Meyer U, Wiesmann H P, Kruse-Lösler B, Handschel J, Stratmann U, Joos U
Department of Maxillofacial Surgery and Plastic and Reconstructive Surgery at the University of Münster, Germany.
Plast Reconstr Surg. 1999 Mar;103(3):800-7. doi: 10.1097/00006534-199903000-00005.
Distraction osteogenesis has become a mainstay in craniofacial surgery. However, there are several unresolved problems concerning the biology of bone regeneration. We investigated the biomechanical effects of mandibular lengthening in 32 rabbits on a cellular and histologic level. The mandible was subjected to a corticotomy, held in a neutral position for 4 days, and then lengthened at various strain rates and frequencies for 10 days. Radiographic, histologic, and electron microscopic examinations showed a strain-related bone regeneration. Application of physiologic strain rates (2000 microstrains or 0.2 percent) led to a bridging of the artificial fracture exhibiting woven ossification, whereas at 20,000 microstrains trabecular bone formation was demonstrated. In contrast, hyperphysiologic strain magnitudes (200,000 microstrains and 300,000 microstrains) showed a fibrous tissue formation. Multiple strain applications (10 cycles/day versus 1 cycle/day) increased the width of the distraction gap without changing the stage of bone regeneration. The gradual distraction of bone in physiologic magnitudes at higher frequencies seems to be desirable for a bony differentiation and may help to improve clinical applications.
牵引成骨术已成为颅面外科手术的主要手段。然而，关于骨再生生物学仍存在一些未解决的问题。我们在细胞和组织学水平上研究了32只兔子下颌骨延长的生物力学效应。对下颌骨进行皮质切开术，使其保持中立位置4天，然后以不同的应变率和频率延长10天。影像学、组织学和电子显微镜检查显示骨再生与应变有关。施加生理应变率（2000微应变或0.2%）导致人工骨折处出现编织骨化桥接，而在20000微应变时则显示有小梁骨形成。相比之下，超生理应变幅度（200000微应变和300000微应变）则显示为纤维组织形成。多次施加应变（每天10次循环与每天1次循环）增加了牵引间隙的宽度，但未改变骨再生阶段。在生理幅度下以较高频率逐渐牵引骨似乎有利于骨分化，并可能有助于改善临床应用。
