Kantonsspital St.Gallen
login

MRI findings of ischiofemoral impingement after total hip arthroplasty are associated with increased femoral antetorsion

Tim Fischer, Christoph Stern, Benjamin Fritz, Patrick O Zingg, Christian Wa Pfirrmann & Reto Sutter

abstract

BACKGROUND
Ischiofemoral impingement (IFI) is a known complication after total hip arthroplasty (THA).

PURPOSE
To assess if increased postoperative (FA) is associated with magnetic resonance imaging (MRI) findings of IFI.

MATERIAL AND METHODS
In 221 patients with THA, two independent readers measured FA, ischiofemoral space (IFS), quadratus femoris space (QFS), edema, and fatty infiltration of quadratus femoris muscle. Three sets of IFI-imaging features were defined: acute IFI (set 1): IFS ≤15 mm or QFS ≤10 mm and edema in the quadratus femoris muscle; chronic IFI (set 2): IFS ≤15 mm or QFS ≤10 mm and fatty infiltration of quadratus femoris muscle Goutallier grade ≥2; acute and chronic IFI (set 3) with both criteria applicable. For each set, FA angles were compared between positive findings of IFI and negative findings of IFI. The t-test for independent samples tested statistical significance.

RESULTS
In 7.2% (16/221) of patients, findings of IFI (IFS ≤15 mm or QFS ≤10 mm and edema, n = 1; fatty infiltration, n = 9; or both, n = 6) were observed. In women, 11.4% (14/123) exhibited findings of IFI compared to 2.0% (2/98) in men. Comparison in set 1 (n = 7): mean antetorsion of 23.9° ± 9.8° (findings of acute IFI) compared to 14.4° ± 9.7° ( = 0.01). Comparison in set 2 (n = 15): mean antetorsion of 16.2° ± 6.3° (findings of chronic IFI) compared to 14.5° ± 9.9° ( = 0.49). Comparison in set 3 (n = 6): mean antetorsion of 20.4° ± 3.8° (findings of acute and chronic IFI) compared to 14.5° ± 9.9° ( = 0.01).

CONCLUSION
After THA, high postoperative FA is associated with MRI findings of acute as well as acute and chronic IFI. Findings of IFI were commonly seen in women.
   
citation Fischer T, Stern C, Fritz B, Zingg P O, Pfirrmann C W, Sutter R. MRI findings of ischiofemoral impingement after total hip arthroplasty are associated with increased femoral antetorsion. Acta Radiol 2021;2841851211021044.
   
type journal paper/review (English)
date of publishing 07-06-2021
journal title Acta Radiol
ISSN electronic 1600-0455
pages 2841851211021044
PubMed 34098775
DOI 10.1177/02841851211021044