RESUMO
Objective To evaluate the influences of femoral rotation on dynamic alignment of the lower extremity in TKA by computer assisted surgical technology.Methods From July 2013 to August 2013,76 consecutive patients with knee osteoarthritis undergone primary-single TKA in our hospital were enrolled,including 46 males and 30 females,aged from 64 to 78 years (average,71 years).All surgeries were completed by the same professional doctor.The PFC (fixed-bearing posterior stabilized) Sigma rotating-platform was selected for all patients,and computer navigation system (Stryker(R) Navigation System Ⅱ-Cart (Stryker corporation,Kalamazoo,Michigan,USA) was used.External rotation osteotomy of the distal femur during TKA was completed according to the pre-operative external rotation angle (ERA),intraoperative transepicondylar axis (TEA) and anteroposterior (AP) line.Passive dynamic alignment of the lower extremity during knee flexion was recorded.The variation trend of hip-knee-ankle (HKA) alignment and the influences of femoral external rotation osteotomy were analysed.Results ERA calculated by the computer navigation system according to Whiteside line,TEA and the mean of Whiteside line and TEA was 5.54°±2.86°,5.21°±2.60° and 5.34°±2.38°.Compared with the ERA measured by CT,no method was better than the other two.Postoperative deviation of HKA alignment from 0° to 90° flexion was associated with the rotational alignment of the femoral component.Trend of HKA alignment during knee flexion tended to be varus,valgus or neutral according to different angles of external rotation osteotomy of the distal femur.Conclusion The HKA alignment changes during the knee flexions.External rotation osteotomy of the distal femur played a crucial role in determining dynamic HKA alignment in TKA.
RESUMO
Objective To investigate the effectiveness of intermittent pneumatic compression (IPC) devices combined with anticoagulants for the prevention of deep vein thrombosis (DVT) after joint replacement surgery.Methods All of 400 patients were involved in this prospective randomized control study with 100 total knee arthroplasty (TKA) patients and 100 total hip arthroplasty (THA) patients in each group.All patients were operated under the general anesthesia.Patients in the control group received 10 mg of rivaroxaban per day beginning 6-8 hours after the surgery.Besides the prescription of rivaroxaban, IPC devices were used just after the anesthesia in the operating theater and lasted for 48 hours in the experimental group.The diagnosis of DVT in the lower extremities was made by color Duplex sonography on the second postoperative day.The incidence rate of DVT and symptomatic pulmonary embolism was recorded.The incidence rates of total DVT, proximal DVT (p-DVT, proximal to the trifurcation of the popliteal vein), distal DVT (d-DVT, in the anterior tibial vein, posterior tibial vein or peroneal vein) and intermuscular DVT were recorded.CT pulmonary angiography was used to confirm the pulmonary embolism if it was suspected.Results The incidence rates of overall, proximal, distal and intermuscular DVT were 9.5％, 0.5％, 0.5％, 8.5％ in the experimental group and 30％, 0.5％, 5.5％, 24％ in the control group respectively.The incidence rates of total DVT, distal DVT and intermuscular DVT were significantly lower in the experimental group.The incidence rate of DVT in TKA patients and THA patients were significantly lower in the experimental group than in the control group respectively.For patients with DVT, enoxaparin was used instead of rivaroxaban, and DVT was found disappeared by color Duplex sonography 10-12 days postoperatively.Conclusion Compared with the use of rivaroxaban alone, IPC devices combined with anticoagulants can significantly reduce the incidence rate of distal DVT and intermuscular DVT in the early postoperative period after joint replacement surgery.