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

摘要:

[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＜="" 骨折＜mcl="" 切除＜mcl="" 切断＜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="" 固定、mcl="" 骨折和="" 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。＜/mcl＞

Abstract:

[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 (Finter = 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.