Table 2.

Imaging modalities of gluteal muscle contracture.

	Features
Plain radiograph	1. Iliac hyper-dense line sign along the lateral iliac cortex in anteroposterior (AP) view
	2. Pelvic obliquity
	Other signs
	1. Increase in the neck shaft angle
	2. Reduction in center-edge angle
	3. External rotation of proximal femur
Magnetic resonance imaging (MRI)	Primary features
	1. Marked atrophy of gluteus maximus
	2. Intramuscular fibrous band
	Secondary features
	1. Medial retraction of the distal belly and tendon
	2. Posteromedial retraction of the iliotibial tract at attachment
	3. Depressed groove at the muscle-tendon junction
	4. External rotation of proximal femur
Computed tomography (CT) scan	1. Atrophy of gluteal muscles
	2. Calcification and necrosis of the injection site
	3. Curly band of fascia
	4. Widened gluteal muscle clearance
Ultrasonography (USG)	1. Thinning of involved muscles
	2. Hyperechoic bands within the muscle bundles suggest fibrosis