Evaluation of Kager’s Triangle as a Radiological Tool in Acute Complete Rupture of the Calcaneus Tendon
DOI:
https://doi.org/10.63403/re.v32i3.419Keywords:
Achilles Tendon, Diagnostic Imaging, Radiography, DiagnosisAbstract
Introduction: Kager’s pre-Achilles fat pad can be visualized on a lateral ankle radiograph as a large triangular radiolucency with sharp, slightly curved borders. Radiographically, this is known as Kager’s triangle. Structural alterations in this area are frequently associated with Achilles tendon injuries.
Objective: to assesses the diagnostic accuracy of Kager’s triangle as a radiographic sign in acute complete rupture of the calcaneal tendon.
Materials and methods: a sample of 100 patients were included, with a case group of 50 patients with surgically confirmed acute complete Achilles tendon rupture, and a control group of 50 healthy individuals. All were evaluated between November 2020 and April 2023. Lateral ankle radiographs were reviewed to identify alterations in Kager’s triangle.
Results: the study found a sensitivity of 84%, specificity of 88%, positive predictive value of 87%, and negative predictive value of 84%, with an interobserver reliability Kappa index of 0.71 (Good: 0.6–0.8).
Conclusion: the radiological sign of Kager’s triangle demonstrates moderate diagnostic accuracy with Good interobserver agreement, though its performance is inferior to that of ultrasound and magnetic resonance imaging. Its main utility lies in settings where advanced imaging techniques are not available. Therefore, it should be considered an auxiliary sign that must always be interpreted alongside clinical findings.
Level of Evidence: III. Retrospective Comparative Cohort Study
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Copyright (c) 2025 Alejandro F. Pérez Morales, Maximo Canales Dominguez, Karla I. Marmolejo Portillo, Jesús I. Cardona Medina , Beatriz M. Padilla Pérez , Andrea T. Perez Moreno, Ariel De La Rosa Guerrero
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