抄録
Objective: We report our experience with the VanguardTM tprosthesis for total knee arthroplasty (TKA) in patients with osteoarthritis (OA) and rheumatoid arthritis (RA).
Methods: Our study involved 23 patients (33 joints) who had undergone TKA at least 6 months earlier. The underlying disease was OA in 15 patients (21 joints) and RA in 8 patients (12 joints) . The mean age was 73.9 years at the time of surgery, and the mean follow-up period was 11.1 months. A posterior cruciate ligament (PCL) -retaining (CR) implant was used in 21 joints and a PCL-substituting (PS) implant was employed in 12 joints. Cement was used for fixation in all joints. Patellar replacement was not performed in any of the joints.
Results: The mean operating time was 81.1±11.7 min. None of the patients showed any problems with respect to ROM, JOA score, and component angles on plain radiographs (α, β, and δ angles) at short-term assessment. In the present series, there were no differences in the operating time and range of motion (ROM) between the CR and PS implant. However, measurement of the γ angle on plain radiographs revealed various outcomes, with placement of the femoral component in a flexed position and notch formation being detected in some patients. We also detected an inappropriate component angle or implant size in some patients. Specifically, there was a gap between the anteromedial aspect of the femur and the implant despite correct component width and anterolateral positioning of the γ angle.
Conclusion: A favorable short-term outcome was observed in patients who underwent TKA using a VanguardTM prosthesis. The sizing and osteotomy of the femur should be performed carefully by a skilled surgeon. Development of a sizing apparatus that allows precise measurement appears to be necessary. Further improvement of the outcome achieved with the VanguardTM TKA can be expected as more skill in sizing and osteotomy of the femur is acquired.
