Publication

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

Journal Paper/Review - Jun 7, 2021

Units
PubMed
Doi

Citation
Fischer T, Stern C, Fritz B, Zingg P, Pfirrmann C, 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)
Journal
Acta Radiol 2021
Publication Date
Jun 7, 2021
Issn Electronic
1600-0455
Pages
2841851211021044
Brief description/objective

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.