Title:The Utility of MRI to Diagnose Ischifemoral Impingement by Assessing the Ischiofemoral and Quadratus Femoris Spaces During Femoral External Rotation
Volume: 17
Author(s): Ping Zhang, Yu Xiang Zhang, Bao Hai Yu, Shu Ying Shao, Xiao Shuai Chen, Xiaoyue Zhou and Jian Zhao*
Affiliation:
- Department of Radiology, The Third Hospital of Hebei Medical University, Hebei Province Biomechanical Key Laboratory of Orthopedics, Shijiazhuang, Hebei 050051,China
Keywords:
Magnetic resonance imaging, ischiofemoral impingement, external rotation, ischiofemoral space, quadratus femoris
space, femoral rotation.
Abstract:
Objective: The purpose of this study was to explore if the dimensions of the ischiofemoral
space on MRI vary with changes in external femoral rotation in Ischifemoral Impingement patients
relative to healthy control; if so, to determine the optimal diagnostic cutoff values of these dimensions
in Ischifemoral Impingement.
Methods: The study included 43 clinically confirmed Ischifemoral Impingement patients and 50
healthy volunteers. All subjects underwent hip MRI examinations with their hips externally rotated
at 0°, 30° and 60°. The IFS and QFS were measured respectively at each angle. The measurements
were compared between the IFI group and the control group to determine the optimal diagnostic
cutoff values for diagnosing IFI by using IFS and QFS measurements.
Results: In the IFI group, the spaces were smaller than those of the control group at all rotation angles
(P < 0.05 for each). When external rotation angles were increased, the IFS and QFS tended to
decrease. QFSs were smaller in the case group than the control group at each rotation angle. The receiver
operating characteristic areas under the curves of IFS and QFS in a neutral position of 0°
were highest.
Conclusion: Both of the IFS and QFS spaces of IFI patients were found to be smaller than those of
control group, regardless of the external hip rotation angles. A neutral position of 0° was deemed
the best position for diagnosing IFI. The diagnostic cutoff values of IFS and QFS were 2.44cm and
1.34cm in the neutral position, respectively.
