Synframe: a preliminary report.

Both endoscopic lumbar spinal surgery and the non-standardized and unstable retractor systems for the lumbar spine presently on the market have disadvantages and limitations in relation to the minimally invasive surgical concept, which have been gradually recognized in the last few years. In an attempt to resolve some of these issues, we have developed a highly versatile retractor system, which allows access to and surgery at the lumbar, thoracic and even cervical spine. This retractor system - Synframe - is based on a ring concept allowing 360 degrees access to a surgical opening in anterior as well as posterior surgery. The ring is concentrically laid over the surgical opening for the approach and is used as a carrier for retractor arms, which are instrumented with either different sizes or types of blades and/or different sizes of Hohmann hooks. In posterior surgery, nerve root retractors can also be installed. This ring also functions as a carrier for fiberoptic illumination devices and different sizes of endoscopes, used to transmit the surgical procedure out of the depth of the surgical exposure for both teaching purposes and for the surgical team when it has no longer direct visual access to the procedure. The ring is stable, being fixed onto the operating table, allowing precise minimally open approaches and surgical procedures under direct vision with optimal illumination. This ring system also opens perspectives for an integrated minimally open surgical concept, where the ring may be used as a reference platform in computer-navigated surgery.