Abstract：
BACKGROUND: Various computer-assisted surgical systems claim to improve the accuracy of cup placement in total hip arthroplasties after assessing spinopelvic mobility to prevent prosthetic impingement. However, no study has yet analyzed the extent of the patient-specific cup anteversion safe zones.
OBJECTIVE: We hypothesized that most patients have a safe zone >10 °, except those with abnormal spinopelvic mobility, who have a much narrower safe zone.
METHODS: We simulated the risks of prosthetic impingement using the planned cup anteversion. The consecutive cohort included 341 patients who underwent total hip arthroplasty. Our primary endpoint was the patient-specific impingement-free zone for cup anteversion, which was then divided into four subgroups: 0 °, 1 ° to 5 °, 6 ° to 10 °, and >10 °. This data was then secondarily analyzed for abnormal spinopelvic mobility (the difference in the spinopelvic tilt [ΔSPT] from a standing to a flexed seated position >20 °).
RESULTS: The mean anteversion safe zone was 22.8 ° with 82.4% (281/341) of patients with a zone strictly >10 °. The mean safe zone was 8.9 ° (+/- 9 °) in patients with an ΔSPT ≥20 ° (18.2%), with 37.1% of these patients having a zone of 0 °, 16.13% a zone between 1 ° and 5 °, 8.06% a zone between 6 ° and 10 ° and 38.71% a zone >10 °. The mean safe zone was 25.9 ° (+/- 9 °) in patients with an ΔSPT <20 ° (81.8%), and the proportion of cases in each zone was 2.51%, 1.08%, 4.3%, and 92.11%, respectively (p < 0.001).
CONCLUSIONS: The safe zone for anteversion appears to be fairly wide in most patients. However, identifying patients at risk of abnormal spinopelvic mobility seems necessary to identify the two-thirds of patients with a narrow safe zone.
METHODS: IV; retrospective study.
OBJECTIVE: We hypothesized that most patients have a safe zone >10 °, except those with abnormal spinopelvic mobility, who have a much narrower safe zone.
METHODS: We simulated the risks of prosthetic impingement using the planned cup anteversion. The consecutive cohort included 341 patients who underwent total hip arthroplasty. Our primary endpoint was the patient-specific impingement-free zone for cup anteversion, which was then divided into four subgroups: 0 °, 1 ° to 5 °, 6 ° to 10 °, and >10 °. This data was then secondarily analyzed for abnormal spinopelvic mobility (the difference in the spinopelvic tilt [ΔSPT] from a standing to a flexed seated position >20 °).
RESULTS: The mean anteversion safe zone was 22.8 ° with 82.4% (281/341) of patients with a zone strictly >10 °. The mean safe zone was 8.9 ° (+/- 9 °) in patients with an ΔSPT ≥20 ° (18.2%), with 37.1% of these patients having a zone of 0 °, 16.13% a zone between 1 ° and 5 °, 8.06% a zone between 6 ° and 10 ° and 38.71% a zone >10 °. The mean safe zone was 25.9 ° (+/- 9 °) in patients with an ΔSPT <20 ° (81.8%), and the proportion of cases in each zone was 2.51%, 1.08%, 4.3%, and 92.11%, respectively (p < 0.001).
CONCLUSIONS: The safe zone for anteversion appears to be fairly wide in most patients. However, identifying patients at risk of abnormal spinopelvic mobility seems necessary to identify the two-thirds of patients with a narrow safe zone.
METHODS: IV; retrospective study.
摘要：
背景：各种计算机辅助手术系统声称在评估脊柱骨盆活动度以防止假体撞击后，可以提高全髋关节置换术中杯放置的准确性。然而,尚未有研究分析患者特有的杯子前倾安全区的范围.
目的：我们假设大多数患者的安全区>10°，除了脊柱骨盆活动异常的人，他们的安全区要窄得多。
方法：我们使用计划的杯前倾模拟了假肢撞击的风险。连续队列包括341例接受全髋关节置换术的患者。我们的主要终点是患者特定的无撞击区，用于杯子前倾，然后分为四个子组：0°，1°到5°,6°到10°,>10°。然后对该数据进行二次分析，以了解异常的脊柱骨盆活动性（从站立到弯曲坐姿的脊柱骨盆倾斜[ΔSPT]的差异>20°）。
结果：平均前倾安全区为22.8°，其中82.4％（281/341）的患者严格>10°。ΔSPT≥20°（18.2%）患者的平均安全区为8.9°（+/-9°），这些患者中37.1%的区域为0°，16.13%1°到5°之间的区域,8.06%的区域在6°和10°之间,38.71%的区域>10°。ΔSPT<20°（81.8%）患者的平均安全区为25.9°（+/-9°），每个区域的病例比例为2.51%，1.08%,4.3%,和92.11%，分别(p<0.001)。
结论：大多数患者的前倾安全区似乎相当宽。然而,确定有脊髓骨盆活动异常风险的患者似乎有必要确定三分之二具有狭窄安全区的患者。
方法：IV；回顾性研究。
目的：我们假设大多数患者的安全区>10°，除了脊柱骨盆活动异常的人，他们的安全区要窄得多。
方法：我们使用计划的杯前倾模拟了假肢撞击的风险。连续队列包括341例接受全髋关节置换术的患者。我们的主要终点是患者特定的无撞击区，用于杯子前倾，然后分为四个子组：0°，1°到5°,6°到10°,>10°。然后对该数据进行二次分析，以了解异常的脊柱骨盆活动性（从站立到弯曲坐姿的脊柱骨盆倾斜[ΔSPT]的差异>20°）。
结果：平均前倾安全区为22.8°，其中82.4％（281/341）的患者严格>10°。ΔSPT≥20°（18.2%）患者的平均安全区为8.9°（+/-9°），这些患者中37.1%的区域为0°，16.13%1°到5°之间的区域,8.06%的区域在6°和10°之间,38.71%的区域>10°。ΔSPT<20°（81.8%）患者的平均安全区为25.9°（+/-9°），每个区域的病例比例为2.51%，1.08%,4.3%,和92.11%，分别(p<0.001)。
结论：大多数患者的前倾安全区似乎相当宽。然而,确定有脊髓骨盆活动异常风险的患者似乎有必要确定三分之二具有狭窄安全区的患者。
方法：IV；回顾性研究。
