Review of existing grading systems for cervical or lumbar disc and facet joint degeneration.

The aim of this literature review was to present and to evaluate all grading systems for cervical and lumbar disc and facet joint degeneration, which are accessible from the MEDLINE database. A MEDLINE search was conducted to select all articles presenting own grading systems for cervical or lumbar disc or facet joint degeneration. To give an overview, these grading systems were listed systematically depending on the spinal region they refer to and the methodology used for grading.

Intradiscal pressure measurements in normal discs, compressed discs and compressed discs treated with axial posterior disc distraction: an experimental study on the rabbit lumbar spine model.

Intervertebral disc (IVD) pressure measurement is an appropriate method for characterizing spinal loading conditions. However, there is no human or animal model that provides sufficient IVD pressure data. The aim of our study was to establish physiological pressure values in the rabbit lumbar spine and to determine whether temporary external disc compression and distraction were associated with pressure changes.

Limitations of the cervical porcine spine in evaluating spinal implants in comparison with human cervical spinal segments: a biomechanical in vitro comparison of porcine and human cervical spine specimens with different instrumentation techniques.

Study Design: Porcine and human cervical spine specimens were in vitro biomechanically compared with different instrumentation techniques.

Objectives: To evaluate whether subaxial porcine cervical spines are a valid model for implant testing in a single level corpectomy.

Summary Of Background Data: Biomechanical in vitro tests are widely used for implant tests, mainly with human spine specimens.

A three-dimensional collagen matrix as a suitable culture system for the comparison of cyclic strain and hydrostatic pressure effects on intervertebral disc cells.

Object: To study intervertebral disc cell mechanobiology, the authors developed experimental systems that allow the application of cyclic strain and intermittent hydrostatic pressure (IHP) on isolated disc cells under equal three-dimensional (3D) culture conditions. The purpose of the study was to characterize disc cell proliferation, viability, morphology, and gene expression in 3D collagen matrices.

Methods: The effects of cyclic strain (1, 2, 4, and 8% strain; 1 Hz) and IHP (0.

Biomechanical in vitro comparison of different mono- and bisegmental anterior procedures with regard to the strategy for fracture stabilisation using minimally invasive techniques.

Endoscopic minimally invasive techniques have become an established method of fracture stabilisation in the spine. In view of this fact, anterior stabilisation strategies must be reconsidered, as monosegmental A 3.1 compression fractures are increasingly being stabilised endoscopically from the anterior aspect using minimally invasive techniques.

Correlation between neck injury risk and impact severity parameters in low-speed side collisions.

Study Design: In vitro acceleration study on human cadaveric cervical spine specimens.

Objectives: To investigate the correlation between the risk to sustain a structural cervical spine injury and vehicle-related impact severity parameters.

Summary Of Background Data: Impact severity parameters, such as the peak acceleration of the vehicle, its mean acceleration, and its velocity change, are often used to predict the whiplash injury risk or to objectify the patient's symptoms even though their correlation to injury is still not well understood.

Solvent-preserved, bovine cancellous bone blocks used for reconstruction of thoracolumbar fractures in minimally invasive spinal surgery-first clinical results.

We investigated the osseointegration of solvent-preserved, xenogenous cancellous bone blocks in the treatment of unstable fractures of the thoracolumbar junction. In 22 patients, the anterior repair procedure was performed by thoracoscopy or minimally invasive retroperitoneal surgery. Twenty-two patients had undergone monosegmental anterior fusion and were surveyed prospectively.

Effect of constrained posterior screw and rod systems for primary stability: biomechanical in vitro comparison of various instrumentations in a single-level corpectomy model.

Cervical corpectomy is a frequently used technique for a wide variety of spinal disorders. The most commonly used approach is anterior, either with or without plating. The results for single-level corpectomy are better than in multilevel procedures.

Influence of screw-cement enhancement on the stability of anterior thoracolumbar fracture stabilization with circumferential instability.

The influence of additional dorsal structure damage on anterior stabilization of a thoracolumbar fracture is still unknown. Screw-cement enhancement can be used to reinforce the stability of anterior instrumentation. We have developed a new anchorage system for fixation of anterior stabilization devices, adapted through geometric optimization and the additional option of cementation after screw insertion.

Prospective multicenter phase II study of irinotecan as third-line therapy in metastatic colorectal cancer and progression after bolus and infusional 5-fluorouracil.

Irinotecan has proven anti-tumor activity as induction treatment in combination with 5-fluorouracil (5-FU) or as second-line treatment after 5-FU in patients with metastatic colorectal cancer. The aim of the present phase II study was to evaluate irinotecan as third-line chemotherapy in patients with colorectal cancer after sequential treatment with bolus 5-FU followed by an infusional 5-FU regimen. Patients pretreated with bolus 5-FU/folinic acid and the infusional 5-FU/folinic acid regimen were treated with 350 mg/m irinotecan i.

Pedicle screws enhance primary stability in multilevel cervical corpectomies: biomechanical in vitro comparison of different implants including constrained and nonconstrained posterior instumentations.

Study Design: 6 human cervical spines were tested in vitro in a biomechanical nondestructive set-up to compare different anterior, posterior and combined instrumentations after a corpectomy C4-C6.

Objectives: To evaluate the primary three-dimensional stability of the different instrumentations.

Summary Of Background Data: The clinical results after stabilization of multilevel corpectomies are often disappointing.

Minimally invasive ventral spondylodesis for thoracolumbar fracture treatment: surgical technique and first clinical outcome.

A new instrumentation system for ventral stabilization of the spine that can be used for an endoscopic and minimally invasive approach was developed. We describe the implantation technique and report on the first clinical results. This prospective study covers the first 45 patients to undergo this new technique since it was introduced in 1999.

Axial compression force measurement acting across the strut graft in thoracolumbar instrumentation testing.

Objective: Current recommendations for spinal implant testing do not consider the determination of axial compression forces of the overbridging implant on the strut graft. No direct data exist on the influence of load transfer through the strut graft and of the kind of instrumentation, especially in thoracolumbar corpectomy models.

Design: Therefore in this biomechanical in vitro study a method for measurement of the axial compression force acting across the strut graft in different thoracolumbar instrumentations was developed.

Enhanced primary stability through additional cementable cannulated rescue screw for anterior thoracolumbar plate application.

Object: The authors conducted a study to investigate the biomechanical in vitro influence of a new anchorage system for fixation of anterior stabilization devices and the possibility of using additional cement after screw insertion to compensate for poor bone quality. The incidence of osteoporosis-related fractures has increased nearly twofold in the last decade. Because of problems associated with anterior screw fixation such as loosening, mechanical failure, and the weakness of osteoporotic bone, current surgical treatments of vertebral body (VB) fractures are problematic.

Posterior atlantoaxial fixation: biomechanical in vitro comparison of six different techniques.

Study Design: Six different techniques for atlantoaxial fixation were biomechanically compared in vitro by nondestructive testing.

Objective: To evaluate the immediate three-dimensional stability of a new atlas claw combined with transarticular screws and alternative techniques for transarticular screw fixation in comparison with established techniques.

Summary Of Background Data: Posterior transarticular screw fixation in combination with wire-bone graft constructs is frequently used for C1-C2 fixation.

The traumatic spondylolisthesis of the axis. A biomechanical in vitro evaluation of an instability model and clinical relevant constructs for stabilization.

Objective: Stepwise destabilization of the traumatic spondylolisthesis C2 with an increasing anterior defect of C2-C3 was investigated. The three-dimensional stabilizing capabilities of posterior transpedicle screw osteosynthesis and two anterior plate systems C2-C3, the H-plate and the titanium locking plate were tested.

Design: A biomechanical in vitro study was performed using a standardized experimental protocol in a spine tester.

Pullout test with three lumbar interbody fusion cages.

Study Design: In vitro biomechanical testing was performed on 12 cadaveric human lumbar spines.

Objective: To determine the initial dislocation resistance, as quantified by the pullout force of three different cage designs.

Summary Of Background Data: Interbody cage devices frequently are used as stand-alone cages in the surgical treatment of degenerative conditions in the lumbar spine.