Department of Pediatric Orthopaedics and Traumatology, Poznan University of Medical Sciences, Poznan, Poland.
Division of Orthopaedic Surgery, The Hospital for Sick Children, University of Toronto, Toronto, Canada.
J Pediatr Orthop B. 2023 May 1;32(3):241-246. doi: 10.1097/BPB.0000000000001077. Epub 2022 Mar 13.
Our investigation aimed to assess the reliability of the femoral head shape classification system devised by Rutz et al . and observe its application in patients with cerebral palsy (CP) at different skeletal maturity levels. Four independent observers assessed anteroposterior radiographs of the hips of 60 patients with hip dysplasia associated with non-ambulatory CP (Gross Motor Function Classification System levels IV and V) and recorded the femoral head shape radiological grading system as described by Rutz et al . Radiographs were obtained from 20 patients in each of three age groups: under 8 years, between 8 and 12 years and above 12 years old, respectively. Inter-observer reliability was assessed by comparing the measurements of four different observers. To determine the intra-observer reliability, radiographs were reassessed after a 4-week interval. Accuracy was checked by comparing these measurements with the assessment of expert consensus. Validity was checked indirectly by observing the relationship between the Rutz grade and the migration percentage. The Rutz classification system's evaluation of femoral head shape showed moderate to substantial intra- and inter-observer reliability (mean κ = 0.64 for intraobserver and mean κ = 0.5 for interobserver). Specialist assessors had slightly higher intra-observer reliability than trainee assessors. The grade of femoral head shape was significantly associated with increasing migration percentage. Rutz's classification was shown to be reliable. Once the clinical utility of this classification can be established, it has the potential for broad application for prognostication and surgical decision-making and as an essential radiographic variable in studies involving the outcomes of hip displacement in CP. Level of evidence: III.
我们的研究旨在评估 Rutz 等人设计的股骨头形状分类系统的可靠性，并观察其在不同骨骼成熟度脑瘫（CP）患者中的应用。四位独立观察者评估了 60 例髋关节发育不良伴非步行 CP（Gross Motor Function Classification System 水平 IV 和 V）患者的前后位髋关节 X 线片，并记录了 Rutz 等人描述的股骨头形状放射学分级系统。在三个年龄组（<8 岁、8-12 岁和>12 岁）中，每组各有 20 例患者获得 X 线片。通过比较四位不同观察者的测量值来评估观察者间的可靠性。为了确定观察者内的可靠性，在 4 周后重新评估 X 线片。通过比较这些测量值与专家共识评估的结果来检查准确性。通过观察 Rutz 分级与迁移百分比之间的关系间接检查有效性。股骨头形状的 Rutz 分类系统评估显示观察者内和观察者间的可靠性为中度至高度（观察者内的平均 κ 为 0.64，观察者间的平均 κ 为 0.5）。专家评估者的观察者内可靠性略高于培训评估者。股骨头形状的等级与迁移百分比的增加显著相关。Rutz 的分类是可靠的。一旦能够确定该分类的临床实用性，它就有可能广泛应用于预测和手术决策，以及作为 CP 髋关节移位结果研究中的基本放射学变量。证据水平：III。
