自控微动带锁髓内钉内固定对骨折愈合影响的X线平片及微血管造影观察

目的 :探讨自控微动带锁髓内钉 (AMLN )固定对骨折愈合的影响及机制。方法 :对 12只山羊两侧股骨干横断截骨 ,分别采用AMLN和GK钉固定 ,术后 7、 14、 2 8、 5 6d分批处死 ,行X线平片、微血管造影及皮质骨的血流量变化检测。结果 :AMLN固定组 ,骨痂早期数量多 ,密度高连续无中断 ,中、后期骨痂质量好 ,成熟程度高 ,骨折边愈合边改建边塑形 ,与此功能相适应 ,皮质骨骨痂内血管丰富 ,5 6d后血管基本恢复正常 ,血管均匀且扩张消失。GK钉固定组 ,骨痂数量少 ,密度低不连续有中断现象 ,骨痂内血管管径细 ,排列紊乱 ,吻合程度比较差。血液流量前者明显优于后者 ,14d后两者相差 43 % (P <0 .0 5 )。结论 :AMLN内固定所建立的有间歇性动应力刺激与传导的生物力学环境 ,使皮质骨骨痂内血管形成及血运丰富 ,骨痂的形成和强度提高 ,加快了骨质重建的速度。

Evaluation of the Results of Auto-control Micro-motion Locking Intramedullary Nail on Fracture Healing

Objective: To observe the effects of auto-control micro-motion locking intramedullary nail on fracture healing by X-ray plane film. Methods:Twelve goats were selected and bilateral femoral shafts were transected. Auto-control micro-motion locking nail was used on one side and Gross-kempf was used on the opposite side. These animals were sacrificed at 7 , 14 , 28 and 56 days postoperatively to perform X-ray plane film, microangiography and the variation of the bone blood flow. Results:In group auto-control micro-motion locking nail, a great deal of continuous callus formed densely in the early stage. In the middle-late stage, the callus matured gradully and arranged regularly. Fracture healing was accompanied by remodelling.the blood vessels in the callus were sufficient with functional needs. The blood vessels were similar to normal vessel tissue aftter 56 days. Blood vessels kept its original shape well and expansion of vessels disappeared. In Gross-kempf group,less loose incontinuous callus formed. The calibre of the blood vessels in the callus was not only tiny but interwoved as well. The degree of anastomosis was not satisfactory. The variation of the blood flow in auto-control micro-motion locking nail group was much better than Gross-kempf group. The difference was 43%( P<0.05 ) after 2 weeks. Conclusion:The biomechanical circumstance of intermittent micromove stress stimulation and conduction provided by auto-control micro-motion locking nail makes the speed of bone healing faster because it not only promotes the formation of blood vessels in callus but increased the strength of callus as well.