大腿骨遠位発生悪性骨腫瘍に対する膝蓋骨半割による関節外切除術例の検討

Extraarticular Resection with Hemipatellectomy for a Malignant Bone Tumor of the Distal Femur

　大腿骨遠位発生悪性骨腫瘍に対し膝蓋骨半割による関節外切除を行い腫瘍用人工関節で再建した8例について術後機能などから問題点を検討した．症例は骨肉腫4例などで，切除縁評価はwide 7例，marginal 1例であり，平均8年6カ月の経過で再発はなかった．機能評価（ISOLS）は平均88％であり，膝の伸展力は6例が良好で，2例は不良であった．本手術は膝関節内浸潤の判定が困難な大腿骨遠位悪性骨腫瘍などに適応があり，伸展機能の維持には四頭筋腱の適切な緊張やmechanical axisの調整が必要である．

　We analyzed surgical outcome in 8 patients with malignant bone tumor of the distal femur treated by extra-articular resection with hemipatellectomy and tumor prosthesis. Four cases involved osteosarcoma. The surgical margin was wide in 7 cases and marginal in 1. Mean follow-up was 102 months. CDF was seen in 4 cases. NED in 2,DOD in 2, and none in recurrence. The functional evaluation was approximately 88％, with knee joint extension favorable in 6 and poor in 2. This surgical technique is therefore indicated for malignant bone tumor cases when tumor propagation into the knee joint is difficult to determine. To maintain knee function, it is important that the PF joint be aligned and that tension of the quadriceps tendon be adequate.