Internal fixation systems in the surgical treatment of spondylolisthesis

The authors of this article describe the surgical procedure for fixation of spondylolisthesis using transpedicular fixation, and offer a comparative evaluation of the DERO, CD, C-CD, SOCON, and STRYKER systems.
The evaluation involved 36 patients operated in the Rehabilitation Clinic at the Lublin Academy of Medicine during the period 1994-2000. In 11 cases the DERO fixation system was used; in 5 cases, fixation with CD or C-CD instrumentation; in 15 cases, using the SOCON system; and in 5 cases with the STRYKER instrumentation.
Indications for surgery included pain and symptoms of nerve root irritation with sciatic neuralgia. The concomitant neurological symptoms resulted from the displacement into the vertebral canal of fragments of the nucleus pulposus, or from bone-related stenosis of the vertebral canal and intervertebral foramina.
Surgical treatment involved decompression of the nerve elements and internal fixation. In all the cases reported here posterior and postero-lateral spondylodesis was performed, while in 20 cases interbody spondylodesis was additionally performed, in 14 cases using interbody plugs.
The authors analyze the reasons for complications, such implants working loose and fatigue fractures.