3312. Ischiofemoral Impingement: Imaging Analysis of Possible Contributing Anatomical Factors
Authors * Denotes Presenting Author
  1. Ivan Platzek *; Dresden University Hospital, Radiology
  2. Krzysztof Nocon; Dresden University Hospital, Radiology
  3. Sophia Blum; Dresden University Hospital, Radiology
  4. Dominik Sieron; Inselspital Bern, Interventional and Pediatric Radiology
  5. Ralf-Thorsten Hoffmann; Dresden University Hospital, Radiology
  6. Jens Goronzy; Dresden University Hospital, Orthopedic Surgery
Ischiofemoral impingement is an often overlooked cause of hip pain. On MRI it typically presents as edema of the quadratus femoris muscle on T2-weighted fat-saturated images. The aim of this current retrospective study was to analyze possible anatomic factors contributing to ischiofemoral impingement in patients undergoing imaging evaluation for hip pain.

Materials and Methods:
The study included 181 consecutive patients (112 women, 69 men, median age 29 y, age range 11 – 61 y), who presented with hip pain and underwent hip joint imaging (MRI and radiographs). MRI examinations were evaluated for signs of ischiofemoral impingement. In total, 265 hips were evaluated in total (both hips in 84 patients, and one hip in 97 patients). The following possible parameters contributing to a narrow ischiofemoral interval were measured: femoral neck-shaft angle, hip length, global hip offset, and femoral torsion. The association between these potential risk factors and MRI signs of ischiofemoral impingement was analyzed using multiple logistic regression.

There were signs of ischiofemoral impingement in MRI in 56 of 265 (38 of 181 patients). Women patients were predominantly affected (33 of 38 affected patients). Logistic regression revealed a significant association between global hip offset and ischiofemoral impingement and between femoral antetorsion (<em>p</em> = 0.001) and ischiofemoral impingement (<em>p</em> = 0.037). Hips with signs of ischiofemoral impingement had less hip offset and more femoral antetorsion when compared with hips without impingement findings. There was no significant relationship between ischiofemoral impingement and femoral neck-shaft angle (<em>p</em> = 0.79) or hip length (<em>p</em> = 0.389).

Short hip offset and a low femoral antetorsion were significantly associated with ischiofemoral impingement. Ischiofemoral impingement as a cause of hip pain should be considered especially in patients displaying these predisposing anatomical factors such as a short hip offset and low femoral antetorsion.