小转子固定和骨水泥强化在骨质疏松性股骨转子间骨折中的应用

Application of small trochanteric fixation and bone cement reinforcement in osteoporotic intertrochanteric fracture of femur

目的探讨小转子固定和骨水泥强化技术对A2型老年骨质疏松性股骨转子间骨折股骨近端防旋髓内钉(proximal femoral nail antirotation,PFNA)内固定后稳定性的生物力学研究及比较。方法选取老年骨质疏松股骨标本24例,制作A2型股骨转子间不稳定骨折模型,采用随机数字表法将其分成骨水泥强化组(n=8)、小转子固定组(n=8)和对照组(n=8)。其中,骨水泥强化组完成PFNA固定后先通过螺旋刀片的中空管道注入骨水泥,小转子固定组在完成PFNA固定后先将环扎钢丝放置在小转子骨块顶端,再将股骨外侧拧紧后对小转子部位予以固定。对照组仅给予PFNA固定。通过生物力学机器测量三组标本骨折端间距、位移情况(滑动位移、压缩位移)和承载力(极限载荷力、最大载荷力),分析不同辅助技术对髓内钉固定后骨折稳定性的影响。结果压缩后骨水泥强化组、小转子固定组骨折端间距均大于对照组,其差异均具有统计学意义(均P<0.05),而骨水泥强化组和小转子固定组比较,其差异无统计学意义(P>0.05);骨水泥强化组和小转子固定组压缩位移均低于对照组,其差异均具有统计学意义(均P<0.05),骨水泥强化组和小转子固定组比较,其差异无统计学意义(P>0.05);而骨水泥强化组和小转子固定组滑动位移均低于对照组,小转子固定组滑动位移低于骨水泥强化组,其差异均具有统计学意义(均P<0.05);骨水泥强化组和小转子固定组极限载荷力和最大载荷力均高于对照组,其差异均具有统计学意义(均P<0.05),而骨水泥强化组和小转子固定组比较,其差异无统计学意义(P>0.05)。结论相对于普通PFNA,骨水泥强化型PFNA和小转子固定PFNA能够有效增加A2型老年股骨转子间不稳定骨折骨折端的稳定性,可以达到早期负重的目的,且小转子固定PFNA在防止骨折端滑动方面效果更优,临床可以结合患者具体情况使用合适的辅助技术。

Objective To explore the biomechanical study and comparison of small trochanter fixation and bone cement reinforcement on the stability of proximal femoral nail antirotation(PFNA)internal fixation after the treatment of A2-type osteoporotic intertrochanteric femoral fractures in the elderly.Methods Twenty-four elderly osteoporotic femoral specimens were selected to create an unstable A2-type intertrochanteric fracture model.According to the random number table method,they were divided into three groups:bone cement reinforcement group(n=8),small trochanter fixation group(n=8),and control group(n=8).In the bone cement reinforcement group,after the completion of PFNA fixation,bone cement was injected through the hollow channel of the spiral blade.In the small trochanter fixation group,after the completion of PFNA fixation,a cerclage wire was placed on the top of the small trochanter bone block,and after tightening the lateral femur,the small trochanter area was fixed.The control group was only given PFNA fixation.The biomechanical machine was used to analyze the fracture end distance,displacement(sliding displacement,compressive displacement),and load-bearing capacity(ultimate load force,maximum load force)of the three groups,and analyzed the impact of different assistive techniques on the stability of the fracture after intramedullary nail fixation.Results After compression,the fracture end distances in the bone cement reinforcement group and the small trochanter fixation group were all greater than that in the control group,and the differences were all statistically significant(all P<0.05),but there was no significant difference between the bone cement reinforcement group and the small trochanter fixation group(P>0.05).The compressive displacements in the bone cement reinforcement group and the small trochanter fixation group were all lower than that in the control group,and the differences were statistically significant(all P<0.05),but there was no significant difference between the bone cement reinforcement group and the small trochanter fixation group(P>0.05).The sliding displacements in both the bone cement reinforcement group and the small trochanter fixation group were lower than that in the control group,and the sliding displacements in the small trochanter fixation group were lower than that in the bone cement reinforcement group,with all differences being statistically significant(all P<0.05);the ultimate load force and maximum load force in both the bone cement reinforcement group and the small trochanter fixation group were all higher than those in the control group,with the differences being statistically significant(all P<0.05),while there was no significant difference between the bone cement reinforcement group and the small trochanter fixation group(P>0.05).Conclusions Compared to conventional PFNA,bone cement-reinforced PFNA and small trochanter fixed PFNA can effectively increase the stability of the fracture ends in unstable A2-type intertrochanteric fractures in the elderly,allowing for early weight-bearing,and the small trochanter fixed PFNA is more effective in preventing sliding displacement of the fracture ends.Clinically,appropriate auxiliary techniques can be used in conjunction with the specific conditions of the patient.