Kaniewska M Schenkel M Eid K Bühler T Kubik-Huch RA Anderson SE 2019 OBJECTIVE 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. RESULTS 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). CONCLUSION 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. https://sonar.ch/global/documents/126499 eng info:eu-repo/semantics/altIdentifier/doi/10.1007/s00256-018-3048-8 info:eu-repo/semantics/altIdentifier/pmid/30178103 Skeletal radiology. - 2019 Femoral fractures Hip Hip joint Magnetic resonance imaging Muscle strength Psoas muscle Reproducibility Skeletal muscle Adult Aged Aged, 80 and over Anatomic Landmarks Female Femoral Fractures Humans Magnetic Resonance Imaging Male Middle Aged Muscle Strength Psoas Muscles Reproducibility of Results Anatomy-based MRI assessment of the iliopsoas muscle complex after pertrochanteric femoral fracture. http://purl.org/coar/resource_type/c_6501