可控性应力与微动对骨折愈合影响的组织学研究

Effects of controlled stress and micromovement on fracture healing

目的 探讨骨折端在不同轴向应力作用下,不同骨折愈合时期所需轴向应力的适宜力值. 方法 32只青山羊均行股骨干中段横行截骨制作骨折模型,按骨折端施加实验动物自身体质量的0倍（对照组）、1/6（A组）、1/3（B组）、1/2（C组）应力分为4组,每组8只.术后4、8周分批处死,每次每组处死4只,行大体观察和组织学观察,测量骨折端骨外膜骨痂面积. 结果 对照组有1只动物骨折端发生成角畸形,实验A、B、C组分别有1、2、4只动物骨折端发生成角畸形.术后4周,对照组、A、B、C组骨折端骨外膜骨痂面积平均值分别为（1.15±0.34）、（1.86±0.28）、（2.18±0.36）、（1.99±0.33）cm^2,A、B、C组分别与对照组比较,骨折端骨痂生成多,骨外膜骨痂面积差异有统计学意义（P〈0.05）.术后8周,沿轴向排列骨外膜骨痂中骨性骨痂多、致密,皮质骨松化明显 对照组、A、B、C组骨折端骨外膜骨痂面积平均值分别为（1.38±0.31）、（2.09±0.23）、（2.69±0.28）、（2.71±0.31）cm^2,A、B、C组分别与对照组比较,B、C组分别与A组比较,差异均有统计学意义（P〈0.05）. 结论 骨折端施加轴向应力时能促进骨折端骨痂生长,较大的应力强度能更好地促进骨折端骨痂生长,但同时会造成骨折愈合成角畸形发生率增高.骨折端施加自身体质量的1/3应力时骨折端成角畸形发生率较低,最适宜促进骨折端骨痂生长.

Objective To study the effects of axial stress stimuli on the healing of the fracture ends at different stages. Methods Thirty-two grey goats were randomized into 4 groups, in which stresses of 0 （control group）, 1/6 （group A）, 1/3 （group B） and 1/2 （group C） of their body weight were applied re-spectively. Transverse osteotomy at the middle shaft of the femur was performed in all groups. The goats were sacrificed in batch at 4 and 8 weeks after operation separately for histological observation and measurement of the callus area at the fracture ends. Results At 4 and 8 weeks after operation, more callus formed and the periosteum callus area at the fracture ends was significantly larger in Groups A, B and C than in the control group （P〈0.05）. In the former groups, more bony callus aligned in the axial direction and the bony callus was dense with obvious spongy transformation of cortical bone. More callus at the fracture ends was observed,more bony callus aligned in the axial direction and the bony callus was dense with obvious spongy transformation of cortical bone in groups B and C than in group A. There was no significant difference in periosteum callus area at the fourth week but obvious difference at the eighth week. There was no significant difference in callus at the fracture ends between groups B and C. Conclusions As stress at the fracture ends can improve the callus formation, it can be strengthened to enhance the effect. The strengthened stress at the fracture ends, however, may increase incidence of angnlation deformity during fracture healing.