Objectives To investigate normal and pathologic values of fatty infiltration (FI) and muscle volume through volumetric quantification of the main hip abductors of patients with unilateral greater trochanteric pain syndrome (GTPS) using 2-point-Dixon MRI. Materials and methods Patients prospectively underwent MRI of both hips: FI of the gluteus minimus (Gmin) and medius (Gmed) muscles were quantified by volumetric fat fractions (3D FF) using 2-point-Dixon MRI. Whole (WMV) and lean muscle volumes (LMV) were calculated for both muscles. 3D FF and volumes were compared between asymptomatic and GTPS hips, using the Wilcoxon signed-rank test. Gender-specific differences were assessed using the Mann–Whitney U test. Results Forty-one patients (mean age 65.0 ± 13.6 years, 27 females) were analyzed. 3D FF in asymptomatic hips was lower than in symptomatic hips (Gmin: 17.8% vs. 19.8%; Gmed: 12.7% vs. 15.9% (all p ≤ 0.02)). Gmin had a higher 3D FF than Gmed (p < 0.001). Females had higher FF (asymptomatic and symptomatic Gmin: 19.4%, 21.8%; asymptomatic and symptomatic Gmed: 13.2%, 16.3%) than males (asymptomatic and symptomatic Gmin: 14.7%, 16.1%; asymptomatic and symptomatic Gmed: 11.8%, 14.9%) for both sides and muscles. Average WMV in asymptomatic hips for Gmin and Gmed were 77.2 cm3, 270.1 cm3 in females, and lower in males (both p < 0.001) with 107.1 cm3, 408.1 cm3, respectively. Conclusion This study offers reference values for 3D FF and volumes of the Gmin and Gmed muscles in asymptomatic elderly hips, which are significantly lower than their GTPS counterparts, with succinctly higher fat fractions in females than males. Women showed significantly lower muscle volume for both muscles than men. Critical relevance statement Volumetric fat fractions of gluteal muscles show significant symptoms and gender related differences, indicating their potential as an imaging biomarker in the common GTPS patient. Key Points <UnorderedList Mark="Bullet"> <ItemContent> In females, asymptomatic hips showed average volumetric fat fractions of 19% for Gmin and 13% for Gmed; with lower values in males, of 15% and 12%, respectively. </ItemContent> <ItemContent> Whole muscle volumes in asymptomatic hips for Gmin and Gmed were 77.2 cm3, 270.1 cm3 in females, and 107.1 cm3, 408.1 cm3 in males. </ItemContent> <ItemContent> Using volumetric fat fractions, abductor muscle fat content was significantly higher in symptomatic GTPS hips compared to asymptomatic hips. </ItemContent> </UnorderedList> Graphical Abstract

Fatty infiltration of the gluteus medius and minimus muscles: volumetric analysis of both hips in patients with unilateral greater trochanteric pain syndrome using 2-point-Dixon MRI

期刊论文
出版模式：

开放获取
发表日期：

2025年12月22日

查看全文

Georg Wilhelm Kajdi,
Sophia Samira Goller,
Patrick Oliver Zingg,
Reto Sutter

摘要

Objectives

To investigate normal and pathologic values of fatty infiltration (FI) and muscle volume through volumetric quantification of the main hip abductors of patients with unilateral greater trochanteric pain syndrome (GTPS) using 2-point-Dixon MRI.

Materials and methods

Patients prospectively underwent MRI of both hips: FI of the gluteus minimus (Gmin) and medius (Gmed) muscles were quantified by volumetric fat fractions (3D FF) using 2-point-Dixon MRI. Whole (WMV) and lean muscle volumes (LMV) were calculated for both muscles. 3D FF and volumes were compared between asymptomatic and GTPS hips, using the Wilcoxon signed-rank test. Gender-specific differences were assessed using the Mann–Whitney U test.

Results

Forty-one patients (mean age 65.0 ± 13.6 years, 27 females) were analyzed. 3D FF in asymptomatic hips was lower than in symptomatic hips (Gmin: 17.8% vs. 19.8%; Gmed: 12.7% vs. 15.9% (all p ≤ 0.02)). Gmin had a higher 3D FF than Gmed (p < 0.001). Females had higher FF (asymptomatic and symptomatic Gmin: 19.4%, 21.8%; asymptomatic and symptomatic Gmed: 13.2%, 16.3%) than males (asymptomatic and symptomatic Gmin: 14.7%, 16.1%; asymptomatic and symptomatic Gmed: 11.8%, 14.9%) for both sides and muscles. Average WMV in asymptomatic hips for Gmin and Gmed were 77.2 cm³, 270.1 cm³ in females, and lower in males (both p < 0.001) with 107.1 cm³, 408.1 cm³, respectively.

Conclusion

This study offers reference values for 3D FF and volumes of the Gmin and Gmed muscles in asymptomatic elderly hips, which are significantly lower than their GTPS counterparts, with succinctly higher fat fractions in females than males. Women showed significantly lower muscle volume for both muscles than men.

Critical relevance statement

Volumetric fat fractions of gluteal muscles show significant symptoms and gender related differences, indicating their potential as an imaging biomarker in the common GTPS patient.

Key Points

In females, asymptomatic hips showed average volumetric fat fractions of 19% for Gmin and 13% for Gmed; with lower values in males, of 15% and 12%, respectively.

Whole muscle volumes in asymptomatic hips for Gmin and Gmed were 77.2 cm³, 270.1 cm³ in females, and 107.1 cm³, 408.1 cm³ in males.

Using volumetric fat fractions, abductor muscle fat content was significantly higher in symptomatic GTPS hips compared to asymptomatic hips.

Graphical Abstract