Ischiofemoral Impingement Syndrome: An Entity With Hip Pain and Abnormalities of the Quadratus Femoris Muscle
June 25th, 2009 Posted by: admin
OBJECTIVE. The purpose of this study was to describe the MRI
findings of an entity in which patients present with hip pain, abnormal MR
signal intensity of the quadratus femoris muscle, and narrowing of the
ischiofemoral space.
MATERIALS AND METHODS. We reviewed MR images of 12 hips in nine
patients with hip pain and abnormal MR signal intensity of the quadratus
femoris muscle. Using axial MR images, two musculoskeletal radiologists
measured the ischiofemoral and quadratus femoris spaces. We also examined
changes to muscles and tendons for the presence of edema and tears. Data were
compared with 11 hips in 10 control subjects. Statistical analyses determined
interobserver variability and differences between groups.
RESULTS. Subjects with an abnormal quadratus femoris muscle were all
women 30-71 years old (mean age, 53 years) and had significantly narrower
ischiofemoral spaces when compared with control subjects (13 ± 5 vs 23
± 8 mm, respectively; p = 0.002). The quadratus femoris space
was significantly narrower in affected subjects (7 ± 3 vs 12 ± 4
mm; p = 0.002). Abnormalities of the quadratus femoris muscle
included edema (100%), partial tear (33%), and fatty infiltration (8%). The
hamstring tendons of affected subjects showed evidence of edema (50%) and
partial tears (25%).
CONCLUSION. Ischiofemoral impingement may represent a cause of hip
pain and should be considered in cases with MR signal abnormality of quadratus
femoris muscle.
