Sometimes there is infection of the sternum subsequent to open heart surgery as well as problems with wires not efectively holding secure union of the sternum. There is a procedure where a flap is placed over the sternum, containing abdominal wall muscle, etc. This serves to protect the chest cavity from minor contact with people and objects, that most people would encounter in daily living. I am providing a link that provides more information that will help you understand condition and treatment.
Thanks for your question, and if you have any further questions or comments you are welcome to reaspond. I wish your father well going forward, take care,
Ken
http://www.dukehealth.org/services/plastic_surgery/programs/sternum_chest_wall_reconstruction
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