内置自加载牵张器重建兔下颌支的实验研究

Mandibular ramus reconstruction using embedded self-loading distractor in a rabbit.

目的 :探索牵张成骨重建下颌支缺损的新方法。方法 :以成年新西兰兔为实验动物 ,手术切除下颌骨一侧部分升支及髁状突 ,造成 1.5cm的节段性骨缺损 ,骨断端”L”形截骨形成传送盘 ,安置可完全埋置于组织内的镍钛记忆合金牵张器 ,术后 2个月时处死实验动物 ,取下颌骨观察骨缺损修复情况。结果 :镍钛记忆合金牵张器能自动完成牵张成骨 ,初步重建了缺损的下颌支 ,组织学检查可见牵张区有良好的新骨再生。结论 :内置镍钛记忆合金牵张器可自动持续弹性加载牵张成骨 ,可望成为一种具有良好应用前景的简便实用技术。

Objective:To develop an automatic and continuous distraction osteogenesis technique by using totally embedded distractor of nickel titanium (Ni-Ti) shape-memory alloy for the reconstruction of mandibular ramus. Methods:16 adult New Zealand rabbits were used in the experiment. Mandibular ramus and condyle on one side was removed to create a 1.5 cm segmental defect. A transport disc was created by 'L' shape osteotomy at the end of the remnant ramus and Ni-Ti distractor was fixed and totally embedded in tissues. The rabbits were sacrificed 2 months after operation and the mandibles were harvested.The bone reconstruction were studied with radiographic and histological examination. Results: 2 months after operation all the animals were alive and mandible function kept well.The Ni-Ti distractors were self-activated and performed distraction osteogenesis automatically. The mandibular ramus achieved preliminary reconstruction. Histological examination showed bone regeneration in the distraction area. Conclusions: Ni-Ti distractor can fulfill automatic and continuous distraction osteogenesis.