Low incidence of deep vein thrombosis after knee arthroscopy without thromboprophylaxis -: A prospective cohort study of 335 patients

Background There is little data on the risk of deep vein thrombosis after knee arthroscopy. Patients and methods We performed a prospective cohort study to establish the incidence of venous thrombo-embolic (VTE) complications after knee arthroscopy in daycare, as detected by bilateral complete compression ultrasonography (CCUS) at day 14 (11-17) postoperatively. 335 patients completed bilateral extended ultrasound. No thromboprophylaxis was given. Results 19 (5.7%; 95% CI: 3.5%-8.7%) showed VTE on CCUS, of whom 2 were symptomatic. 1 patient developed a non-fatal pulmonary embolus during the 8-week follow-up period. There was no difference in immobilization characteristics between the patients who developed postoperative DVT and those who did not; nor could other risk factors be identified. Interpretation Since the incidence of VTE is low and a specific high-risk group for the development of VTE could not be identified, it seems justified to withhold routine pharmacological thromboprophylaxis after arthroscopy of the knee in a daycare setting.