Isobar® Semi-Rigid Rod Alphatec OsseoFix The Isobar is a pedicle screw based semi-rigid rod designed to be part of an adjunct to fusion construct. The Isobar semi-rigid rod provides stabilization and controlled motion of the functional spinal unit while simultaneously sharing load with the interbody device. The load sharing with the interbody device, based on Wolff’s law, increases the potential of a fusion while simultaneously reducing stress on the screw-to-bone and screw-to-rod interfaces. Key Features & Benefits Load sharing construct in compression and bending Enables cyclical loading of the motion segment through semi-rigid fixation Designed to enhance load sharing between the interbody device and the vertebral endplates Designed to reduce stress on the screw-to-bone and screw-to-rod interfaces Over 10 years of clinical history The implantation technique does not differ from implantation technique for rigid rods Implant selection Key Device Dimensions 5.5 mm rod diameter 55 to 400 mm rod length, varies by part number from All components are manufactured from titanium alloy