桡骨头完整性对肘关节稳定性的影响

Effect of radial head integrity on stability of elbow joint

目的探讨桡骨头在肘关节稳定中的作用。方法取40侧成人尸体上肢标本,制成骨-韧带标本,建立桡骨头(RH)骨折时伴有或不伴有尺侧副韧带(UCL)损伤的模型,并随机分成:完整肘关节组、RH切除+UCL完整组、UCL切断+RH完整组和RH切除+UCL切断组,每组10具。在肘关节屈曲0、30、60、90和120度时,测量前臂在施加1.96Nm外翻力矩下的肘外翻松弛度。结果在肘关节不同屈曲角度,完整肘关节的外翻松弛度最小,RH切除时肘外翻松弛度增大,单纯UCL切断时肘外翻松弛度大于单纯RH切除(P<0.05),RH切除+UCL切断时肘外翻稳定性最差。结论在对抗肘关节外翻不稳定中,UCL起主要作用,其次是RH。单纯RH骨折不能复位内固定时,RH切除是可行的;若合并UCL损伤时,可在有效修补UCL的同时作单纯RH切除,必要时行RH置换。

Objective To study the effect of radial head integrity on stability of elbow joint. Methods The fracture models of the radial head（RH） accompanied with or without the injury of the ulnar collateral ligament （UCL） were established in 40 adult cadavers, which were divided into 4 groups of intact, excision of the RH, release of the UCL and excision of the RH combined with release of the UCL with 10 specimens each. The valgus elbow laxity at 0,30,60,90 and 120 degrees of flexion was measured with 1.96-newton-meter valgus torque. Results The least valgus laxity was seen in the intact state and its stability was the best. The laxity increased after resection of the RH. The laxity was more after release of the UCL than that after resection of the RH （P〈0. 05）. The greatest laxity was observed after resection of the RH combined with release of the UCL, so its stability was the worst. Conclusion The UCL is the primary valgus stabilizer of the elbow and the RH was a secondary constraint to resist valgus instability. The resection of the RH is feasible without the injury of other tissue when the fracture can not be replaced and fixed. When there is the injury of the UCL, the resection of the RH can also be performed after the ligament is repaired simultaneously and effectively,and prosthesis replacement is recommended if necessary.