74-year-old male with bilateral quadriceps weakness. Evaluate for nerve impingement. Metallic susceptibility artifact limits evaluation of the right hip and surrounding musculature/soft tissues.Right hip:Metallic susceptibility artifact from a right total hip arthroplasty device limits evaluation. There is a large lobulated focus of fluid signal intensity along the right hip along the lateral margin of the rectus femoris musculature which is incompletely visualized due to metallic susceptibility artifact from the aforementioned right total hip arthroplasty device as well as incompletely characterized on this noncontrast examination, but measures at least 7.8 cm in the craniocaudal dimension and 4.9 cm in the transverse dimension. There is associated partial thickness tearing of the right rectus femoris muscle at the level of the myotendinous junction. The rectus femoris tendon attachment on the anterior inferior iliac spine appears intact. There is atrophy of the right psoas musculature. There is diffuse fatty atrophy of the musculature of the right hip most pronounced within the right gluteus minimus muscle and adductor musculature. Heterogeneous bone marrow may represent residual islands of red marrow.Left hip:There is fatty atrophy of the musculature of the left hip most pronounced within the gluteal musculature. There is nonspecific increased signal abnormality within the rectus femoris and vastus lateralis muscles. The remainder of the imaged musculature of the left hip is normal in appearance. Heterogeneous bone marrow may represent residual islands of red marrow. There is a 14 mm bladder diverticulum along the left posterosuperior bladder.
1. Postoperative changes of a right total hip arthroplasty with a lobulated fluid collection along the anterior and lateral aspect of the right rectus femoris muscle which is incompletely visualized/characterized due to extensive metallic susceptibility artifact. These findings appear most consistent with hematoma/seroma formation related to partial tearing of the right rectus femoris at the level of the myotendinous junction. Superimposed infection cannot be excluded by this examination.2. Fatty atrophy of the musculature of the hips bilaterally as described above.3. Nonspecific increased signal abnormality within the left rectus femoris and vastus lateralis muscle bellies can be seen in subacute denervation or myositis.