切断肢指再接着後の骨長軸成長に関する実験的研究

Longitudinal Bone Growth after Replantation in Immature Rats

砂川 融

切断版指再接着後の骨長軸成長に対する阻血時間の影響を調べる目的で,5週齢ラット後肢切断再接着モデルを作製し,以下の実験を行った。1.切断肢を室温中(約20℃)に放置し,阻血時間を0,2,4,6,9時間とし,術後10過で再接着肢の腰骨を評価した。阻血時間が6時間を超えると長軸成長障害が出現した。組織学的には,腰骨近位成長軟骨帯に部分閉鎖や早期閉鎖を認めた。2.阻血6時間群を術後1,2,4週で評価した。術後1週ですでに長軸成長障害は出現し,組織学的には腰骨近位成長軟骨帯中央部を中心とした広範な壊死像が認められた。術後4週で組織学的に成長軟骨帯は中央部で完全に消失していた。3.切断肢を冷温保存(約4℃)し,阻血6および9時間群を作製して冷温保存の有用性について検討した。冷温保存すれば阻血9時間群においても長軸成長障害は起こらず,組織学的にも何ら異常所見を認めなかった。以上の結果より,次のような結論を得た。すなわち,阻血時間が延長すると再接着肢に術後早期から長軸成長障害が出現した。組織学的には成長軟骨帯の壊死で,阻血による成長軟骨細胞の直接的な障害と同時に,阻血による骨端動脈系の障害による間接的な影響の可能性が示唆された。切断肢指再接着においては阻血時間がなるべく短くなるように努め,特に成長期では切断肢指を冷温保存しておくことが,骨の長軸成長障害を最小限に軽減する効果のあることが確認された。

With the aim of studying the effect of ischemia time on longitudinal bone growth following replantation surgery, hind limb replantation model was produced with 5-week-old rats and the following expertments were conducted. 1. The amputated limb was left at room temperature (20℃) with ischemia time of 0, 2, 4, 6, and 9 hours and the tibia of the replanted limb was evaluated 10 weeks after the surgical procedure. When the ischemia time exceeded 6 hours, growth disturbance of tibia became apparent. Histologically, partial closure and early closure were observed in the epiphyseal plate of the proximal tibia. 2. Evaluation of the rats with 6-hour ischemia was made 1, 2, and 4 weeks after the surgical procedure. Even at one week postoperatively, growth disturbance could be observed, and extensive necrosis was rustologicaUy apparent in the central region of the epiphyseal plate of the proximal tibia. Histologically, there was complete destruction of the epiphyseal plate four weeks postoperatively. 3. Study was made on the usefulness of cold preservation of the amputated limb of the rats with ischemia for 6 and 9 hours. By cold preservation, growth disturbance could not be observed even in rats with ischemia for 9 hours. Furthermore, no abnormal findings could be observed histologically. With extension of the ischemia time, growth disturbance of the replanted limb could be observed with the disturbance becoming apparent soon after the surgical procedure. Necrosis and destruction of the epiphyseal plate observed rustologically suggest direct disturbance of chondrocytes due to ischemia and at the same time the possibility of indirect disturbance of chondrocytes due to disturbance of the epiphyseal vessels attributable to ischemia. Our study indicated that in limb replantation, efforts should be made to restrict the ischemia time to the minimal and that cold preservation of the amputated limb is important.

Replantation

Ischemia

Bone growth

Epiphyseal plate

Experiment

医学 [ 490 ]

日本語

Copyright(c) by Author

[URI] http://ir.lib.hiroshima-u.ac.jp/00020816 ～を参照している

広島大学