Abstract:

BACKGROUND: Spine fusion with rigid fixation is a traditional surgical method for treatment of lumbar degeneration and instability, but the clinical satisfaction rate is low, and there are potential complications. Dynesys is a new non-fusion, dynamic pedicle screw fixation system for the treatment of lumbar degeneration and instability. The system can retain spine function of intervertebral disc and facet joint integrity, maintain the normal movement between segments, as well as have no adverse effects on adjacent segments.
OBJECTIVE: To summarize and analyze Dynesys related studies, introduce its major therapeutic mechanism, biomechanics, treatment results, and indications, and contraindications.
METHODS: A computer-based online search of PubMed database (http://www.ncbi.nlm.nih.gov/sites/entrez); China HowNet Database (http://ckrd.cnki.net/grid20), VIP Database (http://www.cqvip.com/) was performed for related articles published between 1990 and 2010 with key words “Lumbar, Non fusion, Dynesys" in English and Chinese. Repeated researches were excluded. A total of 49 articles were collected and 31 were included.
RESULTS AND CONCLUSION: Dynesys is a nonfusion, dynamic or soft tissue pedicle screw stabilization system for treatment of degeneration and instability of lumbar spine. This new system is based on lumbar stability and preservation of intersegmental kinematics and alleviation of loading at the disc and the facet joints. The treatment results were similar to conventional fusion procedures; in addition, Dynesys is less invasive and eliminates the potential risk of adjacent level degeneration as well as restores the physiological stability of spine. Even if failed, traditional fusion procedure is considered. This nonfusion posterior spinal fixation prevents spinal fusion for some patients, maximizes retention of the spine functions, and is consistent with trend of current functional reconstruction of spinal nonfusion.