Ten RCTs were included in the review with 1,599 patients in the treatment group and 1,480 patients in the control group.
Rosenthal's fail-safe number was 179.
LMWH is efficacious at preventing DVT following total knee arthroplasty compared to patients in the placebo group (RR 0.42; 95% CI: 0.26, 0.67) and patients in the active control groups who received either adjusted dose unfractionated heparin or warfarin (RR 0.73; 95% CI: 0.66, 0.80; number needed to treat (NNT) = 7).
For proximal DVT, LMWH is efficacious compared to patients in the active control groups who received either adjusted dose unfractionated heparin or warfarin (RR 0.58; 95% CI: 0.38, 0.90; number needed to treat (NNT) = 22).
The rate of pulmonary emboli was low in both the LMWH and the control groups, RR 0.55 (95% CI: 0.20, 1.57) which was not statistically significant. NNT was calculated at over 300 patients.
Major bleeding complications were not different between the LMWH and control groups (0-8% versus 0-10%).
The mortality rate was not significantly different between the two groups (0 deaths in the treatment group, 3 deaths in the control group).