Hervé Deramond

Bio: Hervé Deramond is an academic researcher from University of Picardie Jules Verne. The author has contributed to research in topics: Percutaneous vertebroplasty & Magnetic resonance imaging. The author has an hindex of 27, co-authored 83 publications receiving 3573 citations. Previous affiliations of Hervé Deramond include Johns Hopkins University.

The biomechanics of vertebroplasty. The effect of cement volume on mechanical behavior.

Abstract: Study Design. Ex vivo biomechanical study using osreoporotic cadavetic vertebral bodies. Objective. To determine the association between the volume of compent injected during percutaneous vertebroplasty and the restoration of strength and stiffness in osteoporotic vertebral bodies, two investigational cements were studied: Orthocomp (Orthovita, Malvern, PA) and Simplex 20 (Simplex P with 20% by weight barium sulfate content: Stryker-Howmedica-Osteonics, Rutherford, NJ). Summary of Background Data. Previous biomechanical studies have shown that injections of 8-10 mL of cement during vertebroplasty restore or increase vertebral body strength and stiffness; however, the doseresponse association between cement volume and restoration of strength and stiffness is unknown. Methods. Compression fractures were experimentally created in 144 vertebral bodies (T6-L5) obtained from 12 osteoporotic spines harvested from female cadavers. After initial strength and stiffness were determined, the vertebral bodies were stabilized using bipedicular injections of cement totaling 2, 4, 6, or 8 mL and recompressed, after which post-treatment strength and stiffness were measured. Strength and stiffness were considered restored when post-treatment values were not significantly different from initial values. Results. Strength was restored for all regions when 2 mL of either cement was injected. To restore stiffness with Orthocomp, the thoracic and thoracolumbar regions required 4 mL, but the lumbar region required 6 mL. To restore stiffness with Simplex 20, the thoracic and lumbar regions required 4 mL, but the thoracolumbar region required 8 mL. Conclusion. These data provide guidance on the cement volumes needed to restore biomechanical integrity to compressed osteoporotic vertebral bodies.

Percutaneous vertebroplasty : a developing standard of care for vertebral compression fractures

Abstract: Acrylic cements have been used for the augmentation of weakened or partially destroyed bones for decades [(1)][1]. The term vertebroplasty originally described an open surgical procedure that introduces bone graft or acrylic cement to mechanically augment weakened vertebral bodies.

An ex vivo biomechanical evaluation of a hydroxyapatite cement for use with vertebroplasty.

Abstract: STUDY DESIGN: Comparative ex vivo biomechanical study. OBJECTIVE: To determine the strength and stiffness of osteoporotic vertebral bodies subjected to compression fractures and stabilized via bipedicular injections of the following: 1) Simplex P (Stryker-Howmedica-Osteonics, Rutherford, NJ), 2) Simplex P formulated consistent with the practice of vertebroplasty (F2), or 3) BoneSource (Stryker-Howmedica-Osteonics). SUMMARY OF BACKGROUND DATA: Little is known about the mechanical stabilization afforded by new materials proposed for use with vertebroplasty. METHODS: Vertebral bodies (T8-T10 and L2-L4) from each of 10 fresh spines were harvested from female cadavers (81 +/- 12 years), screened for bone density (t score, -3.8 +/- 1.1; bone mineral density, 0.75 +/- 15 g/cm2), disarticulated, and compressed to determine initial strength and stiffness. The fractured vertebral bodies were stabilized via bipedicular injections of 4 mL (thoracic) or 6 mL (lumbar) and then recrushed. RESULTS: Vertebral bodies repaired with Simplex P resulted in significantly greater strength (P < 0.05) relative to their prefracture states, those repaired with BoneSource resulted in the restoration of initial strength for both the thoracic and lumbar level, and those repaired with F2 resulted in significantly greater strength (P < 0.05) in the thoracic region and restoration of strength in the lumbar region. All cement treatments resulted in significantly less stiffness compared with initial values. CONCLUSIONS: All three materials tested restored or increased vertebral body strength, but none restored stiffness. Both new materials show promise for use in percutaneous vertebroplasty, but they need clinical evaluation.

A Phase-Contrast MRI Study of Physiologic Cerebral Venous Flow:

Abstract: Although crucial in regulating intracranial hydrodynamics, the cerebral venous system has been rarely studied because of its structural complexity and individual variations. The purpose of our study was to evaluate the organization of cerebral venous system in healthy adults. Phase-contrast magnetic resonance imaging (PC-MRI) was performed in 18 healthy volunteers, in the supine position. Venous, arterial, and cerebrospinal fluid (CSF) flows were calculated. We found heterogeneous individual venous flows and variable side dominance in paired veins and sinuses. In some participants, the accessory epidural drainage preponderated over the habitually dominant jugular outflow. The PC-MRI enabled measurements of venous flows in superior sagittal (SSS), SRS (straight), and TS (transverse) sinuses with excellent detection rates. Pulsatility index for both intracranial (SSS) and cervical (mainly jugular) levels showed a significant increase in pulsatile blood flow in jugular veins as compared with that in SSS. Mean cervical and cerebral arterial blood flows were 714+/-124 and 649+/-178 mL/min, respectively. Cerebrospinal fluid aqueductal and cervical stroke volumes were 41+/-22 and 460+/-149 microL, respectively. Our results emphasize the variability of venous drainage for side dominance and jugular/epidural organization. The pulsatility of venous outflow and the role it plays in the regulation of intracranial pressure require further investigation.

New technologies in spine: kyphoplasty and vertebroplasty for the treatment of painful osteoporotic compression fractures.

Abstract: Study design Literature review Objectives To describe new treatments for painful osteoporotic compression fractures in light of available scientific literature and clinical experience Summary of background data Painful vertebral osteoporotic compression fractures lead to significant morbidity and mortality This relates to pulmonary dysfunction, eating disorders (nutritional deficits), pain, loss of independence, and mental status change (related to pain and medications) Medications to treat osteoporosis (primarily antiresorptive) do not effectively treat the pain or the fracture, and require over 1 year to reduce the degree of osteoporosis Kyphoplasty and vertebroplasty are new techniques that help decrease the pain and improve function in fractured vertebrae Methods This is a descriptive review of the background leading to vertebroplasty and kyphoplasty, a description of the techniques, a review of the literature, as well as current ongoing studies evaluating kyphoplasty Results Both techniques have had a very high acceptance and use rate There is 95% improvement in pain and significant improvement in function following treatment by either of these percutaneous techniques Kyphoplasty improves height of the fractured vertebra, and improves kyphosis by over 50%, if performed within 3 months from the onset of the fracture (onset of pain) There is some height improvement, though not as marked, along with 95% clinical improvement, if the procedure is performed after 3 months Complications occur with both and relate to cement leakage in both, and cement emboli with vertebroplasty Conclusion Kyphoplasty and vertebroplasty are safe and effective, and have a useful role in the treatment of painful osteoporotic vertebral compression fractures that do not respond to conventional treatments Kyphoplasty offers the additional advantage of realigning the spinal column and regaining height of the fractured vertebra, which may help decrease the pulmonary, GI, and early morbidity consequences related to these fractures Both procedures are technically demanding

Initial outcome and efficacy of kyphoplasty in the treatment of painful osteoporotic vertebral compression fractures

Abstract: Study Design. An Institutional Review Board-approved Phase I efficacy study of inflatable bone tamp usage in the treatment of symptomatic osteoporotic compression fractures. Objectives. To evaluate the safety and efficacy of inflatable bone tamp reduction and cement augmentation, kyphoplasty, in the treatment of painful osteoporotic vertebral compression fractures. Summary of Background Data. Osteoporotic compression fractures can result in progressive kyphosis and chronic pain. Traditional treatment for these patients includes bed rest, analgesics, and bracing. Augmentation of vertebral compression fractures with polymethylmethacryiate, vertebroplasty, has been used to treat pain. This technique, however, makes no attempt to restore the height of the collapsed vertebral body. Kyphoplasty is a new technique that involves the introduction of inflatable bone tamps into the vertebral body. Once inflated, the bone tamps restore the vertebral body back toward its original height while creating a cavity that can be filled with bone cement. Patients and Methods. Seventy consecutive kyphoplasty procedures were performed in 30 patients. The indications included painful primary or secondary osteoporotic vertebral compression fractures. Mean duration of symptoms was 5.9 months. Symptomatic levels were identified by correlating the clinical data with MRI findings. Perioperative variables and bone tamp complications or issues were recorded and analyzed. Preoperative and postoperative radiographs were compared to calculate the percentage height restored. Outcome data were obtained by comparing preoperative and latest postoperative SF-36 data. Results. At the completion of the Phase I study there were no major complications related directly to use of this technique or use of the inflatable bone tamp. In 70% of the vertebral bodies kyphoplasty restored 47% of the lost height. Cement leakage occurred at six levels (8.6%). SF-36 scores for Bodily Pain 11.6-58.7, (P = 0.0001) and Physical Function 11.7-47.4, (P = 0.002) were among those that showed significant improvement. Conclusions. The inflatable bone tamp was efficacious in the treatment of osteoporotic vertebral compression fractures. Kyphoplasty is associated with early clinical improvement of pain and function as well as restoration of vertebral body height in the treatment of painful ostecporotic compression fractures.