Radiographic and safety details of vertebral body stenting : results from a multicenter chart review

Background: Up to one third of BKP treated cases shows no appreciable height restoration due to loss of both restored height and kyphotic realignment after balloon deflation. This shortcoming has called for an improved method that maintains the height and realignment reached by the fully inflated balloon until stabilization of the vertebral body by PMMA-based cementation. Restoration of the physiological vertebral body height for pain relief and for preventing further fractures of adjacent and distant vertebral bodies must be the main aim for such a method. A new vertebral body stenting system (VBS) stabilizes the vertebral body after balloon deflation until cementation. The radiographic and safety results of the first 100 cases where VBS was applied are presented. Methods: During the planning phase of an ongoing international multicenter RCT, radiographic, procedural and followup details were retrospectively transcribed from charts and xrays for developing and testing the case report forms. Radiographs were centrally assessed at the institution of the first/senior author. Results: 100 patients (62 with osteoporosis) with a total of 103 fractured vertebral bodies were treated with the VBS system. 49 were females with a mean age of 73.2 years; males were 66.7 years old. The mean preoperative anterior-middle-posterior heights were 20.3-17.6-28.0 mm, respectively. The mean local kyphotic angle was 13.1°. The mean preoperative Beck Index (anterior edge height/posterior edge height) was 0.73, the mean alternative Beck Index (middle height/posterior edge height) was 0.63. The mean postoperative heights were restored to 24.5-24.6-30.4 mm, respectively. The mean local kyphotic angle was reduced to 8.9°. The mean postoperative Beck Index was 0.81, the mean alternative one was 0.82. The overall extrusion rate was 29.1%, the symptomatic one was 1%. In the osteoporosis subgroup there were 23.8% extrusions. Within the three months followup interval there were 9% of adjacent and 4% of remote new fractures, all in the osteoporotic group. Conclusions: VBS showed its strengths especially in realignment of crush and biconcave fractures. Given that fracture mobility is present, the realignment potential is sound and increases with the severity of preoperative vertebral body deformation

Vertebro-/Kyphoplasty History, Development, Results

Many investigations prove the significant analgetic effect of vertebral augmentation. The reasons for the decrease in pain are found in the stabilization of fracture fragments as well as the toxic-thermic effect of polymethylmethacrylate (PMMA), used in the majority of cases. The techniques, primarily in use since 1984, can be divided in vertebro- and kyphoplasty. Vertebroplasty is the direct injection of PMMA into the trabecular vertebral body, while kyphoplasty uses an inflatable bone tamp to create a cavity which is filled with highly viscous cement allowing a certain degree of vertebral height restoration. Both techniques are used percutaneously. Indications for augmentation are painful osteoporotic vertebral fractures, metastatic osteolyses, and painful or destabilizing vertebral hemangiomas. In this article, an overview of the techniques and the history of their development is provided. The materials used for augmentation, the possibilities, limits, and complications of the techniques are discusse

Zementaugmentation bei Wirbelmetastasen (Vertebro- und Kyphoplastie)

Zusammenfassung: Pathologische Wirbelfrakturen bei Metastasen oder im Rahmen eines multiplen Myeloms können mittels einer Zementaugmentation (Vertebro- oder Kyphoplastie) effizient stabilisiert werden. Die Indikationsstellung beschränkt sich auf Läsionen im Wirbelkörper, sobald die posterioren Elemente involviert sind genügt eine Zementierung nicht mehr, ebenso wenn eine Spinalkanaleinengung/Neurokompression vorhanden ist. Technisch wird gleich verfahren wie bei der osteoporotischen Fraktur - das Extravasationsrisiko ist aber erheblich größer und die klinischen Ergebnisse sind nicht so uniform positiv wie bei Osteoporosefrakturen. Die Zementaugmentation per se ist keine Tumorbehandlung sondern eine Stabilisierung des Wirbels. Osteolysen ohne mechanische Kompromittierung brauchen keine Augmentation. Die Patientenbetreuung sollte interdisziplinär vernetzt erfolge

Experimental ex-vivo validation of PMMA-based bone cements loaded with magnetic nanoparticles enabling hyperthermia of metastatic bone tumors

Percutaneous vertebroplasty comprises the injection of Polymethylmethacrylate (PMMA) bone cement into vertebrae and can be used for the treatment of compression fractures of vertebrae. Metastatic bone tumors can cause such compression fractures but are not treated when injecting PMMA-based bone cement. Hyperthermia of tumors can on the other hand be attained by placing magnetic nanoparticles (MNPs) in an alternating magnetic field (AMF). Loading the PMMA-based bone cement with MNPs could both serve vertebra stabilization and metastatic bone tumor hyperthermia when subjecting this PMMA-MNP to an AMF. A dedicated pancake coil is designed with a self-inductance of 10 mu H in series with a capacitance of 0.1 mu F that acts as resonant inductor-capacitor circuit to generate the AMF. The thermal rise is appraised in beef vertebra placed at 10 cm from the AMF generating circuit using optical temperatures sensors, i. e. in the center of thePMMA-MNPbone cement, which is located in the vicinity of metastatic bone tumors in clinical applications; and in the spine, which needs to be safeguarded to high temperature exposures. Results show a temperature rise of about 7 degrees C in PMMA-MNP whereas the temperature rise in the spine remains limited to 1 degrees C. Moreover, multicycles heating of PMMA-MNP is experimentally verified, validating the technical feasibility of having PMMA-MNP as basic component for percutaneous vertebroplasty combined with hyperthermia treatment of metastatic bone tumors

The current treatment—a survey of osteoporotic fracture treatment. Osteoporotic spine fractures: the spine surgeon's perspective

For the spine surgeon the problems of the osteoporotic spine can be a painful simple compression fracture, the persisting instability after a fracture, the silent loss of posture due to progressive collapse of multiple vertebrae, and neurological complications related to an osteoporotic fracture. The use of polymethylmethacrylate (PMMA) for the reinforcement of osteoporotic vertebral bodies has turned out to be extremely efficient. Although the natural course of pain due to vertebral fractures decreases within the first weeks in the majority of patients, there remains a number of them with persistent pain and/or ongoing vertebral collapse. With percutaneous cement injection one can achieve fast and lasting pain reduction in 80% to 93% of patients. With multilevel injections it is possible to address the severe osteoporotic spine as a whole where we can halt the ongoing collapse and preserve posture efficiently. Rectification of lordosis can be achieved in fresh fractures with the kyphoplasty technique and, even more efficiently, with the lordoplasty procedure. Kyphosis correction ranges from 8.5° to 14°, and restoration of vertebral body (VB) height goes up to 90%. When surgical stabilization is required, the combination of PMMA reinforcement and fixation with screws appears the only alternative in order to anchor the implants in the severely osteoporotic bon

Ex vivo experimental model for percutaneous vertebroplasty: microCT utility

The aim of this study was to develop an ex vivo experimental animal model for percutaneous vertebroplasty, for further application in vivo to test novel bone injectable cements