内侧副韧带与桡骨小头对肘外翻稳定性的作用

Roles of medial collateral ligament and radial head on valgus stability of the elbow

[目的]探讨内侧副韧带(medial collateral ligament,MCL)、桡骨小头(radial head,RH)对肘外翻稳定性的影响,评价单独或联合修复MCL、固定RH骨折的效果。[方法]6具成人新鲜尸体肘关节骨-韧带标本,依次给予:完整肘关节,MCL切断,MCL修复,MCL切断+RH骨折,MCL修复+RH骨折,MCL切断+RH固定,MCL修复+RH固定和MCL修复+RH切除8种处理,在0°~120°屈肘位施加1.5 N·m的外翻载荷下测量外翻角位移。[结果]在屈肘0°位标本8种处理状态下外翻角位移由小至大:完整标本<MCL修复+RH固定<MCL修复<MCL修复+RH骨折<MCL修复+RH切除<MCL切断<MCL切断+RH固定<MCL切断+RH骨折,整体差异有统计学意义(P<0.05)。两两比较,完整标本、MCL修复、MCL修复+RH固定、MCL修复+RH骨折和MCL修复+RH切除间外翻角位移的差异无统计学意义(P>0.05),但以上5组的外翻角位移均显著小于MCL切断、MCL切断+RH固定、MCL切断+RH骨折组(P<0.05)。资料的重复测量方差分析表明,8种标本处理状态间外翻角位移的差异有统计学意义(F_(组间)=227.670,P<0.001),5种不同屈肘角度间外翻角位移的差异有统计学意义(F_(屈角)=13.170,P<0.001),标本处理状态与屈肘角度间存在显著交互作用(F_(交互)=6.143,P<0.001)。[结论]MCL损伤即可引起肘外翻不稳定,合并RH骨折,则导致严重外翻不稳定。单独修复MCL优于单独固定RH骨折,足以恢复外翻稳定性。

[Objective]To explore the role of medial collateral ligament(MCL)and radial head(RH)on elbow valgus stability,and to evaluate the outcomes of MCL repair and RH fracture fixation alone or in combination.[Methods]Six adult cadaveric bone-ligament speci⁃mens were treated and measured successively as follows:intact specimens,MCL cutting,MCL repair,MCL cutting+RH fracture,MCL re⁃pair+RH fracture,MCL cutting+RH fixation,MCL repair+RH fixation and MCL repair+RH resection.The valgus angular displacement(VAD)was measured under 1.5 N·m valgus loading at 0°~120°flexions of the elbow.[Results]The VAD at 0°of elbow flexion ranked down-up as follows:intact specimen<MCL repair+RH fixation<MCL repair<MCL repair+RH fracture<MCL repair+RH resection<MCL cutting<MCL cutting+RH fixation<MCL cutting+RH fracture,with statistically significant overall difference(P<0.05).In term of pairwise comparison,there was no significant difference in VAD between intact specimens,MCL repair,MCL repair+RH fixation,MCL re⁃pair+RH fracture,MCL repair+RH resection(P>0.05),but the above 5 groups had significantly less VAD than MCL cutting,MCL cutting+RH fixation and MCL cutting+RH fracture group(P<0.05).As results of factorial design analysis of variance,there were statistically signifi⁃cant differences in VAD among the 8 specimen treatments(F_(treat)=227.670,P<0.01),statistically significant differences in VAD among 5 de⁃grees of elbow flexions(F_(flexion)=13.170,P<0.01),and significant interaction between specimen treatments and flexions of the elbow(F_(inter)=6.143,P<0.01).[Conclusion]MCL injury does lead to elbow valgus instability,which is considerably deteriorated by accompanied RH fracture.MCL repair alone is superior to RH fracture fixation alone to restore valgus stability.