The impact of incidental pulmonary cement embolism on mortality risk

Cement-Augmented Pedicle Screw Fixation in Patients with Osteoporosis : Safety, Efficacy and Complications

Cement-augmented pedicle screw instrumentation is a widely accepted method for managing osteoporotic fractures, but it carries inherent risks, particularly related to cement leakage and embolism. This study aimed to analyze a clinical case of complications following cement fixation and provide a detailed review of relevant literature. A 70-year-old patient underwent transpedicular screw instrumentation from L2-L4 with polymethyl methacrylate augmentation, which resulted in cement leakage into the spinal canal and subsequent pulmonary embolism. After revision surgery and conservative treatment for the embolism, the patient's condition stabilized, demonstrating that conservative measures can be effective in managing cement embolism. To complement this case, a comprehensive literature review was conducted to explore the causes, prevention, and treatment of complications related to cement augmentation. The findings support that while cement-augmented pedicle screw instrumentation remains a leading technique for osteoporotic fractures, the associated risks are manageable with proper treatment protocols. This study holds practical significance for healthcare professionals by highlighting both the risks and solutions associated with cement fixation, thus contributing to improved patient outcomes and the development of standardized treatment guidelines.

LncRNA MSTRG.22719.16 mediates the reduction of enoxaparin sodium high-viscosity bone cement-induced thrombosis by targeting the ocu-miR-326-5p/CD40 axis

OBJECTIVE

Polymethylmethacrylate (PMMA) bone cement promotes the development of local thrombi. Our study found that a novel material, ES-PMMA bone cement, can reduce local thrombosis. We used a simple and reproducible animal model to confirm the reduction in local thrombosis and explored the associated molecular mechanism.

METHODS

New Zealand rabbits, which were used to model thrombosis using extracorporeal carotid artery shunts, were divided into the following two groups, with 3 rabbits in each group: the PMMA bone cement group and the ES-PMMA bone cement group. Four hours after modelling, experimental samples, including thrombotic and vascular tissues, were collected. Thrombotic samples from the PMMA group and ES-PMMA group were subjected to lncRNA sequencing, and a lncRNA microarray was used to screen the differentially expressed lncRNAs. The expression of thrombomodulin in endothelial cells was quantified in vascular tissue samples. Differences in the lncRNA expression profiles between the thrombotic samples of the PMMA group and ES-PMMA group were assessed by base-to-base alignment in the intergenic regions of genomes. The lncRNA-miRNA-mRNA competitive endogenous RNA (ceRNA) network was established in light of ceRNA theory. Thrombosis was observed in the PMMA group and ES-PMMA group.

RESULTS

The thrombotic weight was 0.00706 ± 0.00136 g/cm in the PMMA group and 0.00551 ± 0.00115 g/cm in the ES-PMMA group. Quantitative real-time polymerase chain reaction (RT-q-CR) and Western blotting revealed that the expression of CD40, which can regulate thrombosis in vascular endothelial cells, was significantly lower in the ES-PMMA group than in the PMMA group. High-throughput sequencing was used to identify 111 lncRNAs with lower expression in the ES-PMMA group than in the PMMA group. Through bioinformatics investigation, lncRNA MSTRG22719.16/ocu-miR-326-5p/CD40 binding sites were selected. Fluorescent in situ RNA hybridization (FISH) was performed to verify the lower expression of lncRNA MSTRG.22719.16 in vascular tissues from the ES-PMMA group. A dual-luciferase reporter gene assay was applied to verify that ocu-miR-326-5p binds the CD40 3'-UTR and targets lncRNA MSTRG.22719.16.

CONCLUSION

Compared with PMMA bone cement, ES-PMMA bone cement can reduce thrombosis through the lncRNA MSTRG.22719.16/ocu-miR-326-5p/CD40 axis.

Case report: Cement entrapped in the inferior vena cava filter after pedicle screw augmentation

Background

Cement leakage into the inferior vena cava (IVC) is one of the most common complications associated with cement vertebroplasty, and can lead to potentially life-threatening complications such as pulmonary cement embolism (PCE). Implantation of an IVC filter is effective in the prevention of fatal pulmonary embolism. Here, we present an extremely rarely case of cement entrapped in an IVC filter after pedicle screw augmentation, and discuss all similar cases reported in the literature.

Case presentation

A 70-year-old female presented with significant back and lower extremities pain and was unable to walk. MRI of the lumbar spine revealed an osteoporotic compression fracture of the L1–L3. She underwent cement-augmented pedicle screws implanted at the L1 and L3 vertebral bodies. A retrievable IVC filter was implanted due to the presence of calf vein thrombosis before cement vertebroplasty. Cement leaked into the IVC and was trapped by the filter, rendering the filter unretrievable using a conventional method. The asymptomatic patient received rivaroxaban 20 mg daily for anticoagulant postoperatively and lifelong anticoagulation was administered to prevent secondary IVC and cemented filter thrombosis.

Methods

A literature search was conducted utilizing the PUBMED/MEDLINE using the following terms: “vertebroplasty,” “complication,” “bone cement,” and “inferior vena cava (IVC),” or “inferior vena cava (IVC) filter.” All relevant articles published in English or in other languages with English abstracts since 1962 were included.

Results

A total of 36 articles were retrieved according to the search strategy. Only 6 out of these 36 studies contained information regarding the inferior vena cava filter and cement. Of the patients, 85.7% (36/42) reported in the literature whose gender was known were female and 14.3% were male. 28.5% (45/158) patients with pulmonary arterial and cardiovascular complications.

Conclusion

Cement embolization occurring in the IVC filter is rare. Accurate knowledge about the lumbar vertebral venous anatomy and skillful operation during vertebral cementoplasty should be required in clinical practice.

Risk factors for pulmonary cement embolism associated with percutaneous vertebral augmentation: A systematic review and meta-analysis

BACKGROUND

Pulmonary cement embolism (PCE) was a rare but fatal complication for percutaneous vertebral augmentation (PVA). Thus we did a systematic review and meta-analysis of cohort studies to investigate the risk factors for PCE after PVA.

METHODS

We systematically searched PubMed, EMBASE, Cochrane library, Google Scholar, web of science, and ClinicalTrial.gov from the establishment of the database to September 2021. All eligible studies assessing the risk factors for PCE after PVA were incorporated. Dichotomous data was calculated by risk difference (RD) from Mantel-Haenszel method (M - H method); continuous data was analyzed by mean difference (MD) from Inverse-Variance method (I-V method). All variables were taken as measure of effect by fixed effect model. Heterogeneity, sensitivity, and publication bias analyses were also performed.

RESULTS

This study totally included 13 studies. According to the Newcastle-Ottawa Scale (NOS), 7 studies were considered as low quality, with NOS< 6. The others were of relatively high quality, with NOS≥6. 144/6251 patients (2.3%) had PCE after PVA. percutaneous vertebroplasty (PVP) (RD = 0.02, 95%CI: [0.01, 0.04], Z = 3.70, P < 0.01), thoracic vertebra (RD = 0.03, 95%CI: [0.01, 0.05], Z = 3.53, P < 0.01), higher cement volume injected per level (MD = 0.23, 95%CI: [0.05, 0.42], Z = 2.44, P = 0.01), more than three vertebrae treated per session (MD = -0.05, 95%CI: [-0.08, -0.02], Z = 3.65, P < 0.01), venous cement leakage (RD = 0.07, 95%CI: [0.03, 0.11], Z = 3.79, P < 0.01) were more likely to cause PCE.

CONCLUSION

This study showed that risk factors for PCE included PVP, thoracic vertebra, higher cement volume injected per level, more than three vertebrae treated per session, venous cement leakage. As a serious complication, PCE should be paid attention and avoided.

Long-Term Outcomes of Peripheral Pulmonary Cement Embolism in Patients with Polymethylmethacrylate Augmentation: A Case Series with a Minimum Follow-Up of Five Years

BACKGROUND

Pulmonary cement embolism (PCE) is a rare but lethal complication. However, few long-term follow-up studies have investigated PCE after polymethylmethacrylate augmentation. This study aimed to investigate both the clinical and imaging outcomes of patients with PCE during a follow-up period of at least 5 years.

METHODS

A total of 1460 patients were initially included in this retrospective study. After exclusion, the clinical and imaging data were analyzed for selected patients, including the augmented level, location and length of the PCE, symptoms, therapy, migration and disintegration of the embolism, foreign body reaction, and status at follow-up.

RESULTS

Twelve female patients (age range, 56-88 years) with PCE and more than 5 years of follow-up (range, 5-13 years) were eventually included. All emboli were found in subsegment pulmonary arteries and were classified as peripheral PCE. Although 2 patients experienced transient symptoms after surgery, the majority of patients (84.6%) were asymptomatic during follow-up. No other reported emboli were observed during the follow-up period. The imaging data showed that the cement embolus could remain in the initial position throughout the long-term follow-up. In terms of the length of the PCE, there was no statistically significant difference between the values post-operation and at the last follow-up time (P > 0.05).

CONCLUSIONS

Patients with peripheral PCE do not develop known late complications. Moreover, polymethylmethacrylate can remain stable and inert in the pulmonary vasculature over the long term. Routine prophylactic anticoagulation may not be necessary for patients with peripheral PCE during follow-up.

Pulmonary Embolism after Core Decompression of the Femoral Head Using Injectable Bone Graft Substitute: A Case Report

The authors report a rare complication regarding the case of an 18-year-old female with bilateral osteonecrosis of the femoral head (ONFH) secondary to the treatment and hematopoietic stem cell transplant (HSCT) of an acute lymphoblastic leukemia (ALL). The patient underwent a bilateral necrotic bone debridement and core decompression (CD) surgery with injectable synthetic bone graft, which unfortunately caused a pulmonary injectable bone graft substitute embolism.

Diagnosis of pulmonary cement embolism using only the bone window setting on computed tomography: a case report

Pulmonary cement embolism (PCE) is one of several complications of percutaneous vertebroplasty and kyphoplasty. Generally, PCE can be easily diagnosed based on typical chest radiograph findings such as single or multiple radiographically dense opacities with a tubular or branch shape in the lung field along with a recent history of percutaneous vertebroplasty or kyphoplasty. These findings can be alarming and may be encountered on routine chest radiographs, even in asymptomatic patients. One study showed that PCEs that were not visualized on chest radiograph were also not shown on chest computed tomography. However, we encountered a patient with dyspnea who had normal chest radiograph findings but was diagnosed with PCE through only the bone window setting on chest computed tomography. The present case will be beneficial to all physicians examining older patients with dyspnea.

Pulmonary cement embolism complicating percutaneous kyphoplasty: A case report

Background

Vertebral cement augmentation procedures, as kyphoplasty (KP) or percutaneous vertebroplasty (PVP), are commonly used for the management of pain of the vertebral column usually due to fractures related to traumatic injury, osteoporosis or metastatic lesion. It is a useful and safe technique with few complications. Among them, symptomatic pulmonary cement embolism (PCE) can happened, even rarely described in the literature, leading to severe cardio-respiratory manifestations depending on the location and size of the cement emboli.

Case presentation

A 55 yo woman presented with atypical chest pain and presyncope three weeks after a motor vehicle accident resulting in an L1 compression fracture treated with kyphoplasty. She was hemodynamically stable. Blood tests showed D-Dimer 0.29 μg/mL, troponin <5ng/mL, Brain Natriuretic Protein 14 ng/mL and a PaO2 of 99 mmHg on arterial blood gas analysis. A computed tomography scan of chest showed linear hyperdense foreign bodies in two segmental pulmonary arteries at the level of middle lobe and right lower lobe compatible with pulmonary cement embolism. Anticoagulation with rivaroxaban for sixth months resulted in resolution of symptoms.

Conclusions

In this case, the pulmonary cement embolism occurred after kyphoplasty, which is associated with less risk of PCE than vertebroplasty. The procedure was done under biplanar fluoroscopy and no leakage of cement was noted, which would raise suspicion for CPE. Repeat imagine after this procedure is not routinely done. This case demonstrates that systematic imaging post procedure should be considered.

An anticoagulation with rivaroxaban seems to be effective in our patient.