Venous thromboembolic disease remains the most common reason for readmission after total hip arthroplasty. Prospective analysis of screening contrast venography was done from 1984 to 2003 in 1972 patients having elective total hip arthroplasty. Patients with deep venous thrombosis or pulmonary embolism received warfarin therapy; those with negative venograms received no further anticoagulation. From 1984 to 1992, patients not completing venography were discharged without warfarin; since 1993, patients without venography received warfarin for 6 weeks. Readmission for deep venous thrombosis, pulmonary embolism, or bleeding was tracked for 6 months. Venograms were completed in 1032 patients; 175 (16.9%) had deep venous thrombosis. Deep venous thrombosis was reduced by a clinical pathway that included continuous epidural anesthesia (14.2% versus 22.5%). The overall readmission rate for venous thromboembolic disease was 1.62%, including 14 pulmonary emboli (three fatal) and 18 femoral deep venous thrombosis. Readmission occurred in 0.27% (1 of 360) patients on continued warfarin, compared with 2.2% (19 of 880) with negative venograms discharged without further anticoagulation. Three patients (0.15%) suffered fatal pulmonary emboli; all had negative venograms and received no outpatient prophylaxis. Extended outpatient warfarin therapy provided effective protection against venous thromboembolic disease readmission. Surveillance venography was a poor predictor of need for continued prophylaxis; all patients should have extended anticoagulation after total hip arthroplasty.
Level of evidence: Therapeutic study, Level I-1 (high-quality randomized trial with statistically significant difference or no statistically significant difference but narrow confidence intervals). See the Guidelines for Authors for a complete description of levels of evidence.