The nurse is caring for a patient who had undergone elective…

The nurse is caring for a patient who had undergone elective left total knee arthoplasty 5 days ago.   During the dressing change today, the incision appears to be dry, pink, warm, and well approximated with staples intact.  The left leg is edematous, warm to the touch, and the calf has mild to moderate erythema.  Which of the following complications may the patient be experiencing?