Post surgery changes to the femurs bilaterally results in significant metallic susceptibility moderate size left hip effusion what does this mean?

Susceptibility: artifact is an expected MRI finding if there is a prosthesis or other metallic foreign body present. It is not an abnormality itself, but a distortion of the image due to the interaction of the metal with the magnetic field, and therefore could obscure an abnormality. A hip effusion is fluid within the hip joint space and generally indicates an inflammatory process.