Osteogenic differentiation of bone marrow stromal cells is hindered by the presence of intervertebral disc cells.

Background: Clinical observations indicate that the presence of nucleus pulposus (NP) tissue during spinal fusion hinders the rate of disc ossification. While the underlying mechanism remains unknown, this observation could be due to incomplete removal of NP cells (NPCs) that secrete factors preventing disc calcification, such as bone morphogenetic protein (BMP) antagonists including noggin and members of the DAN (differential screening selected gene aberrative in neuroblastoma) family.

Methods: Monolayer human bone marrow-derived mesenchymal stem cells (MSCs) were cocultured withNPCs and annulus fibrosus cells (AFCs) embedded in alginate for 21 days.

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.

Vertebral body stenting / stentoplasty.

Osteoporotic vertebral fractures are frequent. Although the majority of fractures follow a benign course, there are certain fracture types which result in severe spinal deformity and / or are associated with neurological complications. These patients should be detected early and undergo surgical treatment.

Complications related to cement leakage in sacroplasty.

Data concerning the safety of sacroplasty in terms of cement leakage is scarce. Frequency, distribution patterns and clinical consequences of cement leakage were assessed in 33 patients (28 female, mean age: 74 +/- 10 yrs; bilateral SIF: n = 30, 63 sacroplasties) treated with sacroplasty between 06/2003 and 11/2010 in a retrospective study using patients' records, operative notes and postoperative radiographs. Cement leakage was noted within the fracture gap (27%), into veins (6%), neuroforamina (3%) or in the intervertebral disc space L5/S1 (2%).

Expert's comment concerning grand rounds case entitled "a traumatic, high-energy and unstable fracture of the C5 vertebra managed with kyphoplasty: a previously unreported case" (by Nasir A. Quraishi and Sherief Elsayed).

Case presentation of a cervical spine fracture treated by kyphoplasty. The review of the case, especially the careful re-assessment of the x-rays reveals that the treatment goals have not been achieved (motion preservation, functional restoration of the vertebral body). The case report is an excellent example of our biased viewpoint in assessing our efforts.

Safety, effectiveness and predictors for early reoperation in therapeutic and prophylactic vertebroplasty: short-term results of a prospective case series of patients with osteoporotic vertebral fractures.

Introduction: Vertebroplasty (VP) is a cost-efficient alternative to kyphoplasty; however, regarding safety and vertebral body (VB) height restoration, it is considered inferior. We assessed the safety and efficacy of VP in alleviating pain, improving quality of life (QoL) and restoring alignment.

Methods: In a prospective monocenter case series from May 2007 until July 2008, there were 1,408 vertebroplasties performed during 319 interventions in 306 patients with traumatic, lytic and osteoporotic fractures.

Cardiovascular changes after PMMA vertebroplasty in sheep: the effect of bone marrow removal using pulsed jet-lavage.

Clinically, the displacement of intravertebral fat into the circulation during vertebroplasty is reported to lead to problems in elderly patients and can represent a serious complication, especially when multiple levels have to be treated. An in vitro study has shown the feasibility of removing intravertebral fat by pulsed jet-lavage prior to vertebroplasty, potentially reducing the embolization of bone marrow fat from the vertebral bodies and alleviating the cardiovascular changes elicited by pulmonary fat embolism. In this in vivo study, percutaneous vertebroplasty using polymethylmethacrylate (PMMA) was performed in three lumbar vertebrae of 11 sheep.

Hierarchical clustering of flow cytometry data for the study of conventional central chondrosarcoma.

We have investigated the use of hierarchical clustering of flow cytometry data to classify samples of conventional central chondrosarcoma, a malignant cartilage forming tumor of uncertain cellular origin, according to similarities with surface marker profiles of several known cell types. Human primary chondrosarcoma cells, articular chondrocytes, mesenchymal stem cells, fibroblasts, and a panel of tumor cell lines from chondrocytic or epithelial origin were clustered based on the expression profile of eleven surface markers. For clustering, eight hierarchical clustering algorithms, three distance metrics, as well as several approaches for data preprocessing, including multivariate outlier detection, logarithmic transformation, and z-score normalization, were systematically evaluated.

DensiProbe Spine: a novel instrument for intraoperative measurement of bone density in transpedicular screw fixation.

Study Design: Cadaver study.

Objective: To determine bone strength in vertebrae by measuring peak breakaway torque or indentation force using custom-made pedicle probes.

Summary Of Background Data: Screw performance in dorsal spinal instrumentation is dependent on bone quality of the vertebral body.

Safety and efficacy of vertebroplasty: Early results of a prospective one-year case series of osteoporosis patients in an academic high-volume center.

Background: Vertebroplasty (VP) is a cost-efficient alternative to kyphoplasty. However, it is considered inferior when it comes to maintaining safety and in vertebral body (VB) height restoration. We assess the safety and efficacy of VP in alleviating pain, improving quality of life (QoL), and restoring alignment.

The effect of pulsed jet lavage in vertebroplasty on injection forces of PMMA bone cement: an animal study.

Percutaneous vertebroplasty, comprising of the injection of polymethylmethacrylate (PMMA) into vertebral bodies, is an efficient procedure to stabilize osteoporotic compression fractures as well as other weakening lesions. Besides fat embolism, cement leakage is considered to be one of the major and most severe complications during percutaneous vertebroplasty. The viscosity of the PMMA during injection plays a key role in this context.

The effect of pulsed jet lavage in vertebroplasty on injection forces of polymethylmethacrylate bone cement, material distribution, and potential fat embolism: a cadaver study.

Study Design: In vitro testing of vertebroplasty techniques including pulsed jet-lavage for fat and marrow removal in human cadaveric lumbar and thoracic vertebrae.

Objective: To develop jet-lavage techniques for vertebroplasty and investigate their effect on cement distribution, injection forces, and fat embolism.

Summary Of Background Data: The main complications of cement vertebroplasty are cement leakage and pulmonary fat embolism, which can have fatal consequences and are difficult to prevent reliably by current vertebroplasty techniques.

Development of a computer-assisted high-pressure Injection device for vertebroplasty.

A novel computer-assisted injection device for the delivery of highly viscous bone cements in vertebroplasty is presented. It addresses the shortcomings of manual injection systems ranging from low-pressure and poor level of control to device failure. The presented instrument is capable of generating a maximum pressure of 5000 kPa in traditional 6-ml syringes and provides an advanced control interface for precise cement delivery from outside radiation fields emitted by intraoperative imaging systems.

Lordoplasty: report on early results with a new technique for the treatment of vertebral compression fractures to restore the lordosis.

Cement augmentation using PMMA cement is known as an efficient treatment for osteoporotic vertebral compression fractures with a rapid release of pain in most patients and prevention of an ongoing kyphotic deformity of the vertebrae treated. However, after a vertebroplasty there is no chance to restore vertebral height. Using the technique of kyphoplasty a certain restoration of vertebral body height can be achieved.

Radiation exposure to the surgeon during fluoroscopically assisted percutaneous vertebroplasty: a prospective study.

Study Design: A prospective case control study design was conducted.

Objectives: The purpose of the current study was to determine the intraoperative radiation hazard to spine surgeons by occupational radiation exposure during percutaneous vertebroplasty and possible consequences with respect to radiation protection.

Summary Of Background Data: The development of minimally invasive surgery techniques has led to an increasing number of fluoroscopically guided procedures being done percutaneously such as vertebroplasty, which is the percutaneous cement augmentation of vertebral bodies.

Clinical measurements of cement injection pressure during vertebroplasty.

Study Design: Clinical study of injection pressure during vertebroplasty.

Objectives: To investigate the range of injection pressures during conventional vertebroplasty interventions and to study the influence of syringe design and cement polymerization time on injection pressure.

Summary Of Background Data: Vertebroplasty is an efficient procedure for the treatment of painful vertebral fractures.

Correlation of radiographic and MRI parameters to morphological and biochemical assessment of intervertebral disc degeneration.

Unlabelled: Degenerative disc disease (DDD) is a common finding in MRI scans and X-rays. However, their correlation to morphological and biochemical changes is not well established. In this study, radiological and MRI parameters of DDD were assessed and compared with morphological and biochemical findings of disc degeneration.

2004 Young Investigator Award Winner: vertebral endplate marrow contact channel occlusions and intervertebral disc degeneration.

Study Design: Intervertebral disc degeneration was evaluated by morphologic appearance, magnetic resonance imaging, and by biochemical matrix composition. Caliber and distribution of openings of the adjacent vertebral osseous endplates were measured.

Objectives: Correlation between occlusion of vertebral endplate openings and intervertebral disc degeneration was quantified.

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.

Surgical treatment with the technique of Galveston-Luque of spine deformities associated with the prune belly syndrome.

In prune belly syndrome (PBS), spine deformities, particularly scoliosis, are the most frequent accompanying orthopedic problem (18%). We give a detailed description of two cases with prune belly-associated spine deformities. A combined anterior-posterior fusion procedure with posterior correction and stabilization according to the Galveston-Luque technique was carried out in both patients.