Which factor most increases the risk for complications in a patient undergoing total knee arthroplasty?

Choice A rationale The use of herbal supplements can pose risks, such as increased bleeding if the patient takes ginkgo or garlic, or interactions with anesthesia. However, these are generally manageable through preoperative screening and temporary cessation of the supplements. While important, they do not represent the same level of systemic risk for major postoperative complications, such as myocardial infarction or heart failure, as a documented history of established cardiovascular disease does in the elderly population. Choice B rationale Being under age 40 is actually a protective factor rather than a risk factor for complications. Younger patients typically have better physiological reserves, faster healing rates, and fewer comorbidities compared to older adults. Most complications in total knee arthroplasty are associated with advanced age, which often brings decreased bone density and impaired cardiovascular function. Therefore, youth generally correlates with better outcomes and a lower likelihood of experiencing systemic complications during or after the surgical procedure. Choice C rationale A vegetarian diet is not a significant risk factor for surgical complications, provided the patient maintains adequate protein and iron intake for wound healing. While extreme nutritional deficiencies can impair recovery, most vegetarians meet their nutritional needs through varied food sources. Protein is essential for collagen synthesis, but a meat-free diet does not inherently predispose a patient to poor surgical outcomes unless it is poorly managed and results in severe anemia or protein-energy malnutrition. Choice D rationale A history of heart disease is a major risk factor for complications during and after total knee arthroplasty. The stress of surgery and anesthesia can strain the cardiovascular system, leading to arrhythmias, myocardial ischemia, or heart failure. Furthermore, heart disease often necessitates the use of anticoagulants, which complicates intraoperative bleeding management and postoperative DVT prophylaxis. Patients with cardiac issues have a reduced ability to compensate for the hemodynamic shifts that occur during major orthopedic operations.