Factors leading to decreased rates of deep vein thrombosis and pulmonary embolism after total knee arthroplasty.

We evaluated a total of 473 knees (264 patients) to determine the prevalence of deep vein thrombosis and pulmonary embolism (PE) in those who were not given thromboprophylaxis after total knee arthroplasty (TKA). Deep vein thrombosis was diagnosed by roentgenographic venography, and PE was diagnosed by perfusion lung scanning. In patients with bilateral TKA, 47 (11%) of 418 venograms showed positive findings for thrombi, whereas in patients with unilateral TKA, 11 (20%) of 55 venograms showed positive findings for thrombi (P = .758). No patient had symptoms of PE, and findings for the perfusion lung scans were negative in all patients. We neither treat our patients for deep vein thrombosis and PE prophylactically nor therapeutically unless patient has a symptomatic PE.