Risk Factors for Cement Leakage in Percutaneous Vertebroplasty for Osteoporotic Vertebral Compression Fractures: An Analysis of 1456 Vertebrae Augmented by Low-Viscosity Bone Cement

Development of patient-tailored preoperative assessment of percutaneous vertebroplasty

Percutaneous vertebroplasty (PVP), a minimally invasive surgery technique, has become the common treatment for osteoporotic vertebral compression fractures (OVCF). The complications of PVP will lead to severe damage to spinal neuro systems due to bone cement leakage. A patient tailored preoperative assessment approach was developed to reduce the risks of complications in this study. The porcine OVCF model was fabricated to mimic the patient vertebral fracture in vitro using decalcification process. The 3D reconstructed model based on the imagological examination data acquired from the porcine vertebral bone was implemented for finite element (FE) simulation. The vertebral body with bone cement injected was scanned using CT for comparison with the finite element simulation results. This study showed a practical method for predicting the flow of bone cement in OVCF, which enabled the surgeons to evaluate the bone cement flow during preoperative assessment to reduce the cement leakage risks.

Hydraulic Polymethylmethacrylate Pressure Delivery System Versus Manual Balloon Tamp System in Balloon Kyphoplasty

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Osteoporotic vertebral compression fractures (VCFs) are prevalent among the elderly population, and Balloon kyphoplasty (BKP) is a minimally invasive solution for these. However, Polymethylmethacrylate (PMMA) leakage is a significant complication with potentially severe consequences. This study compares the safety and efficacy of manual balloon tamp system (MTS) and hydraulic Polymethylmethacrylate pressure delivery system (HPDS) in BKP.

METHODS

A retrospective study involving 160 patients, comparing MTS (2008-2014) and HPDS (2016-2020) cohorts, assessed PMMA leakage, radiation exposure, and surgery duration.

RESULTS

PMMA leakage occurred in 52.8% of MTS and 62.5% of HPDS cases. Intradiscal leakage was the most common pattern in both groups. Multivariate logistic regression revealed that multilevel BKP and HPDS were associated with higher PMMA leakage rates. Radiation exposure was significantly lower with HPDS, while surgery duration was shorter.

DISCUSSION

This study provides novel insights into PMMA leakage and radiation exposure in BKP. HPDS was associated with a higher PMMA leakage rate. HPDS, however, offers advantages in terms of reduced radiation exposure and shorter surgery duration. Multilevel BKP also increased the risk of leakage. Further investigation is needed to better understand the impact of HPDS on PMMA leakage.

CONCLUSION

This study underscores that while HPDS offers advantages regarding radiation exposure and surgery duration, it is associated with a higher PMMA leakage rate.

Combined vertebroplasty and pedicle screw insertion for vertebral consolidation: feasibility and technical considerations

PURPOSE

To assess the feasibility and technical accuracy of performing pedicular screw placement combined with vertebroplasty in the radiological setting.

METHODS

Patients who underwent combined vertebroplasty and pedicle screw insertion under combined computed tomography and fluoroscopic guidance in 4 interventional radiology centers from 2018 to 2023 were retrospectively assessed. Patient demographics, vertebral lesion type, and procedural data were analyzed. Strict intra-pedicular screw positioning was considered as technical success. Pain score was assessed according to the Visual Analogue Scale before the procedure and in the 1-month follow-up consultation.

RESULTS

Fifty-seven patients (38 men and 19 women) with a mean age of 72.8 (SD = 11.4) years underwent a vertebroplasty associated with pedicular screw insertion for the treatment of traumatic fractures (29 patients) and neoplastic disease (28 patients). Screw placement accuracy assessed by post-procedure CT scan was 95.7% (89/93 inserted screws). A total of 93 pedicle screw placements (36 bi-pedicular and 21 unipedicular) in 32 lumbar, 22 thoracic, and 3 cervical levels were analyzed. Mean reported procedure time was 48.8 (SD = 14.7) min and average injected cement volume was 4.4 (SD = 0.9) mL. A mean VAS score decrease of 5 points was observed at 1-month follow-up (7.7, SD = 1.3 versus 2.7, SD = 1.7), p < .001.

CONCLUSION

Combining a vertebroplasty and pedicle screw insertion is technically viable in the radiological setting, with a high screw positioning accuracy of 95.7%.

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.

Efficacy and safety of robot-assisted versus fluoroscopy-assisted PKP or PVP for osteoporotic vertebral compression fractures: a systematic review and meta-analysis

Percutaneous vertebral augmentation (PVA), which includes percutaneous kyphoplasty (PKP) and percutaneous vertebroplasty (PVP). Robot-assisted (RA) and fluoroscopy-assisted (FA) are important methods for treating osteoporotic vertebral compression fractures (OVCFs), though it is still unclear which is superior. This analysis aimed to compare the efficacy and safety of RA and FA. PubMed, Web of Science, Cochrane Library, and China National Knowledge Infrastructure were systematically searched, the outcomes included surgical parameters (leakage rate, operation time, number of fluoroscopic, injection volume, inclination angle), and clinical indexes (hospital stays, Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Cobb angle, the midline height of vertebral). Thirteen articles involving 1094 patients were included. RA group produced better results than the FA group in the leakage rate (OR = 0.27; 95% CI 0.17-0.42; P < 0.00001), number of fluoroscopic (WMD = - 13.88; 95% CI - 18.47 to - 9.30; P < 0.00001), inclination angle (WMD = 5.02; 95% CI 4.42-5.61; P < 0.00001), hospital stays (WMD = - 0.32; 95% CI - 0.58 to - 0.05; P = 0.02), VAS within 3 days (WMD = - 0.19; 95% CI - 0.26 to - 0.12; P < 0.00001), Cobb angle within 3 days (WMD = - 1.35; 95% CI - 2.56 to - 0.14; P = 0.003) and Cobb angle after 1 month (WMD = - 1.02; 95% CI - 1.84 to - 0.20; P = 0.01). But no significant differences in operation time, injection volume, ODI, the midline height of vertebral, and VAS score after 1 month. Our analysis found that the RA group had lower cement leakage rates, number of fluoroscopic and hospital stays, a larger inclination angle, better short-term pain improvement, and Cobb angle improvement. It is worth acknowledging that robotic-assisted surgery holds promise for the development of spine surgery. The study was registered in the PROSPERO (CRD42023393497).

Optimizing percutaneous vertebroplasty: extra-facet puncture for osteoporotic vertebral compression fractures

PURPOSE

To assess the safety and efficacy of the extra-facet puncture technique applied in unilateral percutaneous vertebroplasty (PVP) for treating osteoporotic vertebral compression fractures.

METHODS

Demographics (age, gender, body mass index and underlying diseases) were recorded for analyzing. Visual analog scale (VAS) and Oswestry Disability Index (ODI) scores as well as their corresponding minimal clinically important difference (MCID) were used to evaluate clinical outcomes. The segmental kyphotic angle, the vertebral compression ratio and bone cement distribution pattern were evaluated by the plain radiographs. The facet joint violation (FJV) was defined by the postoperative computed tomography scan. Binary logistic regression analysis was performed to investigate relationships between multiple risk factors and residual back pain.

RESULTS

VAS and ODI scores in both traditional puncture group and extra-facet puncture group were significantly decreased after PVP surgery (p < 0.05). However, no significant difference was observed between the two groups according to VAS and ODI scores. The proportion of patients achieving MCID of VAS and ODI scores was higher in extra-facet puncture group as compared to traditional puncture group within a month (p < 0.05). Finally, multivariate logistic regression analysis showed that FJV (odds ratio 16.38, p < 0.001) and unilateral bone cement distribution (OR 5.576, p = 0.020) were significant predictors of residual back pain after PVP surgery.

CONCLUSIONS

Extra-facet puncture percutaneous vertebroplasty can decrease the risk of FJV and it also has the advantage of more satisfied bone cement distribution.

Interpretable Machine Learning Model to Predict Bone Cement Leakage in Percutaneous Vertebral Augmentation for Osteoporotic Vertebral Compression Fracture Based on SHapley Additive exPlanations

STUDY DESIGN

Retrospective study.

OBJECTIVES

Our objective is to create comprehensible machine learning (ML) models that can forecast bone cement leakage in percutaneous vertebral augmentation (PVA) for individuals with osteoporotic vertebral compression fracture (OVCF) while also identifying the associated risk factors.

METHODS

We incorporated data from patients (n = 425) which underwent PVA. To predict cement leakage, we devised six models based on a variety of parameters. Evaluate and juxtapose the predictive performances relied on measures of discrimination, calibration, and clinical utility. SHapley Additive exPlanations (SHAP) methodology was used to interpret model and evaluate the risk factors associated with cement leakage.

RESULTS

The occurrence rate of cement leakage was established at 50.4%. A binary logistic regression analysis identified cortical disruption (OR 6.880, 95% CI 4.209-11.246), the basivertebral foramen sign (OR 2.142, 95% CI 1.303-3.521), the fracture type (OR 1.683, 95% CI 1.083-2.617), and the volume of bone cement (OR 1.198, 95% CI 1.070-1.341) as independent predictors of cement leakage. The XGBoost model outperformed all others in predicting cement leakage in the testing set, with AUC of .8819, accuracy of .8025, recall score of .7872, F1 score of .8315, and a precision score of .881. Several important factors related to cement leakage were drawn based on the analysis of SHAP values and their clinical significance.

CONCLUSION

The ML based predictive model demonstrated significant accuracy in forecasting bone cement leakage for patients with OVCF undergoing PVA. When combined with SHAP, ML facilitated a personalized prediction and offered a visual interpretation of feature importance.

Complication Pattern After Percutaneous Cement Discoplasty: Identification of Factors Influencing Reoperation and Length of Hospital Stay

OBJECTIVE

Percutaneous cement discoplasty (PCD) was introduced to treat symptomatic vertical instability of the lumbar spine in a minimally invasive way. The aim of the present study was to analyze the complication pattern after PCD and to identify factors that predict the chance of cement leakage, reoperation, and length of hospital stay (LOS).

METHODS

patients were treated with PCD within the study period. Clinical features and complications were analyzed by applying descriptive statistics, whereas perioperative factors predictive of cement leakage, reoperation, and LOS were identified by regression models.

RESULTS

Cement leakage rate was 30.4% in the total cohort; however, only fifth of them were symptomatic. Cement leakage itself did not have a significant influence on clinical outcome. Other complications and nonsurgical adverse events were registered only in 2.0% of cases. Age, subcutaneous fat tissue thickness, low viscosity cement, lower level of surgeon's experience and the number of operated levels were identified as risk factors of cement leakage (P < 0.01; c-index = 0.836). Type of procedure, Charlson comorbidity score, reoperation, and nonsurgical adverse events significantly increased the LOS (P < 0.01). Cement leakage, early surgical practice, and increased subcutaneous fat tissue thickness were risk factors for reoperation (P < 0.01; c-index = 0.72).

CONCLUSIONS

PCD is a relatively safe and effective procedure for treating spinal instability caused by advanced-stage disc degeneration characterized by vacuum phenomenon. Cement leakage is not uncommon but is only a radiologic complication without clinical consequences in most cases. On the other hand, it can increase the LOS and is a significant risk factor for reoperation.

Establishment and validation of a nomogram for predicting new fractures after PKP treatment of for osteoporotic vertebral compression fractures in the elderly individuals

BACKGROUND

To investigate the risk factors for new vertebral compression fractures (NVCFs) after percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fractures (OVCFs) and to create a nomogram to predict the occurrence of new postoperative fractures.

METHODS

This was a retrospective analysis of the clinical data of 529 OVCF patients who received PKP treatment in our hospital from June 2017 to June 2020. Based on whether there were new fractures within 2 years after surgery, the patients were divided into a new fracture group and a nonnew fracture group. Univariate and multivariate analyses were used to determine the risk factors for the occurrence of NVCFs after surgery. The data were randomly divided into a training set (75%) and a testing set (25%). Nomograms predicting the risk of NVCF occurrence were created based on the results of the multivariate analysis, and performance was evaluated using receiver operating characteristic curves (ROCs), calibration curves, and decision curve analyses (DCAs). A web calculator was created to give clinicians a more convenient interactive experience.

RESULTS

A total of 56 patients (10.6%) had NVCFs after surgery. The univariate analysis showed significant differences in sex and the incidences of cerebrovascular disease, a positive fracture history, and bone cement intervertebral leakage between the two groups (P < 0.05). The multivariate analysis showed that sex [OR = 2.621, 95% CI (1.030-6.673), P = 0.043], cerebrovascular disease [OR = 28.522, 95% CI (8.749-92.989), P = 0.000], fracture history [OR = 12.298, 95% CI (6.250-24.199), P = 0.000], and bone cement intervertebral leakage [OR = 2.501, 95% CI (1.029-6.082), P = 0.043] were independent risk factors that were positively associated with the occurrence of NVCFs. The AUCs of the model were 0.795 (95% CI: 0.716-0.874) and 0.861 (95% CI: 0.749-0.974) in the training and testing sets, respectively, and the calibration curves showed high agreement between the predicted and actual states. The areas under the decision curve were 0.021 and 0.036, respectively.

CONCLUSION

Female sex, cerebrovascular disease, fracture history and bone cement intervertebral leakage are risk factors for NVCF after PKP. Based on this, a highly accurate nomogram was developed, and a webpage calculator ( https://new-fracture.shinyapps.io/DynNomapp/ ) was created.

Development of a nomogram model for prediction of new adjacent vertebral compression fractures after vertebroplasty

BACKGROUND

Vertebroplasty is the main minimally invasive operation for osteoporotic vertebral compression fracture (OVCF), which has the advantages of rapid pain relief and shorter recovery time. However, new adjacent vertebral compression fracture (AVCF) occurs frequently after vertebroplasty. The purpose of this study was to investigate the risk factors of AVCF and establish a clinical prediction model.

METHODS

We retrospectively collected the clinical data of patients who underwent vertebroplasty in our hospital from June 2018 to December 2019. The patients were divided into a non-refracture group (289 cases) and a refracture group (43 cases) according to the occurrence of AVCF. The independent predictive factors for postoperative new AVCF were determined by univariate analysis, least absolute shrinkage and selection operator (LASSO) logistic regression, and multivariable logistic regression analysis. A nomogram clinical prediction model was established based on relevant risk factors, and the receiver operating characteristic curve (ROC), calibration curve, and decision curve analysis (DCA) were used to evaluate the prediction effect and clinical value of the model. After internal validation, patients who underwent vertebroplasty in our hospital from January 2020 to December 2020, including a non-refracture group (156 cases) and a refracture group (21 cases), were included as the validation cohort to evaluate the prediction model again.

RESULTS

Three independent risk factors of low bone mass density (BMD), leakage of bone cement and "O" shaped distribution of bone cement were screened out by LASSO regression and logistic regression analysis. The area under the curve (AUC) of the model in the training cohort and the validation cohort was 0.848 (95%CI: 0.786-0.909) and 0.867 (95%CI: 0.796-0.939), respectively, showing good predictive ability. The calibration curves showed the correlation between prediction and actual status. The DCA showed that the prediction model was clinically useful within the whole threshold range.

CONCLUSION

Low BMD, leakage of bone cement and "O" shaped distribution of bone cement are independent risk factors for AVCF after vertebroplasty. The nomogram prediction model has good predictive ability and clinical benefit.

Comparison of clinical effects of percutaneous vertebroplasty with two different puncture approaches on the treatment of thoracolumbar osteoporotic vertebral compression fractures with narrow pedicles: a retrospective controlled study

PURPOSE

To evaluate the effects of percutaneous vertebroplasty (PVP) with conventional transpedicle approach (CTA) or basal transverse process-pedicle approach (BTPA) on the treatment of thoracolumbar osteoporotic vertebral compression fractures (TL-OVCFs) with narrow pedicles.

METHODS

A retrospective study of TL-OVCFs with narrow pedicles was performed, including 78 cases of CTA and 84 cases of BTPA. The surgical outcomes, radiographic parameters [the width and height of the pedicle (PW, PH), the inclination angle of puncture (PIA)] and clinical indicators [visual analog scale (VAS) score, Oswestry Disability Index (ODI)] of two groups were compared.

RESULTS

In terms of surgical outcomes of them, there was no difference in operation time (P > 0.05), while the volume of bone cement, the incidence of bone cement leakage and rate of good bone cement distribution were significantly worse in the CTA group (4.4 ± 0.6 ml vs. 5.5 ± 0.5 ml, 37.2% vs. 20.2%, 52.6% vs. 79.8%, P < 0.05). As for radiographic parameters and clinical indicators of them, the differences were not observed in the PH, PW, preoperative VAS score and ODI (P > 0.05), whereas the PIA, VAS score and ODI at 1 day postoperatively were significantly better in the BTPA group (17.3 ± 2.1° vs. 29.6 ± 2.8°, 2.7 ± 0.7 vs. 2.1 ± 0.8, 32.8 ± 4.6 vs. 26.7 ± 4.0, P < 0.05).

CONCLUSION

The study provided solid evidence that PVP with BTPA had more advantages in the treatment of TL-OVCFs with narrow pedicles, which can better relieve postoperative pain.

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.

Comparison of unipedicular and bipedicular kyphoplasty for treating acute osteoporotic vertebral compression fractures in the lower lumbar spine: a retrospective study

BACKGROUND

Unipedicular and bipedicular approaches for percutaneous kyphoplasty are reportedly both effective in treating osteoporotic vertebral compression fractures (OVCFs). However, most studies have reported thoracolumbar fractures, with few reports describing the treatment of the lower lumbar spine. Here, we compared the clinical and radiological results of unipedicular and bipedicular approaches for percutaneous kyphoplasty for treating osteoporotic vertebral compression fractures.

METHODS

We retrospectively reviewed the records of 160 patients who underwent percutaneous kyphoplasty for lower lumbar (L3-L5) osteoporotic vertebral compression fractures between January 2016 and January 2020. Patient characteristics, surgical outcomes, operation time, blood loss, clinical and radiological features, and complications were compared between two groups. Cement leakage, height restoration, and cement distribution were calculated from the radiographs. Visual pain analog scale (VAS) and Oswestry Disability Index (ODI) were calculated before surgery, immediately post-surgery, and 2 years after surgery.

RESULTS

The mean age, sex, body mass index, injury time, segmental distribution, and morphological classification of fractures before surgery did not differ significantly between the groups. The results showed significant improvements in the VAS score, ODI score, and vertebral height restoration in each group (p < 0.05), with no significant differences between the two groups (p > 0.05). The mean operation time and extent of blood loss were lower in the unipedicular group than those in the bipedicular group (p < 0.05). Different types of bone cement leakage were observed in both groups. Leakage rate was higher in the bipedicular group than in the unipedicular group. Patients in the bipedicular group showed greater improvement in bone cement distribution than those in the unipedicular group (p < 0.05).

CONCLUSIONS

The clinical and radiological results of unipedicular percutaneous kyphoplasty for treating osteoporotic vertebral compression fractures in the lower lumbar region were similar to those of bipedicular percutaneous kyphoplasty. However, the unipedicular approach resulted in shorter surgical time, less blood loss, and less bone cement leakage. Thus, the unipedicular approach may be preferable owing to its several advantages.

[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.

Distribution of bone voids in the thoracolumbar spine in Chinese adults with and without osteoporosis: A cross-sectional multi-center study based on 464 vertebrae

Bone void is a novel intuitive morphological indicator to assess bone quality but its use in vertebrae has not been described. This cross-sectional and multi-center study aimed to investigate the distribution of bone voids in the thoracolumbar spine in Chinese adults based on quantitative computed tomography (QCT). A bone void was defined as a trabecular net region with extremely low bone mineral density (BMD) (<40 mg/cm³), detected by an algorithm based on phantom-less technology. A total of 464 vertebrae from 152 patients (51.8 ± 13.4 years old) were included. The vertebral trabecular bone was divided into eight sections based on the middle sagittal, coronal, and horizontal planes. Bone void of the whole vertebra and each section were compared between healthy, osteopenia, and osteoporosis groups and between spine levels. Receiver operator characteristic (ROC) curves were plotted and optimum cutoff points of void volume between the groups were obtained. The total void volumes of the whole vertebra were 124.3 ± 221.5 mm³, 1256.7 ± 928.7 mm^3, and 5624.6 ± 3217.7 mm³ in healthy, osteopenia, and osteoporosis groups, respectively. The detection rate of vertebrae with bone voids was higher and the normalized void volume was larger in the lumbar than in thoracic vertebrae. L3 presented the largest void (2165.0 ± 3396.0 mm³), while T12 had the smallest void (448.9 ± 699.4 mm³). The bone void was mainly located in the superior-posterior-right section (40.8 %). Additionally, bone void correlated positively with age and increased rapidly after 55 years. The most significant void volume increase was found in the inferior-anterior-right section whereas the least increase was found in the inferior-posterior-left section with aging. The cutoff points were 345.1 mm³ between healthy and osteopenia groups (sensitivity = 0.923, specificity = 0.932) and 1693.4 mm³ between osteopenia and osteoporosis groups (sensitivity = 1.000, specificity = 0.897). In conclusion, this study demonstrated the bone void distribution in vertebrae using clinical QCT data. The findings provide a new perspective for the description of bone quality and showed that bone void could guide clinical practice such as osteoporosis screening.

PVP with or without microwave ablation for the treatment of painful spinal metastases from NSCLC: a retrospective case-control study

OBJECTIVE

To compare the clinical efficacy of percutaneous vertebroplasty (PVP) alone and microwave ablation (MWA) combined with PVP for the treatment of painful spinal metastases from non-small cell lung cancer (NSCLC).

METHODS

From October 2014 to October 2021, the data of 58 NSCLC patients with refractory painful spinal metastases (visual analog scale score ≥ 5) were retrospectively collected and analyzed. Patients in Group A (n = 30) and Group B (n = 28) received PVP alone and MWA combined with PVP, respectively. The primary endpoint was pain relief. The secondary endpoints were quality of life (QoL), local tumor progression (LTP), and complications.

RESULTS

The technical success rate was 100% in both groups. Patients in both groups showed similar pain relief at 1-12 weeks, but patients in Group B still showed sustained pain relief at 24 weeks compared to those in Group A (p = 0.03). The assessment of QoL showed similar changes. LTP (33.00% vs. 7.14%, p = 0.02) and cement leakage rates (40.00% vs. 7.14%, p = 0.03) were lower in Group B. The multivariate analysis demonstrated spinal metastases with a maximum diameter ≤ 3.0 cm (p = 0.027) and MWA combined with PVP (p = 0.028) were two independent protective factors for LTP. For cement leakage, spinal metastases with vertebral body compression (p = 0.019) was an independent risk factor, while MWA combined with PVP (p = 0.042) was an independent protective factor.

CONCLUSION

MWA combined with PVP for painful spinal metastases from NSCLC performed more sustained pain relief (>6 months) and ultimately improved QoL with lower LTP and cement leakage rates, compared to PVP alone.

A predictive nomogram for intradiscal cement leakage in percutaneous kyphoplasty for osteoporotic vertebral compression fractures combined with intravertebral cleft

BACKGROUND

For patients with osteoporotic vertebral compression fractures (OVCFs) treated with percutaneous kyphoplasty (PKP), the occurrence and risk factors of intradiscal cement leakage should be characteristic of the presence of intravertebral cleft (IVC). This study aimed to identify risk factors for intradiscal leakage in individuals with OVCFs combined with IVC treated with PKP and build a powered and well-calibrated predictive nomogram.

METHODS

This study retrospectively reviewed consecutive patients who underwent PKP at our center between January 2016 and May 2021. Patients diagnosed with OVCFs combined with IVC were identified, and the incidence of different types of bone cement leakage was recorded. Risk factors for intradiscal leakage among the demographic, perioperative baseline, and radiologic data were identified, following which a nomogram was developed and verified.

RESULTS

A total of 109 eligible patients were included, and the intradiscal leakage rate was 32.1%. Compression rate (odds ratio [OR] 0.025; 95% confidence interval [CI] 0.002-0.264; P = 0.002) and cemented vertebral body fraction (OR 44.122; 95% CI 2.790-697.740; P = 0.007) were identified as independent risk factors. A predictive nomogram with good predictive power (C-statistic = 0.786) and fitness of data (Hosmer-Lemeshow goodness-of-fit test, P = 0.092) was established to build a quantitative relationship between the risk factors and intradiscal leakage.

CONCLUSION

The incidence rate of intradiscal leakage in PKP for OVCFs combined with IVC was 32.1%. Compression rate and cemented vertebral body fraction were identified as independent risk factors. A powered and well-calibrated nomogram was established to accurately predict the probability of intradiscal leakage. Further prospective and multicenter studies are required to verify and calibrate our findings.

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.

The impact of intravertebral cleft on cement leakage in percutaneous vertebroplasty for osteoporotic vertebral compression fractures: a case-control study

Background

The impact of intravertebral cleft (IVC) on cement leakage in percutaneous vertebroplasty (PVP) for osteoporotic vertebral compression fractures (OVCFs) has been discussed. However, the results were conflicting, as the study population and cement leakage classification were heterogeneous. The aim of the study was to evaluate the impact of IVC on the incidence of leakage through vein, leakage through cortex as well as general leakage in PVP for OVCFs.

Methods

All patients with OVCFs who underwent PVP between January 2016 and June 2019 at our institution were retrospectively reviewed. Patients were eligible for this case-control study if they were diagnosed as single level fracture in spine. After inclusive and exclusive criteria were met, a total of 139 patients with IVC were enrolled as the study group. Non-IVC controls were matched in a 1:1 ratio in age (within 3 years), sex and fracture severity with patients in study group. Cement leakage were classified into four types [type B (through basivertebral vein), type S (through segmental vein), type-C (through a cortical defect), and type D (intradiscal leakage)], furtherly into two types [venous type (type-B or/and type S) and cortical type (type-C or/and type-D)]. A general leakage rate and a specific leakage rate per each type were compared between both groups.

Results

Each group included 139 patients. Groups were homogenous for age, sex, fracture severity, fracture location, fracture type, cement volume, puncture approach and property of cement. Compared with control group, IVC group had a significantly lower rate of type-B (20.9% vs. 31.7%, P = 0.041), type-S (24.5% vs. 52.5%, P = 0.000), and venous type leakage (37.4% vs. 67.6%, P = 0.000), a significantly higher rate of type-C (25.9% vs. 12.2%, P = 0.004), type-D (16.5% vs. 6.5%, P = 0.009), and cortical type leakage (40.3% vs. 16.5%, P = 0.000), no significant difference on the rate of general leakage (67.6% vs. 76.3%, P = 0.109).

Conclusion

IVC decreased the risk of cement leakage through vein and increased the risk of cement leakage through cortex. However, it had no significant effect on the occurrence of general leakage.