Comparison of radiofrequency kyphoplasty and balloon kyphoplasty in combination with posterior fixation for the treatment of vertebral fractures.

BACKGROUND: In case of complex vertebral fractures, posterior fixation is often required for correction of deformity and instability. Fixation is commonly supported by balloon kyphoplasty (BKP) anterior. A development of BKP is radiofrequency-targeted vertebral augmentation (RF-TVA), which leads to comparable results for augmentation and pain relief. OBJECTIVE: This prospective study evaluates the outcome of posterior fixation combined with RF-TVA or BKP, respectively. METHODS: VAS, ODI, kyphosis angle and vertebral height of 44 patients were evaluated preoperatively, 3 and 12 months postoperatively. RESULTS: Both treatments improved vertebral height and kyphosis angle. At 12 months, vertebral height restoration was still significantly better in the BKP group (p < 0.001) and the improvement of kyphosis angle was comparable between both groups (p = 0.71). VAS and ODI improvements were significantly better in the RF-TVA group (p < 0.001). 8% of BKP patients had cement extravasations, compared to 10.5% in the RF-TVA group (p = 1.0). CONCLUSIONS: Combining posterior fixation with RF-TVA leads to better results of VAS and ODI, whereas the vertebral height restoration was favorable for patients treated with BKP. Cement leakage was comparable between both groups. It was asymptomatic and within reported ranges. Limitations of this study are the patient number and different stabilization instrumentation.

[Radiofrequency kyphoplasty combined with posterior fixation in the treatment of burst fractures]. / Radiofrequenzkyphoplastie in Kombination mit posteriorer Fixierung zur Behandlung von Wirbelsäulenfrakturen.

PURPOSE: Radiofrequency kyphoplasty is an advancement of the balloon kyphoplasty and offers comparable results with a shorter operation time and a lower risk of cement leakage. This prospective study investigates the outcome of radiofrequency kyphoplasty in combination with posterior fixation by a cement-augmented screw system. Accordingly, statistical analyses of the treatment data were performed. MATERIALS AND METHODS: 19 patients (mean age: 74.5 ± 7.2 years) with osteoporotic vertebral burst fractures were included in the study. All of them required a surgical intervention for treating the fracture. Thereby, the vertebrae were augmented by radiofrequency kyphoplasty and a posterior fixation by cement-augmentable screws was performed. To evaluate the effectiveness and safety of the procedure, pain was measured with the visual analog scale (VAS) and functional impairment was analysed by measuring the Oswestry disability index (ODI). Furthermore, a radiographic analysis of the anterior and medial height of the vertebrae and the degree of kyphosis were undertaken. All data were recorded preoperatively, 3 to 4 days postoperatively, 3 months postoperatively and 6 months postoperatively and any additionally occurring cement leakage was documented. RESULTS: The treatment showed a significant reduction of pain and improvement of the functional impairment at the 3 to 4 days postoperative evaluation (pVAS < 0.001, pODI < 0.001). The further follow-ups demonstrated an ongoing improvement of the VAS and ODI from each measurement to the next (pVAS_post-3 M < 0.001, pVAS_3 M-6 M = 0.17, pODI_post-3 M < 0.001, pODI_3 M-6 M = 0.004). The height of the vertebrae was significantly improved after the surgery (p_anterior < 0.001, p_medial < 0.001) and reduced slightly from follow-up to follow-up, but still remained higher than the preoperative value. The degree of kyphosis was also significantly improved after the surgery (p < 0.001), whereby a significant deterioration was shown at the following examinations (p_post-3 M = 0.023, p_3 M-6 M = 0.016). But even as the height decreased the degree of kyphosis was still improved in relation to the preoperative values. During the surgery cement leakage occurred in 3 cases (15.79 %). CONCLUSION: Radiofrequency kyphoplasty is a safe and effective procedure for the treatment of vertebral compression fractures in combination with the use of posterior fixation by cement-augmentable screws with an acceptable rate of cement leakage.

[Radiofrequency kyphoplasty - an innovative method for the treatment of vertebral compression fractures - comparison with conservative treatment]. / Radiofrequenz-Kyphoplastie - ein innovatives Verfahren zur Behandlung von vertebralen Kompressionsfrakturen - Vergleiche mit konservativer Behandlung.

OBJECTIVE: An evaluation of treatment protocols was used to expand the documentation of efficacy and safety of radiofrequency kyphoplasty (RFK). Additionally, a comparison of this new and innovative procedure with conservative treatment was carried out. PATIENTS, MATERIALS AND METHODS: Patients with painful osteoporotic vertebral fractures according to the common findings in an orthopaedic university hospital were included in the comparison study in which the indication for surgical intervention action according to the DVO guidelines was interdisciplinary confirmed. For the comparison group, patients with the same clinical and radiological findings were recruited who rejected a surgical intervention. For surgery, the StabiliT® Vertebral Augmentation System for a radiofrequency kyphoplasty by the company DFine was used. The cement was injected with a "multiplex controller". Thus, the results of the new method were compared to those of a group that was treated conservatively. RESULTS: The radiofrequency kyphoplasty (n = 114) resulted in an average decrease of VAS scores by almost 60 mm, which increased during the follow-up. Similarly, the Oswestry scores showed a marked improvement by 46 % points after 6 weeks. The mean increase in vertebral body height was 2.8 mm after radiofrequency kyphoplasty. In the conservatively treated group only very small changes compared to the initial findings were registered during the 6-week observation period. Accordingly, 33 of 67 patients decided after 6 weeks for surgery, which led to corresponding improvements (VAS, Oswestry, vertebral body height). Noteworthy is the low rate of cement leakage in the radiofrequency kyphoplasty group of 6 % (n = 7). CONCLUSIONS: Radiofrequency kyphoplasty offers a secure superiority over conservative treatment regarding clinical efficacy. In addition, the fractured vertebrae can be better targeted and erected, a longer processing time of the cement is ensured, a high interdigitation of the cement with the bone is guaranteed, the rate of cement leakage is low, the risk of radiation for the surgeon is minimised, and the operation time is shortened.

[Kiva® VCF Treatment System - clinical study on the efficacy and patient safety of a new system for augmentation of vertebral compression fractures]. / Kiva® VCF Treatment System - klinische Studie zur Wirksamkeit und Patientensicherheit mit einem neuen System zur Augmentation von vertebralen Kompressionsfrakturen.

BACKGROUND: As a further alternative to previously used vertebral augmentation methods, the Kiva VCF Treatment System® was clinically investigated. MATERIAL AND METHODS: The pilot study included 24 patients (mean age 74 years, 34 vertebrae). RESULTS: During an operation period of 16.6 minutes on average 2.2 ± 1 mL of PMMA cement were injected. 87 % of patients were satisfied or very satisfied with this treatment. In 2 cases leakage of cement has been registered. The pain intensity was already reduced after 7 days to 69.5 mm (VAS scale 0-100). After 30 days, the difference from baseline was 76 mm. Significant improvements have also been shown in the Oswestry Score (functional ability), physical performance and mental well-being. CONCLUSION: On the basis of these results, the new augmentation can be described as being effective in the treatment of painful vertebral fractures.

[Comparative findings of balloon kyphoplasty in patients with vertebral fractures due to osteoporosis, metastases and myeloma]. / Vergleichende Befunderhebungen der Ballonkyphoplastie bei Patienten mit Wirbelkörperfrakturen infolge von Osteoporose, Metastasen und Myelomen.

OBJECTIVE: By evaluations of treatment protocols, the documentation of balloon kyphoplasty regarding efficacy, duration of action and safety should be expanded. In addition, the evaluations should help to clarify the differences in balloon kyphoplasty for patients with vertebral fractures concerning efficacy and safety in relation to the underlying diseases: osteoporosis, bone metastases or myeloma. MATERIAL AND METHODS: In order to reposition the endplates of the vertebrae a balloon was inserted after placement of the working channels. After removal of the balloon, the resulting caverns were filled with PMMA. The radiological and clinical follow-up examinations were carried out over a period of up to 3 years. The clinical and radiological findings before and after treatment at specified visits were transferred to a statistical programme and evaluated. RESULTS: The comparisons of the postoperative results according to the initial diagnosis (metastases: n = 222, osteoporosis: n = 122, myeloma: n = 122) demonstrated significant differences with respect to the cement leakage (14 %, 5 %, 7.5 %), but in all cases without any clinical relevance. The small differences related to the reduction in pain intensity (VAS > 50 mm in each group) after surgery were up to 12 months with no clinical significance. Also in the Oswestry score no differences between the 3 groups were registered. In the case of osteoporosis patients, due to the lower starting position a more significant increase of vertebral body height could be achieved by the kyphoplasty than in the comparison groups of patients with metastases or myeloma (∅ 3.1 mm vs. 0.4-0.5 mm; P < 0.001). Consequently, the kyphosis angle decreased in the osteoporotic group also more strongly than in the comparison groups. CONCLUSIONS: It is evident that the pain relief in the vast majority of cases started immediately after surgery. Additionally, a significant improvement in functioning (Oswestry score) was registered. Both clinical parameters - as far as they could be checked - showed a steady degree of improvement over a period of at least 3 years. This comparative analysis led to the conclusion that balloon kyphoplasty can be successfully applied indiscriminately in patients with vertebral fractures as a result of osteoporosis and also to fractures associated with bone metastases or with myeloma.

Passive immunization with neutralizing antibodies interrupts the mouse mammary tumor virus life cycle.

Mouse mammary tumor virus (MMTV) infects the host via mucosal surfaces and exploits the host immune system for systemic spread and chronic infection. We have tested a neutralizing rat monoclonal antibody specific for the retroviral envelope glycoprotein gp52 for its efficiency in preventing acute and chronic mucosal and systemic infection. The antibody completely inhibits the superantigen response and chronic viral infection following systemic or nasal infection. Surprisingly however, the antibody only partially inhibits the early infection of antigen-presenting cells in the draining lymph node. Despite this initially inefficient protection from infection, superantigen-specific B- and T-cell responses and systemic viral spread are abolished, leading to complete clearance of the retroviral infection and hence interruption of the viral life cycle. In conclusion, systemic neutralizing monoclonal antibodies can provide an efficient protection against chronic retroviral amplification and persistence.

Quantitative control of MHC class II expression by the transactivator CIITA.

Activation of T lymphocytes is quantitatively controlled by the level of expression of MHC class II molecules. Both constitutive and inducible expression of MHC class II genes is regulated by the transactivator CIITA, which is itself tightly regulated. Since the level of MHC class II molecules expressed is a functionally essential parameter, it was of interest to explore whether MHC class II expression is quantitatively controlled by the level of the transactivator. This report shows that in a variety of experimental conditions one does indeed observe, in both mouse and man, a quantitative control of MHC class II expression by the level of CIITA. This relationship between the regulator gene, which behaves as a rate-limiting factor, and its target genes clarifies our understanding of the quantitative modulation of MHC class II expression, and thus of T lymphocyte activation.

Activation of the MHC class II transactivator CIITA by interferon-gamma requires cooperative interaction between Stat1 and USF-1.

CIITA is the mediator of MHC class II gene induction by interferon-gamma (IFNgamma). The CIITA gene is itself selectively activated via one of its four promoters (PIV). We show here that three cis-acting elements, the GAS, the E box, and the IRF-1-binding site, as well as the transacting factors Stat1 and IRF-1, are essential for activation of CIITA promoter IV by IFNgamma. Stat1 binds to the GAS site only in the presence of the ubiquitous factor USF-1, which binds to the adjacent E box. Indeed, Stat1 and USF-1 bind to the GAS/E box motif in a cooperative manner. The specificity for CIITA activation by IFNgamma is thus dictated by the GAS/E box motif and by the selective interaction of IFNgamma-activated Stat1 and USF-1. This clarifies the missing link in the overall pathway of IFNgamma activation of MHC-II expression.

Expression of MHC class II molecules in different cellular and functional compartments is controlled by differential usage of multiple promoters of the transactivator CIITA.

The highly complex pattern of expression of major histocompatibility complex class II (MHC-II) molecules determines both the immune repertoire during development and subsequently the triggering and the control of immune responses. These distinct functions result from cell type-restricted expression, developmental control and either constitutive or inducible expression of MHC-II genes. Yet, in these various situations, MHC-II gene expression is always under the control of a unique transactivator, CIITA. Here we show that the CIITA gene is controlled by several distinct promoters, two of which direct specific constitutive expression in dendritic cells and B lymphocytes respectively, while another mediates gamma-interferon-induced expression. Thus the cellular, temporal and functional diversity of MHC-II expression is ultimately controlled by differential activation of different promoters of a single transactivator gene. This provides novel experimental tools to dissect compartment-specific gain or loss of MHC-II function in vivo.

Complementation cloning of an MHC class II transactivator mutated in hereditary MHC class II deficiency (or bare lymphocyte syndrome).

Hereditary major histocompatibility complex (MHC) class II deficiency (or bare lymphocyte syndrome) is a form of severe primary immunodeficiency with a total lack of MHC class II expression. It is due to a defect in the regulation of MHC class II genes. A novel gene was isolated by complementation cloning, using an MHC class II-negative mutant cell line. This gene (CIITA) functions as a transactivator of MHC class II gene expression and restores expression of all MHC class II isotypes in mutant cells. In addition, CIITA fully corrects the MHC class II regulatory defect of cells from patients with bare lymphocyte syndrome. In this disease we have identified a splicing mutation that results in a 24 amino acid deletion in CIITA, resulting in loss of function of the transactivator. Hence, the CIITA gene is essential for MHC class II gene expression and has been shown to be responsible for hereditary MHC class II deficiency.

A rapid micro scale method for the detection of lysopine and nopaline dehydrogenase activities.

A rapid and sensitive method has been developed to determine lysopine dehydrogenase (EC 1.5.1-) and nopaline dehydrogenase activities in crown gall tumour tissues. By this method, enzyme activities as low as 0.2 micrometerol octopine or nopaline per h per g fresh weight tumour tissue can still be detected. In non-infected young pea seedlings, no lysopine dehydrogenase activity was detected.

Properties of D(+)-lysopine dehydrogenase from crown gall tumour tissue.

D(+)-Lysopine dehydrogenase of an octopine-type Crown Gall tumour has been partially purified and a number of kinetic parameters have been determined. D(+)-Lysopine dehydrogenase catalyzes the reductive condensation of pyruvate and one of at least six different L-amino acids, as well as the reverse reactions, with preferential use of NADP(H) as a cofactor. The optimal pH for both reductive and oxidative reactions has been determined. At pH 6.8, L-lysine has of all the amino acids the lowest Km value, while at the same pH the highest V was found with L-arginine and L-histidine. The isoelectric point of D(+)-lysopine dehydrogenase is about 4.5.