骨盆髋臼三维记忆内固定系统对犬骨盆弓状线部骨折力学性能的影响

目的:建立一种骨盆弓状线部骨折的动物模型,探讨骨盆髋臼三维记忆内固定系统(acetabular tri-dimen-sional memory fixation system,ATMFS)对骨折愈合及力学性能的影响。方法:选用10只成年杂种家犬,建立双侧髋臼臼顶上方1.5cm处的横形骨折动物模型,分别采用ATMFS前柱固定器和6孔重建钢板内固定,于术后1、2、4、8、12周各取2只动物,行X线检查、大体观察和生物力学测试。结果:动物术后12～24h开始站立行走,定期复查未发现骨折端移位及内固定断裂。ATMFS侧骨折端无凌乱骨痂,术后4周即可见连续性骨痂通过骨折线。生物力学测试发现术后第1、2周两侧生物力学强度差异无显著性统计学意义(P>0.05),第4、8周ATMFS侧骨折端生物力学强度明显高于钢板侧(P<0.05),术后第12周两侧生物力学强度差距缩小,但ATMFS侧仍大于钢板侧。结论:通过双侧髋臼臼顶上方的横形截骨能够建立可靠的骨盆弓状线部骨折动物模型,ATMFS的解剖位固定和其产生的持续顺应生理力线的压应力能够促进骨折愈合。

Effect of acetabular tri-dimetional memory fixation system (ATMFS) on the mechanical property of canine iliopectineal crest fracture

Objective:To establish an animal model of iliopectineal crest fracture and explore the effect of ATMFS on the mechanical property of canine iliopectineal crest fracture.Methods:Ten adult mixed breed dogs(no significant individual difference)were made transverse fracture at bilateral iliopectineal crest 1.5 cm above the dome of acetabulum,which were fixed with ATMFS and steel plate respectively.The X-ray,macropathological observation and biomechanical test were analyzed at 1,2,4,8,12 weeks after operation.Results:Animals started walking at 12 to 24 hours postoperatively.Regular examination did not detected fracture displacement and internal fixation broken.There was no disordered bony callus at ATMFS sides.Successive bone callus can be observed at 4 weeks after operation.There was on significant difference of the union strength at the first and second week(P>0.05)and ATMFS side was superior than the steel side at the 4th and 8th week(P<0.05).The disparity diminuted at the 12th week but ATMFS side was still larger than steel side.Conclusion:The animal model can be established through transverse osteotomy at bilateral iliopectineal crest,which is an effective method to study the mechanism of compression and bone formation at pelvis and acetabulum.Anatomic fixation and persistent compression corresponding with physiological line of force with ATMFS can promote bone union.