation of pain was immediate after a year with the following postoperative results: VAS (1.7) and Oswestry (19%). The only complication was the temporary neuritis with a spontaneous resolution.

CONCLUSIONS

The injection of small amounts of cement, lower than the ones referred to by literary sources, obtains clinical results similar to the ones obtained by injecting higher amounts and it reduces the number of cement leaks and further complications.

Acute abdomen after vertebroplasty-A rare complication

Introduction

In recent years, as the concept of minimally invasive treatment has been accepted by the majority of patients, the application of percutaneous vertebroplasty in osteoporotic vertebral compression fractures has gradually increased, and research on the adverse complications of bone cement leakage has gradually deepened.

Case

Here, we report a rare case of acute pancreatitis after vertebroplasty. The patient had no previous history of pancreatitis and presented with obvious abdominal pain after vertebroplasty. Abdominal CT examination revealed that the leaking bone cement penetrated the anterior wall of the L1 vertebral body into the diaphragm, and the heat released by the polymerization reaction caused inflammation and damage to the adjacent pancreas, resulting in poor blood flow to the pancreatic tissue and leading to acute pancreatitis. Early postoperative symptomatic treatment was given to the patient, and the corresponding symptoms were gradually relieved. During postoperative follow-up, the leaking cement did not degrade, but the patient had no symptoms.

Conclusion

Lesions of adjacent organs caused by bone cement leakage are rare, and clinicians often ignore the association between such complications and vertebroplasty. This case report will provide guidance and a reference for clinicians.

Current status and challenges of percutaneous vertebroplasty (PVP)

A narrative review regarding percutaneous vertebroplasty (PVP) for osteoporotic vertebral fracture (OVF) is provided herein, addressing the epidemic of OVF in Japan, the latest response to the criticism of PVP for OVFs, the indications and potential risks of PVP for OVFs, and a future perspective for PVP. Each year in Japan, approximately 32,000 patients aged 55 years or older suffer from chronic low back pain for several months to several years due to a compression fracture. PVP is one of the surgical treatments for an OVF, and it is less invasive compared to the traditional open surgery. PVP is suitable for OVF patients who have difficulty walking as assessed by the modified Yokoyama's activities of daily living (ADL) scoring system, and for patients with Kummell's disease diagnosed by CT and MRI examinations. Serious adverse events related to PVP occur in 1.1-3.3% of the cases, but direct deaths from PVP are extremely rare at less than 1%. Recent studies demonstrated that OVF patients treated with PVP are less likely to die after the treatment than non-surgically treated patients, which conflicts with the Cochran reviews' conclusion not supporting PVP for OVFs. Novel robotic systems and procedure-support devices are being developed, providing a next step toward fully automated PVP procedures.

A novel puncture approach via point "O" for percutaneous kyphoplasty in patients with L4 or L5 osteoporotic vertebral compression fracture

This study introduced a novel point "O" puncture approach for percutaneous kyphoplasty (PKP) in patients with L4 or L5 osteoporotic vertebral compression fracture (OVCF) and evaluated its clinical and radiographic outcomes. Between September 2019 and December 2020, we compared the clinical and radiographic outcomes in 31 cases (36 vertebrae) using the "O" entry point PKP intervention (O-PKP) and 31 cases (37 vertebrae) using transverse the process-pedicle approach PKP intervention (T-PKP). No serious postoperative complications were observed in any of the participants. Only two T-PKP patients experienced intervertebral disc space leakage. Compared with the T-PKP patients, the O-PKP patients showed shorter operative time and fluoroscopy times (P < 0.05), comparable blood loss and cement volume (P > 0.05), improved VAS and ODI scores at the final follow-up (P < 0.05), better increases in the vertebral compression ratio (P < 0.05), comparable Cobb angle (P > 0.05), comparable anteroposterior bone cement distribution, enhanced bilateral bone cement distribution (P < 0.05), and larger sagittal and transverse angles (P < 0.05). Herein, O-PKP was indicated for patients with L4 or L5 OVCF. This puncture approach showed significant advantages over T-PKP not only in terms of pain relief, surgery and fluoroscopy times but also in the puncture angle, vertebral reconstruction, and symmetrical cement distribution.

Biomechanical evaluation of percutaneous cement discoplasty by finite element analysis

Background

Percutaneous cement discoplasty (PCD) is a minimally invasive treatment for degenerative lumbar spine disease, but the relationship between decompression effect on the nerve root and different doses of bone cement is uncertain.

Purpose

To investigate the indirect decompression effect of cement with different doses on nerve roots and the biomechanical changes on the spine during PCD using finite element analysis (FEA).

Methods

FEA was adapted to analyze the mechanical changes in the lumbar vertebrae before and after the application of PCD.CT scan images of adult males were utilized to establish a finite element model of the lumbar vertebral body using mimics and Pro/E software. The images were divided into four models: the normal model (normal, model N), the disc degeneration model (high, model H), the intervertebral disc injected with 3 mL of bone cement (model H1), and the intervertebral disc injected with 5 mL of bone cement (model H2). All models were analyzed using the ABAQUS6.14.2 software. The normal physiological movements were simulated, and the mechanical changes in the lumbar vertebrae were observed prior to and after the cement filling application.

Results

The stress of the nerve root in model H was the largest. The nerve root stress in the model H2 was the smallest during flexion, extension, left bending, right bending, left rotation, and right rotation at 90%, 44%, 25%, 56%, 56%, and 51% of the normal benchmark, respectively. After the injection of bone cement, the nerve root stress is reduced. The greater the amount of cement, the lesser the nerve root stress. The motion was reduced in models H, H1, and H2, and there were differences between models H1 and H2. Cartilage endplate stress was less in model H2 than in model H1.

Conclusions

The nerve root stress increased after degeneration and decreased after intervertebral height recovery through cement injection, resulting in a significant indirect decompression effect.The stress of the nerve root decreased with the increase in the amount of cement injection.