Department of Orthopaedic Surgery, University of Bern, Inselspital, Freiburgstrasse, 3010 Bern, Switzerland.
Clin Orthop Relat Res. 2012 Dec;470(12):3355-60. doi: 10.1007/s11999-012-2477-2.
Understanding acetabular pathomorphology is necessary to correctly treat patients with hip complaints. Existing radiographic parameters classify acetabular coverage as deficient, normal, or excessive but fail to quantify contributions of anterior and posterior wall coverage. A simple, reproducible, and valid measurement of anterior and posterior wall coverage in patients with hip pain would be a clinically useful tool.
QUESTIONS/PURPOSES: We (1) introduce the anterior wall index (AWI) and posterior wall index (PWI), (2) report the intra- and interobserver reliability of these measurements, and (3) validate these measurements against an established computer model.
We retrospectively reviewed 87 hips (63 patients) with symptomatic hip disease. A validated computer model was used to determine total anterior and posterior acetabular coverage (TAC and TPC) on an AP pelvis radiograph. Two independent observers measured the AWI and PWI on each film, and the intraclass correlation coefficient (ICC) was calculated. Pearson correlation was used to determine the strength of linear dependence between our measurements and the computer model.
Intra- and interobserver ICCs were 0.94 and 0.99 for the AWI and 0.81 and 0.97 for the PWI. For validation against the computer model, Pearson r values were 0.837 (AWI versus TAC) and 0.895 (PWI versus TPC). Mean AWI and PWI were 0.28 and 0.81 for dysplastic hips, 0.41 and 0.91 for normal hips, 0.61 and 1.15 for hips with a deep acetabulum.
Our data suggest these measures will be helpful in evaluating anterior and posterior coverage before and after surgery but need to be evaluated in asymptomatic individuals without hip abnormalities to establish normal ranges.
Level III, diagnostic study. See Instructions for Authors for a complete description of levels of evidence.
了解髋臼的形态学变化对于正确治疗髋部不适的患者非常重要。现有的影像学参数将髋臼覆盖程度分为不足、正常和过度，但无法量化前壁和后壁覆盖的贡献。对于髋部疼痛患者，一种简单、可重复且有效的前壁和后壁覆盖测量方法将是一种非常有用的临床工具。
问题/目的：我们（1）引入了前壁指数（AWI）和后壁指数（PWI），（2）报告了这些测量方法的观察者内和观察者间可靠性，（3）并将这些测量方法与已建立的计算机模型进行了验证。
我们回顾性地分析了 87 髋（63 例患者）的髋部症状性疾病。使用经过验证的计算机模型确定骨盆正位片上髋臼的总前壁和后壁覆盖（TAC 和 TPC）。两名独立观察者对每张图像进行了 AWI 和 PWI 的测量，并计算了组内相关系数（ICC）。皮尔逊相关性用于确定我们的测量值与计算机模型之间线性相关性的强度。
AWI 和 PWI 的观察者内和观察者间 ICC 分别为 0.94 和 0.99 以及 0.81 和 0.97。与计算机模型验证的皮尔逊 r 值分别为 0.837（AWI 与 TAC）和 0.895（PWI 与 TPC）。发育不良髋部的平均 AWI 和 PWI 分别为 0.28 和 0.81，正常髋部为 0.41 和 0.91，髋臼较深的髋部为 0.61 和 1.15。
我们的数据表明，这些测量方法将有助于评估手术前后的前壁和后壁覆盖情况，但需要在没有髋部异常的无症状个体中进行评估，以建立正常范围。
III 级，诊断研究。有关证据水平的完整描述，请参见作者说明。
