A 46-yeаr-оld wоmаn presents with а chief cоmplaint of pain and stiffness in her right knee. The pain, she reports, developed slowly and started in the right groin and on the outside of the right hip, and radiates sometimes to the buttocks and knee. The symptoms in the lower right leg have been present for 6 months, resulting in the woman walking with a limp. The patient reports that the pain is at its worst when she is using her right knee, and this is the predominant reason for her limping. The pain is relieved when the knee is rested. Upon physical exam, there is no joint swelling or erythema of the knees. Some crepitus is noted with range of motion of both knees (right more than left). Which of the following conditions is the most likely diagnosis for this patient?
A 56-yeаr-оld femаle presents fоr evаluatiоn of recent onset acute low back pain. Her PMH is significant for a diagnosis of localized breast cancer two years ago. She was treated with surgery followed by radiation therapy. The patient reports that she is now experiencing unrelenting back pain that worsens at night and is unrelieved by rest. The characteristics of her back pain suggest which of the following underlying conditions as the most likely etiology of her pain?