Venous thrombosis after total hip replacement. Combined monitoring as a guide for prophylaxis and treatment.

Monitoring of 140 patients after hip-replacement arthroplasty using both impedance plethysmography and 125I fibrinogen scanning of the lower extremities showed that half had no evidence of thrombosis, one-quarter had moderate or extensive thrombosis, and one-quarter had abnormal scans only. In the patients with only abnormal scans the process appeared to resolve spontaneously. The findings by impedance plethysmography therefore appeared to differentiate non-invasively between thromboses that would and would not resolve, and it is suggested that for some patients a monitoring regimen may be preferable to routine prophylaxis.