Finite element modeling of kinematic and load transmission alterations due to cervical intervertebral disc replacement.

Study Design: A parametric finite element investigation of the cervical spine.

Objective: To determine what effect, if any, cervical disc replacement has on kinematics, facet contact parameters, and anterior column loading.

Summary Of Background Data: Anterior cervical discectomy and fusion has been a standard treatment for certain spinal degenerative disorders, but evidence suggests that fusion contributes to adjacent-segment degeneration.

Finite element lumbar spine facet contact parameter predictions are affected by the cartilage thickness distribution and initial joint gap size.

Current finite element modeling techniques utilize geometrically inaccurate cartilage distribution representations in the lumbar spine. We hypothesize that this shortcoming severely limits the predictive fidelity of these simulations. Specifically, it is unclear how these anatomically inaccurate cartilage representations alter range of motion and facet contact predictions.

First experiences with semi-autonomous robotic harvesting of protein crystals.

The demonstration unit of the Universal Micromanipulation Robot (UMR) capable of semi-autonomous protein crystal harvesting has been tested and evaluated by independent users. We report the status and capabilities of the present unit scheduled for deployment in a high-throughput protein crystallization center. We discuss operational aspects as well as novel features such as micro-crystal handling and drip-cryoprotection, and we extrapolate towards the design of a fully autonomous, integrated system capable of reliable crystal harvesting.

Thermal effects of glenoid reaming during shoulder arthroplasty in vivo.

Background: Glenoid component loosening is a common cause of failure of total shoulder arthroplasty. It has been proposed that the heat generated during glenoid preparation may reach temperatures capable of producing osteonecrosis at the bone-implant interface. We hypothesized that temperatures sufficient to induce thermal necrosis can be produced with routine drilling and reaming during glenoid preparation for shoulder arthroplasty in vivo.