Comparative biomechanical analysis of two techniques of radiolunate plate-fusion: oblique screw vs. parallel screws.

The purpose of this prospective randomized comparative biomechanical study on four pairs of human cadaveric forearms was to discern whether primary stability following plate arthrodesis differs from the position of the screws. Four wrists were randomly assigned to either group such that one wrist of each pair was fixed via parallel screws and the other via an oblique screw crossing the radius and the lunate. Under fluoroscopic guidance, passive extension and flexion of each wrist was performed using a spring balance.

Process optimized minimally invasive total hip replacement.

The purpose of this study was to analyse a new concept of using the the minimally invasive direct anterior approach (DAA) in total hip replacement (THR) in combination with the leg positioner (Rotex- Table) and a modified retractor system (Condor). We evaluated retrospectively the first 100 primary THR operated with the new concept between 2009 and 2010, regarding operation data, radiological and clinical outcome (HOOS). All surgeries were perfomed in a standardized operation technique including navigation.

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.

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.

Electromagnetic induction heating of an orthopaedic nickel--titanium shape memory device.

Shape memory orthopaedic implants made from nickel-titanium (NiTi) might allow the modulation of fracture healing, changing their cross-sectional shape by employing the shape memory effect. We aimed to show the feasibility and safety of contact-free electromagnetic induction heating of NiTi implants in a rat model. A water-cooled generator-oscillator combination was used.

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.

Radiolunate fusion in the rheumatoid wrist via three point fixation with a mini-titanium-T-plate and oblique screw.

Purpose: Traditional surgical techniques for radiolunate arthrodesis typically result in an unsatisfactory primary stability. Thus cast immobilisation is implemented until bone healing is complete. Nonunion and implant dislocation are frequent complications.

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.

Three-dimensional measurement of femoral antetorsion: comparison to a conventional radiological method.

Purpose: The aim of our study was to produce a 3-D reconstruction of a CT dataset and compare it to the conventional method, with that same dataset, in terms of precision and the influence of femoral positioning.

Methods: A mechanical support was developed to rigidly fix the femur in a designated position. After measuring the real AT, a CT scan with different femur positions was performed.

Rotational stability of femoral osteosynthesis in femoral fractures - navigated measurements.

Rotational malalignment after intramedullary nailing of femoral fractures is common, and symptoms occur when malrotation reaches 15 degrees . Intraoperative measurement of rotation remains difficult, and multiple techniques have been described to address this. Regardless of the method used, rotational toggling may occur between the interlocking screws and the screw holes.

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.