目的:关节成形术外科医生传统上在仰卧位X线片上评估全髋关节置换术(THA)后的杯取向。当代的髋部脊柱分析提供了站立信息,功能杯的方向。这项研究旨在(i)表征仰卧和站立时的杯子方向;(ii)确定姿势之间的方向差异;(iii)确定与方向差异大小相关的因素。
方法:这是一个2个中心,多外科医生,prospective,连续队列研究。包括419个主要THA(57%的女性;平均年龄:64岁,标准偏差[SD]11)。所有患者均接受仰卧位和站立的骨盆前后和骨盆外侧平片。测量了杯的取向和脊柱骨盆参数。目标杯取向定义为倾斜/前倾40°/20°±10°。>5°的姿势之间的取向变化(Δ倾斜度/Δ前倾)被定义为临床上显著的。变异性定义为2×SD。
结果:倾斜度从40°(仰卧)增加到42°(站立),对应的Δ倾斜度为2°(95%置信区间[CI]2-3)。前倾从25°(仰卧)增加到30°(站立),对应于5°的Δ前倾(CI5-6)。仰卧时,69%(CI65-74)的THA在目标范围内,但站立时只有44%(CI39-49)在目标范围内,导致站立时另外26%(CI21-30)偏离目标。从仰卧到站立,在47%(CI42~52)的病例中观察到前倾有临床意义的改变(>5°).女性的Δ前倾高于男性(6°,CI5-7vs5°,CI4-5)对应于1°的差值(CI1-2),这取决于倾斜度的变化,站立杯前倾,年龄,站立骨盆倾斜。
结论:站立时杯的倾斜度和版本增加,但由于患者因素存在显着的变异性。
OBJECTIVE: Arthroplasty surgeons traditionally assess cup orientation after total hip arthroplasty (THA) on supine radiographs. Contemporary hip-spine analyses provide information on standing, functional cup orientation. This study aims to (i) characterize cup orientations when supine and standing; (ii) determine orientation differences between postures; and (iii) identify factors associated with magnitude of orientation differences.
METHODS: This is a 2-center, multi-surgeon, prospective, consecutive cohort study. 419 primary THAs were included (57% women; mean age: 64 years, standard deviation [SD] 11). All patients underwent supine and standing antero-posterior pelvic and lateral spinopelvic radiographs. Cup orientation and spinopelvic parameters were measured. Target cup orientation was defined as inclination/anteversion of 40°/20° ± 10°. A change in orientation (Δinclination/Δanteversion) between postures > 5° was defined as clinically significant. Variability was defined as 2 x SD.
RESULTS: Inclination increased from 40° (supine) to 42° (standing) corresponding to a Δinclination of 2° (95% confidence interval [CI] 2-3). Anteversion increased from 25° (supine) to 30° (standing) corresponding to a Δanteversion of 5° (CI 5-6). When supine, 69% (CI 65-74) of THAs were within target, but only 44% (CI 39-49) were within target when standing, resulting in a further 26% (CI 21-30) being out of target when standing. From supine to standing, a clinically significant change in anteversion (> 5°) was seen in 47% (CI 42-52) of cases. Δanteversion was higher in women than in men (6°, CI 5-7 vs 5°, CI 4-5) corresponding to a difference of 1° (CI 1-2), which was dependent on tilt change, standing cup anteversion, age, and standing pelvic tilt.
CONCLUSIONS: Cup inclination and version increase upon standing but significant variability exists due to patient factors.