可動型と固定型人工膝関節置換術後の可動域

Range of Motion after Total Knee Arthroplasty with a Mobile-Bearing Prosthesis or a Fixed-Bearing Prosthesis

　人工膝関節置換術における可動型と固定型のインサートはどちらが優れているかは明らかにされていない．本研究の目的は術後の可動域とHSS（Hospital for special surgery）scoreを比較することである．32例に固定型を30例に可動型のインプラントを用いて前向き研究を行った．術中操作やリハビリテーションは同様に行った．術後1年の可動域は固定型で－0.9/125.3°，可動型で－1.8/123.4°であり，HSS scoreは90.1と88.0であり，両者には有意差は認められなかった．術後短期の可動域，HSS scoreは，可動型と固定型は同等の成績であった．

　There is still controversy as to whether mobile bearing or fixed bearing total knee arthroplasty is superior. The purpose of this study was to compare the postoperative range of motion (ROM) and HSS (Hospital for Special Surgery) score of a group of 32 patients who received a fixed-bearing posterior stabilized prosthesis and a group of 30 patients who received a mobile-bearing prosthesis. The surgical procedure and postoperative rehabilitation were the same in both groups. One year after the operation range of motion was －0.9/125.3° in the group that received the fixed-type prosthesis and －1.8/123.4° in the group that received the mobile-type prosthesis, their HSS scores were 90.1 and 88.0, respectively. The differences between the two groups were not significant. We found no advantage to mobile-bearing arthroplasty over fixed-bearing arthroplasty with regard to range of motion, HSS score at the short-follow-up examination.