I tell my patients that if you have back pain before the surgery from causes other than the hip, then the back pain is going to be aggravated after hip replacement surgery. The reason is because the pain from the hip is gone and the only pain that the patient realizes is pain from the back. Therefore, the patient feels that the pain from the back is aggravated.
By doing hip replacement surgery I am not fixing the back. I am doing anything with the back. I am only treating the pain in the hip joint. However, if the patient is walking a little bit tilted from the hip problem, the back pain may go away after the hip replacement surgery.