The Perioperative Continuation of Aspirin in Patients Undergoing Arthroscopic Surgery of the Knee

Background: The perioperative withdrawal of aspirin increases the risk of cardiac, neurologic, and vascular thromboembolic events. The safety of continuing aspirin in patients undergoing knee arthroscopy is unknown. Hypothesis: Perioperative continuation of aspirin does not increase surgical complications or worsen outcomes in patients 50 years of age and older undergoing knee arthroscopy. Study Design: Cohort study; Level of evidence, 3. Methods: This is a single-center, institutional review board–approved, prospective matched dual-cohort study comparing the surgical complication rates and postoperative outcomes of patients taking daily aspirin with those of unmedicated controls. Ninety patients who were 50 years of age or older and taking 81 mg or 325 mg daily aspirin were matched to 90 controls. Patients were matched on age, surgery type, and the use of a tourniquet. A complication was defined as bleeding, wound dehiscence, or wound infection requiring reoperation. Postoperative outcome measures including hematoma formation, extent of ecchymosis (mm), visual analog scale (VAS) scores for pain and swelling, and the Knee Injury and Osteoarthritis Outcome Score (KOOS) were collected preoperatively and postoperatively (10-14 days and 4-6 weeks). Results: There were no complications (0%) in either cohort. There was no difference in hematoma formation (aspirin, 1.8%; controls, 2.4%; P = .79), incidence of ecchymosis (aspirin, 17%; controls, 21%; P = .70), or the average extent of ecchymosis (aspirin, 124.6 mm; controls, 80.3 mm; P = .36) between patients taking aspirin and controls. There was no significant difference in pre- or postoperative knee range of motion between controls and patients taking aspirin. The KOOS subscores and VAS pain scores were similar between patients taking aspirin and controls at baseline and at follow-up. Conclusion: The perioperative continuation of daily aspirin in patients 50 years of age and older undergoing arthroscopic procedures of the knee is safe and does not result in an increased rate of bleeding or wound complications requiring reoperation. Continued aspirin use in patients 50 years of age and older had no significant effect on postoperative physical examination measures or patient-rated outcome scores.