Polymethylmethacrylate Leakage Research Articles

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

Retrospective cohort study. Osteoporotic vertebral compression fractures (VCFs) are prevalent among the elderly population, and Balloon kyphoplasty (BKP) is a minimally invasive solution for these. However, Polymethylmethacrylate (PMMA) leakage is a significant complication with potentially severe consequences. This study compares the safety and efficacy of manual balloon tamp system (MTS) and hydraulic Polymethylmethacrylate pressure delivery system (HPDS) in BKP. A retrospective study involving 160 patients, comparing MTS (2008-2014) and HPDS (2016-2020) cohorts, assessed PMMA leakage, radiation exposure, and surgery duration. PMMA leakage occurred in 52.8% of MTS and 62.5% of HPDS cases. Intradiscal leakage was the most common pattern in both groups. Multivariate logistic regression revealed that multilevel BKP and HPDS were associated with higher PMMA leakage rates. Radiation exposure was significantly lower with HPDS, while surgery duration was shorter. This study provides novel insights into PMMA leakage and radiation exposure in BKP. HPDS was associated with a higher PMMA leakage rate. HPDS, however, offers advantages in terms of reduced radiation exposure and shorter surgery duration. Multilevel BKP also increased the risk of leakage. Further investigation is needed to better understand the impact of HPDS on PMMA leakage. This study underscores that while HPDS offers advantages regarding radiation exposure and surgery duration, it is associated with a higher PMMA leakage rate.

In‐situ leakage detection of single bag filter in baghouse based on the resistance change of conductive polymer fibers

AbstractBaghouse is effective for controlling the particles emitted from industrial production, and the in‐situ leakage detection of a single bag filter is essential for maintaining the high filtration performance of the whole baghouse. In the present study, the changes of PM emission concentration induced by the leakage of the bag filter materials was studied. The results showed that the concentration of particles in the size range of 20–1000 nm significantly increased when the bag filter sample had three holes with a diameter of ~500 μm. In order to prevent the loss induced by the leakage of bag filter, a resistance sensing method was developed to detect the early leakage of single bag filter. The effectiveness of proposed sensing method was verified by detecting the leakage of polymethyl methacrylate (PMMA) bag filter. A sensing grid made of PMMA conductive threads was embedded in the PMMA bag filter, and the resistance change (ΔR) induced by the broken of sensing grid was used as sensing signal. The ΔR of sensing grid was 3.24, 3.31, and 3.05 Ω, respectively, when the bag filter failed due to the mechanical stress, chemical corrosion, and thermal erosion. Moreover, a model was proposed to predict the numbers of broken conductive PMMA threads that could indicate the damage area of the failed bag filter.

Percutaneous pedicle screw fixation combined with percutaneous vertebroplasty for the treatment of thoracic and lumbar metastatic tumors

With the greatly prolonged survival of cancer patients, more and more patients develop bone metastasis, especially spinal metastasis. Therefore, it is very important to choose the best surgical plan for patients with spinal metastasis in different conditions. This paper aims to evaluate the clinical efficacy of percutaneous pedicle screw fixation (PPSF) combined with percutaneous vertebroplasty (PVP) for the treatment of thoracic and lumbar metastatic tumors. Forty patients with thoracic and lumbar metastatic tumors were treated with PPSF combined with PVP and followed up for 6-33 months. The visual analog scale (VAS) and the Barthel Index of activities of daily living (BIADL) were used to evaluate the pain intensity and quality of life before surgery and at 7 days, 3 months, and 6 months after the treatment. In this study, a total of 40 patients were followed up for 6-33 months (the mean time was 14.87 months). The VAS scores of all patients were significantly decreased, while the BIADL scores were significantly increased. No patients suffered from complications such as infection, pedicle screw loosening, or polymethylmethacrylate leakage. Spine stability was observed in all surviving patients during the follow-up. PPSF combined with PVP is a new and viable treatment for thoracolumbar metastases in patients with a poor systemic condition, patients who refuse to undergo a conventional open procedure such as en bloc corpectomy, and in patients with vertebral instability or pathological fracture without significant spinal compression. Patients with spinal metastases have a great risk of spinal instability and even spinal cord compression while enduring pain. Therefore, timely and appropriate surgical treatment is an effective means to stabilize the spine and avoid spinal cord compression. PPSF combined with PVP is an effective new surgical method for the treatment of multilevel spinal metastases.

CEMENTING THE SIDE EFFECTS OF KYPHOPLASTY: CEMENT EMBOLI IN THE CARDIOPULMONARY SYSTEM

CEMENTING THE SIDE EFFECTS OF KYPHOPLASTY: CEMENT EMBOLI IN THE CARDIOPULMONARY SYSTEM

Transoral vertebroplasty for the treatment of C2 painful metastatic lesions; evaluation and outcome

ObjectiveA small number of studies supports vertebroplasty at the C2 vertebral body due to the documented technical challenges, the rarity of C2 osteolytic metastatic lesions, and the existence of potentially serious consequences linked to this particular anatomical area. Vertebroplasty, in such a situation, can be performed through a transoral, an anterolateral, or an open approach. All are supported by a limited number of studies with absence of a significant clinical trial assessing the efficacy, safety, and feasibility of vertebroplasty for the C2 vertebral body. We, herein, summarize a single-institution experience on C2 transoral vertebroplasty. Patients and MethodsThis is a retrospective analysis of the records of a single tertiary institute hospital and the clinical visits of nine patients with C2 osteolytic metastatic lesions treated by transoral fluoroscopically guided vertebroplasty between May 2016 and May 2021. ResultsThe median period of the last clinical follow-up was 23 months (range, 9–60 months). The intraoperative amount of polymethyl methacrylate (PMMA) injected and recorded in the surgical report was 2 mL (1.5–2.5 mL). Postoperative immediate imaging showed that the cement filling percentage in relation to the C2 mass was 70% (40–85%). The PMMA leakage through the needle track and into the paravertebral spaces was observed in only one patient (11.1%), without significant vascular and neurological consequences. Stability was maintained during the follow-up period. The postoperative median pain rating scale (PRS) score was 1 (0−2) immediately after the end of the operation and 0 (0−2) at the last visit. The recorded postoperative Pain Rating Scale (PRS) score was correlated with the cement filling percentage (rs= −0.9, p = 0.0008; Spearman correlation). ConclusionTransoral vertebroplasty is considered feasible and efficient technique in the treatment of secondary osteolytic lesions in the C2 vertebra. Further long-term and larger comparative randomized studies are required to perform a more comprehensive analysis of this technique.

Percutaneous Sacroplasty with or without Radiofrequency Ablation for Treatment of Painful Sacral Metastases.

Percutaneous sacroplasty is a variation of percutaneous vertebroplasty that has gained attention as a therapeutic option for patients with painful sacral insufficiency fractures due to osteoporosis or metastases. Additionally, percutaneous sacroplasty can also be used to treat painful sacral metastases without a pathologic fracture. The purpose of this retrospective study was to compare the efficacy and safety of fluoroscopy-guided percutaneous sacroplasty alone versus percutaneous sacroplasty plus radiofrequency ablation for the treatment of painful sacral metastases. For this retrospective study, 126 patients (with a total of 162 painful sacral metastases) were enrolled from October 2012 to February 2021 and assigned to receive either percutaneous sacroplasty plus radiofrequency ablation (n = 51, group A) or percutaneous sacroplasty alone (n = 75, group B). Four different approaches were used for percutaneous sacroplasty: transiliac, interpedicular, anterior-oblique, and posterior. The Visual Analog Scale, Oswestry Disability Index, and Karnofsky Performance Scale were used to evaluate outcomes. The Visual Analog Scale, Oswestry Disability Index, and Karnofsky Performance Scale scores showed significant improvement in both groups after treatment (P < .05). The overall pain relief rate was significantly better in group A than in group B (90% versus 76%, P = .032). There were no significant differences in the incidence of polymethylmethacrylate leakage between the 2 groups or among the 4 different approaches (P > .05). Both percutaneous sacroplasty alone and the combination of percutaneous sacroplasty and radiofrequency ablation are safe and effective for treatment of painful sacral metastases. The combination of percutaneous sacroplasty and radiofrequency ablation appears to be more effective than percutaneous sacroplasty alone.

Percutaneous Vertebroplasty with the Polymethyl Methacrylate - Gelatin Sponge Complex in the Treatment of Patients with Osteoporotic Vertebral Compression Fractures Accompanied by Superior Endplate Injurie.

To explore the clinical efficacy of percutaneous vertebroplasty (PVP) combined with the polymethyl methacrylate-gelatin sponge (PMMA-GS) complex in the treatment of patients with osteoporotic vertebral compression fractures (OVCFs) accompanied by superior endplate injuries MATERIAL and METHODS: A total of 77 OVCF patients with superior endplate injuries who were treated with PVP from January 2017 to December 2020 were retrospectively analyzed. The visual analogue scale (VAS) score, Oswestry disability index (ODI), and injured vertebral height ratio at one day (1d) before surgery, three days (3d) after surgery, and one year (1y) after surgery were compared between both groups. Besides, the surgical duration, PMMA (polymethyl methacrylate) injection volume, PMMA leakage rate, and adjacent vertebral fracture rate were compared between these two groups. Among these patients, there were 39 individuals treated with PVP combined with the PMMA-GS complex (the observation group) and 38 individuals treated with PVP (the control group). These patients in both groups completed the surgery successfully. There were no such complications as pulmonary embolism, hemopneumothorax, rib fracture, spinal cord nerve injuries, and vital organ injuries. In these two groups, the VAS score, ODI, and injured vertebral height ratio 1d before surgery were significantly different from those 3d and 1y after surgery (p < 0.05). However, there was no significant difference in these indexes between both groups (p > 0.05). There was no significant difference in the surgical duration and PMMA injection volume between both groups (p > 0.05). However, the PMMA leakage rate and adjacent vertebral fracture rate in the observation group were significantly lower than those in the control group (p < 0.05). Compared with traditional PVP, this therapy PVP combined with PMMA-GS complex in the treatment of OVCF patients with superior endplate injuries can effectively reduce the incidence of PMMA leakage and the incidence of adjacent vertebral fracture rate.

Clinical Outcome and Histological Findings After Induced Leakage of PMMA Loaded With Methotrexate and Cisplatin During Vertebroplasty: Experimental Model in Pigs.

Animal experimental model. To study the clinical behavior and histological changes in the spinal cord, nerve roots and perivertebral muscles of the spine after induced leakage of polymethylmethacrylate (PMMA) loaded with antiblastic drugs during vertebroplasty in an animal model of pigs. We performed vertebroplasty on 25 pigs. The animals were divided into 3 groups: vertebroplasty with PMMA alone (control group), vertebroplasty with PMMA loaded with methotrexate (MTX) and vertebroplasty with PMMA loaded with cisplatin (CYS). At 2 vertebral levels, epidural and prevertebral, massive cement leaks were induced. Animals were evaluated daily. Two weeks later, the pigs were sacrificed, and the tissues that came in contact with the cement were analyzed. The clinical results for each of the groups were reported. The control group had no clinical alterations. In the MTX group, 2 pigs died before 1 week due to pneumonitis. In the CYS group, 4 animals had motor impairment, and 3 of the 4 had paraplegia. The histological results were as follows: the control and MTX groups showed synovial metaplasia, inflammatory reaction, crystal deposits, and giant cell reaction in the dura mater and muscle and all the animals in the CYS group had spinal cord and muscular necrosis. Massive cement leak after vertebroplasty with PMMA loaded with cisplatin is extremely toxic to the spinal cord and muscles around the spine. Therefore, its use cannot be recommended for the treatment of vertebral metastases. Using PMMA loaded with methotrexate seems to be a safe procedure, but further research is needed.

Safety and Efficacy With Augmented Second-Generation Perforated Pedicle Screws in Treating Degenerative Spine Disease in Elderly Population.

Degenerative spine disease is a common cause of low back pain in people age 65 years or older. Nonsurgical treatment is tried first, but if it is unsuccessful, surgery is advocated. This has special connotations for both underlying disease and the biomechanical characteristics of osteoporotic bone. We conducted an observational study to investigate the clinical and radiological outcome in patients in this age group with poor bone quality and degenerative lumbar instability treated with fusion using perforated pedicle screws augmented with polymethylmethacrylate (PMMA). We collected prospective data on treatment, outcome, and patient characteristics from our institution's database. The primary outcome was a change in pain and physical function measured by the visual analog scale, the Core Outcome Measures Index, and the Oswestry Disability Index. Control participants were also analyzed for secondary complications such as hardware mobilization, fusion (as apparent on radiographs), and adjacent fractures or adjacent degenerative disc disease. We included 89 patients who underwent surgery between October 2015 and February 2018 at a mean age of 78 years (range, 67-88 years) and were then monitored for at least 12 months (range, 12-40 months). Findings on pain and function questionnaires showed improvement at 6 months after surgery, maintained at the final evaluation; 90% of patients had final score increases of ≥15 points. No patient developed clinical complications secondary to PMMA leakages. One patient had nonunion and screw breakage. No other patient had clinical or radiological nonunion. Of the control participants, 6 had adjacent disc disease, with 2 of them requiring instrumentation extension. Six deep infections required surgical revision without removal of material. PMMA-augmented cannulated pedicle screw instrumentation in spine fusion effectively and safely treats degenerative lumbar disease in patients who are age 65 years or older with poor bone quality.

Comparison of unilateral and bilateral polymethylmethacrylate-augmented cannulated pedicle screw fixation for the management of lumbar spondylolisthesis with osteoporosis

BackgroundCannulated pedicle screw (CPS) augmented by polymethylmethacrylate (PMMA) can achieve satisfactory clinical efficacy in the treatment of lumbar spondylolisthesis with osteoporosis. However, accurate application of CPSs will help to avoid the difficulty of screw revision and reduce the incidence of PMMA-related complications. This study aimed to investigate the mid-term efficacy of CPS compared to unilateral and bilateral applications in this common lumbar degenerative disease.MethodsMay 2011 and May 2018, 50 patients with lumbar spondylolisthesis with osteoporosis who underwent posterior fixation and fusion using traditional pedicle screws or CPSs were included in the study. Patients were divided into two groups based on the application: the unilateral PMMA-augmented CPS group (UC, n = 29) and the bilateral PMMA-augmented CPS group (BC, n = 21). Operation time, blood loss, average hospitalization time, PMMA leakage, and other complications were recorded. The visual analog scale (VAS) and Oswestry disability index (ODI) scores were used to evaluate symptom recovery. Radiographic results were compared for intervertebral fusion and screw loosening.ResultsThere were no significant differences in the baseline data of the two groups.The VAS and ODI scores improved significantly after surgery (P < 0.05), with no significant differences between the groups (P > 0.05). The operation time and blood loss in the UC group were significantly lower than those in the BC group (P < 0.05). However, the loss of intervertebral disk height and Taillard index did not differ significantly between the groups. The rates of PMMA leakage in the UC and BC groups were 7.0% and 11.9%, respectively (P < 0.05). Bony fusion was achieved in all groups without screw loosening at the last follow-up. Only one patient experienced superficial infection in both groups, while cerebrospinal fluid leakage was observed in two patients in the BC group.ConclusionsUnilateral application of PMMA-augmented CPS may provide adequate clinical safety and effectiveness in the surgical treatment of lumbar spondylolisthesis with osteoporosis.

Biomechanical study of injectable hollow pedicle screws for PMMA augmentation in severely osteoporotic lumbar vertebrae: effect of PMMA distribution and volume on screw stability.

OBJECTIVEThe purpose of this study was to compare stability of injectable hollow pedicle screws with different numbers of holes using different volumes of polymethylmethacrylate (PMMA) in severely osteoporotic lumbar vertebrae and analyze the relationship between screw stability and distribution and volume of PMMA.METHODSForty-eight severely osteoporotic cadaveric lumbar vertebrae were randomly divided into 3 groups-groups A, B, and C (16 vertebrae per group). The screws used in group A had 4 holes (2 pairs of holes, with the second hole of each pair placed 180° further along the thread than the first). The screws used in group B had 6 holes (3 pairs of holes, placed with the same 180° difference in position). Unmodified conventional screws were used in group C. Each group was randomly divided into subgroups 0, 1, 2, and 3, with different volumes of PMMA used in each subgroup. Type A and B pedicle screws were directly inserted into the vertebrae in groups A and B, respectively, and then different volumes of PMMA were injected through the screws into the vertebrae in subgroups 0, 1, 2, and 3. The pilot hole was filled with different volumes of PMMA followed by insertion of screws in groups C0, C1, C2, and C3. Distributions of PMMA were evaluated radiographically, and axial pull-out tests were performed to measure the maximum axial pullout strength (Fmax).RESULTSRadiographic examination revealed that PMMA surrounded the anterior third of the screws in the vertebral bodies (VBs) in groups A1, A2, and A3; the middle third of screws in the junction area of the vertebral body (VB) and pedicle in groups B1, B2, and B3; and the full length of screws evenly in both VB and pedicle in groups C1, C2, and C3. In addition, in groups A3 and B3, PMMA from each of the screws (left and right) was in contact with PMMA from the other screw and the PMMA was closer to the posterior wall and pedicle than in groups A1, A2, B1, and B2. One instance of PMMA leakage was found (in group B3). Two-way analysis of variance revealed that 2 factors-distribution and volume of PMMA-significantly influenced Fmax (p < 0.05) but that they were not significantly correlated (p = 0.078). The Fmax values in groups in which screws were augmented with PMMA were significantly better than those in groups in which no PMMA was used (p < 0.05).CONCLUSIONSPMMA can significantly improve stability of different injectable pedicle screws in severely osteoporotic lumbar vertebrae, and screw stability is significantly correlated with distribution and volume of PMMA. The closer the PMMA is to the pedicle and the greater the quantity of injected PMMA used, the greater the pedicle screw stability is. Injection of 3.0 mL PMMA through screws with 4 holes (2 pair of holes, with the screws in each pair placed on opposite sides of the screw) produces optimal stability in severely osteoporotic lumbar vertebrae.

Sacral Insufficiency Fractures : How to Classify?

ObjectiveThe diagnosis of insufficiency fractures of the sacrum in an elder population increases annually. Fractures show very different morphology. We aimed to classify sacral insufficiency fractures according to the position of cortical break and possible need for intervention.MethodsBetween January 1, 2008 and December 31, 2014, all patients with a proven fracture of the sacrum following a low-energy or an even unnoticed trauma were prospectively registered : 117 females and 13 males. All patients had a computer tomography of the pelvic ring, two patients had a magnetic resonance imaging additionally : localization and involvement of the fracture lines into the sacroiliac joint, neural foramina or the spinal canal were identified.ResultsPatients were aged between 46 and 98 years (mean, 79.8 years). Seventy-seven patients had an unilateral fracture of the sacral ala, 41 bilateral ala fractures and 12 patients showed a fracture of the sacral corpus : a total of 171 fractures were analyzed. The first group A included fractures of the sacral ala which were assessed to have no or less mechanical importance (n=53) : fractures with no cortical disruption (“bone bruise”) (A1; n=2), cortical deformation of the anterior cortical bone (A2; n=4), and fracture of the anterolateral rim of ala (A3; n=47). Complete fractures of the sacral ala (B; n=106) : parallel to the sacroiliac joint (B1; n=63), into the sacroiliac joint (B2; n=19), and involvement of the sacral foramina respectively the spinal canal (B3; n=24). Central fractures involving the sacral corpus (C; n=12) : fracture limited to the corpus or finishing into one ala (C1; n=3), unidirectional including the neural foramina or the spinal canal or both (C2; n=2), and horizontal fractures of the corpus with bilateral sagittal completion (C3; n=8). Sixty-eight fractures proceeded into the sacroiliac joint, 34 fractures showed an injury of foramina or canal.ConclusionThe new classification allowes the differentiation of fractures of less mechanical importance and a risk assessment for possible polymethyl methacrylate leaks during sacroplasty in the direction of the neurological structures. In addition, identification of instable fractures in need for laminectomy and surgical stabilization is possible.

Percutaneous Vertebroplasty for the Treatment of Osteoporotic Thoracolumbar Fractures with Posterior Body Involved in Elderly Patients.

To present the results of vertebroplasty for treating thoracolumbar burst fractures without neurological deficit. Twelve patients (aged ≥65 years) with thoracolumbar fractures but without neurological deficits underwent vertebroplasty. In all fracture cases, the anterior and middle columns of the vertebrae were affected and the canal was mildly compressed. To assess the clinical symptoms and the effects of the procedure, patient mobility and pain were assessed prior to the procedure and at 1 day and 3 months after the procedure. Improvements in pain and mobility were observed immediately after vertebroplasty in all patients. These results were observed for 3 months. Significant improvements were also noted at 1 day and 3 months after vertebroplasty. Pain was reduced by at least 4 levels after 3 months. No co-morbidities were observed. However, computed tomography revealed polymethylmethacrylate leakage through the endplate fracture site into the disc space or paravertebral space in four vertebrae and minimal intracanal leakage through the fracture line in one patient. Vertebroplasty is assumed to be contraindicated in patients with osteoporotic thoracolumbar fractures with posterior body involvement. However, this procedure was successfully performed to safely treat such fractures without causing neurological deficits. Percutaneous vertebroplasty may be an alternative method for treating thoracolumbar burst fractures that prevents major surgical complications. Moreover, it helps patients achieve early mobilization and pain relief.

EMG-Guided Percutaneous Placement of Cement-Augmented Pedicle Screws for Osteoporotic Thoracolumbar Burst Fractures.

Percutaneous techniques have increasingly gained popularity in recent years. The application of technological innovation, including neuromonitoring techniques, has the potential to increase the safety and efficacy of these procedures. Thirty patients suffering from osteoporotic dorsolumbar burst fracture were prospectively enrolled in this study. The patients underwent percutaneous fenestrated pedicle screw fixation augmented with polymethylmethacrylate (PMMA) injection. A novel surgeon-dedicated neuromonitoring device was used in order to increase the safety and the accuracy of the screw insertion. A second group of 30 patients who did not undergo neuromonitoring during percutaneous pedicle screw placement, matched for demographic characteristics, constituted the control group. A total of 296 screws were inserted. All treated patients had a good outcome, documented by an improvement in visual analogue scale (VAS) scores. Excellent trajectories were achieved in all patients. Cobb's angle and anterior vertebral height were satisfactorily restored in all study group patients. Three misplaced screws in three patients and a case of PMMA leakage without neurological deficits were observed in the control group, whereas no complication was recorded in the study group (p = 0.03). Neuromonitoring in cement-augmented percutaneous pedicle screw placement appears to improve surgeon confidence during surgery, reducing the risk of screw misplacement or cement leakage.

Calcium Phosphate Cement Leakage During Balloon Kyphoplasty Causing Incomplete Paraplegia: Case Report and Review of the Literature

Introduction: Bone cement leakage is the most common, however, it can have potentially disastrous complications during vertebroplasty and balloon kyphoplasty (BK). Polymethylmethacrylate (PMMA) is the most commonly used bone filler, however, calcium phosphate (CP) has been successfully used in spine surgery as a vertebral filler because it is not associated with exothermal reaction and is biologically very close to the vertebral bone. CP leakage during vertebral augmentation is extremely rare.Case Presentation: A 72-year-old woman with an A2/AO type fracture of L1-vertebra underwent a transpedicular BK at the L1-vertebra with CP plus short segment pedicle screw construct (T12-L2) by minimally invasive surgery (MIS). Continuous neuromonitoring and fluoroscopy were used in this case, although no pathological signs were recorded because of the low radiopacity of CP. Two days later, incomplete paraplegia was presented due to intra and extradural cement leakage. The patient underwent an emergency T12-L2 wide decompression for removal of an epidural leak of CP plus durotomy for intradural CP removal. After removal of the cement, there was improvement of neurologic function. CP leakage should have occurred because of a violation of the medial right pedicle wall by the BK trockar and subsequently CP injection both intra and extradural. Since no direct intraoperative nerve root injury occurred, there was no pathologic sign during intraoperative neuromonitoring.Conclusions: PMMA leakage is well documented in the literature as a common complication during BK. Calcium phosphate leakage during vertebral augmentation is rare. Furthermore, delayed onset of neurologic deficit due to CP leakage has never been reported in the current literature. Spine surgeons and interventional radiologists should always be aware of this potential disastrous complication.

Intracardiac bone cement embolism as a complication of vertebroplasty: management strategy.

Vertebroplasty carries multiple complications due to the leakage of polymethylmethacrylate (PMMA) into the venous system through the iliolumbar or epidural veins. The rate of venous cement complications may vary from 1 to 10%, with cement extravasation into the venous system in 24% of patients. Emboli may further migrate into the right heart chambers and pulmonary arteries. Patients may vary in presentation from asymptomatic or symptoms such as syncope to life-threatening complications. We present a case of a 57-year-old lady diagnosed with osteoporosis who underwent a staged antero-posterior fixation with PMMA vertebroplasty of progressive thoraco-lumbar kyphosis caused by osteoporotic fractures to T12, L1 and L2 vertebral bodies. Four weeks after the operation, the patient developed symptoms of left-sided chest pain, tachycardia and tachypnea. CT pulmonary angiogram (CTPA) found a high-density material within the right atrium, whilst ECHO demonstrated normal systolic function. The patient was commenced on enoxaparin at therapeutic dose of 1.5mg/kg for 3months and remained asymptomatic. Follow-up ECHO found no change to the heart function and no blood clot on the PMMA embolus. Factors influencing the decision about conservative treatment included symptoms, localisation of the embolus, as well as time lapse between vertebroplasty and clinical manifestation. Patients that are commonly asymptomatic can be treated conservatively. The management of choice is anticoagulation with low-molecular-weight heparin or warfarin until the foreign body epithelialises and ceases in becoming potentially thrombogenic. Symptomatic patients with thrombi in the right atrium are commonly managed via percutaneous retrieval, whilst those with RV involvement or perforation are commonly managed with surgical retrieval. Management of individual patients should be based on individual clinical circumstances. Patients presenting with intracardiac bone cement embolism related to spinal procedures require thorough clinical assessment, cardiology input, and if required, surgical intervention.

Computer Simulation and Analysis on Flow Characteristics and Distribution Patterns of Polymethylmethacrylate in Lumbar Vertebral Body and Vertebral Pedicle.

This study was designed to analyze the flow and distribution of polymethylmethacrylate (PMMA) in vertebral body through computer simulation. Cadaveric lumbar vertebrae were scanned through electron beam tomography (EBT). The data was imported into Mimics software to build computational model. Vertebral body center and junction of pedicle and vertebral body were chosen as injection points. Silicone oil with viscosity of 100,000 cSt matching with PMMA bone cement was chosen for injection. The flow and distribution of silicone oil were analyzed using Fluent software. In vertebral body, silicone oil formed a circle-like shape centered by injection point on transverse and longitudinal sections, finally forming a sphere-like shape as a whole. Silicone oil diffused along lateral and posterior walls forming a circle-like shape on transverse section centered by injection point in pedicle, eventually forming a sphere-like shape as a whole. This study demonstrated that silicone oil flowed and diffused into a circle-like shape centered by injection point and finally formed a sphere-like shape as a whole in both vertebral body and pedicle. The flow and distribution of silicon oil in computational model could simulate PMMA distribution in vertebral body. It may provide theoretical evidence to reduce PMMA leakage risk during percutaneous vertebroplasty.

Liquid Nitrogen or Phenolization for Giant Cell Tumor of Bone?

The rate of recurrence of giant cell tumor of bone is decreased by use of adjuvant treatments such as phenol, liquid nitrogen, or polymethylmethacrylate (PMMA) during curettage. We assessed recurrence and complication rates and functional outcome after curettage with use of phenol and PMMA, liquid nitrogen and PMMA, and liquid nitrogen and bone grafts. We retrospectively compared the relative effectiveness of treatment of giant cell tumors of bone at two tertiary centers with a regional function from 1990 to 2010. The 132 (of 201) patients who met the inclusion criteria had a mean age of thirty-three years (range, eleven to sixty-nine years). Treatment assignment depended purely on the center, with primary treatment consisting of curettage with use of phenol and PMMA (n = 82) at one center and with use of either liquid nitrogen and PMMA (n = 26) or liquid nitrogen and bone grafts (n = 24) at the other center. Recurrence and complication rates were determined, and functional outcome was assessed on the basis of the Musculoskeletal Tumor Society (MSTS) score. The mean duration of follow-up was eight years (range, two to twenty-two years). Recurrence rates were comparable among the groups (28% for phenol and PMMA, 31% for liquid nitrogen and PMMA, and 38% for liquid nitrogen and bone grafts; p = 0.52). Soft-tissue extension increased the recurrence risk (hazard ratio [HR] = 2.1, 95% confidence interval [CI] = 1.1 to 4.0, p = 0.024). The complication rate was 33% after use of liquid nitrogen and bone grafts, 27% after liquid nitrogen and PMMA, and 11% after phenol and PMMA (p = 0.019); complications included osteoarthritis, infection, postoperative fracture, nonunion, transient nerve palsy, and PMMA leakage. The complication risk was increased by the presence of a pathologic fracture (HR = 4.1, 95% CI = 1.7 to 9.5, p = 0.001) and use of liquid nitrogen (HR = 3.9, 95% CI = 1.5 to 10, p = 0.006 for liquid nitrogen and bone grafts; HR = 3.1, 95% CI = 1.1 to 8.6, p = 0.028 for liquid nitrogen and PMMA). The mean MSTS score was 26 (range, 8 to 30) and was comparable among all three groups (p = 0.52). Recurrence rates were comparable for treatment with phenol and PMMA, liquid nitrogen and PMMA, and liquid nitrogen and bone grafts. Complication rates were higher after use of liquid nitrogen. The functional outcome was excellent in all three cohorts.

Is Kiva Implant Advantageous to Balloon Kyphoplasty in Treating Osteolytic Metastasis to the Spine? Comparison of 2 Percutaneous Minimal Invasive Spine Techniques

Prospective, parallel-group, controlled, comparative randomized study. To compare cement leakage rate and efficacy for vertebral body restoration of balloon kyphoplasty (BK) versus Kiva novel implant with polymethylmethacrylate (PMMA) for treating osteolytic vertebral body metastasis. Minimally invasively vertebral augmentation techniques with PMMA are mostly performed for treating osteoporotic compression fractures. The Kiva implant with PMMA offers better vertebral body restoration and less PMMA leakage than BK in osteoporotic fractures. No previous study compared leakage rate and efficacy for vertebral body restoration in traditional BK and Kiva with PMMA in osteolytic vertebral body metastases. This study examined 23 patients (71 ± 13 yr) with 41 osteolytic vertebral bodies, who received Kiva with low viscosity PMMA and 24 patients (70 ± 11 yr) with 43 vertebral body osteolyses, who were reinforced with BK and high viscosity PMMA. All osteolyses were graded as Tomita 1 to 3. Anterior vertebral body height ratio (AVBHr), posterior vertebral body height ratio (PVBHr), and middle vertebral body height ratio (MVBHr), Gardner kyphotic deformity, PMMA leakage and were measured and compared between the groups. Visual analogue scale and Oswestry Disability Index were used for functional outcome evaluation. No patient survived after 3 months. Asymptomatic PMMA leakage occurred in 4 (9.3%) vertebrae in the BK group solely (2 to the spinal canal, in Tomita grade 3 osteolysis) Anterior, posterior and middle vertebral body height ratio, Gardner angle improved insignificantly in both groups. Visual anlogue scale and Oswestry Disability Index improved postoperatively similarly in both groups (P < 0.001). BK and Kiva provided equally significant spinal pain relief in patients with cancer with osteolytic metastasis. The absence of cement leakage in the Kiva group and absence of neurological complication in the BK group leakages reflects the safety of both augmentation techniques even in significant osteolysis. The lack of cement leakage in the Kiva cases, although low viscosity PMMA was used, increases this implant safety in augmenting severely destructed thoracolumbar vertebrae and sacrum from osteolytic metastasis. 1.

Outcome of long-axis percutaneous sacroplasty for the treatment of sacral insufficiency fractures with a radiofrequency-induced, high-viscosity bone cement

Our goal was to assess the technical results in patients who underwent long-axis sacroplasty for the treatment of sacral insufficiency fractures (SIF) by radiofrequency-induced high-viscosity bone cement augmentation. Twelve patients with bilateral sacral fractures were treated by augmentation with radiofrequency-activated, high-viscosity polymethylmethacrylate (PMMA) bone cement under local anesthesia. CT-guided sacroplasty was performed by using a long-axis approach through a single entry point. Thirty-six vertebrae were treated in 12 sessions under a combination of CT and fluoroscopic guidance using a bilateral access and a cavity-creating osteotome prior to remote-controlled, hydraulically driven cement injection. The visual analogue scale (VAS) score before sacroplasty and at 1 and 3 months after the treatment was obtained. PMMA leaks were evaluated retrospectively using the post-interventional CT. The mean amount of high-viscosity PMMA injected per patient was 7.8 ml. No major adverse events were observed. In the first 4 days after the procedure, the mean VAS score decreased from 8.1 ± 1.9 to mean 3.1 ± 1.2 and was followed by a gradual but continuous decrease throughout the rest of the follow-up period at 24 weeks (mean 2.2 ± 1.1) and 48 weeks (mean 2.1 ± 1.4). CT fluoroscopy-guided sacral augmentation was safe and effective in all 12 patients with osteoporotic SIF.