Biomechanics of fixation systems to the cervical spine.

The biomechanical evaluation of a cervical spine implant must include flexural and torsional testing if it is used for stabilizing a traumatic unstable motion segment. A cadaveric model is presented that allows flexural and torsional testing of a cervical spine motion segment, measuring the tilting angle, the translation, and the torsional angle. After measuring the intact segments, in the first series, a so-called posterior instability was created and stabilized posteriorly with the hook-plate and sublaminar wiring; anteriorly with the H-plate; and with combinations of these implants.

Diaphyseal fractures of both bones of the lower leg with associated injury of the ankle mortise.

Fractures of both bones of the lower leg may be accompanied by a disruption of the mortise with a shortening of the fibula. This combination was observed in four cases reported in this paper. The incidence of this injury may be higher if proper physical and radiological examinations are performed.