A Clinical Comparison of All-Polyethylene and Metal-Backed Tibial Components in Total Knee Arthroplasty in Chai Nat Hospital-การเปรียบเทียบผลลัพธ์ทางคลินิกของการผ่าตัดเปลี่ยนข้อเข่าเทียมระหว่าง All-Polyethylene และ Metal-Backed Tibial Components ในโรงพยาบาลชัยนาท

บทคัดย่อ

         Total knee arthroplasty is a predictable and successful procedure for osteoarthritis of the knee.The purpose of the present study was to compare results between all-polyethylene component and a metal-backed tibial component. From August 1997 to March 2007, 235 total knee arthroplasties
were performed in 189 patients at the Chai Nat Hospital. All patients required primary total knee arthroplasty and prospectively to receive either a cemented posterior cruciate ligament substituting prosthesis all-polyethylene component or a metal-backed tibial component with identical articular surfaces. All patients received identical cemented femoral and all-polyethylene patella implants.
Descriptive statistics and t-test were employed in the analysis. In all there were 206 joints in 159 patients (71 all-polyethylene tibias and 135 metal-backed tibias), 37 men and 122 women who were followed for a year. The diagnosis was primary osteoarthritis in 93.20 percent of this population. The preoperative Knee Society score in the group of patients who received an all-polyethylene tibial
component was 56.51 points, improved to 92.51 points at the latest followup, whereas in the group of patients who received a metal-backed tibial component, the score improved from 55.87 to 92.83 points. Knee functional scores increased from preoperative values of 50.99 to 72.18 points in the patients who received all-polyethylene tibial components, and 49.41 to 72.78 points in the other
group. Range of motion measured at latest followup averaged 122.32 degrees in patients who received an all-polyethylene tibial component and 121.30 degrees in the patients who received a metal-backed component. These differences between clinical outcomes of the two groups were not statistically significant. Total knee arthroplasty with a well-designed, contemporary congruent
all-polyethylene tibial component functions equivalently to its metal-backed tibial component; it is less costly and improves quality of life. 

Key words: knee osteoarthritis, all-polyethylene tibial component, metal-backed tibial component, total knee arthroplasty