泪滴下缘在全髋关节置换重建髋臼解剖中心高度中的作用

摘要

背景:全髋关节置换中髋臼假体的位置十分重要,其理想位置是恢复其解剖性旋转中心,泪滴下缘作为一个重要的稳定的影像学标记,对臼杯位置的影像学评估以及指导术中假体正确安放具有重要的意义.目的:探讨泪滴下缘在恢复解剖髋关节旋转中心高度的作用.方法:选择107例对侧髋关节正常的单侧全髋关节置换患者的病历资料和术后双侧髋关节正位片,臼杯下缘与泪滴下缘平齐,测量臼杯旋转中心及对侧正常髋臼旋转中心的高度、水平距离,以及臼杯外展角和前倾角,使用配对样本t 检验检测臼杯中心高度与对侧正常髋臼中心高度有无差异.使用散点图及Pearson相关系数评估两者高度差与外展角、前倾角的关系.结果与结论:①臼杯中心高度显著高于对侧正常髋臼中心的高度(P < 0.001),其中100例(93.4%)两者的差距为0-5 mm,7例(6.6%)大于5 mm;②但当臼杯下缘较泪滴下缘下移1.5-2.0 mm时,与对侧差异无显著性意义(P =0.345,0.331);③臼杯中心高度与对侧正常髋臼中心的高度之差与臼杯的外展角和前倾角相关性可(r=0.376,0.310,P均 < 0.001);④提示在全髋关节置换重建髋臼时,臼杯下缘低于泪滴下缘1.5-2.0 mm时,能精确地复制生理性髋关节旋转中心高度.%BACKGROUND: The position of acetabular prosthesis is very important in total hip arthroplasty; its ideal position is to restore its anatomical hip center of rotation. As the inferior edge of the teardrop is an important stable imaging marker, it is of great significance to evaluate the position of acetabular cup and guide the correct intraoperative placement of prosthesis. OBJECTIVE: To investigate the effect of the lower edge of the teardrop on restoring anatomical hip center height in total hip arthroplasty. METHODS: Medical records and anteroposterior images of 107 unilateral total hip arthroplasty with normal contralateral acetabulum and lower edge of cup at the same level as lower edge of the teardrop were reviewed. Center height and horizontal distance as well as cup inclination and anteversion were measured radiographically. The paired t test was used to compare data between left and right sides of hip center height. Scatterplots and Pearson's correlation coefficients were used to evaluate the association between the difference of the height of two hip centers, cup anteversion and inclination angle. RESULTS AND CONCLUSION: (1) The height of cup center was significantly higher than that of contralateral hip joint center (P < 0.001). Whereas 93.4% (100 cases) of absolute differences between them were in the range from 0 mm to 5 mm, only 6.6% (7 cases) were more than 5 mm. (2) However, when the lower edge of cup was 1.5-2.0 mm inferior to the lower edge of the teardrop, there was no statistical differences between them (P=0.345 and 0.331). (3) There was a weak correlation between the difference of the height of two hip centers with inclination and anteversion (r=0.376, 0.310, P < 0.001). (4) The position of cup with its inferior edge 1.5-2.0 mm below the inferior edge of the teardrop can exactly replicate the anatomic hip center.