Duplex ultrasonography after total hip or knee arthroplasty.

We prospectively studied all patients admitted for total hip (THR) or knee (TKR) arthroplasty from July 2000 to February 2001. No pharmacological anticoagulation was given. All patients received a standardized postoperative rehabilitation regimen. Forty-six patients with known risk factors for deep vein thrombosis (DVT) were excluded. Eighty patients were studied (22 THR, 58 TKR; 55 women, 25 men). Mean age was 68 (30-90) years. Duplex ultrasonography on both lower limbs was performed on days 5-7 postoperatively. Location and extent of any thrombus were documented. In patients with distal DVT, a follow-up scan was done on days 10-14. If proximal propagation was observed, patients received full anticoagulation. If no propagation was detected, the distal thrombus was considered stable and clinical observation was continued. In the THR group, 1/22 and in the TKR group 9/58 were found to have distal DVT. All were asymptomatic. On follow-up scanning, none showed proximal propagation. All patients were followed up for at least 18 months, and none showed postthrombotic symptoms. Isolated distal DVT in "low-risk" Chinese patients after THR or TKR is not uncommon. Clinically they are usually "silent." If routine perioperative pharmacologic antithrombotic prophylaxis is not practiced, monitoring with duplex ultrasonography may need to be considered.