Anatomy-based MRI assessment of the iliopsoas muscle complex after pertrochanteric femoral fracture
To evaluate the quality of the iliopsoas muscle complex after pertrochanteric femoral fracture, using MRI; to propose an anatomy-based evaluation of the iliopsoas muscle complex; and to determine the inter-reader reliability of two classifications of fatty muscle degeneration.
Materials and methods
We included adult patients with a displaced lesser trochanter following pertrochanteric femoral fracture. Muscle quality was evaluated using the Goutallier and Slabaugh classifications at three levels (L4/L5, L5/S1, and the anterior inferior iliac spine). Two radiologists independently reviewed the MRIs, and force measurement was performed on both hips. Linear mixed-effects models were used to determine the effect of fracture on muscle quality and strength, and Cohen’s kappa statistic was used to assess inter-reader agreement.
In the 18 patients included, the iliopsoas muscle complex showed higher grades of fatty muscle degeneration on the fractured side than on the non-fractured side. The mean difference between muscle strength on the fractured vs the non-fractured side was −12 N (p > 0.05). Inter-reader agreement for the Goutallier and Slabaugh classifications was good and very good respectively (weighted K = 0.78 and 0.85 respectively).
Fatty muscle degeneration of the iliopsoas muscle complex after pertrochanteric femoral fracture was evident using both classification systems; however, fatty muscle degeneration resulted in only a minimal reduction of muscle strength. To provide a thorough assessment of iliopsoas muscle complex quality, we suggest evaluating it at different anatomical levels. Regarding inter-reader agreement, the Slabaugh classification was superior to the Goutallier classification.
KeywordsHip Hip joint Muscle strength Femoral fractures Skeletal muscle Psoas muscle Magnetic resonance imaging Reproducibility
We would like to thank the statistician, Andreas Schötzau Dipl.-Math. (email@example.com) and the medical illustrator, Dr Piotr Golofit (firstname.lastname@example.org) for their contributions to this study. We also thank Jane Charbonneau, DVM, from Edanz Group (www.edanzediting.com/ac) for editing a draft of this manuscript.
This radiology research was partially funded by a Young Researchers Grant awarded by the European Society of Musculoskeletal Radiology (ESSR) during the ESSR Annual Meeting in Bari, Italy, June 2017. This project has been accepted for the European Congress of Radiology 2018 (“Anatomy-based MR classification of the iliopsoas muscle complex after pertrochanteric femur fracture”, Control #: 1786, Session Date/Time: 3/1/2018 10:30:00 AM – 3/1/2018 12:00:00 PM).
Compliance with ethical standards
Conflicts of interest
The authors declare that they have no conflicts of interest.
This radiological study is part of a prospective orthopaedic study that was approved by the Ethical Review Committee (EKNZ BASEC 2016-00612) of our institution.
Informed consent was obtained from all individual participants included in the study.
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