A new approach to implant alignment and ligament balancing in total knee arthroplasty focussing on joint loads.

Preservation and recovery of the mechanical leg axis as well as good rotational alignment of the prosthesis components and well-balanced ligaments are essential for the longevity of total knee arthroplasty (TKA). In the framework of the OrthoMIT project, the genALIGN system, a new navigated implantation approach based on intra-operative force-torque measurements, has been developed. With this system, optical or magnetic position tracking as well as any fixation of invasive rigid bodies are no longer necessary.

Assessment of optical localizer accuracy for computer aided surgery systems.

The technology for localization of surgical tools with respect to the patient's reference coordinate system in three to six degrees of freedom is one of the key components in computer aided surgery. Several tracking methods are available, of which optical tracking is the most widespread in clinical use. Optical tracking technology has proven to be a reliable method for intra-operative position and orientation acquisition in many clinical applications; however, the accuracy of such localizers is still a topic of discussion.

Electromagnetic tracking for CT-guided spine interventions: phantom, ex-vivo and in-vivo results.

An electromagnetic-based tracking and navigation system was evaluated for interventional radiology. The electromagnetic tracking system (CAPPA IRAD EMT, CASinnovations, Erlangen, Germany) was used for real-time monitoring of punctures of the lumbar facet joints and intervertebral disks in a spine phantom, three pig cadavers and three anaesthesized pigs. Therefore, pre-interventional computed tomography (CT) datasets were transferred to the navigation system and puncture trajectories were planned.

[Soft-tissue management in primary knee arthroplasty: common techniques, navigation and force-sensing devices].

Soft-tissue management is essential for the outcome in total knee arthroplasty. In combination with osseous resections and component positioning, correction of the underlying ligamentous dysbalance should yield a stable joint throughout the flexion arc. Different "philosophies" with regard to technique, timing and tactics in ligament balancing are described.

A comparison of continuous wave Doppler radar to impedance cardiography for analysis of mechanical heart activity.

The paper compares the data obtained from a continuous wave Doppler radar sensor based on a commercially available microwave motion sensor KMY24 to an impedance cardiograph measured using a Cardiac Output Monitor (Medis Niccomo). Both sensors are used to analyze the mechanical activity of the heart. System parameters, signal content and robustness are discussed.