Spinal transpedicular drill guide: design and application.

Short-segment stability problems of the spine, such as fracture, pseudoarthrosis, tumor, degenerative disc, and spondylolisthesis should be resolved by short-segment stabilization methods. The "rod long, fuse short" technique using traditional Harrington or Luque rods still have unavoidable problems of facet arthritis at the segments temporarily instrumented but not grafted. Transpedicular fixation of the spine is currently being used in many systems. Biomechanical studies have shown that three-level transpedicular fixation is more rigid than five-level fixation of Harrington or Luque rods. Regardless of the system used, the primary concern is how the transpedicular screw can be inserted safely through the pedicle as deep into the vertebral body as possible. A spinal transpedicular drill guide has been designed for transpedicular screws, and a prototype has been completed. Cadaver studies have been carried out and transpedicular screw position has been confirmed by computed tomography scan. Early clinical experience has demonstrated its efficacy and safety.