摘要目的 探讨股骨隐蔽性高能量骨折骨痂形成障碍实验模型的建立及骨痂形成障碍的预防方法.方法 取成年犬20只,随机分为A、B两组,每组10只.造成闭合的左侧股骨横断形或短斜形骨折,手持骨折两端,用两骨折端沿骨干纵轴方向平行刺伤骨膜及邻近肌肉10次,刺伤深度为骨端重迭1.5 cm.A组立即行切开复位8孔钢板内固定.B组先行手法复位经皮经大转子细克氏针临时固定,10d后行切开复位8孔钢板内固定.分别于术后2、4、6、8、12周每组各处死2只犬,取出骨折标本,行大体和组织切片观察骨痂生长情况.并于术后3、6、9、12周行患侧X线片检查. 结果 大体及组织学观察结果显示:A组动物术后2周骨折处可见坏死渗液腔；术后4周渗液腔缩小,骨端发白,无组织覆盖；术后6周骨端已无渗液,骨端吸收；术后8 ～12周无任何内、外骨痂生长,骨端进一步吸收,骨生长活动完全停滞,成功建立股骨骨痂形成障碍的实验模型.B组术后2周可见侧方骨痂的芽生,术后4周直接骨痂开始芽生,术后6周直接骨痂开始会合,术后8～12周产生正好填平骨折间隙的骨痂愈合.术后12周X线片亦显示:A组骨端萎缩吸收,骨折间隙增宽；B组断端骨痂桥接稳定. 结论 本研究成功建立了早期切开复位内固定所引发的股骨隐蔽性高能量骨折骨痂形成障碍的实验模型.延期手术可以预防骨痂形成障碍.

abstractsObjective To explore ways to prevent lack of callus formation by establishing an experimental model of hidden high-energy femoral fractures with disrupted callus formation.Methods Twenty adult dogs were randomly divided into 2 equal groups to create models of closed transverse or short oblique fracture at the left hind legs after anaesthetized.The periosteum and muscles surrounding the fracture ends were stabbed by the ends longitudinally 10 times till the ends overlapped 1.5 cm.Group A was subjected to immediate open reduction and internal fixation with an 8-hole plate while group B to manual reduction and temporary fixation with a fine percutaneous Kirschner wire to stabilize the bone ends through the greater trochanter for 10 days followed by delayed open reduction and internal fixation with an 8-hole plate.At 2,4,6,8 and 12 weeks post-treatment,2 dogs in each group were sacrificed to harvest fracture specimens to observe callus growth by gross and histological examinations.Results In group A,a necrotic exudate cavity appeared around the fracture at 2 weeks,the exudate cavity narrowed and whitish bone ends were covered by no tissue at 4 weeks,the exudate disappeared and the bone ends were absorbed at 6 weeks,and no internal or external callus growth was observed at 8 to 12 weeks and the bone ends were further absorbed,indicating an experimental model of lack of femoral callus formation was successfully created.In group B,lateral callus sprouting was observed at 2 weeks,direct callus sprouting began at 4 weeks,callus formation at both ends was observed to meet each other at 6 weeks,and the callus growth bridged the fracture gap at 8 to 12 weeks.X-rays showed widened fracture gaps due to absorbed bone ends in group A and steady bridging of the gaps by callus growth in group B.Conclusions The present experiment successfully established an experimental model of hidden high-energy femoral fracture with disrupted callus formation caused by early open reduction and internal fixation.Delayed surgery may prevent lack of callus formation.