Biomechanical comparison of instrumented and uninstrumented multilevel cervical discectomy versus corpectomy.

Study Design: In vitro flexibility test comparing biomechanics of cervical corpectomy versus discectomy with and without instrumentation.

Objectives: To evaluate whether the additional effort required to perform multilevel discectomies instead of corpectomies is worthwhile biomechanically.

Summary Of Background Data: Both cervical corpectomy and discectomy have been shown to be effective clinically.

Biomechanical comparison of two new atlantoaxial fixation techniques with C1-2 transarticular screw-graft fixation.

Object: Two new techniques for atlantoaxial fixation have been recently described. In one technique, C-2 intralaminar screws are connected with C-1 lateral mass screws; in the second, C-1 and C-3 lateral mass screws are interconnected and C-2 is wired sublaminarly. Both techniques include a C1-2 interspinous graft.

Biomechanical assessment of anterior lumbar interbody fusion with an anterior lumbosacral fixation screw-plate: comparison to stand-alone anterior lumbar interbody fusion and anterior lumbar interbody fusion with pedicle screws in an unstable human cadaver model.

Study Design: Human lumbosacral cadaveric specimens were tested in an in vitro biomechanical flexibility experiment using physiologic loads in 5 sequential conditions.

Objective: To determine the biomechanical differences between anterior lumbar interbody fusion (ALIF) using cylindrical threaded cages alone or supplemented with an anterior screw-plate or posterior pedicle screws-rods.

Summary Of Background Data: Clinically and biomechanically, stand-alone ALIF performs modestly in immobilizing the unstable spine.

A biomechanical comparison of three anterior thoracolumbar implants after corpectomy: are two screws better than one?

Object: A flexibility experiment using human cadaveric thoracic spine specimens was performed to determine biomechanical differences among thoracolumbar two-screw plate, single-screw plate, and dual-rod systems. A secondary goal was to investigate differences in the ability of the systems to stabilize the spine after a one- or two-level corpectomy.

Methods: The authors evaluated 21 cadaveric spines implanted with a titanium mesh cage and three types of anterior thoracolumbar supplementary instrumentation after one-level thoracic corpectomies.