Retrieval Analyses of Dynesys® Polymeric Implants from a United States Investigational Device Exemption Study

摘要

The Dynesys System (Zimmer GmbH, Winterthur, Switzerland) is a dynamic stabilization device developed for treating lumbar degenerative disease. The system has pedicle screws that are manufactured from Ti-6Al-7Nb, a titanium alloy that has been in clinical use in many other orthopedic devices; spacers that are manufactured from polycarbonate urethane (PCU); and cords that are manufactured from braided polyethylene terephthalate (PET).The system was first implanted in Europe in 1994 and introduced to the European market in 1999. To date it has been implanted in over 42,000 patients worldwide. In 2003, an FDA approved, prospective, randomized Investigational Device Exemption (IDE) clinical trial of the system began. The objective of the study was to compare non-fusion using the Dynesys System with fusion using pedicle screws and metal rods. Enrolled patients suffered from leg and lower lumbar symptoms and presented with evidence of spinal stenosis with up to grade I degenerative spondylolisthesis.