Efficacy of fixed minidose warfarin prophylaxis in total hip replacement.

OBJECTIVE

To determine whether a small fixed perioperative dose of warfarin would prevent deep vein thrombosis after total hip replacement.

DESIGN

Prospective, randomised, double blind placebo controlled trial.

SETTING

Winford Orthopaedic Hospital, Bristol.

SUBJECTS: 148 patients having primary total hip replacement.

INTERVENTION: Warfarin 1 mg given daily for one week before and three weeks after surgery.

MAIN OUTCOME MEASURE: Deep vein thrombosis diagnosed by the iodine-125 labelled fibrinogen uptake method.

RESULTS

Deep vein thrombosis occurred in 25 (34%) of the patients given warfarin and 19 (26%) of the controls (difference 8%; 95% confidence interval -6.8% to 22.8%).

CONCLUSION

Fixed minidose warfarin does not prevent deep vein thrombosis after total hip replacement.