Treatment with low-molecular-weight heparin (LMWH) for one week after knee arthroscopy reduced the incidence of deep vein thrombosis, venous thromboembolism, and all-cause mortality to a greater degree than wearing full-length graduated compression stockings; there were no significant differences between groups in the incidence of bleeding complications.

Researchers randomly assigned 1,761 consecutive patients (mean age, 42 years) undergoing knee arthroscopy to apply full-length graduated compression stockings (n = 660) for seven days or to receive a daily LMWH injection for seven (n = 657) or 14 days (n = 444) after surgery. Bilateral leg ultrasonography was performed at the end of the treatment period. Patients with normal ultrasonography findings were followed for an additional three months to determine the cumulative incidence of asymptomatic proximal deep venous thrombosis, symptomatic venous thromboembolism, and all-cause mortality. Equally important was the safety of the LMWH treatments, as measured by the seven- or 14-day cumulative incidence of bleeding events.

The three-month cumulative incidence of asymptomatic proximal deep venous thrombosis, symptomatic venous thromboembolism, and all-cause mortality was significantly lower in the seven- and 14-day LMWH groups (0.9% in each) than in the compression stockings group (3.2%). The most common outcome was symptomatic distal deep venous thrombosis. There were no significant differences in the cumulative incidence of bleeding events: 0.3% in the graduated compression stockings group, 0.9% in the seven-day LMWH group, and 0.5% in the 14-day LMWH group. The 14-day LMWH group, in fact, was stopped after seven days because of potential safety concerns.

The authors recommend thromboprophylaxis with LMWH for one week after knee arthroscopy.

Julie Chu, MSN

Camporese G, et al. Ann Intern Med 2008;149(2):73-82.