It appears that the incidence of symptomatic DVT is one fifth to one tenth of the incidence of venography detected DVT.
Although venography diagnosed DVT rates have been found consistently higher in total knee arthroplasty versus total hip arthroplasty, rates of symptomatic venous thromboembolic complications were similar between surgeries.
No apparent differences in efficacy among the various LMWH were found in the prevention of venographically diagnosed thromboembolism in patients undergoing hip or knee arthroplasty.
LMWH were significantly more efficacious than UFH at preventing venography detected DVT in patients undergoing total hip or knee arthroplasty.
LMWH were significantly more efficacious than warfarin at preventing venography detected total DVT in patients undergoing knee arthroplasty. No such difference was observed in patients undergoing hip arthroplasty.
Warfarin prophylaxis was as equally efficacious as LMWH in preventing symptomatic thromboembolic complications following total hip arthroplasty. Although warfarin was found to be more efficacious than LMWH in total knee arthroplasty, the cost-effectiveness analysis assumed similar efficacy due to limited data.
Meta-analysis of four major trials showed the risk of major bleeds was more than double with LMWH prophylaxis than warfarin.