Quantitative Evaluation of Articular Involvement of Posterior Malleolus Associated with Operative Indication: A Comparative Study of Six Methods Based on Radiography and CT

Kun Zhang,Dongdong Wang,Xiaoyang Jia,Minfei Qiang,Shuguang Wang,Yanxi Chen,Song Chen

doi:10.1155/2020/6745626

Kun Zhang, Dongdong Wang + Show 5 more

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https://doi.org/10.1155/2020/6745626

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Abstract

The aim of this study was to compare the values of six methods in measuring the involvement of posterior malleolus and to demonstrate the reliability and reproducibility of each method. Three independent orthopaedic surgeons, retrospectively, measured 106 cases. The difference between the six methods was analyzed using Bonferroni-corrected paired t-tests after one-way ANOVA. The agreement between the six methods was analyzed using Bland–Altman analysis. The intraclass correlation coefficient (ICC) was used to assess intraobserver reproducibility and interobserver reliability. Significant differences were observed between values of any two of the six measurement methods (P < 0.0033), except between any two of the plane radiograph linear, axial CT linear, sagittal CT linear, and 3D CT linear. The Bland–Altman plots demonstrated poor agreement between values of any two of the six methods. The lowest intraobserver reproducibility was 0.46 (moderate) for resident surgeon using plain radiographs. The intraobserver reproducibility for three surgeons using two-dimensional (2D) and 3D images was almost perfect (ICC, 0.82–0.96). The lowest interobserver reliability was 0.41 (moderate) between chief and attending surgeon using plain radiographs, and it improved to almost perfect (ICC, 0.81–0.95) with the use of 3D CT images. The standard error of measurement showed almost the same results as ICC values. The existing operative indications which were determined based on plain radiography are neither reliable nor suitable for other measurement methods. Both 3D linear and 3D surface measurement methods are reliable and reproducible in measuring posterior fragment involvement, and experience is not so crucial. Operative indications for posterior malleolar fractures need to be redefined based on the 3D measurement method.

Highlights

Ankle fractures are among the most common lower limb fractures, accounting for about 9% of all fractures [1]
Trauma patients were retrospectively reviewed at our hospital between May 2009 and December 2015. e inclusion criteria were ankle fracture with posterior malleolar fragment, which was confirmed by CT or surgery, between the ages of 20 and 75. e exclusion criteria were patients with pathologic fractures, Haraguchi type II or III posterior malleolar fractures or without standard lateral radiographs, or 16-row spiral CT examinations
Compared to 3D CT linear, the articular involvement measured using plain radiographs and CT linear decreased by 8% and about 3%, respectively

Summary

Introduction

Ankle fractures are among the most common lower limb fractures, accounting for about 9% of all fractures [1]. Many scholars recommended anatomical reduction and internal fixation for treatment of ankle fractures [3,4,5]. Still no consensus was achieved on the operative indication for posterior malleolar fractures [6]. Several scholars suggested operative fixation of posterior malleolar fractures when more than 25% of the tibial plafond is involved [7,8,9]. A biomechanical study involving 16 cadaveric specimens suggested operation when >33% of the joint is involved based on their findings that displaced posterior malleolar fractures produce a significant decrease in contact area with 33% or greater involvement of the joint [11]. The indications were different, they were all based on a specific percentage. erefore, precise estimate of the articular involvement of posterior

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