自体髂骨再造桡骨头维持肘关节稳定的实验研究

Reconstruction of radial head with autogenous iliac bone enhance stability of elbow joint:animal experimental study

目的利用兔动物模型进行实验研究,评价桡骨小头切除后用自体髂骨与尺骨冠突桡侧面融合再造桡骨头的骨愈合效果。方法选用健康成年新西兰白兔24只,随机分为实验组和对照组,每组各12只。实验组切除单侧桡骨头颈,取自体髂骨块行桡骨头再造。对照组在麻醉后行传统单侧桡骨小头切除术。2组在术后第4、8、12周分别处死4只白兔,通过大体标本测量肘关节外翻角的变化,进行影像学和骨组织形态计量分析观察骨愈合的效果。结果 2组肘关节外翻角随观察时间延长而逐渐增加,对照组增加幅度相对较大,而实验组增加幅度相对更小。大体标本肘关节外翻角测量(肘伸直位):术后12周时,对照组桡骨小头切除侧为(19.6±2.8)°,实验组桡骨头切除重建侧为(5.6±1.8)°,组间差异有统计学意义(t=4.004,P=0.028)。对照组术后均未见明显骨痂形成,实验组术后8周骨痂面积X线评分显著高于术后4周(t=5.175,P=0.014),术后12周显著高于术后8周(t=8.891,P=0.003)。实验组术后4周骨融合面部分软骨痂形成,术后8周再造骨融合面有较多骨痂形成,骨板排列无规律,术后12周再造骨融合面有大量新生骨痂形成;对照组桡骨小头切除后缺损处仅为纤维组织填充。结论改良桡骨头切除自体髂骨再造重建手术治疗Mason Ⅲ型桡骨小头骨折安全可行,自体髂骨块再造桡骨头能与尺骨冠突桡侧面牢固愈合,术后稳定性及融合效果良好。

Objective To evaluate bone healing effect of autogenous iliac bone graft reconstruction at the lateral side of proximal ulna after radial head resection with animal model.Methods Twenty-four healthy adult New Zealand white rabbits were randomly assigned to two groups：control group （n =12）,radial head was resected in unilateral forelimb;the experimental group（n =12）,autogenous iliac bone graft was implanted at the lateral side of proximal ulna after radial head resection.At 4,8 and 12 weeks after operation,elbow valgus angle,X-ray film,and bone histomorphometry were observed.Results The valgus angle of the 2 groups increased gradually.The control group increased significantly,while the experimental group had a relatively small increase.Twelve weeks after the operation,the average valgus angles of operated side in the control group were （19.6±2.8）degrees,while the average valgns angles in the experimental group were （5.6±1.8）degrees,there was significant difference between the two groups （t =4.004,P =0.028）.No osteotylus was observed in control group.In the experimental group,X-ray efficacy score at 8 weeks was significantly higher than X-ray efficacy score at 4 weeks（t =5.175,P =0.014）,and X-ray efficacy score at 12 weeks was significantly higher than that at 8 weeks（t =8.891,P =0.003）.In the experimental group,cartilage callus and some callus formation was observed at 4 weeks.More callus formation was observed at 8 weeks,with the bone plate arranged irregularly.At 12 weeks after operation,large amount of bone callus formed in the operated area.In the control group,the radial bone defect was always filled with fibrous scar tissue,without new trabecular bone.Conclusion The modified radial head excision surgery with iliac bone autograft reconstruction is safe and feasible.Postoperative stability and good fusion effect in our study suggested that the surgical method is effective,and provides a biological basis for further development of clinical application.