In the elderly patients with hip fracture, some often take antiplatelet drugs such as clopidogrel due to the ischemic cardiovascular or cerebrovascular diseases. In traditional practice, these patients often need to stop medication for 5-7 days before surgery. But on the other hand, delayed surgery will lead to a significant increase in fracture related complications. Therefore, the appropriate time for drug withdrawal is particularly important in this population.

Thromboelastography is a monitoring method that can accurately judge the anticoagulation status of patients. We hope to use thromboelastography to guide the time of drug withdrawal, shorten the time of drug withdrawal as much as possible, and reduce the incidence of fracture related complications without increasing the risk of massive hemorrhage.

Inclusion Criteria:

• hip fracture and operation
• taking clopidogrel for more than one week before injury, with or without taking aspirin at the same time

Exclusion Criteria:

• high energy injury (such as traffic accident, falling from height), bilateral hip fracture, multiple fractures or injuries, pathological fracture
• malignant tumor patients
• hormone users
• patients with recent active bleeding or bleeding ulcer
• primary or secondary coagulation dysfunction or depression caused by other reasons than taking antiplatelet drugs (for example, taking warfarin)
• patients with other acute or unstable diseases requiring delayed surgery (acute heart failure, myocardial infarction, cerebral infarction, cerebral hemorrhage, severe pulmonary infection, deep vein thrombosis or pulmonary embolism, etc.)