The radiological outcome of lumbar spinal fusion using a South African-developed dynamic spinal fixation system.

Objectives: To investigate the radiological outcome of the use of a new Cape Town-developed spinal fixation system.

Design: One hundred and fifty-five patients underwent posterior lumbar spinal fusions with this fixation system and autogenous bone graft more than a year ago. Of these 121 were available for radiological follow-up.

Setting: Spinal pedicle fixation systems are in common use in spinal fusion surgery. Most systems use rigid screws with a high rate of implant failure. In South Africa most spinal implants are imported and expensive, and this prompted the development of a locally manufactured dynamic spinal fixation system with the aim of producing a cheaper and more effective system with a lower risk of implant failure.

Outcome Measures: A visual assessment of 1-year post-surgery radiographs by a qualified independent observer looking particularly at the rate of fusion and the incidence of implant failure.

Results: Bone fusion rates were comparable to all other pedicle fixation systems but implant failure rates were considerably less than in systems using rigid screws and more comparable to a similar dynamic spinal fixation system.

Conclusions: This spinal fixation system is safe and effective in aiding bone fusion. It has a low rate of implant failure and is currently cheaper than all imported spinal fixation systems. It has therefore achieved the objectives that prompted its inception.