PFI-TT: Surgical Robotic System for Long Bone Fracture Alignment

Rowan University, Glassboro NJ

Investigators

Abstract

The broader impact/commercial potential of this Partnerships for Innovation - Technology Translation (PFI-TT) project is to greatly reduce malalignments and associated complications from femoral (thigh bone) fracture surgery. More than half of all fractures occur in long bones like the femur. In the United States, 430,000 femur fractures occur annually; and globally, motor vehicle accidents cause an estimated 1-3 million femoral shaft fractures each year. Surgery to manually align long bones is arduous and difficult due to the bone’s elongated anatomy and the opposing strength of the surrounding muscles, requiring the surgeon and medical staff to exert high traction forces during the procedure. Poor alignment of the bone fragments is a potentially serious complication, and one-third of patients experiencing this require additional corrective surgery that increases costs and more complications. The proposed robot reduces healthcare costs by eliminating repeated operations and decreasing procedure times. This benefits patients, surgeons, and hospitals by improving patient outcomes and reduces the cost of care. The proposed project develops an orthopedic surgical robotic system for long-bone fracture surgeries. A malrotation of 15° or more occurs in 28% of patients. Malalignment leads to leg-length discrepancies and abnormal gait. The proposed concept consists of a surgical robot, bone-gripping system, and force-feedback controller to manipulate the robot. This enables the surgeon to accurately apply large traction forces and precisely align the fractured bone. The proposed architecture consists of a 3-armed manipulator with two wide-open rings; it facilitates positioning the leg inside the robot, providing a large workspace for surgical maneuvers. The objectives are to: (1) optimize the design to provide highly accurate alignment of bone segments and (2) develop a force-feedback controller to accurately align bone segments, coupled with software to predict muscle forces. To achieve these objectives, the research will employ mechanical design optimization, analytical modeling, computation, experimentation, and testing on cadavers. The outcome will be a robotic platform that can be further integrated with image-guided path-planning algorithms for anatomic alignment of long-bone fractures. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.