特発性大腿骨内顆と脛骨内顆骨壊死に対する人工膝単顆置換術（UKA）の短期治療成績

Short-term Results of Unicompartmental Knee Arthroplasty for Spontaneous Medial Femoral and Tibial Condyle Osteonecrosis of the Knee

　特発性大腿骨内顆と脛骨内顆骨壊死に対する人工膝単顆置換術(UKA)の治療成績(平均経過期間は20.2カ月)について検討した．対象は2007年以降，保存療法が無効な症例15例である．最終調査時のKnee Arthroplasty Rating System of the Hospital for Special Surgery(HSS score)において平均86点であった．1例を除いて夜間痛もなくなり，UKA自体の脱転，弛みなどは生じていない．術後短期成績ではあるが，特発性膝骨壊死に対してUKAは有効であると考えられる．

　We report the short-term results of unicompartmental knee arthroplasty for spontaneous medial femoral and tibial condyle osteonecrosis of the knee (average follow-up period 20.2 months) The subject of this study was the 15 cases since 2007 in which conservative therapy ineffective.

　The average score at the time of the final follow-up examination was 86 points according to the Knee Arthroplasty Rating System of the Hospital for Special Surgery (HSS Score).　Night pain and dislocation and loosening of the unicompartmental knee arthroplasty (UKA) developed in only one case.　Based on the short-term postoperative results UKA appears to be an effective method for treating spontaneous osteonecrosis of the knee (SPONK).