Robot-assisted endoscope guidance versus manual endoscope guidance in functional endonasal sinus surgery (FESS).

Background: Having one hand occupied with the endoscope is the major disadvantage for the surgeon when it comes to functional endoscopic sinus surgery (FESS). Only the other hand is free to use the surgical instruments. Tiredness or frequent instrument changes can thus lead to shaky endoscopic images.

The effect of distal tibial rotation during high tibial osteotomy on the contact pressures in the knee and ankle joints.

Purpose: Intraoperative fracture of the lateral cortex fractures of the tibia is a potential complication of high tibial osteotomy (HTO), which may result in inadequate rotational alignment of the distal tibia. Our aim was to determine how rotational malalignment of the distal tibial segment distal would affect intraarticular contact pressure distribution in the knee and ankle joints.

Methods: A medial, L-shaped opening-wedge HTO was performed on seven human lower body specimens.

Effect of medial opening wedge high tibial osteotomy on intraarticular knee and ankle contact pressures.

High tibial osteotomy (HTO) is a commonly used surgical technique for treating moderate osteoarthritis (OA) of the medial compartment of the knee by shifting the center of force towards the lateral compartment. Previous studies have documented the effects of HTO on the biomechanics of the knee. However, the effects of the procedure on the contact pressures within the ankle joint have not been as well described.

Software-based matching of x-ray images and 3D models of knee prostheses.

Background: Revision joint replacements are challenging surgical tasks. Knowing the exact type of primary prosthesis is essential to avoid long preoperative organisation, long operation times, and especially loss of bone and soft-tissue during operation. In daily routine there is often no information about the primary prosthesis.

Workspace and pivot point for robot-assisted endoscope guidance in functional endonasal sinus surgery (FESS).

Background: For the further development of robot-assisted endoscope guidance in functional endoscopic sinus surgery (FESS), ground data about the workspaces and endoscope movements in conventional FESS are needed.

Methods: Applying a self-developed marker-based tracking system, we collected the pose data (position and orientation) of the endoscope and all other instruments used in five real sinus surgeries.

Results: The automated segmentation of the endoscope poses shows the shape of a hourglass, with a pivot region or pivot point at the 'waistline' of the hourglass, close to the nasal entrance in the nasal dome.

Hierarchical pose estimation for human gait analysis.

Articulated structures like the human body have many degrees of freedom. This makes an evaluation of the configuration's likelihood very challenging. In this work we propose new linked hierarchical graphical models which are able to efficiently evaluate likelihoods of articulated structures by sharing visual primitives.

Hands-on robotic distal interlocking in intramedullary nail fixation of femoral shaft fractures.

Introduction: Intramedullary nailing has become the gold standard in the treatment of femoral shaft fractures. This procedure involves the placement of distal interlocking bolts using the freehand technique. Accurate placement of distal interlocks can be a challenging task, especially in inexperienced hands.

The Lower Saxony research network design of environments for ageing: towards interdisciplinary research on information and communication technologies in ageing societies.

Worldwide, ageing societies are bringing challenges for independent living and healthcare. Health-enabling technologies for pervasive healthcare and sensor-enhanced health information systems offer new opportunities for care. In order to identify, implement and assess such new information and communication technologies (ICT) the 'Lower Saxony Research Network Design of Environments for Ageing' (GAL) has been launched in 2008 as interdisciplinary research project.

A standardized fracture reduction model for long bones--implication and evaluation in the femur.

Fractures of the femoral bone are frequent injuries with a wide range of affected individuals. New treatment strategies and technologies are being explored permanently. Their quality is biomechanically judged by the accuracy of the anatomical reduction.

Robotized access to the medullary cavity for intramedullary nailing of the femur.

Introduction: The insertion site for an antegrade femoral intramedullary nail in the treatment of a femoral shaft fracture has traditionally been performed using a free-hand technique. An inappropriate starting point can result in suboptimal nail insertion leading to malreduction, or iatrogenic fracture. Furthermore, repeated attempts to establish the optimal starting point can cause additional soft tissue trauma and radiation exposure.

Robot-assisted fracture reduction using three-dimensional intraoperative fracture visualization: an experimental study on human cadaver femora.

Closed fracture reduction can be a challenging task. Robot-assisted reduction of the femur is a newly developed technique that could minimize potential complications and pitfalls associated with fracture reduction and fixation. We conducted an experimental study using 11 human cadaver femora with intact soft tissues.

3D visualized robot assisted reduction of femoral shaft fractures: evaluation in exposed cadaveric bones.

The main problems in intra-medullary nailing of femoral shaft-fractures are leg-length discrepancies and rotational differences with an incidence of 2-18% and 20-40% respectively. These may lead to severe postoperative sequelae such as additional correctional operations and difficult rehabilitation. Insufficient visualization can be considered the main reason for these complications.

A rat model for evaluating physiological responses to femoral shaft fracture reduction using a surgical robot.

The first step in treatment of displaced femoral shaft fractures is adequate reduction of the fracture fragments. Manually performed, reduction can be challenging, and is frequently associated with soft tissue damage, especially when repeated reduction attempts are made. The magnitude of local and systemic inflammatory responses caused by prolonged and repeated reduction maneuvers has not been fully established.

Ex vivo evaluation of force data and tissue elasticity for robot-assisted FESS.

The objective of this study was to describe and evaluate soft tissue and bone properties of nasal cavity and paranasal sinuses in ex vivo preparations for a safe robot-assisted endoscope movement during functional endoscopic sinus surgery (FESS). In a first experiment we measured forces exerted by the endoscope during FESS with a force/torque sensor. In a second experiment we used a purpose built device to exert forces on chosen tissue structures.

Analysis of manual segmentation in paranasal CT images.

Manual segmentation is often used for evaluation of automatic or semi-automatic segmentation. The purpose of this paper is to describe the inter and intraindividual variability, the dubiety of manual segmentation as a gold standard and to find reasons for the discrepancy. We realized two experiments.

Overdistraction of the fracture eases reduction in delayed femoral nailing: results of intraoperative force measurements.

Background: (Initial) primary external fixation of femoral shaft fractures followed by secondary intramedullary nailing is a concept of damage control orthopedics. We hypothesized that external fixation with overdistraction of the fracture might reduce reduction forces and shorten reduction time during the secondary nailing.

Methods: An experimental study on seven patients with eight fractures of the femoral shaft was conducted.

Forces and torques during fracture reduction: Intraoperative measurements in the femur.

Reduction is a crucial step in fracture treatment. We determined intraoperative peak forces and torques during fracture reduction in seven patients with eight fractures of the femoral shaft. All fractures were temporarily stabilized by external fixation.