Diagnosis of deep venous thrombosis after total knee arthroplasty: a comparison of ultrasound and venography studies.

BACKGROUND A prospective clinical study was performed to compare the diagnostic accuracy between ultrasound and venography of deep venous thrombosis (DVT) after total knee arthroplasty (TKA). METHODS This series consisted of 55 patients (43 women and 12 men) with an average age of 61 (range, 51-81) years who underwent TKA. No pharmaceutical prophylaxis for DVT was administered. Ultrasound and venographic studies were performed to detect DVT within 5 to 7 days postoperatively. RESULTS The incidence of DVT was 36% (20 of 55) by clinical examination, 42% (23 of 55) by ultrasound study, and 58% (32 of 55) with venography. The difference in number of cases of DVT determined between ultrasound and venography study was marginally significant statistically (p=0.082). When the venographic results were used as the baseline reference, the sensitivity and specificity of the ultrasound study in the diagnosis of DVT after TKA were 87% and 63%, respectively. CONCLUSION Ultrasound is a reasonably good alternative to venography in the diagnosis of DVT after TKA. Ultrasound is non-invasive, safe, and convenient. Ultrasound can be used as the initial screening test for clinically suspected DVT to be followed by venography in cases of equivocal results of the ultrasound study and in patients with negative ultrasound results but clinically evident DVT.