Pedicle screw breakage in a vertebral body: A rare complication in a dynamic stabilization device

The Dynesys system is a nonfusion pedicle-screw stabilization system, an implant device designed to preserve intersegmental kinematics and reduce loading at facet joints. Several biomechanical in vitro experiments and clinical studies have proven the efficacy of the Dynesys. The most common complication associated with the use of this system is loosening of the pedicle screw. We present here a case of a patient who developed the rare complication of pedicle screw breakage following Dynesys instrumentation. Seven months after surgery, the patient experienced progressive, intractable back pain radiating to both the buttocks. Radiography revealed breakage of the left L5 pedicle screw in addition to a halo sign around the right pedicle screw. Revision surgery with a new Dynesys instrumentation and autologous bone graft was used to treat this complication.