(HealthDay News) – Local facet joint contact pressures are not significantly altered during sagittal bending after the implantation of a ProDisc-C device at the C5–C6 level in cadaveric human cervical spines, according to a study published online Sept 12 in The Spine Journal.

Joel A. Bauman, MD, from the University of Pennsylvania in Philadelphia, and colleagues conducted a biomechanical study using seven C2–T1 osteoligamentous cadaveric cervical spines instrumented with a transducer to measure the C5–C6 facet pressure profiles during physiological sagittal bending. Pressure was measured before and after implantation of a ProDisc-C at the C5–C6 level.

The researchers found that, following implantation, the mean C5–C6 range of motion increased significantly, from 9.6±5.1 degrees in the intact condition to 16.2±3.6 degrees after implantation. During extension there was no significant difference in the facet contact pressure between the intact (64±30 kPa) and implanted (44±55 kPa) conditions, despite the changes in rotation. There was also no difference in facet pressure during flexion.

“Although implantation of a ProDisc-C arthroplasty device at the C5–C6 level increases angular rotations, it does not significantly alter the local facet pressure at the index level in flexion or extension,” the authors write. “Using a technique that preserves the capsular ligament, this study provides the first direct measurement of cervical facet pressure in a disc arthroplasty condition.”

Several authors disclosed financial ties to the medical device industry.

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