CT-Based Classification Systems for Intra-Articular Calcaneal Fractures: The Inter- and Intraobserver Variations as well as Integrality

Zhongzheng Wang,Shaobo Liang,Yuchuan Wang,Ze Gao,Siyu Tian,Kuo Zhao,Wei Chen,Zhiyong Hou,Yingze Zhang

doi:10.1053/j.jfas.2021.12.007

Abstract

The aim of this study was to measure the inter- and intraobserver variations as well as integrality of the Zwipp, Crosby-Fitzgibbons, Sanders, and Eastwood-Atkins classification systems based on more accurate CT scans. Five hundred and forty-nine patients with intra-articular calcaneal fractures from January 2018 to December 2019 taken from a database in our level-I trauma center (3 affiliated hospitals) were included. For each case, normative CT (1 mm slices) scans were available. Four different observers reviewed all CT scans 2 times according to these 4 most prevalent fracture classification systems (FCSs) within a 2-month interval. For these 4 FCSs, the kappa [κ] coefficient was used to evaluate interobserver reliability and intraobserver reproducibility, and the percentage that can be classified was used to indicate integrality. The κ values were measured for Zwipp (κ = 0.38 interobserver, κ = 0.61 intraobserver), Crosby-Fitzgibbons (κ = 0.48 interobserver, κ = 0.79 intraobserver), Sanders (κ = 0.40 interobserver, κ = 0.57 intraobserver), and Eastwood-Atkins (κ = 0.44 interobserver, κ = 0.72 intraobserver). Furthermore, the integralities were calculated for Zwipp (100%), Crosby-Fitzgibbons (100%), Sanders (92%) as well as Eastwood-Atkins (89.6%). Compared with previous literatures, CT scanning with higher accuracy can significantly improve intraobserver reproducibility of Zwipp and Eastwood-Atkins FCSs, but it has no positive effect on variability of Sanders FCS and interobserver reliability of Crosby-Fitzgibbons FCS. In terms of integrality, Zwipp and Crosby-Fitzgibbons FCSs appear to be superior to the other 2 FCSs.

Highlights

Several primary fracture classification systems (FCSs) have been widely used for intra-articular calcaneal fractures
This study retrospectively reviewed all consecutive patients with unilateral or bilateral calcaneal fractures who had undergone hospitalization in the same level-I trauma centre (3 affiliated hospitals) from January 2018 to December 2019
0.40), and Eastwood-Atkins (κ = 0.44) FCSs, which was shown in table 3

Summary

Introduction

Several primary fracture classification systems (FCSs) have been widely used for intra-articular calcaneal fractures. The purpose of this study was to measure the inter- and intra-observer variations as well as integrality of the Zwipp, Crosby-Fitzgibbons, Sanders, and Eastwood-Atkins classification systems based on more accurate CT scans. Based on whether the fracture line involves the posterior facet, calcaneal fractures are divided into two categories intra- and extra-articular fractures. 70%-75% of calcaneal fractures belong to the former [5,6]. Despite extensive clinical experience of these injuries, the complex and displaced intra-articular calcaneal fractures remain difficult to treat. Over the past few decades, more than a dozen diverse fracture classification systems (FCSs) for intra-articular calcaneal fractures have been proposed but the optimal FCS remains controversial [7]

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Discussion

Conclusion