変形性股関節症に対するオマリー変法筋解離術の長期成績

Long-Term Clinical Results of the Modified O'Malley's Muscle Release Operation for Osteoarthritis of the Hip

　抄録：教室における変形性股関節症に対するオマリー変法筋解離術90例93関節の術後平均20年の長期成績を検討した．約7割の症例では術直後ないし1年以内に明らかな除痛効果が得られ，術後平均14年頃から疼痛の再発傾向が認められた．約2割の症例では術後約5年の経過で徐々に疼痛が軽減したが，その後の疼痛の再発傾向は少なかった．約1割の症例では明らかな除痛効果は得られなかった．THAなど追加手術を受けた時点を終点とした生存曲線では，術後10年，20年における生存率は90％，71％で，追加手術を受けていない症例の術後平均20年におけるJOAスコアは72点であった．術後，疼痛点は経過年数に，また，歩行能力とADL点は加齢にそれぞれ相関して徐々に低下する傾向がみられた．筋解離術は変形性股関節症に対する他の関節温存手術の成績と比較して遜色ない長期成績を示し，その手術侵襲が小さいことからも有用性の高い術式と思われる．

　The long-term (mean 20 years) clinical results of the modified O'Malley's muscle release operation for osteoarthritis of the hip were evaluated in 90 patients (93 hips). Eighty-one cases were in women and nine cases were in men, and the average age of the patients at the time of surgery was 48 years old. Re-operation had been performed in 28 hips (total hip arthroplasty in 27 hips, and arthrodesis in 1), and the survival rate with re-operation as the end-point was 90％ at ten years and 71％ at twenty years. Immediate postoperative pain relief was obtained in 69％ of the patients, whereas the hip pain gradually decreased (between 2～8 years) in 23％. Adequate pain relief was not obtained in 8％. The average hip function score (Japanese Orthopaedic Association score) was 72 points at the final follow-up. The pain score gradually decreased, and the decrease was significantly corelated with time after the operation. The ADL and walking ability scores gradually decreased, and the decreases were significantly corelated with the age of the patient. Deterioration in the range of hip motion was affected by both time after the operation and the age of the patient, which seemed to be the factor that limited hip function most. It was concluded that the muscle release operation for osteoarthritis of the hip is an efficient procedure for achieving pain relief and delaying prosthetic surgery, especially in young patients. Hip joint function, however, gradually deteriorates with time after surgery, which may necessitate total hip arthroplasty.