Cement Leakage Research Articles

Comparative Efficacy of Three Minimally Invasive Procedures for Kümmell's Disease: A Systematic Review and Network Meta-Analysis.

BackgroundPercutaneous vertebroplasty (PVP), percutaneous kyphoplasty (PKP), and bone-filling mesh containers(BFC) are three viable minimally invasive techniques that have been used to treat Kümmell’s disease(KD). However, there is still debate as to which is safer and more effective. This study summarized the pros and cons of the three techniques in the treatment of KD through network meta-analysis(NMA).MethodsAll eligible published clinical control studies comparing PVP, PKP, and BFC for KD up to December 2021 were collected by online search of Cochrane Library, PubMed, Embase, CNKI, Wanfang Database, and Chinese biomedical literature database. Data were extracted after screening, and Stata 16.0 software was used to perform the network meta-analysis.ResultsFour randomized controlled trials (RCTs) and 16 retrospective case-control studies (CCTs) with a total of 1114 patients were included. The NMA results showed no statistical difference between the 3 procedures in terms of improving patients’ clinical symptoms. PKP was most likely to be the most effective in correcting kyphosis, while BFC was likely to be the most effective in managing the occurrence of cement leakage. No statistical differences were found in the incidence of new vertebral fractures in adjacent segments.ConclusionsRanking analysis showed that BFC has the highest likelihood of being the optimal procedure for the treatment of KD, based on a combined assessment of effectiveness in improving patients’ symptoms and safety in the occurrence of adverse events.

Comparison of vesselplasty and percutanous kyphoplasty in the treatment of Kümmell disease

To compare the efficacy between vesselplasty and percutanous kyphoplasty (PKP) in the treatment of Kümmell disease. The clinical data of patients with Kümmell disease from July 2018 to December 2019 were retrospectively analyzed. According to the different therapeutic methods, the patients were divided into vesselplasty group and PKP group. There were 20 patients in vesselplasty group, including 2 males and 18 females, aged from 54 to 83 years with an average of (67.40±7.44)years, 1 case of T10 fracture, 3 cases of T12 fracture, 9 cases of L1 fractures, 5 cases of L2 fractures and 2 cases of L3 fractures. There were 20 patients in PKP group, including 3 males and 17 females, aged from 56 to 81 with an average of(67.20±7.01) years, 2 cases of T10 fracture, 1 case of T11 fracture, 6 cases of T12 fracture, 10 cases of L1 fracture and 1 case of L3 fracture. Visual analogue scale(VAS), Cobb angle, anterior vertebral height were recorded before operation, 1 day after operation and 1 year after operation. Oswestry Disability Index(ODI) was recorded before operation, 1 month after operation and 1 year after operation. And bone cement leakage rate was compared between two groups after operation. All the patient were followed up for more than 1 year. In vesselplasty group, VAS score was 1.20±0.41, ODI was(13.50±3.10)%, Cobb angle was(17.20±3.12)° and anterior vertebral height was(20.20±1.35) mm at 1 year after operation. In PKP group, VAS score was 1.15±0.40, ODI was (13.20±3.00)%, Cobb angle was (17.10±3.19)° and anterior vertebral height was (20.10±1.37) mm at 1 year after operation. These index was significantly better than pre-operation through intra-group comparison(P<0.05), and there was no statistically difference between the two groups(P>0.05). There were 20 cases (20 vertebrae) in vesselplasty group, of which 1 case had bone cement leakage at the upper endplate, with a leakage rate of 5%(1/20). In PKP group, there were 20 cases (20 vertebrae), 3 cases of upward endplate leakage(3/7), 1 case of downward endplate leakage(1/7), 1 case of leakage to the front of the vertebral body(1/7), 2 cases of leakage to the side of the vertebral body(2/7), with a leakage rate of 35% (7/20). The difference between two groups was statistically significant(P<0.05). Vesselplasty in the treatment of Kümmell disease can better reduce leakage rate of bone cement and reduce complications.

Effect of bone cement distribution on the clinical outcome of unilateral transpedicular puncture for spinal osteoporotic fractures

To investigate the effects of different bone cement morphology distribution on the clinical efficacy of unilateral percutaneous vertebroplasty(PVP) for spinal osteoporotic fractures. The clinical data of 66 patients with osteoporotic vertebral compression fractures received unilateral PVP treatment from January 2019 to April 2020 were retrospectively analyzed. There were 16 males and 50 females, including 83 vertebral bodies, 45 thoracic vertebrae and 38 lumbar vertebrae, and 55 patients with single-segment, 6 double-segment, 4 three-segment and 1 four-segment. The age ranged from 60 to 93 years with an average of (76.83±8.65) years. The included patients were admitted to hospital 1 to 10 days after onset, and were diagnosed by anteroposterior and lateral X-rays, MRI and bone density examination before surgery. According to the shape of bone cement in postoperative X-ray, the patients were divided into O-shaped group (28 cases) and H-shaped group (38 cases). In O-shaped group, the bone cement presented agglomeration mass distribution in the affected vertebra in postoperative X-ray while the bone cement presented disseminated honeycomb distribution in the affected vertebrae in H-shaped group. Bone cement injection volume was collected in two groups. The intraoperative bone cement leakage and postoperative adjacent vertebral fractures were observed. The VAS of the two groups before operation and 1 day, 1 month, 6 months and 1 year after operation were compared;and ODI of the two groups 1 day, 6 months and 1 year after operation were compared. The kyphosis angle and anterior height of the affected vertebrae were measured before operation and 1 week, 1 year after operation. All 66 patients completed 1-year follow-up, and all patients healed well at the puncture site after surgery. There were 1 case and 8 cases of bone cement leakage in O-shaped group and H-shaped group during surgery respectively (P<0.05), but no serious complications occurred. One case occurred adjacent vertebral fracture in both groups during one-year follow-up (P>0.05). There was no statistical significance in injection amount of bone cement between the two groups (P>0.05). The VAS scores of O-shaped group and H-shaped group were 7.89±0.79, 2.75±1.08, 0.46±0.58, 0.36±0.49 and 8.00±1.04, 2.58±1.15, 0.53±0.56, 0.42±0.50 before operation, 1 day, 6 months, 1 year after operation respectively, and there was no statistical significance(P>0.05), and the VAS scores were 0.96±0.58 and 1.18±0.83 at 1 month after operation respectively, with statistical significance(P<0.05). The ODI scores of O-shaped group and H-shaped group were 12.43±3.78, 10.00±2.46, 8.43±1.50 and 12.11±3.68, 9.53±2.35, 8.32±1.51 at 1 day, 6 months and 1 year after surgery respectively, and there was no statistical significance between the two groups(P>0.05). There were no statistical significance in kyphotic angles and anterior height before surgery and 1 week, 1 year after surgery between two groups (P>0.05). No matter the distribution of bone cement is O-shape or H-shape, it can achieve good clinical effect, and the prognosis effect is equivalent. Therefore, when performing unilateral puncture PVP surgery, it is not necessary to deliberately increase the puncture angle of the puncture needle in order to achieve the full diffusion of the affected vertebrae, so as to reduce the risk of damaging important structures and bone cement leakage.

Cement augmentation in spinal surgery

Bone cement has been used in spinal surgery for as long as 50years. In contemporary spinal surgery, cement augmentation of fractured osteoporotic vertebrae in the form of vertebroplasty/kyphoplasty as well as cement augmentation of pedicle screws in instrumented procedures of any etiology are established as standard procedures. Both procedures are very effective, although the benefits of vertebroplasty/kyphoplasty procedures have been controversially discussed in the past. Overall, complications rarely occur. The most relevant complication is cement leakage, which is asymptomatic in the majority of cases but in the worst case might lead to neurological deficits, embolic events and even circulatory collapse. Prevention of cement leakage is therefore crucial. Risk factors for cement leakage and preventive measures are presented in acomprehensive review based on the available literature.

Safety and Efficacy of Bone Cement (Spinofill®) for Vertebroplasty in Patients with Osteoporotic Compression Fracture : A Preliminary Prospective Study.

ObjectiveAlthough several commercialized bone cements are used during percutaneous vertebroplasty (PVP) for patients with osteoporotic vertebral compression fracture (OVCF), there are no reports using domestic products from South Korea. In this study, we investigated the safety and efficacy of Spinofill® (Injecta Inc., Gunpo, Korea), a new polymethyl methacrylate product. MethodsA prospective, single-center, and single-arm clinical trial of 30 participants who underwent PVP using Spinofill® for painful thoracolumbar OVCF was performed with 6-months follow-up. Clinical and surgical outcomes included the Visual analog scale (VAS), Korean-Oswestry disability index (K-ODI), and Odom’s criteria, complication rate, and recurrence rate. Radiological outcomes were evaluated by measuring the findings of postoperative computed tomography and simple radiograph. ResultsThe pain of VAS (from 8.95±1.05 to 4.65±2.06, p<0.001) and the life quality based on K-ODI (from 33.95±5.84 to 25.65±4.79, p<0.001) improved significantly, and successful patient satisfaction were achieved in 20 patients (66.7%) 1 day after surgery. These immediate improvements were maintained or more improved during the follow-up. There was no surgery- or product-related complications, but OVCF recurred in two patients (6.7%). Favorable cement interdigitation was reported in 24 patients (80.0%), and extra-vertebral cement leakage was reported in 13 patients (43.0%). The mean vertebral height ratio (from 60.49%±21.97% to 80.07%±13.16%, p<0.001) and segmental kyphotic angle (from 11.46°±8.50° to 7.79°±6.08°, p=0.002) improved one day after surgery. However, these short-term radiological findings somewhat regressed at the end. ConclusionThe overall outcomes of PVP using Spinofill® were as favorable as those of other conventionally used products.

Improved Method for Testing Integrity Loss of Wells with Sustained Casing Pressure

The pressure bleed-down/build-up (B/B) testing is enforced by the Bureau of Safty and Environmental Enforcement (BSEE) regulations in the US for gas-leaking wells with recurrent casing head annular pressure dubbed “Sustained Casing Pressure” (SCP). The bleed down test involves bleeding the pressure with a needle valve. Once the pressure reached to zero or stabilized, the valve is closedand a 24-h pressure monitoring starts. Analysis of the tests mandated by regulations involves merely a qualitative assessment of the low or high level of environmental risk measured by leak size. A quantitative analysis—based on mathematical models—has been already proposed and used for sizing cement leaks but the models give ambiguous results due to oversimplifying assumptions of the cement leak system and disregard for the testing procedure. This work addresses shortcomings of the current B/B testing and analysis methods by approaching the testing procedure as a source of useful information about the system of annular well leakage. We demonstrate that using a mathematical model for globally matching all stages of the B/B test data would prioritize the pressure bleed-down stage over the buildup stage thus making the latter stage mostly irrelevant in providing information on the whole gas migration system. We verify the hypothesis that a stage-wise analysis would improve the results by separately considering three stages of the B/B test: pressure bleed down, constant flow (steady-state), and pressure buildup, and, then, comparatively reconciling values of the system parameters. The stage-by-stage approach is feasible because—as shown by the sensitivity analysis—each stage is controlled mostly by a single parameter. Also presented is the development of an improved procedure for performing the B-B test. The study shows that the operational parameters controlled by the test operator—duration and size of the needle valve opening, and pressure recording time step, might significantly change values of the test output—the minimum bleed down, and the maximum 24-h buildup pressures. It is also found that the zero bleed-down pressure does not necessarily indicate that the leak is small as it also depends upon the length and properties of the annular fluid column above the cement top.

Risk factors for recollapse of new vertebral compression fractures after percutaneous kyphoplasty in geriatric patients: establishment of a nomogram

BackgroundThe main objective of this study was to investigate the risk factors for recollapse of new vertebral compression fractures (NVCFs) after percutaneous kyphoplasty (PKP) treatment for osteoporotic vertebral compression fracture (OVCF) and to construct a new nomogram model.MethodsWe retrospectively analysed single-level OVCFs from January 2017 to June 2020, randomizing patients to a training set and a testing set. In the training set, independent risk factors for NVCFs in OVCF patients treated with PKP were obtained by univariate and multivariate regression analyses. These risk factors were then used as the basis for constructing a nomogram model. Finally, internal validation of the built model was performed in the testing set using the consistency index (C-index), receiver operating characteristic (ROC) curves, calibration curves and decision curve analysis (DCA).ResultsIn total, 371 patients were included in this study. NVCFs occurred in 21.7% of the training set patients, and multivariate regression analysis showed that a low Hounsfield unit (HU) value, cement leakage, and thoracolumbar (TL) junction fracture were independent risk factors for NVCF after PKP. The C-index was 0.81 (95% CI: 0.74–0.81), and the validation showed that the predicted values of the established model were in good agreement with the actual values.ConclusionsIn this study, three independent risk factors were obtained by regression analysis. A nomogram model was constructed to guide clinical work and to make clinical decisions relatively accurately to prevent the occurrence of vertebral recollapse fractures.

Therapeutic Efficacy of Third-Generation Percutaneous Vertebral Augmentation System (PVAS) in Osteoporotic Vertebral Compression Fractures (OVCFs): A Systematic Review and Meta-analysis.

Purpose This study aimed to assess whether the third-generation PVAS was superior to percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP) in treating patients with OVCFs. Methods Databases, including Pubmed, Embase, and Cochrane library, were searched to identify relevant interventional and observational articles in vivo or in vitro comparing the third-generation PVAS to PVP/PKP in OVCFs patients. A meta-analysis was performed under the guidelines of the Cochrane Reviewer's Handbook. Results 11 in vivo articles involving 1035 patients with 1320 segments of diseased vertebral bodies and 8 in vitro studies enrolling 40 specimens with 202 vertebral bodies were identified. The vivo studies indicated no significant differences were found in visual analog scale (VAS), Oswestry Disability Index (ODI), operation time, or injected cement volume (P > 0.05). The third-generation PVAS was associated with significant improvement in vertebral height and Cobb angle (P < 0.05) and also with a significantly lower risk of cement leakages and new fractures (P < 0.05). The vitro studies suggest that the third-generation PVAS was associated with better anterior vertebral height (AVH) and kyphotic angle (KA) after deflation and cement. No significant differences were found in stiffness or failure load after cement between the two groups (P > 0.05). Conclusion Based on current evidence, although providing similar improvement in VAS and ODI, the third-generation PVAS may be superior to PVP/PKP in local kyphosis correction, vertebral height maintenance, and adverse events reduction. Further high-quality randomized studies are required to confirm these results.

Establishment and Validation of a Nomogram for the Risk of New Vertebral Compression Fractures After Percutaneous Vertebroplasty in Patients With Osteoporotic Vertebral Compression Fractures: A Retrospective Study.

PurposeNew vertebral compression fractures(NVCFs) after minimally invasive surgery in patients with osteoporotic vertebral compression fracture (OVCF) is a challenging issue worldwide. Predicting the occurrence of NVCFs is key to addressing such questions. Therefore, we aimed to investigate the risk factors for patients who developed NVCFs after undergoing surgical treatment and establish a nomogram model to reduce the occurrence of NVCFs.MethodsThis study is a retrospective analysis that collected the general characteristics and surgical features of patients who underwent surgical treatment at 2 central institutions between January 2017 and December 2020. Patients were divided into training and testing sets based on the presence or absence of NVCFs. Independent risk factors for NVCFs were obtained in the training set of patients, and then a nomogram model was constructed. Internal and external validation of the nomogram model was performed using the consistency index (C index), receiver operating characteristic curve(ROC), calibration curves, and decision curve analysis (DCA).ResultsA total of 562 patients were included in this study. Patients from the first center were used for nomogram construction and internal validation, and patients from the second center were used as an external validation population. Multivariate regression analysis showed that age, Hounsfield unit (Hu) value, cement leakage, and thoracolumbar (TL) junction fracture were independent risk factors for NVCFs after minimally invasive surgery. The C index was .85, and the validation of internal and external validation shows that the predicted values of the established model is in good agreement with the actual values.ConclusionsIn this study, 4 independent risk factors were obtained by regression analysis, and a nomogram model was constructed to guide clinical work. The application of this model can help surgeons to make more accurate judgments to prevent the occurrence of NVCFs.

Clinical effect of unilateral balloon infusion of low dose bone cement in PKP for osteoporotic thoracolumbar compression fractures in the elderly.

The study was undertaken to determine the clinical effectiveness of percutaneous kyphoplasty (PKP) with unilateral balloon infusion of low dose of bone cement for treatment of osteoporotic vertebral compression fractures (OVCFs) in the elderly. A retrospective study was carried out. A total of 36 patients with OVCFs treated by PKP from August 2019 and August 2020 were included. Patients were divided into two groups according to the amount of bone cement infused into the vertebral body. The amount of cement in conventional-dose group was 3.5-6.0 mL and the amount of cement in small-dose group was 1.8-3.0 mL. Pain relief before and after the operation were evaluated, and the leakage of bone cement in the two groups was also observed. Two groups of patients have obtained a good clinical efficacy. Pain has significant differences before and after the operation (p < 0.05). More importantly, compared with conventional-dose group, small-dose group has lower bone cement leakage rate (p < 0.05). PKP with small-dose bone cement infusion can obtain the same clinical effects of conventional-dose, but the incidence of bone cement leakage is lower and safe.

Comparison of Unipedicular and Bipedicular Percutaneous Kyphoplasty for Kummell's Disease.

Objective:To compare the clinical efficacy of unipedicular and bipedicular percutaneous kyphoplasty (PKP) for Kummell’s disease.Methods:A retrospective study was performed to review 40 patients with stage I and II Kummell’s disease who underwent PKP in our hospital from January 2015 to June 2018. Based on the transpedicular approach of PKP, those patients were randomly divided into unipedicular group (n = 19) and bipedicular group (n = 21). Operative time, bone cement injection volume and cement leakage rate were compared in the two groups. Pre- and post-operative visual analogue score (VAS), local kyphotic angle and average vertebral height were also evaluated.Results:All patients underwent surgery successfully. Compared with preoperative condition, VAS was significantly decreased at 1 day after operation and the last follow-up in both groups (P < .05), and local kyphotic angle and average vertebral height were restored markedly (P < .05). Operative time of both groups had no significant difference (P > .05). Bone cement injection volume was larger in bipedicular group (P < .05). At 1 day after operation and the last follow-up, the local kyphotic angle and average vertebral height in bipedicular group were restored better than those in unipedicular group (P < .05). There were 4 cases of cement leakage in both groups, with leakage rates of 21.1% and 19.0%, respectively, and the difference was not significant (P > .05).Conclusion:Both unipedicular and bipedicular PKP are effective for treating patients with stage I and II Kummell’s disease, while postoperative pain relief and imaging results in bipedicular group were better than those in unipedicular group.

Multilevel Percutaneous Fenestrated Screw Fixation with Bone Cement Augmentation in Adult Lumbar Spinal Deformity

Objective: Fenestrated screw fixation with bone cement augmentation has been demonstrated to increase the pullout strength. Bone cement augmentation is performed to prevent screw failure. Although bone cement screw fixation and fenestrated screw fixation have been compared in many studies, there has been no study on the clinical effects and complication in long level percutaneous bone cement screw fixation. The study aimed to investigate the safety and efficacy of multilevel percutaneous fenestrated screw fixation with bone cement augmentation in the adult lumbar spinal deformity.Methods: We performed a retrospective study of 15 patients who underwent multilevel percutaneous fenestrated screw fixation (PFSF) with bone cement augmentation in a single spine surgeon between January 2018 and December 2020. The incidence of screw failure, body mass index (BMI), bone mineral density (BMD), past history, Visual analogue scale (VAS) score, Oswestry disability index (ODI), sagittal vertical axis (SVA), pelvic Tilt (PT), pelvic incidence (PI), sagittal slope (SS), lumbar lordosis (LL) and Cobbs angle were investigated in the patients.Results: All patients underwent percutaneous screw fixation using a bone cement additive. Mean BMD was –2.0±0.8. The mean percutaneous fenestrated screw fixation level was 6. The mean VAS score changed from 7.14 preoperatively to 4.57 postoperatively (1 month after the surgery), to 3.71 at the last follow-up. The mean ODI changed from 45.21 preoperatively to 32.5 postoperatively, to 27.0 at the last follow-up. The mean LL changed from 23.6 preoperatively to 32.96 postoperatively, to 31.67 at the last follow-up. The mean PT changed from 32.67 preoperatively to 28.11 postoperatively, to 28.70 at the last follow-up. The mean PI - LL changed from 35.20 preoperatively to 22.56 postoperatively, to 22.76 at the last follow-up. The mean Cobb’s angle decreased from 18.30 preoperatively to 6.27 postoperatively, to 5.98 at the last follow-up. The mean SVA changed from 76.65 preoperatively to 46.15 postoperatively, to 48.46 at the last follow-up. The bony fusion rate was 73.3%. There were screw loosening in 4 patients, rod fracture in 1 patient and screw fracture in 3 patients. Among the 3 patients with screw fracture, 1 patient required reoperation. Cement leakage occurred towards the anterior body of the vertebrae in 2 patients but no symptoms were observed.Conclusion: Although the current study examined a small sample with relatively short term follow up periods, our study results demonstrate that multilevel PFSF with bone cement augmentation can result in good clinical and radiological outcomes for lumbar spinal deformity. However, larger size screws or smaller through-hole screws are required to prevent screw fracture.

Translated article] Efficacy of cement restrictors: Experimental study and development of a classification

IntroductionCement restrictors (CRs) are devices that allow occlusion of the femoral canal in order to obtain greater interdigitation of the cement between the bone and a better pressurization, which generates an increase in the survival of cemented stems. The aim of this study was to evaluate the efficacy of the different CRs used and propose a classification of this device. Materials and methodsAn experimental study was carried out, where 7 CR references of different designs and manufacturers were taken. Later, tests were carried out on 9 chlorinated polyvinyl chloride tubes for each reference, to achieve a total of 63 tests. ResultsIn our study, 34.9% of the CRs in ultra high molecular weight polyethylene failed, presenting migration and allowing cement to leak while none of the gelatin RC failed. ConclusionThe RC with an umbrella design proved to be the less effective, presented a higher incidence of migration and cement leakage, while the gelatin CRs were the best performers. Based on the results of this study, an analysis of the CR design was carried out and a classification was proposed that divides these devices into 2 types.

Extraction of cement leakages and malpositioned spindles complicating percutaneous interventions: why, when and how?

Cement leakages in soft tissues are a common occurrence during cementoplasty. They may cause chronic pain, and thus treatment failure. Spindle malposition during reinforced cementoplasty may cause vascular, nerve or cartilage injury. Our goal was to evaluate the rate of cement leakage/spindle extraction and describe the techniques used. This retrospective monocentre study included 104 patients who underwent reinforced cementoplasty and 3425 patients who underwent cementoplasty between 2012 and 2020. Operative reports and fluoroscopic images were reviewed to identify extraction attempts and their outcomes. Six patients (5.8%) had a malpositioned spindle, and all of them underwent spindle extraction during reinforced cementoplasty, with an 80% success rate. A total of 7 attempts were performed, using 2 different techniques. One thousand one hundred thirty patients (32%) had a cement leak in soft tissues, and 7 (0.6%) underwent cement leakage extraction during cementoplasty, with a 100% success rate. A total of 10 attempts were performed, using 3 different techniques. No major complication related to the extraction procedures occurred. Spindle malpositions and soft tissue cement leakages are not uncommon. We described 5 different percutaneous techniques that were safe and effective to extract spindles and paravertebral cement fragments. • Soft tissue cement leakages or spindle malpositions are a non-rare occurrence during cementoplasty, and may cause technical failure and/or chronic pain. • Most soft tissue cement fragments and malpositioned spindles can easily be extracted using simple percutaneous techniques.

Percutaneous Cement-Augmented Screws Short Fixation for the Treatment of Severe Osteoporotic Vertebral Burst Fractures

This study aims to evaluate the therapeutic reliability of posterior percutaneous cement-augmented screws short fixation (PASF) in patients with severe osteoporotic vertebral burst fractures (OVBFs). Single-level OVBFs with an anterior vertebral body height reduction ≥60% were included. A Frailty Index was used for preoperative frailty assessment. Back pain and related disability were assessed through the visual analog scale (VAS) and Oswestry Low Back Pain Disability Index (ODI), administered at injury time, preoperatively, postoperatively, at 12 months and at last patient follow-up evaluation. The main radiologic outcomes were represented by Cobb angle (CA) and anterior vertebral body compression percentage, measured at injury time, preoperative, postoperatively and at 12-month examination. In addition, the incidence of cement leakages and hardware failures was assessed. Thirty-three patients met the inclusion criteria. All patients were frail (76%) or semi-frail (24%). Significant vertebral body height restoration and segmental kyphosis improvement after PASF were documented (anterior vertebral body compression percentage, -40 [-43 to -37] vs. -67 [-70 to -65], P= 0.0001; CA, 10 [8-12] vs.24 [23-26], P= 0.0001). The mean VAS and ODI scores documented optimal and long-enduring pain relief and related disability reduction after PASF (VAS score, 2 [2-3] vs. 8 [7-8], P= 0.0001; ODI, 22 [17-26] vs. 64 [60-69], P=0.0001). Only 1 cement leakage (3%), asymptomatic, occurred. After a mean follow-up of 33 months, no early/late hardware failures were reported. The clinical and radiologic results of this study suggest that PASF could be a safe and effective treatment option for severe OVBFs when conservative treatments have failed.

A novel bone cement injector augments Chinese osteoporotic lumbar pedicle screw channel: a biomechanical investigation

BackgroundThe study aimed to (1) create a series of pedicle injectors with different number of holes on the sheath especially for the Chinese elderly patients and (2) further investigate the effects of the injectors on the augmentation of pedicle screw among osteoporotic lumbar pedicle channel.MethodsThis 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 elderly patients. Mechanical test experiments were performed on the bone cement injectors according to the 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-hole group, 6-hole group, and 8-hole group. 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 h 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 material testing system 858 (MTS-858) mechanical tester.ResultsThe 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 differences between the 4-hole, 6-hole, 8-hole, and straight pore groups were 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 group (217.29 ± 49.68 N), 6-hole group (228.39 ± 57.83 N), and straight pore group (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.ConclusionsThe 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.

Cement leakage in percutaneous vertebroplasty for spinal metastases: a retrospective study of risk factors and clinical outcomes

ObjectiveThe objective of this research was to investigate the risk factors of cement leakage in patients with metastatic spine tumors following percutaneous vertebroplasty (PVP).MethodsSixty-four patients with 113 vertebrae were retrospectively reviewed. Various clinical indexes, including age, sex, body mass index (BMI), smoking history, drinking history, chemotherapy history, radiotherapy history, primary cancer, location, other metastases, collapse, posterior wall defects, the laterality of injection, and the injected cement volume were analyzed as potential risk factors. Multivariate analyses were conducted to identify the independent risk factors.ResultsThe cement leakage was found 64 in 113 treated vertebrae (56.63%), in which the incidence of each type was shown as below: spinal canal leakage 18 (15.93%), intravascular leakage around the vertebrae 11 (9.73%), and intradiscal and paravertebral leakage 35 (30.97%). Tomita classification (P = 0.019) and posterior wall destruction (P = 0.001) were considered strong risk factors for predicting cement leakage in general. The multivariate logistic analysis showed that defects of the posterior wall (P = 0.001) and injected volume (P = 0.038) were independently related to the presence of spinal canal leakage. The postoperative visual analog scale (VAS) and activities of daily living (ADL) scores showed significant differences compared with the pre-operative parameters (P < 0.05). No significant differences were found in every follow-up time between the leakage group and the non-leakage group for pain management and improvement of activities in daily life.ConclusionIn our study, Tomita classification and the destruction of the posterior wall were independent risk factors for leakage in general. The defects of the posterior wall and injected volume were independently related to the presence of spinal canal leakage. The PVP procedure can be an effective way to manage the pain.

Radiofrequency Ablation and Augmentation in the Management of Spinal Metastases: Clinical Experience in 41 Patients

To evaluate functional outcome after combined radiofrequency ablation and vertebral augmentation in patients with metastatic spinal tumors using visual analog scale and Oswestry Disability Index scores. This retrospective study included 41 patients with metastatic spinal tumors. There were 19 women and 22 men with a mean age of 67 years (range, 45-87 years). Visual analog scale and Oswestry Disability Index were used to assess the intensity of pain and quality of life. The assessments were performed before the procedure and at 1 week and 1, 2, 3, and 6 months after the procedure. No serious complications were seen in the periprocedural period. Two patients (4.8%) had transient neurological motor deficits without cement leakage, and 1 patient had a pulmonary embolism with transient mild symptoms. The comparison of preprocedural visual analog scale and Oswestry Disability Index scores with postprocedural scores up to 6 months after treatment revealed significant pain control and good functional state. Spinal metastasis is a frequent entity in the growing population of patients with cancer. A multidisciplinary approach using several nonsurgical and minimally invasive methods (e.g., radiofrequency ablation, vertebroplasty, balloon kyphoplasty) is key to successful management, and combining these procedures is effective against spinal metastatic pain.

Whether the Unilateral Transverse Process-pedicle Approach has Advantages over the Traditional Transpedicle Approach: A Systematic review and Meta-analysis.

To summarize the literature and compare the advantages and disadvantages of the unilateral transverse process-pedicle approach (UTPA) and conventional transpedicular approach (CTPA) vertebral augmentation in the treatment of osteoporotic vertebral compression fractures (OVCF). A single researcher performed a systematic literature review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Online scientific databases were searched in September 2021 for English- and Chinese-language publications. A series of comparative studies were included, with UTPA as the main intervention and CTPA as the comparison indicator. A meta-analysis was performed for studies that reported clinical outcome indicators. The χ2 was used to study heterogeneity between trials, and the I2 statistic was calculated to estimate variation across studies. A total of eight studies were included for meta-analysis, all of which were observational studies with mixed bias risk. There were 613 subjects in the UTPA group and 488 subjects in the CTPA group. The results of the meta-analysis showed that there was no difference between the UTPA group and the CTPA group in terms of visual analogue scale scores (p=0.31), Oswestry Disability Index scores (p=0.50), correction of kyphosis angle (p=0.65), and the amount of bone cement (p=0.13), but the UTPA group had a shorter operative time (p<0.001), bone cement leakage rates (p=0.02), and fluoroscopy times than the CTPA group (p<0.001). Partial analysis results had a high risk of bias, and the most common source of bias was that there was high heterogeneity between studies, and the sensitivity can only be reduced by a random effect model, and some studies (four items) did not clearly describe the confounders that they controlled. The limited evidence obtained in this study proves that the new puncture method does not have more advantages than the traditional technique, so it is no longer meaningful to continue to obsess over the impact of the puncture method on surgical outcome.

Association between bone turnover markers, BMD and height loss of cemented vertebrae after percutaneous vertebroplasty in patients with osteoporotic vertebral compression fractures

IntroductionPercutaneous vertebroplasty (PVP) was recently performed for treating patients with osteoporotic vertebral compression fractures (OVCF). However, recompression of cemented vertebra with significant vertebral height loss occurred in the patients after PVP was observed during the follow-up period. The purpose is to explore the risk factors among several potential predictors for the height loss of treated vertebral bodies after PVP in patients with OVCF.MethodsA study of 93 patients who had undergone PVP between May 1, 2016, and March 1, 2019, at the Spine Center of Huadong Hospital Affiliated to Fudan University was conducted. The fractured vertebral height loss ratio ≥ 15% at final follow-up were defined as cemented vertebra recompression. The following variables were measured and collected: age, gender, body mass index (BMI), bone mineral density (BMD), volume of bone cement injected, bone cement leakage, fractured vertebra segment, contact between bone cement and endplates, serum of calcium and phosphorus, and six kinds of bone turnover markers.ResultsMann–Whitney U test and Univariate Logistic regression analysis showed that the cemented vertebra recompression was correlated with BMD, contact between bone cement and endplates, parathyroid hormone (PTH), and 25-hydroxy vitamin D3 (25-OH-D3). Following multivariate modeling, multiple factors logistic regression elucidated that high BMD (P < 0.001, OR = 0.089) and high level of serum 25-OH-D3 (P = 0.012, OR = 0.877) were negatively correlated with the cemented vertebra recompression after PVP.ConclusionDecreased BMD and lower level of serum 25-OH-D3 might be two critical and significant risk factors for the height loss of cemented vertebrae after PVP.