Color duplex Doppler ultrasound scanning for detection of deep venous thrombosis in total knee and hip arthroplasty patients: Incidence, location, and diagnostic accuracy compared with ascending venography

Abstract

Ninety-nine patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) were prospectively studied for deep venous thrombosis (DVT) of the lower extremity. Eighty-three hips in 42 THA patients and 107 knees in 57 TKA patients were studied with noninvasive color duplex Doppler ultrasound flow scanning and ascending venography 3–9 days after surgery. In all patients, surveillance studies were performed within 24 hours. The ultrasonographer and radiologist were blinded to the study. The incidence of DVT was significantly greater following TKA (61%) than THA (17%) ( P < .001). After TKA, significantly more DVT was found in the ipsilateral (32 of 57 patients) versus contralateral knees (3 of 50 patients), and more thrombi were located below the knee (34 of 107 knees) than above the knee (1 of 107 knees) ( P < .001). More thrombi were found in the contralateral limb after THA (5 of 41 patients vs 3 of 42 patients), but this was not significant. Two patients developed nonfatal pulmonary emboli. The sensitivity of color flow scanning was relatively poor initially (67% of above-knee patients and 57% of below-knee patients), but improved in the last 50 patients (100% of above-knee patients and 79% of below-knee patients). Negative predictive values exceeded 90% in the THA group and 87% in the TKA group. Positive predictive values ranged from 89 to 100%. Specificity was always above 96%. Longitudinal ultrasound scanning with the newer Quantum 2000 angiodynograph (Issaquah, WA) provided the best image quality. Direct imaging of the thrombus and lack of augmentation was diagnostic of deep venous thrombosis as opposed to compressibility. Color duplex Doppler ultrasound flow scanning effectively predicts the presence of DVT in the above-knee segment in patients undergoing THA or TKA. The sensitivity in locating below-knee thrombi has significantly increased to 79% and appears to be technician-dependent.