Abstract: Devices and methods for spinal fixation employ at least first and second plates that are configured to allow progressive sliding advancement of the plate members toward one another and limit movement of the plate members away from one another after installation. A spring member associated with one bone plate may engage toothed section(s) on the other bone plate. The bone plates may each have arms that are spaced from one another and engaged by corresponding arms on the other bone plate. There may be more than two bone plates, with multiple restricted movement regions.

Abstract: A method of manufacturing a resorbable balloon designed to contain bone cement for vertebroplasty or kyphoplasty applications is described. The resorbable balloon can be inserted into a vertebral body following vertebral cavitation and filled with bone cement. The balloon remains in place in the vertebral body and resorbs over time. Methods and apparatus are also described for delivering therapeutic agents using collapsible, resorbable balloons. The balloons may be nested and filled with various therapeutic agents that are released over time at rates dependent upon structures and degradation rates of the balloons. Furthermore, the function of the hollow devices can encompass both encapsulation and therapeutic substance delivery roles simultaneously.