小児悪性骨腫瘍に対する延長型人工関節の使用経験

Experience with an Extendable Prosthesis for Malignant Bone Tumors in Children

　抄録：延長型人工関節は小児悪性骨腫瘍に対する患肢再建方法においては，将来的な脚長差を補正できる有用な再建方法の1つである．今回われわれは延長型人工関節を用いて患肢再建を行った5例についての機能評価や，問題点などを検討した．機能的にはほぼ満足する結果ではあるが，X線上大腿骨遠位置換例の2例において，International Symposium of Limb Salvage（ISOLS）のX線評価では，bone remodelingはともにfairであった．小児例の患肢温存方法の選択は腫瘍の部位，年齢，さらに化学療法の効果などを考慮して検討しなくてはいけない．特に延長型人工関節は一期的に脚長差を改善し，患肢再建が可能であるが，延長方法や延長量，人工関節に伴う諸問題など解決すべき課題はあると思われた．

　Extendable prostheses are a useful means of reconstruction for correcting possible future leg-length discrepancy after surgery for malignant bone tumors in childhood. In this study we assessed functions and problems in five patients who underwent limb reconstruction with an extendable prosthesis. The results were mostly satisfactory in terms of functional outcome, but use of a radiologic implant evaluation system as described at the international symposium on limb salvage revealed poor results in the anchorage category in two patients with femoral distant replacement.

　Limb salvage operations must be selected on the basis of tumor site, age, and the effects of chemotherapy. Although extendable prostheses temporarily improve leg-length discrepancy and allow limb reconstruction, problems, including the method and amount of extension and various problems associated with prosthesis, appeared to be in need of solution.