全髋置换后修补闭孔外肌对髋关节稳定性的影响

目的 研究闭孔外肌及其覆盖区髋关节囊的解剖特点,探讨髋关节屈曲内旋下闭孔外肌对髋关节的稳定作用.方法 取10具20侧甲醛液固定的成人尸体髋标本,左侧10髋解剖出闭孔外肌,屈曲内旋时触摸体会股骨头对闭孔外肌的膨顶;裸露闭孔外肌区的髋关节,分别测量髋关节屈曲30°、60°、90°和各屈曲角度加内旋15°时股骨头软骨面超出髋臼唇的距离;右侧10髋解剖出髋关节囊,测量后方关节囊各部厚度,观察坐股韧带走行.结果 闭孔外肌是紧贴髋关节囊后下部的唯一肌肉,在髋屈曲内旋时股骨头膨顶闭孔外肌;随着屈曲角度的增大,膨顶程度(后脱位倾向)也加大,同一屈曲角度下内旋比不内旋膨顶程度大.髋后方关节囊的厚度具有不均一性,较薄弱的两部处在闭孔外肌区,坐股韧带主干未经过闭孔外肌区,闭孔外肌区是髋后方关节囊的相对薄弱区.结论 闭孔外肌是髋关节囊后下部唯一的动力抵挡,易诱发后脱位的髋屈曲内旋体位下,抵挡股骨头脱位的主要有闭孔外肌和此肌覆盖区的关节囊,但此区关节囊相对薄弱,因此在全髋置换后应对闭孔外肌进行修补.

The effect of obturator externus in enhanced posterior soft tissue repair of total hip replacement

Objective To investigate anatomic feature of obturator externus and the region of hip joint capsule covered by it and to probe hip stabilization offered by obturator externus in hip flexion and internal rotation.Methods Ten adult cadaver pelvises were used.Following dissection and measurement,ten left hips were used for obturator externus experiment.After touching and understanding obturator externus in hip flexion and internal rotation,the distance of femoral head cartilage side exceeding acetabular labrum in exposed obturator externus region was measured in hip flexion 30°、60°、90°and internal rotation 15°adding to different hip flexion angle.Ten left hips were used for hip joint capsule experiment.Following dissection,the average thickness of every part of the posterior hip joint capsule was measured and the ischiofemorale ligament was observed.Results Obturator externus was the unique muscle tightly sticking to posteroinferior parts of hip joint capsule.In hip flexion and internal rotation,obturator externus was expanded and pushed by femoral head.The extent of expansion and push increases following hip flexion angle's increase.In the same flexion angle,the extent of expansion and push on internal rotation was greater than that of non-rotation.The thickness in the posterior hip joint capsule was ununiformity.Two weaker parts located at obturator externus region,ischiofemorale ligament trunk did not go through obturator externus region.Obturator externus region of hip capsule was weaker than other region.Conclusion Obturator externus is the unique dynamic sustain muscle to posteroinferior parts of hip joint capsule.Obturator externus and the region of hip joint capsule covered by it mainly are main factor which prevent femoral head from dislocation in hip flexion and internal rotation condition.But this region of hip joint capsule is weaker.So obturator externus should not be ignored in enhanced posterior soft tissue repair of total hip replacement.