Abstract
Total knee arthroplasty (TKA) is one of the most successful surgeries to relieve pain and dysfunction caused by severe arthritis of the knee. Despite developments in prophylactic methods, deep venous thrombosis (DVT) and pulmonary embolism (PE) continue to be a serious complication following TKA. Otherwise DVT/PE is known to be a relatively low incidence in Asian patients, its accurate incidence is still controversial. Therefore, we prospectively investigated the incidence of DVT/PE after primary TKA by contrast enhanced computed tomography (CE-CT) and venous ultrasonography (US) in Japanese Patients.
Methods
We prospectively investigated 51 patients who underwent primary TKA at the hospital from July 2013 to December 2013. All were of Japanese ethnicity. The mean age at the surgery was 74.9 years and average BMI was 26.0. There were 45 (88.2%) cases of osteoarthritis and 5 (9.8%) of rheumatoid arthritis. A single knee surgery team performed all operations with cemented type prostheses by utilizing pneumatic tourniquet. There were 21 cases of one-staged bilateral TKA and 30 of unilateral TKA. All patients were applied intermittent pneumatic compression (IPC) until 24 hours and graduated compression stockings for 3[高木1] weeks after the operation. Beginning from the day after the surgery, the patients were allowed walking with walker, along with the gradual range of motion exercise for physical thromboprophylaxis. Low-dose unfractionated heparin (LDUH) as a chemical thromboprophylaxis was administered subcutaneously for 3 days after the surgery. Informed consent was obtained regarding this thromboprophylaxis protocol. CE-CT and venous US were performed at the 4th day after surgery and images were read by a single senior radiologist team. The patients without DVT/PE by examination, they did not take additional chemical thromboprophylaxis. In cases of existence of DVT, continuous heparin administration and oral warfarin were applied and adjusted in appropriate dose for treatment. Warfarin was continued to be applied for at least three months until the patients had no symptoms and normal D-dimer level. In cases of PE, additional ultrasonic echocardiography (UCG) was performed, and then we consulted cardiologist to treat for PE.
Results
CE-CT was performed in 42 patients (82.3%), otherwise nine patients (17.7%) could not take the examination because of exclusion criteria. There was no side-effect regard to contrast medium. The incidence of DVT and/or PE was 32 patients (62.7%), including two PE (3.9%), 21 DVT (41.1%) and nine both PE and DVT (17.6%). Six-teen patients were used LDUH routinely for 3 days after surgery. Five patients were used continuous heparin administration and oral warfarin instead of using LDUH because of medical co-morbidities. Additional continuous heparin administration and oral warfarin after LDUH use was needed in 26 patients. Three patients who had duodenal ulcer with chronic pancreatitis, massive PE with right heart strain and multiple DVT/PE with HIT antibody were needed another treatment.
Conclusion
We prospectively investigated 51 patients for DVT/PE after primary TKA using CE-CT and venous US. The incidence of DVT/PE after primary TKA was 62.7%, including 21.5% of PE, as high frequency in Japanese patients.
