Rectus Capitis Posterior Minor: Histological and Biomechanical Links to the Spinal Dura Mater.

Study Design: Serial histological investigation was performed on 10 cadaveric specimens and biomechanical tests were performed on five specimens, both focused on the tissue connexion between the rectus capitis posterior minor (RCPMi) and the spinal dura.

Objective: This study had two components: to clarify the microscopic structure of the tissue link between RCPMi and the dura mater, and to evaluate the mechanical role of this tissue complex.

Summary Of Background Data: Dissection-based and imaging-based reports have suggested a connective tissue link between the RCPMi and the dura mater at the posterior-atlanto-occipital (PAO) level.

Electromagnetically tracked personalized templates for surgical navigation.

Purpose: An electromagnetic (EM) surgical tracking system was developed for orthopedic navigation. The reportedly poor accuracy of point-based EM navigation was improved by using anatomical impressions, which were EM-tracked personalized templates. Lines, rather than points, were consistently used for calibration and error evaluation.

Principal components of wrist circumduction from electromagnetic surgical tracking.

Purpose: An electromagnetic (EM) surgical tracking system was used for a functionally calibrated kinematic analysis of wrist motion. Circumduction motions were tested for differences in subject gender and for differences in the sense of the circumduction as clockwise or counter-clockwise motion.

Methods: Twenty subjects were instrumented for EM tracking.

A Toroidal Probe for Measuring Surgically Exposed Joint Centers.

Maintaining the hip center can improve the success of a total hip arthroplasty. A novel probe design, based on mating a toroid with a sphere, was used for kinematic measurements of the femoral head center and implant center in a pre-clinical study of hip joints. In an electromagnetically tracked implementation tested in a laboratory environment, the device measured a spherical center to within 1.

Personalized Guides for Registration in Surgical Navigation.

Personalized guides are increasingly used in orthopedic procedures but do not provide for intraoperative re-planning. This work presents a tracked guide that used physical registration to provide an anatomy-to-tracking coordinate frame transformation for surgical navigation. In a study using seven femoral models derived from clinical CT scans used for hip resurfacing, a guide characterization FRE of 0.

Comparing conventional and computer-assisted surgery baseplate and screw placement in reverse shoulder arthroplasty.

Background: Preoperative planning and intraoperative navigation technologies have each been shown separately to be beneficial for optimizing screw and baseplate positioning in reverse shoulder arthroplasty (RSA) but to date have not been combined. This study describes development of a system for performing computer-assisted RSA glenoid baseplate and screw placement, including preoperative planning, intraoperative navigation, and postoperative evaluation, and compares this system with a conventional approach.

Materials And Methods: We used a custom-designed system allowing computed tomography (CT)-based preoperative planning, intraoperative navigation, and postoperative evaluation.

Articular surface remodeling of the hip after periacetabular osteotomy.

Purpose: Periacetabular osteotomies are a family of surgical procedures used to treat hip dysplasia. In a periacetabular osteotomy, the operating surgeon aims to increase acetabular coverage of the femoral head. The surgical correction has mechanical goals of increasing the stability of the joint and to improving the pressure distribution across the acetabulum.