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Background 30% of myeloma patients suffer from vertebral compression fractures (VCF). Consequently, augmentation often becomes inevitable to prevent further problems. This study evaluated the interaction of radiation therapy (RT) and radiofrequency kyphoplasty (RFK) in the treatment of myeloma associated VCF. Methods Eighty-six myeloma patients with VCF were treated with RFK followed by radiation therapy (RFK group) or vice versa (RT group). Visual analgoue scale (VAS), Oswestry-Disability-Index (ODI), vertebral height and kyphosis angle were assessed preoperatively, 3-4 days, 3 and 6 months postoperatively. Adverse events like cement leakage or additional fractures were documented. Results Both groups achieved comparable outcomes, but the course of VAS and kyphosis angle differed. Early postoperative kyphosis angles improved significantly in the RFK group, but significantly worsened afterwards. The RT group showed a trend towards significantly improvement postoperatively and minor worsening afterwards. VAS remained constant in the RT group and worsened in the RFK group after 6 months. More cement leakages and additional fractures were noted in the RT group. Conclusions RFK is an effective method for treating VCF in myeloma patients independent of treatment order with regard to radiation therapy. However, RT should be conducted after RFK to minimize risks of cement extrusion and additional fractures.

Study design A retrospective study. Summary of background data Cement leakage is a frequent occurrence in vertebroplasty and is also the main source of complications. Continuous radiographic evaluation is mandatory to detect cement leakage during injecting cement into the vertebral body, while the operator is subjected to x-ray radiation exposure. Objective The aim of this study was to evaluate the feasibility and safety of vertebroplasty performed on patients and operators for the treatment of osteoporotic and malignant vertebral compression fractures using a remote control injection system. Materials and methods Institutional review board approval was obtained for this retrospective study. Clinical charts and postoperative radiographs were obtained for 74 patients (114 levels) who underwent vertebroplasty. The study group included 46 cases (71 levels) of benign osteoporotic fractures and 28 cases (43 levels) of different malignant metastatic lesions. Under fluoroscopic guidance, cement was injected using a remote control injection system, while the operator was standing outside the radiation field. The location and degree of leakage at each treated level were recorded. Results Cement leakage rate reached 47.4% across all treated levels. No severe leakage in any location was observed. A total of 35 leakages were detected in 71 levels and 24 leakages were detected in 43 levels in the benign and malignant fracture group, respectively. The overall rate of cement leakages and the location of the leakages were not statistically different between the benign and malignant fracture group (P=0.60, P=0.45). With the operator standing outside the radiation field to inject cement, the radiation dose to operators was avoided during cement injection. Conclusions Vertebroplasty using a remote control injection system was feasible and safe in treatment of osteoporotic and malignant compression fractures. The cement injection system had potential benefits to decrease the leakage rate in treating malignant fractures and eliminate injection dose to operators under lateral fluoroscopic monitoring.

PURPOSE Cement leakage and adjacent vertebral fractures are not uncommon after percutaneous augmentation. However, conclusive identification of risk factors for postprocedural complications remains elusive. The anticipation of leakage and successive fractures through the identification of risk factors will help physicians better inform patients of potential complications and establish procedural refinements key to risk reduction. The aim of this retrospective study was to summarize available reports of the risk factors for cement leak and adjacent vertebral fracture in or after kyphoplasty for osteoporotic vertebral compression fractures. METHODS A total of 102 cases of bilateral percutaneous kyphoplasty (PKP), performed between January 2014 and December 2016, were retrospectively reviewed. Each case surveyed in this review included a minimum 1-year follow-up and data on age, sex, bone mineral density, Visual Analog Scale score, preoperative compression rate, kyphotic angle, treatment time, the volume of cement, and the intactness of the vertebral posterior wall (computed tomography scan) were collected. Pearson χ test and independent samples test were used to determine the relative risk factors of cement leak and adjacent vertebral fracture in patient subsets. RESULTS Diabetic status and alteration in the Cobb angle after PKP exhibited a statistically significant correlation with the incidence of new adjacent vertebral fracture (group B) (P

BackgroundOsteolytic lesions of the atlas (C1) are challenging to treat by vertebroplasty due to the vicinity of the vertebral artery and the spinal cord.ObjectiveTo present our experience with transoral vertebroplasty (TOV) for osteolytic lesions of the lateral mass of the atlas.MethodsRetrospective case series involving 15 consecutive patients (nine male, six female, mean age 63 years) who underwent TOV for the treatment of an osteolytic lesion of the lateral mass of the atlas. Among the osteolytic lesions, 10/15 (67%) were bone metastases from various cancers; 4/15 (27%) were lesions related to multiple myeloma; and one lesion (7%) was an aggressive hemangioma. All the TOVs were performed under general anesthesia and in most cases (10/15; 67%) in a hybrid angiosuite combining a C-arm flat panel and a CT scan. The remaining five patients were treated under biplane fluoroscopic guidance.ResultsVertebroplasty of the lateral mass of C1 through a transoral route was feasible in all cases. Significant pain relief was obtained in most cases (1 month average decrease in Numeric Rating Scale: 4.9±4.1). No major complication was recorded. In 7/15 cases (47%), cement leakage surrounding the C1 lateral mass was seen; none of these leakages had a significant clinical consequence. No additional spine surgery was required in any of the patients.ConclusionTOV of osteolytic lesions of the lateral mass of the atlas is feasible and seems safe and effective, providing pain relief and bone stabilization.

Background: The purpose of this study was to review recent research related to the analgesic effect of ablation therapy combined with cementoplasty, as well as to identify the duration of analgesic effect and risk for cement leaks. Methods: A systematic literature search using PubMed, Web of Science, and annual meeting proceedings of the oncology society and other organizations were conducted. Results: Twelve retrospective studies met the inclusion criteria. Four of the studies included in the review assessed the changes immediately after treatment. Five studies were subjected to analyses of analgesic effect of combined percutaneous thermal ablation and Cementoplasty at 24 weeks after treatment. Incidences of leakage of bone cement during surgery were detected in 4 out of 12 studies. The change of mean pain scores at 1 days, at 1 week, and at 4 weeks, 12 weeks, and 24 weeks after treatment were −3.90 (95% CI: −4.80 to −3.00), −4.55 (95% CI:−5.46 to −3.64), −4.78 (95% CI: −5.70 to −3.86), −5.16 (95% CI: −6.39 to −3.92), and −5.91 (95% CI: −6.63 to −5.19). The relative risk of cement leakage was 0.10 (95% CI: −6.63 to −5.19). Conclusions: Our systematic review suggested that thermal ablation combined with cementoplasty could be a safe and effective intervention for the management of bone metastases-induced pain. Keywords: Thermal ablation, Cementoplasty, Bone metastases, Analgesia, Pain management, Palliative care

Objective To evaluate the clinical effect of the second puncture and injection technique during a percutaneous vertebroplasty (PVP) procedure. Methods Patients treated with a second puncture and injection (group A) or a single puncture and injection (group B) during PVP at our institution during 2010–2017 were reviewed. Vertebral height loss, visual analogue scale (VAS) score, Oswestry disability index (ODI), adjacent vertebral fractures, and cement leakage were compared between the groups. Results A total of 193 patients were enrolled (86 cases in group A, 107 cases in group B). The follow-up period was 15.64 (12–20) months. The loss of anterior (group A 0.01 ± 0.03; group B 0.14 ± 0.17) and middle (group A 0.13 ± 0.12; group B 0.16 ± 0.11) vertebral height in group B was significantly higher than that in group A (P < 0.05). The VAS score and ODI were also significantly higher in group B than in group A at the final follow-up; the VAS score and ODI in group B were 1.65 ± 0.70 and 14.50 ± 4.16, respectively, and those in group A were 1.00 ± 0.74 and 12.81 ± 4.02, respectively (P < 0.05). Three patients in group A and two in group B experienced adjacent vertebral fractures. Regarding mild, moderate, and severe cement leakage, there were 25 (29%), 5 (5%), and 0 cases, respectively, in group A and 28 (26%), 3 (2.8%), and 1 (0.009%) case, respectively, in group B (P > 0.05). Conclusions The second puncture and injection technique may effectively increase the dispersion of cement, thus preventing recompression of the cemented vertebral body, and it does not increase the risk of cement leakage or adjacent vertebral fracture.

Background Vertebral compression fracture is one of the most common complications of osteoporosis. In this study an unilateral curved vertebroplasty device was developed, and the safety, effectiveness, and surgical parameters of curved vertebroplasty (CVP) in the treatment of painful osteoporotic vertebral compression fractures was investigated and compared with traditional bipedicular vertebroplasty (BVP). Methods We investigated 104 vertebral augmentation procedures performed over 36 months. CVP and BVP procedures were compared for baseline clinical variables, pain relief (Visual Analog Scale, VAS), disability improvement (Oswestry Disability Index, ODI), operation time, number of fluoroscopic images, volume of cement per level, and cement leakage rate for each level treated. Complications and refracture incidence were also recorded in the two groups. Results The VAS and ODI in both group had no significant difference preoperative (P > 0.05), and a significant postoperative improvement in the VAS scores and ODI was found in both group (P P 0.05). Neither group had any serious complications. Five and two patients in the BVP group developed refractures at non-adjacent and adjacent levels, respectively, with one patient developing refractures twice; however, none of the patients in the CVP group developed refractures at any level. Conclusions Our findings revealed that both CVP and BVP were safe and effective treatments for osteoporotic vertebral compression fractures, and CVP entails a shorter operation time, less exposure to fluoroscopy, and lower rate of cement leakage.

Background Foraminal stenosis, a common disorder occurring in elderly patients, is often caused by narrowing of the foramen, resulting in the confinement of neural structures by the tissue and vertebrae. Full-endoscopic lumbar foraminoplasty (FELF) is an effective treatment option for patients with foraminal stenosis. However, to the best of our knowledge, no previous study has reported the treatment of symptomatic cement leakage. We report a case of symptomatic cement leakage treated with FELF with the patient under local anesthesia. Case Description An 85-year-old woman was admitted to our spine unit because of lower back pain. The patient had presented with lower back pain and new-onset left thigh pain after vertebroplasty performed 3 months previously. The patient was not able to walk and was bedridden. To overcome this problem, T12 percutaneous vertebroplasty and left transforaminal L3-L4 foraminoplasty was performed with the patient under local anesthesia. After surgery, the patient was able to walk and was discharged 4 days postoperatively. Conclusion The present report has shown that FELF can successfully remove symptomatic cement leakage, resulting in pain relief.

To evaluate and compare clinical outcomes and cement leakage of high-viscosity bone cement versus low-viscosity bone cement vertebroplasty in treating osteoporotic vertebral compression fractures with intravertebral cleft.The study included 72 patients with osteoporotic vertebral compression fractures with intravertebral cleft, who were divided into high-viscosity cement (HVC) (38 cases) and low-viscosity cement (LVC) (34 cases) groups according to the viscosity of bone cement used. Cement leakage, visual analog scale score, Oswestry Disability Index, and kyphotic angle (KA) were evaluated.All patients were followed for at least 12 months. Overall cement leakage rate was 18.4% in the HVC group, lower than the rate of 61.8% obtained in the LVC group. A statistically significant difference was found in the overall cement leakage rate between the groups (P0.05). Visual analog scale and Oswestry Disability Index scores were significantly improved after percutaneous vertebroplasty without significant differences between the HVC and LVC groups (P0.05). The KA of patients from both groups was also significantly corrected immediately after surgery. Although the KA gradually increased in both groups during the follow-up period, there was no statistically significant difference between the HVC and LVC groups in KA during follow-up (P0.05).Percutaneous vertebroplasty using HVC to treat osteoporotic vertebral compression fractures with intravertebral cleft significantly reduces cement leakage and improves the safety of the operation. In terms of clinical efficacy and prevention of augmented vertebral recollapse, HVC may not have obvious advantages.

BACKGROUND: Our purpose was to evaluate the efficacy of the extrapendicular approach for unilateral percutaneous vesselplasty in dealing with Kummell disease patients. METHODS: Twenty-seven patients undergoing vesselplasty at our institution were enrolled in the study. Vesselplasty was performed using percutaneous extrapendicular technique. Pain, restoration of vertebral body height, and cement leakage were evaluated in the process. RESULTS: Substantial pain relief was attained in all the patients. The visual analogue scale improved significantly from pre- to postoperation (P

Percutaneous vertebroplasty (PVP) is a minimally invasive treatment that has been widely used for the treatment of osteoporotic vertebral compression fractures and vertebral tumors. However, the maximum number of vertebral segments treated in a single PVP remains controversial. Furthermore, PVP may cause complications, including cement leakage, pulmonary embolism, bone cement toxicity, and spinal nerve-puncture injury. We report the rare case of a patient who underwent multilevel PVP for vertebral metastases, with no bone cement leakage or spinal cord injury, but who developed temporary paraparesis.

Highlights • Cement leak is common for percutaneous vertebroplasty in metastatic spinal disease. • A proposed and validated algorithm can screen patients with high cement leak risk. • The algorithm included four significant characteristics. • The validation group AUROC was 0.69, and the goodness-of-fit test P-value was 0.50., Objectives To investigate the epidemiology of cement leaks and further develop an algorithm to detect the high risk of cement leaks among advanced cancer patients with metastatic spinal disease treated with percutaneous vertebroplasty. Methods This study retrospectively analyzed 309 patients with metastatic spinal disease treated with percutaneous vertebroplasty. Patients were randomly divided into a training group and a validation group. In the training group, 13 potential characteristics were analyzed for their abilities to predict cement leaks. Discal cement leakage and paravertebral cement leakage were excluded from the analysis. Those characteristics identified as having significant predictive value were used to develop a predictive algorithm. Internal validation of the algorithm was performed based on discrimination and calibration qualities. Results Overall, cement leaks occurred in 61.17% (189/309) patients. Among the 13 characteristics analyzed, younger age (P = 0.03), extravertebral bone metastases (P = 0.02), increased number of treated vertebrae levels (P

Background A uperior adjacent vertebral fracture (SAVF) is a common complication after kyphoplasty. Intra-disc leakage is a significant risk factor of SAVF. However, to date, no studies on the prevention of SAVF after intra-disc leakage have been conducted. This study sought to evaluate the clinical outcome of prophylactic vertebral augmentation in high-risk patients, and explore the other risk factors of SAVF. Methods Of 2,571 patients who received kyphoplasty, 82 with intra-disc leakage were retrospectively enrolled in the study, and divided into 2 groups based on whether they had a superior level of prophylactic vertebral augmentation. To ensure that any possible early complications were examined, there was a minimum follow-up period of 12 months. Results The pre-operation parameters were comparable between the 2 groups. In the non-prophylactic group, 9 of 59 (15.3%) patients had SAVF superior to the level of intra-disc leakage. Of these 9 SAVF cases, 8 fractures (88.9%) occurred within 6 months after surgery. Overall, 14 (23.7%) patients developed a new fracture. In the prophylactic group, no patients had a SAVF (0.0%), but 3 (13.0%) had remote fractures (P=0.047 and 0.284). No complications were associated with vertebral augmentation. Further, the risk factor analysis showed that patients with comorbidities and a history of corticoid use had a higher risk of fracture compared with patients with none of these risk factor. (odds ratios: 12.0, 95% confidence interval (CI): 1.0- 143, and 34.3, 95% CI: 3.2-364.5, respectively). Conclusions Prophylactic vertebral augmentation can prevent SAVF without complications. Patients with comorbidities and a history of corticoid use had a higher risk of SAVF compared with patients without corticoid use. Thus, we recommend prophylactic vertebral augmentation in the selected high-risk patients.

Background: Cement leakage is regarded as a typical complication of cement-based augmentation of vertebral fractures. The gold standard is balloon kyphoplasty (BK). Recent methods, such as radiofrequency kyphoplasty (RFK), must be compared with BK in terms of therapeutic success and complication rates. It is unclear whether the cement leakage rate in RFK is lower than with BK and whether this has any clinical relevance. Therefore, the aim of our prospective clinical study was to compare RFK with BK with respect to cement leakage rates and associated clinical complications. Patients and Methods: After prospective randomisation, 100 patients (76 women and 24 men with an average age of 78.5 years) or 162 vertebral bodies were treated by BK (n = 79) or RFK (n = 83). We evaluated the parameters “localisation of cement leakage” (epidural, intradiscal, extracorporal, intravascular) and “clinical relevance”. Results: More cement is used in BK (5.2 ml) than in RFK (4.0 ml, p = 0.001). Cement leakage was found in 48/79 patients (60.8 %) with BK and 53/83 patients (63.9 %) with RFK (p = 0.420). Even subanalysis by location showed no significant difference between the two methods. Despite the high leakage rates, we experienced only two cases (1× BK, 1× RFK) with intravascular leakage in the inferior vena cava, with interventional endovascular salvage. Conclusion: The two examined kyphoplasty methods (BK vs. RFK) have the same high rates of cement leakage, but are rarely associated with clinically manifest complications. Clinically relevant differences between the two compared kyphoplasty methods could not be found.

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To evaluate the efficacy and safety of high viscosity bone cement in the percutaneous vertebroplasty (PVP) for treatment of single-level osteoporotic vertebral compression fractures. Eighty patients were enrolled in this study. All patients were received PVP, and they were divided into 2 groups according to the viscosity of bone cement, either high viscosity bone cement (HV group) or low viscosity cement (LV group). Oswestry Disability Index questionnaire and visual analog scale as clinical assessments were quantified. The operative time and injected bone cement volume were recorded. The anterior vertebral height (AVH) and bone cement leakage were evaluated in the radiograph. No significant difference was observed in the operative time. Both groups showed significant improvements in pain relief and functional capacity status (visual analog scale and Oswestry disability index scores) after surgery. Less bone cement volume was injected into the the injured vertebra in the HV group and statistical significance was found between both groups. In the HV group, there was lower leakage rate and less patients of severe leakage compared with the LV group. However, the correction of AVH showed no significant differences between the 2 groups and no significant loss of AVH was observed in 2 groups. High-viscosity and low-viscosity PVP have the similar effects in improving quality of life and relieving pain. There were lower cement leakage rate and less patients of severe leakage in the PVP with high-viscosity bone cement.

Introduction: Our aim in this clinical trial was to compare the safety and efficacy of highviscosity cement (HVC) with low-viscosity cement (LVC) for the treatment of osteoporotic vertebrae fractures in terms of pain, functional capacity and cement leakage in the percutaneous vertebroplasty procedure (PVP). Methods: From March 2013 to February 2015, 76 patients with vertebrae compression fracture who were admitted into hospital and treated with PVP were reviewed. Pre- and postoperative clinical characteristics of each patient were obtained by using The Visual Analog Scale (VAS) score to evaluate back pain, Oswestry Disability Index (ODI) as a functional assessment. Cement leakage,injected cement volume and the complications assessed due to medical records. Results: VAS and ODI scores improved (P0.05).Paravertebral cement leakage was significantly higher in the LVC group (P

Percutaneous vertebroplasty consists of percutaneous injection of polymethylmethacrylate (PMMA) via a transpedicular approach for the treatment of collapsed osteoporotic or metastatic vertebrae. Even if percutaneous vertebroplasty is considered to be minimally invasive, threatening complications can occur. Cement leakage is the most common complication of percutaneous vertebroplasty. Rigorous patient selection and individual therapeutic strategy may reduce the occurrence of leakage, in particular the risk of cement entry into the venous system and the spinal canal is the potent major hazard of this technique. Cement pulmonary and cardiac embolism are reported in literature as a cause of unexpected death after percutaneous vertebroplasty. Authors report a fatal case of pulmonary cement embolization occurred after vertebroplasty with haemopericardium, due to the perforation of the right atrium wall from a cement solidified fragment. A complete post mortem examination documented the presence of multiple cement fragments in the pulmonary arteries and transmural perforation of the wall of the right atrium by a whitish needle-like foreign body. Pulmonary microembolization was observed under polarized light.

OBJECTIVE To report our initial experience of percutaneous sacroplasty (PSP) with an interpedicular approach for treating painful sacral metastases involving multiple sacral vertebral bodies. MATERIALS AND METHODS This study prospectively enrolled 10 consecutive patients (six men and four women; mean age, 56.3 ± 13.8 years) who underwent PSP for painful sacral metastases involving multiple sacral vertebral bodies from March 2017 to September 2018. Visual analogue scale (VAS) scores, Oswestry disability index (ODI) values, and the number of opioids prescribed to the patients were assessed before and after PSP. The procedure duration, length of hospitalization, and complications were also recorded. RESULTS Mean VAS and ODI declined significantly from 6.90 ± 1.20 and 74.40 ± 5.48 before the procedure to 2.70 ± 1.34 and 29.60 ± 14.57 after the procedure, respectively (p < 0.01). The median number of opioids prescribed per patient decreased from 2 (interquartile range [IQR] 1-3) pre-procedure to 1 (IQR 0-3) post-procedure (p < 0.01). Nine of the 10 patients showed no or decreased opioid usage, and only 1 patient showed unchanged usage. The mean procedure duration was 48.5 ± 3.0 minutes. The average length of hospitalization was 4.7 ± 1.7 days. Extraosseous cement leakage occurred in three cases without causing any clinical complications. CONCLUSION PSP with an interpedicular approach is a safe and effective treatment in patients with painful sacral metastases involving multiple sacral vertebral bodies and can relieve pain and improve mobility.

In a minimally invasive surgery, using a bone cement being radiologically detectable is vital to the success of the procedure and avoiding cement leakage in the early stage. The radiopacity of calcium phosphate cement (CPC) is inadequate, thus limiting its clinic application in this area. In this work, bismuth aluminate (BiA) was employed as a radiopaque agent for CPC. The influences of BiA on physicochemical, radiopaque and in vitro biocompatible properties of CPC were investigated. With the increasing content of BiA, the setting time and the compressive strength of CPC were augmented, while the injectability of the cement pastes was reduced. The radiopacity of CPC was significantly improved by adding more than 6 wt.% BiA. CPC specimens with less than 12 wt.% BiA showed good cellular affinity. Moreover, the CPC containing 6 and 9 wt.% BiA promoted the cell growth and ALP activity of mouse bone marrow mesenchymal stem cells when compared with the control. On the basis of its improved radiopacity and cytocompatibility, the radiopaque CPC with 6 ~ 9 wt.% BiA is expected to be a potential substitute for bone defect restoration via minimally invasive surgery. CPC with bismuth aluminate reveals better radiopacity and cell affinity along with proper physicochemical properties.

Testung der Primärstabilität unzementierter und PMMA-augmentierter Pedikelschrauben in einem In-vitro-Modell mit osteoporotischen Knochen Die Osteoporose, eine Erkrankung, die vorwiegend den älteren Menschen betrifft. Die durch die Verminderung der Knochenmasse in der Wirbelsäule entstehenden Erkrankungen verursachen hohe Kosten. Eine Form des operativen Vorgehens besteht in der dorsalen Instrumentierung der Wirbelsäule mit den unterschiedlichsten Systemausführungen, die alle mit Pedikelschrauben in den Pedikeln der Wirbel befestigt werden und zur besseren Verankerung z. B. mit PMMA zementiert werden können. Zwei verschiedene Zementiertechniken werden bei soliden und fenestrierten Pedikelschrauben angewendet. In dieser randomisierten In-vitro-Studie wurden die Wirbel von 5 humanen Wirbelsäulenpräparaten auf drei Studiengruppen verteilt. In den beiden Pedikeln eines Wirbels wurden zementierte und unzementierte solide Pedikelschrauben, zementierte fenestrierte und unzementierte solide Pedikelschrauben sowie zementierte solide und zementierte fenestrierte Pedikelschrauben einander gegenübergestellt. Die Durchmesser der Pedikelschrauben betrugen 6mm, mit Ausnahme von 6 Pedikelschrauben mit 7mm Durchmesser. Die Schraubenlängen betrugen 45±5mm. Verwendet wurde hochviskoser PMMA-Zement in den Zementmengen von 1ml und 3ml. Zur Bestimmung der Verankerungsfestigkeit von den unzementierten und zementierten Pedikelschrauben in den humanen Wirbelkörpern wurden die axialen Auszugskräfte der Pedikelschrauben mit Hilfe einer Materialprüfmaschine MTS 858 Mini Bionix bestimmt. Die Knochendichte der Wirbel wurde mit dem DXA-Verfahren ermittelt. Zusätzlich wurden die Eindrehmomente gemessen. Die statistischen Tests wurden mit dem Statistikpro- gramm SPSS 22 durchgeführt. Es konnte gezeigt werden, dass die Mittelwerte der maximalen Auszugskräfte der zementierten soliden und fenestrierten Pedikelschrauben, unabhängig von der verwendeten Zementmenge, signifikant größer als die entsprechenden Mittelwerte der maximalen Auszugskräfte der unzementierten Pedikelschrauben waren. Die Gleichwertigkeit der Verankerungsfestigkeit der zementierten soliden und zementierten fenestrierten Pedikelschrauben, unabhängig von der verwendeten Zementmenge, konnte belegt werden. Die mittleren maximalen Auszugskräfte der mit 3ml zementierten Schrauben lagen signifikant höher als die mittleren maximalen Auszugskräfte der mit 1ml zementierten Schrauben. Auszugsfestigkeit und Eindrehmoment der Pedikelschrauben hingen von der Knochenmineraldichte ab. Zwischen Auszugskräften und Eindrehmomenten wurde eine positive Korrelation festgestellt. Die Versagensarten ließen sich in Pedikelbrüche und Schraubenausrisse unterteilen. Der Anteil der Pedikelbrüche an den Versagensarten stieg mit der Erhöhung der Zementmenge an. Unterhalb eines BMD von 0,8g/cm2 überwogen die Pedikelbrüche, oberhalb davon die Schraubenausrisse. Zwischen den mittleren maximalen Auszugskräften der thorakalen und lumbalen Pedikelschrauben gab es keine signifikanten Unterschiede. Die Zementkörper der mit 3ml zementierten fenestrierten Pedikelschrauben aus der Gesamtgruppe C lagen zu 100% im vorde- ren, mittleren und hinteren Wirbelkörper, nur 33% davon im Pedikelbereich. Die Zementleckagen traten hauptsächlich an den solide zementierten Schrauben und bei Zementmengen von 3ml auf. Die fenestrierten Pedikelschrauben sind teurer in der Anschaffung als die soliden Pedikelschrauben, haben aber bei Zementierung eine etwas geringere Leckagerate und sind klinisch einfacher zu implantieren und zu zementieren. Mit diesen Vorteilen stellen sie deshalb eine interessante Auswahlmöglichkeit zu den zementierten soliden Pedikelschrauben dar., Testing of the primary stability of uncemented and PMMA augmented pedicle screws in an in-vitro model with osteoporotic bones Osteoporosis is a disease concerning predominantly elderly people. The costs for the diseases of the vertebral column caused by the reduction of the bone mass are high. One form of surgical procedure consists in the dorsal instrumentation of the spine with a variety of system versions, which are all fixed with pedicle screws in the pedicles of the vertebrae and for better bolting, for example, can be cemented with PMMA. Two different types of cementation techniques are applied to solid and fenestrated pedicle screws. In this randomized in-vitro study the vertebrae from 5 preparations of human vertebral columns were distributed to 3 study groups. Cemented and uncemented solid pedicle screws, cemented fenestrated and uncemented solid pedicle screws, and cemented solid and cemented fenestrated pedicle screws were juxtaposed in both of the two pedicles of a vertebra. The diameters of the pedicle screws were 6mm, with exception of 6 pedicle screws of 7mm. The screw lengths were 40mm, 45mm and 50mm. Highly viscous PMMA cement was used in volumes of 1ml and 3ml. To determine the anchoring strength of the uncemented and cemented pedicle screws in the human vertebrae, the axial extraction forces of the pedicle screws were determined with a material testing machine MTS858 Mini Bionix. The bone mineral density of the vertebrae was determined with the DXA method. In addition, the screw-in torques were measured. The statistical tests were carried out with the statistics program SPSS 22. Irrespective of the amount of cement used, it was shown that the mean values of the maximum extraction forces of the cemented solid and cemented fenestrated pedicle screws were significantly greater than the mean values of the maximum extraction forces of the uncemented pedicle screws. The equality of the anchoring strength of the cemented solid and the cemented fenestrated pedicle screws, independently of the used amount of cement, could be documented. The mean maximum pull-out forces of the 3ml cemented screws were significantly higher than the mean maximum pull-out forces of the 1ml cemented screws. Extraction strength and screw-in torque of the pedicle screws depended on the bone mineral density. Between extraction forces and screw-in torques a positive correlation could be observed. The types of failure could be divided into fractioning of pedicles and in screw pull-outs. The percentage of pedicle fractures relating to the types of failure increased with the increase in the amount of cement. Below a BMD of 0.8g/cm2, the pedicle fractures predominated, above that value the screw pull-outs dominated. There were no significant differences between the mean values of maximal extraction forces of the thoracic and the lumbar pedicle screws. The cement bodies of the 3ml cemented fenestrated pedicle screws of group C were located to 100% in the anterior, medial and posterior vertebral body, only 33% of them in the pedicle area. Cement leakages appeared mainly on solid cemented pedicle screws and with cement amounts of 3ml. The fenestrated pedicle screws are more expensive to purchase than the solid pedicle screws, but the cement leakage rate is somewhat lower and are clinically easier to implant and cement. With these advantages, the fenestrated pedicle screw is an interesting alternative to the cemented solid pedicle screw.

Vertebral Compression Fractures refer to the collapse of a vertebral body under excessive trauma to the spine. The surgical procedure to relieve pain and restore the normal height of the vertebral body is called vertebroplasty, in which a small amount of cement is injected into the spine. The problem with vertebroplasty is that the amount of cement injected is not accurate and leads to leakage into discs, which may develop into adjacent vertebral fractures. The current study aims at assessing the stress incurred on the adjacent vertebrae after vertebroplasty and the accurate cement levels required. The data in the form of CT images of the spine were acquired from a normal subject. A three-Dimensional model was generated by identifying the Regions of Interest (T11-L3), after performing volume and surface rendering techniques using Mimics and 3-MATIC. A force of 600 N was applied to the vertebrae for varying conditions of Bone Mineral Density (BMD), and the stress levels were calculated individually. Then, three fractures were induced at L1 and the corresponding 3-D models were generated. The stress levels on the fractured spine for forces of 600, 1200 and 1800 N were assessed. To assess the conditions after vertebroplasty, cement was injected in the fractured spine using Boolean Operations, which helped in optimizing the cement level. Results showed that the amount of cement required for the three cases were 4.5631, 5.5771 and 6.5849 mL respectively. Stress levels for the cement injected spine were analyzed, and were found to be much lesser than the stress incurred in the fractured cases with similar BMD. Among the adjacent vertebrae L2 was found to have a higher stress. Thus, this work seems to be clinically highly relevant in estimating the exact amounts of cements to be injected for different fracture cases thereby avoiding excessive cement leakage into the discs.

Purpose Cement leakage is a typical complication of kyphoplasty for vertebral fractures. It is unclear if cement application intraoperatively can be improved by using other techniques of visualization and which kind of postoperative imaging should be recommended to detect cement extravasation accurately. Objective To compare the rates of cement leakage detected by intraoperative fluoroscopy, postoperative radiography, and postoperative computed tomography (CT) in a retrospective study. Patients and Methods The study included 78 patients (60 women and 18 men; 115 vertebral bodies) who were treated with two kinds of kyphoplasty. The patients underwent intraoperative fluoroscopy and postoperative radiography and CT. After surgery, the images were evaluated to compare cement leakage rates and locations in the three visualization techniques. Leakage locations were described as epidural, intradiskal, extravertebral, or intravascular. Results Compared with CT, intraoperative fluoroscopy regularly detected intradiskal leakage (75%) but had a considerably lower sensitivity for visualizing epidural (21%), extravertebral (31%), and intravascular (51%) cement leakages. A comparison of radiography and CT showed that radiography had a high sensitivity for detecting intradiskal (82%) and intravascular (70%) cement extrusions but a lower sensitivity in identifying epidural (42%) and extravertebral (50%) leaks. Therefore, the CT scan overall was best in detecting location and accuracy. Conclusion CT detected more cement leaks than any of the other investigated techniques, especially epidural, extravertebral, and intravascular cement leakages. To achieve the best accuracy, only CT provides complete information.

Background: High-viscosity cement (HVC) has been gradually applied in percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP). Although HVC has been reported to reduce cement leakage, different opinions exist. To assess the complications of HVC in cement leakage in the treatment of vertebral compression fractures and to evaluate the clinical effect of HVC compared with low-viscosity cement (LVC). Methods: EMBASE, PubMed, Science Direct, Google Scholar and Cochrane Library databases were comprehensively searched from their inception to August 2017. Two researchers independently searched for articles and reviewed all retrieved studies. Forest plots were used to illustrate the results. The Q-test and I2 statistic were employed to evaluate between-study heterogeneity. Potential publication bias was assessed by funnel plot. Results: HVC reduced the occurrence of cement leakage (risk ratio (RR) = 0.38, 95% confidence interval (CI) = 0.29 to 0.51, P < 0.00001), especially in the disc space (RR = 0.45, 95% CI = 0.45 to 0.80, P = 0.007) and the vein (RR = 0.54, 95% CI = 0.35 to 0.85, P = 0.008) but not in the intraspinal space (RR = 0.48, 95% CI = 0.19 to 1.23, P = 0.13) or the paravertebral area (RR = 0.63, 95% CI = 0.32 to 1.22, P = 0.17). No significant differences in the visual analogue scale (VAS), Oswestry Disability Index (ODI), injected cement volume or adjacent vertebral fracture were noted between HVC and LVC (P > 0.05). Conclusion: Compared with LVC, HVC results in a reduced incidence of cement leakage for the treatment of vertebral compression fractures, especially in the disc space and vein but not in the intraspinal space or the paravertebral area. In addition, HVC yields the same satisfactory clinical effect as LVC.

Objective. To assess the risk factors of bone cement leakage into the spinal canal. Material and Methods . Results of 150 vertebroplasties were analyzed: out of them 56 procedures were performed through bipedicular and 94 - through unipedicular approach. The morphology of vertebrobasilar system was assessed by preoperative CT scans. After surgery the CT study was repeated to assess a degree of intracanal cement leakage and a needle-tip position relative to the midline. The correlation between cement leakage rate and mentioned predictors was estimated using logistic regression analysis. Results . Surgical technique (unipedicular or bipedicular approach) did not influence the rate of intracanal cement leakage. The distance from the midline to the needle-tip and the type of vertebrobasilar system were found to be significant predictive factors. Conclusion . The needle-tip position close to the midline and magistral type of vertebrobasilar system are risk factors of intracanal cement leakage during vertebroplasty, while the applied technique has no significant impact on complication rate.

PURPOSE This study aimed at assessing the cement leakage rate and the filling pattern in patients treated with vertebroplasty, kyphoplasty and stentoplasty with and without a newly developed lavage technique. STUDY DESIGN Retrospective clinical case-control study. METHODS A newly developed bipedicular lavage technique prior to cement application was applied in 64 patients (45.1 %) with 116 vertebrae, ("lavage" group). A conventional bipedicular cement injection technique was used in 78 patients (54.9 %) with 99 levels ("controls"). The outcome measures were filling patterns and leakage rates. RESULTS The overall leakage rate (venous, cortical defect, intradiscal) was 37.9 % in the lavage and 83.8 % in the control group (p

Background and purposeMany studies demonstrate that both kyphoplasty and vertebroplasty are superior to conservative therapy in the treatment of osteoporotic vertebral body compression fractures. We performed a systematic review and meta-analysis of studies comparing the outcomes of vertebroplasty and kyphoplasty, which included prospective non-randomized, retrospective comparative, and randomized studies.Materials and methodsWe searched MEDLINE, EMBASE, and the Web of Science databases for studies of kyphoplasty versus vertebroplasty from 1 January 1990 to 30 November 2014 and compared the following outcomes: procedure characteristics, pain and disability improvement, complications and anatomic outcomes. A subgroup analysis was performed comparing pain outcomes based on the risk of bias.Results29 studies enrolling 2838 patients (1384 kyphoplasty and 1454 vertebroplasty) were included. 16 prospective non-randomized studies, 10 retrospective comparative studies, and 3 randomized controlled studies were included. No significant differences were found in mean pain scores between the two groups postoperatively (2.9±1.5 kyphoplasty vs 2.9±1.7 vertebroplasty, p=0.39) and at 12 months (2.7±1.8 kyphoplasty vs 3.2±1.8 vertebroplasty, p=0.64). No significant differences were found in disability postoperatively (34.7±7.1 kyphoplasty group vs 36.3±7.8 vertebroplasty group, p=0.74) or at 12 months (28.3±16 kyphoplasty group vs 29.6±13.9 vertebroplasty group, p=0.70). Kyphoplasty was associated with lower odds of new fractures (p=0.06), less extraosseous cement leakage (pConclusionsNo significant difference was found between vertebroplasty and kyphoplasty in short- and long-term pain and disability outcomes. Further studies are needed to better determine if any particular subgroups of patients would benefit more from vertebroplasty or kyphoplasty in the treatment of vertebral body compression fractures.