Masayoshi Saito1, Sachiyuki Tsukada2, Kazuki Yoshida3, Yasuaki Okada1, Atsushi Tasaki1. 1. Department of Orthopaedic Surgery, St. Luke's International Hospital, 9-1 Akashicho, Chuo-ku, Tokyo, 104-8560, Japan. 2. Department of Orthopaedic Surgery, St. Luke's International Hospital, 9-1 Akashicho, Chuo-ku, Tokyo, 104-8560, Japan. s8058@nms.ac.jp. 3. Department of Epidemiology, Harvard T. H. Chan School of Public Health, 677 Huntington Ave, Boston, MA, 02115, USA.
Abstract
PURPOSE: Radial magnetic resonance imaging (MRI) along the axis of the femoral head neck is the gold standard for detection of cam deformity of the proximal femur. This study was performed to identify which plain radiographic projection was best correlated with radial MRI. METHODS: Five different plain radiographic projections and 18 slices of radial MRI were applied to 35 consecutive hips with groin pain and positive impingement sign. Alpha angles were measured to detect the asphericity of the femoral head-neck junction in all images. Radiographs were taken in anteroposterior pelvis, cross-table lateral, 90° Dunn, 45° Dunn and modified 45° Dunn views. Pearson's correlation coefficients were determined to assess the association between the alpha angle obtained from radial MRI and each radiographic technique. The sensitivity, specificity, positive and positive predictive values and accuracy of plain radiographic alpha angle measurements were assessed using a threshold alpha angle value of 50.5° for cam deformity. RESULTS: Pearson's correlation coefficients in the alpha angle values between MRI and plain radiographic projections were 0.45, 0.70, 0.62, 0.81 and 0.69 for the anteroposterior pelvis, cross-table lateral, 90° Dunn, 45° Dunn and modified 45° Dunn views, respectively. In terms of sensitivity and accuracy, the 45° Dunn view had the greatest values. CONCLUSIONS: Alpha angle of the 45° Dunn view was best correlated with that of radial MRI. The 45° Dunn view had better sensitivity and accuracy than other radiographic projections. The 45° Dunn view may be preferable for screening of cam deformity. LEVEL OF EVIDENCE: II.
PURPOSE: Radial magnetic resonance imaging (MRI) along the axis of the femoral head neck is the gold standard for detection of cam deformity of the proximal femur. This study was performed to identify which plain radiographic projection was best correlated with radial MRI. METHODS: Five different plain radiographic projections and 18 slices of radial MRI were applied to 35 consecutive hips with groin pain and positive impingement sign. Alpha angles were measured to detect the asphericity of the femoral head-neck junction in all images. Radiographs were taken in anteroposterior pelvis, cross-table lateral, 90° Dunn, 45° Dunn and modified 45° Dunn views. Pearson's correlation coefficients were determined to assess the association between the alpha angle obtained from radial MRI and each radiographic technique. The sensitivity, specificity, positive and positive predictive values and accuracy of plain radiographic alpha angle measurements were assessed using a threshold alpha angle value of 50.5° for cam deformity. RESULTS: Pearson's correlation coefficients in the alpha angle values between MRI and plain radiographic projections were 0.45, 0.70, 0.62, 0.81 and 0.69 for the anteroposterior pelvis, cross-table lateral, 90° Dunn, 45° Dunn and modified 45° Dunn views, respectively. In terms of sensitivity and accuracy, the 45° Dunn view had the greatest values. CONCLUSIONS: Alpha angle of the 45° Dunn view was best correlated with that of radial MRI. The 45° Dunn view had better sensitivity and accuracy than other radiographic projections. The 45° Dunn view may be preferable for screening of cam deformity. LEVEL OF EVIDENCE: II.
Authors: John C Clohisy; John C Carlisle; Robert Trousdale; Young-Jo Kim; Paul E Beaule; Patrick Morgan; Karen Steger-May; Perry L Schoenecker; Michael Millis Journal: Clin Orthop Relat Res Date: 2008-12-02 Impact factor: 4.176
Authors: John C Clohisy; John C Carlisle; Paul E Beaulé; Young-Jo Kim; Robert T Trousdale; Rafael J Sierra; Michael Leunig; Perry L Schoenecker; Michael B Millis Journal: J Bone Joint Surg Am Date: 2008-11 Impact factor: 5.284
Authors: Lene B Laborie; Trude G Lehmann; Ingvild Ø Engesæter; Deborah M Eastwood; Lars B Engesæter; Karen Rosendahl Journal: Radiology Date: 2011-05-25 Impact factor: 11.105
Authors: Miguel O Castro; Vasco V Mascarenhas; P Diana Afonso; Paulo Rego; Florian Schmaranzer; Reto Sutter; Ara Kassarjian; Luca Sconfienza; Michael Dienst; Olufemi R Ayeni; Paul E Beaulé; Pedro Dantas; Radhesh Lalam; Marc-André Weber; Filip M Vanhoenacker; Tobias Johannes Dietrich; Lennart Jans; Philip Robinson; Apostolos H Karantanas; Iwona Sudoł-Szopińska; Suzanne Anderson; Iris Noebauer-Huhmann; Oliver Marin-Peña; Diego Collado; Marc Tey-Pons; Ehrenfried Schmaranzer; Mario Padron; Josef Kramer; Patrick O Zingg; Michel De Maeseneer; Eva Llopis Journal: Eur Radiol Date: 2021-01-07 Impact factor: 5.315
Authors: Thomas D Alter; Derrick M Knapik; Martina Guidetti; Alejandro Espinoza; Jorge Chahla; Shane J Nho; Philip Malloy Journal: Orthop J Sports Med Date: 2022-05-06
Authors: Mark J Scholes; Joanne L Kemp; Benjamin F Mentiplay; Joshua J Heerey; Rintje Agricola; Matthew G King; Adam I Semciw; Peter R Lawrenson; Kay M Crossley Journal: Scand J Med Sci Sports Date: 2022-01-24 Impact factor: 4.645
Authors: Christoph E Albers; Nicholas Wambeek; Markus S Hanke; Florian Schmaranzer; Gareth H Prosser; Piers J Yates Journal: J Hip Preserv Surg Date: 2016-11-10