TY - JOUR
T1 - Exorotated radiographic views have additional diagnostic value in detecting an osseous impediment in patients with posterior ankle impingement
AU - Dobbe, Johannes G. G.
AU - Streekstra, Geert J.
AU - Blankevoort, Leendert
AU - Wiegerinck, Johannes I.
AU - Maas, Mario
AU - Zwiers, Ruben
AU - van Dijk, C. Niek
AU - On behalf of the Ankle Platform Study Group
AU - Plaaß, Christian
AU - Rips, Leho
AU - Mansur, Nacime Salomão Barbachan
AU - Sampathkumar, Kandasam
AU - Ovidiu, Muntean George
AU - Russo, Alessandro
AU - Burg, Alon
AU - Kurup, Harish
AU - Boszczyk, Andrzej
AU - Gerards, Rogier M.
AU - Barwick, Thomas
AU - Jayaprasad, P. S.
AU - Kim, David
AU - Bojanic, Ivan
AU - Darabos, Nikica
AU - Vulcano, Ettore
AU - Paulick, Risi Michelethomas
AU - Kumar, Mohan
AU - Laval, Georges
AU - Vasilakakos, Theofanis
AU - Lopez Astegiano, Valeria
AU - Daguerre, Gaston
AU - Hajduk, Grzegorz
AU - Ceccarini, Paolo
AU - de Diego Gutiérrez, V. ctor
AU - Brown, Christopher
AU - Pécsi, Örs
AU - Verbeek, Diederik
AU - Thilak, Jai
AU - Koukoulias, Nikolaos
AU - el Hage, Samer
AU - Miranda, Vitor
AU - Seybold, Jeffrey
AU - Millán, Angélica
AU - de Arimathéa Brandão, José
AU - Lins, Carolina
AU - Pahlplatz, Thijs M. J.
AU - van Bergen, Christiaan J. A.
AU - Weel, Hanneke
AU - Doornberg, Job N.
AU - Lansdaal, Joris R.
AU - Opdam, Kim T. M.
AU - de Leeuw, Peter A. J.
PY - 2019
Y1 - 2019
N2 - Objectives A standard lateral radiograph is the first step in the diagnostic workup in patients with posterior ankle pain. Because of overprojection by other structures at suboptimal radiographic projection angle, often an os trigonum is not discovered or erroneously be mistaken for a hypertrophic posterior talar process. The aim of this study was to identify the projection angles at which a radiograph is optimal for detecting bony impediments in patients suffering from posterior ankle impingement. Methods Using ankle CT scans of patients with posterior ankle impingement, digitally reconstructed radiographs (DRRs) simulating 13 different radiographic projection angles were generated. The ankle CT scans served as a reference for the detection of an os trigonum and hypertrophic posterior talar process. Members of the Ankleplatform Study Group were invited to assess the DRRs, for presence or absence of an os trigonum or hypertrophic posterior talar process. Diagnostic accuracy and interobserver reliability were estimated for each projection angle. In addition, the diagnostic accuracy of the standard lateral view in combination with the rotated views was calculated. Results High sensitivity for detecting an os trigonum was found for +15° (90.3%), +20° (81.7%) and +25° (89.7%) degrees of exorotation. Specificity in this range of projection angles was between 89.6% and 97.8%. Regarding the presence of a hypertrophic posterior talar process, increased sensitivity was found for +15° (65.7%), +20° (61.0%), +25° (60.7%), +30° (56.3%) and +35° (54.5%). Specificity ranged from 78.0% to 94.7%. The combination of the standard lateral view in combination with exorotated views showed higher sensitivity. For detecting an os trigonum, a negative predictive value of 94.6% (+15°), 94.1% (+20°) and 96.1% (+25°) was found. Conclusion This study underlines the additional diagnostic value of exorotated views instead of, or in addition to the standard lateral view in detecting an osseous impediment. We recommend to use the 25° exorotated view in combination with the routine standard lateral ankle view in the workup of patients with posterior ankle pain. Level of evidence Level III.
AB - Objectives A standard lateral radiograph is the first step in the diagnostic workup in patients with posterior ankle pain. Because of overprojection by other structures at suboptimal radiographic projection angle, often an os trigonum is not discovered or erroneously be mistaken for a hypertrophic posterior talar process. The aim of this study was to identify the projection angles at which a radiograph is optimal for detecting bony impediments in patients suffering from posterior ankle impingement. Methods Using ankle CT scans of patients with posterior ankle impingement, digitally reconstructed radiographs (DRRs) simulating 13 different radiographic projection angles were generated. The ankle CT scans served as a reference for the detection of an os trigonum and hypertrophic posterior talar process. Members of the Ankleplatform Study Group were invited to assess the DRRs, for presence or absence of an os trigonum or hypertrophic posterior talar process. Diagnostic accuracy and interobserver reliability were estimated for each projection angle. In addition, the diagnostic accuracy of the standard lateral view in combination with the rotated views was calculated. Results High sensitivity for detecting an os trigonum was found for +15° (90.3%), +20° (81.7%) and +25° (89.7%) degrees of exorotation. Specificity in this range of projection angles was between 89.6% and 97.8%. Regarding the presence of a hypertrophic posterior talar process, increased sensitivity was found for +15° (65.7%), +20° (61.0%), +25° (60.7%), +30° (56.3%) and +35° (54.5%). Specificity ranged from 78.0% to 94.7%. The combination of the standard lateral view in combination with exorotated views showed higher sensitivity. For detecting an os trigonum, a negative predictive value of 94.6% (+15°), 94.1% (+20°) and 96.1% (+25°) was found. Conclusion This study underlines the additional diagnostic value of exorotated views instead of, or in addition to the standard lateral view in detecting an osseous impediment. We recommend to use the 25° exorotated view in combination with the routine standard lateral ankle view in the workup of patients with posterior ankle pain. Level of evidence Level III.
UR - https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85078575445&origin=inward
U2 - https://doi.org/10.1136/jisakos-2019-000272
DO - https://doi.org/10.1136/jisakos-2019-000272
M3 - Article
SN - 2059-7754
VL - 4
SP - 181
EP - 187
JO - Journal of ISAKOS
JF - Journal of ISAKOS
IS - 4
ER -