Experimental study of bone lengthening by epiphyseal plate distraction

本研究的目的是建立兔骨膜牵张骨延长术模型，并探讨其成骨机制。为建立新型下颌骨牵张兔三维模型，实验动物双侧下颌骨截骨后，将手指外固定器固定于上颌骨，将克氏针固定于下颌骨。用弹性橡皮筋牵引下颌骨向前，观察到良好的成骨效果。采用兔股骨远端无截骨外牵引器牵张，探讨其牵张成骨的机制。牵张10d后，组织学观察显示，相对快速牵张组(0.6 mm/d)的软骨基质明显多于缓慢牵张组(0.3 mm/d)。进一步的调查，如长期随访，评估应力对骨骺钢板和骨和周围软组织生长已被计划。

The aim of this study is to develop the rabbit model of bone lengthening by epiphyseal distraction and to investigate the mechanism of the bone formation in the epiphyseal distraction method. To develop the new three-dimensional mandibular distraction rabbit model, an external fixation device for finger was fixed to the upper jaw and Kirshner wire was set to the lower jaw of the experimental animal after bilateral osteotomy to the mandible. The mandible was distracted to forward with the elastic rubber bands and good bone formation was observed. For the investigation of the mechanism of the bone formation in the epiphyseal plate distraction, a rabbit distal femur epiphyseal plate was distracted with external distraction device without osteotomy. After 10days distraction, the histological findings revealed that much more cartilage matrix in relatively rapid distraction (0.6mm/day) group than slow distraction (0.3mm/day) group. Further investigation such as long-term follow-up, evaluation of stress to the epiphyseal plate and bone and surrounding soft tissue growth have been planning.