University of Massachusetts Medical School
In 2006 nearly 700,000 open heart surgeries were performed, each of which required a surgical bisection of the sternum. After surgery, the sternum must be fixated back together a process that usually uses cerclage wires. In a small subset of patients, these wires are ineffective at providing fixation which leads to malunion and infection of the sternum. Rigid fixation is proposed to be a better solution; however screw-plate systems are not currently optimized for the sternum. Different screw types and depths were assessed by cyclic loading (0 to 50N) in osteoporotic human sternum for 15,000 cycles. Using these results, an optimal rigid fixation system was proposed. A composite screw with novel locking head was designed that was shown to minimize displacement based on a proof of concept.
Worcester Polytechnic Institute
Major Qualifying Project
All authors have granted to WPI a nonexclusive royalty-free license to distribute copies of the work, subject to other agreements. Copyright is held by the author or authors, with all rights reserved, unless otherwise noted.