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.

A step towards individualized, anatomy-based surgical concepts for orbital decompression in Graves' orbitopathy.

The surgical armamentarium for orbital decompression in Graves'orbitopathy (GO) includes techniques for orbital wall resection using local incisions, but also techniques for orbital rim advancement or resection of the greater sphenoid wing, which require a coronal or even transcranial approach. Up to now the choice of technique rather depends on the surgeon;s preference than on objective criteria. The goal of our CT-based research project is to define morphological orbital parameters which potentially could influence the result of a given technique for orbital decompression in thyroid eye disease.

Temperature evaluation during PMMA screw augmentation in osteoporotic bone--an in vitro study about the risk of thermal necrosis in human femoral heads.

The use of polymethylmethacrylate (PMMA) bone cement to augment hip screws reduces cut-out risk but is associated with an exothermic reaction. This in vitro investigation evaluated the risk of thermal necrosis when augmenting the implant purchase with PMMA. A pilot study analyzed the effects of different PMMA layer thicknesses on temperatures around an implant.

Injection biomechanics of in vitro simulated vertebroplasty - correlation of injection force and cement viscosity.

Cement leakage is considered to be one of the major and most severe complications during percutaneous vertebroplasty. The viscosity of the material plays a key role in this context. At high cement viscosity, the risk of leakage is reduced; however, injection forces are highly increased, rendering injection difficult or even impossible.

Simple endoscope tested for atraumatic screw removal technique in trauma surgery.

A simple endoscopic device was designed and tested for atraumatic removal of bone screws. It consists of a transparent rod modified to allow illumination of the surgical field. A special retractor helps to display the implant buried in a thick layer of tissue.

Mechanical torque measurement predicts load to implant cut-out: a biomechanical study investigating DHS anchorage in femoral heads.

Introduction: Bone strength plays an important role in implant anchorage. Bone mineral density (BMD) is used as surrogate parameter to quantify bone strength and to predict implant anchorage. BMD can be measured by means of quantitative computer tomography (QCT) or dual energy X-ray absorptiometry (DXA).

Biomechanical evaluation of a new augmentation method for enhanced screw fixation in osteoporotic proximal femoral fractures.

A biomechanical investigation on eight pairs of human cadaver proximal femurs was performed to evaluate the impact of a new augmentation method on the internal fixation of osteoporotic proximal femur fractures. The study focused on enhancing implant purchase to reduce the incidence of implant cut-out in osteoporotic bone. In a left-right comparison, a conventional hip screw fixation (control) was compared to the new cement augmentation method.

Augmentation of osteoporotic bone: effect of pulsed jet-lavage on injection forces, cement distribution, and push-out strength of implants.

Demographic change in the population leads to higher incidence of fragility fractures. Fracture fixation with standard implants may lead to implant cut-out due to reduced purchase. Augmentation of the bone stock with bone cements might overcome this problem.

Augmentation of implant purchase with bone cements: an in vitro study of injectability and dough distribution.

Vertebroplasty is widely used to treat (augment) osteoporotic fractures of the spine. This technique--with or without metallic implants--might have more widespread indications, if the mechanics of the injection and distribution of the cement dough through cannulated instruments and implants were better understood. This study was performed to investigate injectability of calcium phosphate and acrylic bone cements through implant prototypes, which featured different perforated sleeve designs.

Fixation principles in metaphyseal bone--a patent based review.

Osteoporotic changes start in cancellous bone due to the underlying pathophysiology. Consequently, the metaphyses are at a higher risk of "osteoporotic" fracture than the diaphysis. Furthermore, implant purchase to fix these fractures is also affected by the poor bone quality.

Computer aided reduction and imaging.

Reduction is one of the key procedures in orthopedic trauma surgery and has been acknowledged as one of the conditions for a good outcome in intraarticular and extra-articular fractures. The information available to the surgeon during the reduction maneuver can be divided into visual and tactile information. The optimal implementation of these parameters, combined with the surgeon's individual experience, will significantly affect the results of the operation.