Material and Methods

From November 2011 to July 2014 inclusive, 72 patients with a diagnosis of osteoarthritis underwent unilateral primary TKA using a computed tomography (CT) free navigation system. Patients were randomly divided into two groups: group T (n=40) was given 2000 mg (40 ml) of TA and group W (n=32) was given 40 ml sterile saline only. All operations were performed under total anaesthesia through the medial mid-vastus approach. Cemented posterior stabilised or cruciate retaining prostheses were used. The patella was resurfaced. After tourniquet release and wound suture, TA or saline was infused into the knee joint in addition to the drained-clamped method for 2 hours. For VTE prophylaxis, all patients received bilateral intermittent pneumatic calf compressors, thromboembolic deterrent stockings, and subcutaneous injection of enoxaparin (4000IU daily). We evaluated the hematocrit, hemoglobin and the postoperative estimate of bleeding. At postoperative days 4, extremity venous ultrasonography was performed for the investigation of venous thromboembolism in the latest 40 patients and contrast-enhanced CT was performed in the latest 34 patients without a previous history of asthma and diminished renal function. The present study received institutional review board approval, and informed consent was obtained from all patients.

Purpose

The purpose of this study was to compare the kinematics of the three different types of prosthesis in navigation-based in vivo simulation.

(Material and Method) Studies were carried out on 15 osteoarthritis Knees using the CT-free navigation system (Kolibri Knee, Brain LAB). Fourteen patients were female and one patient was male with mean age of 72 years. Five knees were implanted with the CR knee, 5 knees were implanted with the PS knee and 5 knees were implanted with PS mobile knee by navigated measured resection technique (PFC-sigma knee system, DePuy, Warsaw, IN). Intra-operative knee kinematics during passive range of motion from full extension to 130 degrees of knee flexion was measured after implantation while patella reduced and tourniquet released. While supporting the foot with one hand, the surgeon used his opposite hand to gently lift the thigh, flexing the hip and knee. Three types of prosthesis were compared for following factors: Presence of condylar lift-off (the gap difference greater than 1mm between medial gap and lateral gap) and anterior-posterior (AP) displacement of the center of femur relative to the tibia.

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.