Grosso Matthew J, Plaskos Christopher, Pierrepont Jim, Saxena Arjun
Connecticut Joint Replacement Institute, Hartford, CT.
Corin Ltd, Raynham, MA, USA.
Arthroplast Today. 2023 Sep 19;23:101192. doi: 10.1016/j.artd.2023.101192. eCollection 2023 Oct.
The aims of this study were to (1) assess the degree of variation in acetabular component placement and combined anteversion in a large cohort of dislocating total hip arthroplasties; (2) assess the spinopelvic characteristics of the cohort; and (3) examine the association between cup anteversion and reported direction of instability.
A commercial database of 245 dislocating total hip arthroplasties referred for postoperative computed tomography and functional radiographic imaging and analysis were reviewed. Spinopelvic parameters and cup and stem positions were measured in the supine, standing, flex-seated, and anterior pelvic plane (APP) positions. Spinopelvic characteristics were stratified by high, neutral, and low cup anteversion using thresholds of >35° and <15° anteversion in standing, respectively.
In the dislocation cohort, 62%, 45%, and 42% of cups were within the safe zone in supine, standing, and the APP, respectively ( < .001). Patients with high vs neutral or low cup anteversion had significantly stiffer spines, more posterior pelvic tilt in standing, greater changes in pelvic tilt, and higher sagittal imbalance. Of the 45 patients with high cup anteversion and reported instability direction, 60% and 40% were reported to have posterior and anterior instability, respectively, with no differences in spinopelvic characteristics.
In this dislocating cohort, there is a decreased percentage of cups within the safe zone in the APP and standing position compared to the supine reference. In addition, we found that patients having poor spinopelvic characteristics and high cup anteversion can still dislocate, suggesting that adjusting cup anteversion alone may not be sufficient for preventing instability.
本研究的目的是：（1）评估大量全髋关节置换术后脱位患者髋臼假体位置及联合前倾角的变异程度；（2）评估该队列患者的脊柱骨盆特征；（3）研究髋臼前倾角与报告的不稳定方向之间的关联。
回顾了一个商业数据库，该数据库包含245例因术后计算机断层扫描及功能影像学检查和分析而转诊的全髋关节置换术后脱位患者。在仰卧位、站立位、屈髋坐位和骨盆前位平面（APP）测量脊柱骨盆参数以及髋臼杯和股骨柄位置。根据站立位时前倾角>35°和<15°的阈值，将脊柱骨盆特征分为高、中和低髋臼前倾角。
在脱位队列中，分别有62%、45%和42%的髋臼杯在仰卧位、站立位和APP位处于安全区内（P<0.001）。与中或低髋臼前倾角患者相比，高髋臼前倾角患者的脊柱更僵硬，站立时骨盆后倾更大，骨盆倾斜变化更大，矢状面失衡更高。在45例有高髋臼前倾角且报告了不稳定方向的患者中，分别有60%和40%报告有后方和前方不稳定，脊柱骨盆特征无差异。
在这个脱位队列中，与仰卧位参考相比，APP位和站立位处于安全区内的髋臼杯百分比降低。此外，我们发现脊柱骨盆特征较差且髋臼前倾角高的患者仍可能脱位，这表明仅调整髋臼前倾角可能不足以预防不稳定。
