髋臼横韧带定位髋臼假体前倾校正骨盆旋转

目的通过观察后外侧入路全髋关节置换术中骨盆的旋转变化,探讨术中骨盆旋转对髋臼假体前倾角植入的影响,评估使用髋臼横韧带作髋臼假体前倾定位的准确性以及对骨盆旋转角度变化的校正作用。 方法2015年1月至2016年1月河池市第三人民医院关节外科收治的行初次THA的40例44髋的髋关节疾病患者纳入本研究。纳入标准为：初次THA术的患者,术前、术后CT扫描质量符合标准、能确定髋臼解剖前倾角、髋臼假体前倾角的患者。排除标准：髋臼发育不良、强直性脊柱炎、既往有髋关节严重创伤手术史以及翻修术等,术前、术后双髋关节CT扫描,CT横断面上骨盆明显倾斜、两侧髋关节的中心显示明显不在同一层面、难以确定水平线测量前倾角的患者,予以排除。手术均采用侧卧位后外侧入路,切皮前将1枚施氏针以垂直于地面方向打入髂骨嵴,术中髋臼假体的前倾角,以髋臼横韧带为参照标志,通过直接参照或间接参照髋臼横韧带进行髋臼挫磨及安装臼杯,使髋臼假体开口平行韧带进行安放,在此过程中用摄像机记录施氏针相对于地面的角度变化,确定手术过程中骨盆旋转度数,同时测量并记录挫磨髋臼及安放假体时,相对于身体长轴髋臼手术前倾角的数值。术后通过CT测量髋臼假体前倾角,对术中手术前倾角和术后髋臼假体的前倾角、术前髋臼解剖前倾角数据进行t检验分析。 结果术中骨盆旋转发生在本研究中的平均度数为(18±4)°。44个髋关节中,所有的病例都能对髋臼横韧带进行辨认,术中手术前倾角平均为(33±5)°,有93%(41髋)的病例大于Lewinnek提出的"安全区"的前倾角上限25°,余下的7%(3个髋)也全部大于24°。术后CT测量髋臼假体的解剖前倾角为(21±10)°,与术前髋臼解剖前倾角度(19±7)°比较,差异无统计学意义(t＝1.264,P >0.05)。 结论在后外侧入路THA术中,体位改变骨盆前旋转会影响髋臼假体植入的准确性,使用髋臼横韧带作为解剖标志指导髋臼假体前倾角度的植入,可以排除患者体位改变骨盆旋转对前倾角的影响,提高髋臼假体放置的准确性。

Pelvic rotation correction by using transverse acetabular ligament for acetabular component anteversion orientation in total hip arthroplasty

ObjectiveTo investigate the effects of pelvic rotation on acetabular component placement by measuring the pelvic rotation intraoperively, and evaluate the accuracy and the correction of pelvic rotation by using transverse acetabular ligament for acetabular component anteversion orientation during total hip arthroplasty(THA) with posterolateral approach. MethodsForty patients (44 hips) undergoing primary THA in HeChi Third People’s Hospital from January 2015 to January 2016 were enrolled in this study. All the patients were positioned in the lateral decubitus position, THA was performed through posterolateral approach. A Steinmann pin (the sentinel pin) was inserted through the iliac crest at 90° to the floor to assess the degree of pelvic rotation with reference to the floor. The acetabulum and transverse acetabular ligament (TAL) were exposed, and the acetabular component anteversion were positioned with TAL orientation, in which the inferomedial rim of the cup had been positioned parallel to TAL intraoperatively. The degree of pelvic rotation during the operation was determined by the angle of Steinmann pin relative to the ground which was recorded with the camera. At the same time, the degree of operative anteversion relative to the long axis body was measured and recorded. CT scan was applied to measure radiographic cup anteversion and preoperative native acetabular anteversion. Acetabular component anteversion, operative acetabular anteversion, preoperative native acetabular anteversion were statistically analyzed by t test . ResultsIn this study, pelvic rotation occurred in each case, the mean rotation angle was estimated (18±4) °. TAL was identified, the operative acetabular anteversion angle was (33±5) ° in average. The operative acetabular anteversion was larger than 24°, and in 93% of the cases (41 hip) it was larger than 25°(the upper limit of Lewinnek’s safe zone). No statistical difference was found between mean angle of acetabular component anteversion measured by CT scan (21±10)° and preoperative native acetabular anteversion (19±7) °(t=1.264, P >0.05). ConclusionsForward rotation of the patient will affect the accuracy of the acetabular component positioning during posterolateral approach to THA. TAL can be used as an anatomical landmark for anteversion orientation to correct pelvic rotation at the time of cup placement, and help the cup to be placed in a more precise orientation at the correct degree of anteversion.