Multilevel percutaneous vertebroplasty: safety, efficacy and long-term outcomes

<p><strong>Background:</strong> The pain in vertebral compression fractures is severe, leading to reduced mobility and quality of life. Percutaneous vertebroplasty is a minimally invasive procedure for treating various spinal pathologies. This study evaluated the usefulness and safety of multilevel PVP (two to three vertebrae) in managing VCF.</p><p><strong>Methods:</strong> This retrospective study evaluated 59 vertebral levels in 28 patients with VCF who had been operated on for multilevel PVP (two to three levels). There were 22 females and six males, and their ages ranged from 36 to 79 years, with a mean age of 68.95 years. We had injected two levels in 25 patients and three levels in 3 patients. The visual analogue scale was used for pain intensity measurement, and plain X-ray films, computed tomography scan and magnetic resonance imaging was used for radiological assessment. The mean follow-up period was 13.8 months (range, 11-19).</p><p><strong>Results:</strong> Significant pain improvement was recorded in 26 patients (92.85%). More remarkable improvement in pain was noticed in the immediate postoperative period than in the subsequent follow-ups. Asymptomatic bone cement leakage anteriorly and into the disk spaces in two patients. Isolated anterior leakage has occurred in one patient. There was no encounter of pulmonary embolism.</p><p><strong>Conclusions:</strong> Multilevel PVP for the treatment of VCF is a safe and effective procedure that can significantly reduce pain and improve patient condition without any significant morbidity. It is considered a cost-effective procedure allowing a rapid restoration of patient mobility.</p><p> </p>

Machine Learning Applications for the Prediction of Bone Cement Leakage in Percutaneous Vertebroplasty

Background: Bone cement leakage is a common complication of percutaneous vertebroplasty and it could be life-threatening to some extent. The aim of this study was to develop a machine learning model for predicting the risk of cement leakage in patients with osteoporotic vertebral compression fractures undergoing percutaneous vertebroplasty. Furthermore, we developed an online calculator for clinical application.Methods: This was a retrospective study including 385 patients, who had osteoporotic vertebral compression fracture disease and underwent surgery at the Department of Spine Surgery, Liuzhou People's Hospital from June 2016 to June 2018. Combing the patient's clinical characteristics variables, we applied six machine learning (ML) algorithms to develop the predictive models, including logistic regression (LR), Gradient boosting machine (GBM), Extreme gradient boosting (XGB), Random Forest (RF), Decision Tree (DT) and Multilayer perceptron (MLP), which could predict the risk of bone cement leakage. We tested the results with ten-fold cross-validation, which calculated the Area Under Curve (AUC) of the six models and selected the model with the highest AUC as the excellent performing model to build the web calculator.Results: The results showed that Injection volume of bone cement, Surgery time and Multiple vertebral fracture were all independent predictors of bone cement leakage by using multivariate logistic regression analysis in the 385 observation subjects. Furthermore, Heatmap revealed the relative proportions of the 15 clinical variables. In bone cement leakage prediction, the AUC of the six ML algorithms ranged from 0.633 to 0.898, while the RF model had an AUC of 0.898 and was used as the best performing ML Web calculator (https://share.streamlit.io/liuwencai0/pvp_leakage/main/pvp_leakage) was developed to estimate the risk of bone cement leakage that each patient undergoing vertebroplasty.Conclusion: It achieved a good prediction for the occurrence of bone cement leakage with our ML model. The Web calculator concluded based on RF model can help orthopedist to make more individual and rational clinical strategies.

Vesselplasty versus vertebroplasty in the treatment of osteoporotic vertebral compression fractures with posterior wall rupture

Objective This study was performed to compare the effectiveness and safety of vesselplasty versus vertebroplasty in the treatment of osteoporotic compression fractures with posterior wall rupture. Methods Patients who underwent treatment of a single osteoporotic vertebral compression fracture with posterior wall rupture from January 2016 to February 2020 were retrospectively reviewed. They were divided into a vesselplasty group (n = 17) and a vertebroplasty group (n = 43). Pain relief, radiographic outcomes, and bone cement leakage were compared between the two groups. Results There were no significant differences in the operation time, postoperative pain relief, vertebral compression recovery, or local Cobb angle improvement between the two groups. However, the overall bone cement leakage rate (29.4% vs. 67.4%) and spinal canal leakage rate (0.0% vs. 30.2%) were significantly lower in the vesselplasty group than vertebroplasty group. Conclusions Vesselplasty offers similar pain relief and vertebral compression recovery but lower spinal canal leakage compared with vertebroplasty. Vesselplasty is thus a better option than vertebroplasty for patients with osteoporotic compression fractures with posterior wall rupture.

Establishment and validation of a nomogram and web calculator for the risk of new vertebral compression fractures and cement leakage after percutaneous vertebroplasty in patients with osteoporotic vertebral compression fractures

Purpose The aim of this work was to investigate the risk factors for cement leakage and new-onset OVCF after Percutaneous vertebroplasty (PVP) and to develop and validate a clinical prediction model (Nomogram). Methods Patients with Osteoporotic VCF (OVCF) treated with PVP at Liuzhou People’s Hospital from June 2016 to June 2018 were reviewed and met the inclusion criteria. Relevant data affecting bone cement leakage and new onset of OVCF were collected. Predictors were screened using univariate and multi-factor logistic analysis to construct Nomogram and web calculators. The consistency of the prediction models was assessed using calibration plots, and their predictive power was assessed by tenfold cross-validation. Clinical value was assessed using Decision curve analysis (DCA) and clinical impact plots. Results Higher BMI was associated with lower bone mineral density (BMD). Higher BMI, lower BMD, multiple vertebral fractures, no previous anti-osteoporosis treatment, and steroid use were independent risk factors for new vertebral fractures. Cement injection volume, time to surgery, and multiple vertebral fractures were risk factors for cement leakage after PVP. The development and validation of the Nomogram also demonstrated the predictive ability and clinical value of the model. Conclusions The established Nomogram and web calculator (https://dr-lee.shinyapps.io/RefractureApp/) (https://dr-lee.shinyapps.io/LeakageApp/) can effectively predict the occurrence of cement leakage and new OVCF after PVP.

Comparison of Pedicle Screw Fixation With or Without Cement Augmentation Combined With Single-segment Isthmic Spondylolisthesis in Osteoporotic Spine

PurposeThis study aims to investigate the necessity of cement-augmented pedicle screw fixation in single-segment isthmic spondylolisthesis with osteoporosis.MethodFifty-nine cases were reviewed retrospectively. Thirty-three cases were in the polymethylmethacrylate-augmented pedicle screw (PMMA-PS) group, and the other 26 cases were in the conventional pedicle screw (CPS) group. Evaluation data included operation time, intraoperative blood loss,hospitalization cost, hospitalization days, rates of fusion, screw loosening, bone cement leakage, visual analog scores (VAS) , Oswestry disability index (ODI) , Lumbar Lordosis（LL）, Pelvic Tilt（PT） and Sacral Slope（SS）. ResultsThe operation time and blood loss in the CPS group decreased significantly compared to the PMMA-PS group (P < 0.05). The average hospitalization cost of the PMMA group was significantly higher than that of the CPS group (P < 0.05). There was no significant difference for the average hospital stay between the 2 groups (P > 0.05). The initial and the last follow-up postoperative VAS and ODI improved significantly in the two groups (P < 0.05). There were no significant differences in VAS and ODI at each time point between the 2 groups (P > 0.05). The last postoperative spine-pelvic parameters were significantly improved compared with preoperation (P < 0.05). In the PMMA-PS group, the fusion rate was 100%. The fusion rate was 96.15% in the CPS group. No significant difference was found between the two groups for the fusion rate (P > 0.05). Nine cases in the PMMA-PS group had bone cement leakage (27.27%). There was not screw loosening in the PMMA-PS group. There were 2 cases of screw loosening in the CPS group. There were no significant differences in screw loosening, postoperative adjacent segment fractures, postoperative infection or postoperative revision between the 2 groups (P > 0.05). ConclusionsThe use of PMMA-PS on a regular basis is not recommended for posterior lumbar interbody fusion for the treatment of single-segment isthmic spondylolisthesis with osteoporosis.

A Novel Bone Cement Injector Augments Osteoporotic Lumbar Pedicle Screw Channel: A Biomechanical Investigation

Background: The study aimed to invent a series of pedicle injectors and investigated the effects of the injectors with different number of holes on the augmentation of pedicle screw using bone cement in osteoporotic lumbar pedicle channel.Methods: This study used the biomechanical test module of polyurethane (Pacific Research Laboratory Corp, USA) to simulate the mechanical properties of human osteoporotic cancellous bone. The bone cement injectors were invented based on anatomical parameters of lumbar pedicle in Chinese. Mechanical test experiments were divided into three groups, namely, a local augmentation group, a full-length augmentation group, and a control group. The local augmentation group included three subgroups including 4 holes, 6 holes, and 8 holes and all holes were laterally placed. The full-length augmentation group was a straight-hole injector. The control group was defined that pedicle screws were inserted without any cement augmentation. Six screws were inserted in each group and the maximum insertion torque was recorded. After 24 hours of injecting acrylic bone cement, routine X-ray and CT examinations were performed to evaluate the distribution of bone cement. The axial pull-out force of screws was tested with the help of the MTS 858 mechanical tester.Results: The bone cement injectors were consisted of the sheaths and the steel-rods and the sheaths had different number of lateral holes. The control group had the lowest maximum insertion torque as compared with the 4-hole, 6-hole, 8-hole, and straight pore groups (P<0.01), but the difference between the 4-hole, 6-hole, 8-hole, and straight pore groups was no statistical significance. The control group had the lowest maximum axial pull-out force as compared with the other four groups (P<0.01). Subgroup analysis showed the 8-hole group (161.35±27.17 N) had the lower maximum axial pull-out force as compared with the 4-hole (217.29±49.68 N), 6-hole (228.39±57.83 N), and straight pore groups (237.55±35.96 N) (P<0.01). Bone cement was mainly distributed in 1/3 of the distal end of the screw among the 4-hole group, in the middle 1/3 and distal end of the screw among the 6-hole group, in the proximal 1/3 of the screw among the 8-hole group, and along the long axis of the whole screw body in the straight pore group. It might indicate that the 8-hole and straight-hole groups were more vulnerable to spinal canal cement leakage. After pullout, bone cement was also closely connected with the screw without any looseness or fragmentation.Conclusions: The bone cement injectors with different number of holes can be used to augment the pedicle screw channel. The pedicle screw augmented by the 4-hole or 6-hole sheath may have similar effects to the straight pore injector. However, the 8-hole injector may result in relatively lower pull-out strength and the straight pore injector has the risks of cement leakage as well as cement solidarization near the screw head.

A Lateral Opening Injection Tool Used In Percutaneous Vertebroplasty To Treat Asymptomatic Osteoporotic Vertebral Burst Fractures: A Retrospective Study In 66 Cases

Background: This study aimed to assess the results of percutaneous vertebroplasty (PVP) with a lateral opening injection tool for treating asymptomatic osteoporotic vertebral burst fractures (OVBFs) patients.Methods: 66 patients diagnosed with acute asymptomatic OVBFs with a spinal canal occupational ratio under 20% were treated with bilateral PVP using a lateral opening injection tool in our study. The related clinical outcomes and images were assessed, including Visual Analogue Scale (VAS), vertebral height (VH) ratio (=fractured VH/ adjacent nonfractured VH), the bone union of the fractured vertebral posterior wall, bone cement distribution, and complications.Results: The VAS scores were 3.80±0.40 at postoperative one day and 0.59±0.41 at last follow-up, significantly lower than 8.37±0.49 at pre-operation (P<0.05). The vertical distribution of bone cement in 60 cases contacted the upper and lower endplates of fractured vertebras. There was no leakage of bone cement in the spinal canal or displacement of posterior wall fracture to the spinal canal in all cases. There was asymptomatic cement leakage in 7 cases. The mean anterior, middle and posterior vertebral height ratios were significantly increased after PVP compared with preoperative values in all patients (P<0.05). At 6 months follow-up, there was no significant height loss of the vertebral body. Three months postoperatively, the posterior wall of fractured vertebral bodies was healed in all cases according to CT images. Conclusions: PVP using a lateral opening injection tool was effective and safe for treating asymptomatic OVBF patients.

Development and validation of a prognostic model of vertebral refracture after percutaneous kyphoplasty

Purpose: To investigate the factors influencing refracture after percutaneous kyphoplasty and to develop and validate a prognostic model.Method: We retrospectively collected clinical data in 392 patients with osteoporotic vertebral compression fractures who underwent percutaneous kyphoplasty at the Affiliated Hospital of Xuzhou Medical University from 1 January 2018 to 1 January 2020.Predictors significantly associated with refracture after PKP were selected based on last absolute shrinkage and selection operator regression. Then a prognostic model were developed and internal validated using enhanced Bootstrap validation.Results: Among the 392 patients who included in this study, there were 19 refracture after percutaneous kyphoplasty(4.8%). Four factors were selected by least absolute shrinkage and selection operator regression for significant association with refracture after percutaneous kyphoplasty, including body mass index, bone mineral density, unilateral puncture, and bone cement leakage. After enhance Bootstrap validation, the bias-corrected curve of the model fitted well with the apparent curve, with the area under ROC curve of 0.931 and 95% CI of (0.789,0.936).Conclusion: The prognostic model developed based on four clinical profiles: body mass index, bone mineral density, unilateral puncture, and bone cement leakage can be used to identify those at most risk of refracture after percutaneous kyphoplasty.

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.