Ohio State’s Ehud Mendel, MD, and William Marras, PhD, are taking personalized medicine in spine surgery to another level with their sophisticated spine modeling. Using computed tomography (CT) scans and magnetic resonance imaging (MRI), Dr. Marras and his team at Ohio State’s Spine Research Institute build person-specific, dynamic models that represent muscle location and size, subject motion and muscle activities, include anatomic detail, and take advantage of flexible multi-body dynamics to enable a surgeon to assess various surgical approaches for each patient before setting foot in the operating room. Dr. Marras, who directs the Spine Research Institute and is a professor in the departments of Physical Medicine and Rehabilitation, Orthopaedics and Neurological Surgery at Ohio State, has been honing his spine modeling techniques for more than 30 years. His interactive, computer-generated, biomechanical models enable spine surgeons to calculate forces on various tissues, muscles and bones under different exertions and test conditions. Two in vivo (inside the body) methods are used to validate the models and are based on the ability to match measured and predicted external loads and intervertebral kinematics. Currently, the success rate for traditional spine surgeries is around 50 percent due to many variables and unknown factors that affect outcomes. Dr. Mendel, who directs the Spine Program and is a professor in the departments of Neurological Surgery, Orthopaedics, Internal Medicine and Integrated Systems Engineering at Ohio State, partially credits his high surgical success rate to these advanced spine modeling capabilities and the ability to test different surgical options and their likely outcomes in advance. For example, the model may reveal a better screw placement location than surgeons had originally proposed. Utilizing spine modeling, physicians can develop and practice techniques to create an individualized treatment plan for each patient and each surgery.