Background

The Foot Posture Index (FPI) was originally validated only against two dimensional radiographic imaging at the time of its inception since weight bearing three dimensional (3D) imaging did not exist. This technology is now widely available but it is not known if the FPI will continue to correlate well against it.

Research question: How does the clinical assessment tool of FPI correlate against 3D biometrics of foot alignment assessed on weight bearing computerised tomography (WBCT)?

Methods

The FPI and 3D biometrics of 66 feet in 33 patients presenting to a single foot and ankle unit were assessed by two observers independently. All measurements were assessed for intra-rater and inter-rater reliability, and the association between the clinically assessed FPI and radiologically assessed 3D biometrics was identified.

Results

The FPI demonstrated excellent intra-rater and good inter-rater reliability. All 3D biometric measures demonstrated excellent intra-rater and inter-rater reliability. A strong and significant correlation was identified between the FPI and 3D biometrics overall although subgroup analysis revealed the strength of association dropped when the hindfoot had a valgus alignment.

Significance

This study confirmed that the FPI is a valid tool for assessing foot position. However, correlation between the FPI and 3D biometrics fell in the valgus aligned hindfoot so caution must be used when the FPI is used for assessment in this population.

中文翻译：

---

脚姿势指数和承重计算机断层扫描3D生物特征之间的关系来定义脚的对齐方式。

背景

由于不存在负重三维（3D）成像，因此最初仅在针对二维放射线照相成像时才对足部姿势指数（FPI）进行了验证。该技术现已广泛使用，但尚不知道FPI是否会继续与其很好地相关。

研究问题：FPI的临床评估工具与在负重计算机断层扫描（WBCT）上评估的足部对齐的3D生物特征如何相关？

方法

由两名观察员独立评估了33例单脚和脚踝单元患者中66英尺的FPI和3D生物特征。评估了所有测量的评估者内部和评估者之间的可靠性，并确定了临床评估的FPI与放射学评估的3D生物特征之间的关联。

结果

FPI显示出出色的内部评估者和良好的内部评估者可靠性。所有3D生物特征测量均显示出出色的内部评估者和内部评估者可靠性。尽管亚组分析显示，当后脚进行外翻对准时，关联强度下降，但FPI和3D生物特征识别之间总体上存在强而显着的相关性。

意义

这项研究证实FPI是评估脚部位置的有效工具。但是，FPI和3D生物特征之间的相关性在后足外翻对齐后脚处下降，因此在将FPI用于该人群的评估时必须谨慎。