A 63-year-old White man presents with bowing deformity of his legs, gait abnormality, and tingling and weakness in his left leg. The nurse practitioner suspects Paget’s disease of bone (PDB). Which of the following most closely describes the pathophysiology of PDB?

Choice A reason: This describes osteoarthritis, not Paget’s disease. Osteoarthritis involves degeneration of joint cartilage and synovial structures, whereas Paget’s disease affects bone remodeling. Choice B reason: Paget’s disease of bone is characterized by excessive osteoclastic bone resorption followed by disorganized osteoblastic bone formation. The newly formed bone is structurally abnormal—larger, less dense, and more vascular—making it prone to deformity and fracture. This explains the patient’s bowing and neurological symptoms due to nerve compression. Choice C reason: This describes rheumatoid arthritis, an autoimmune condition affecting the synovium. Paget’s disease is not autoimmune and does not primarily involve joint inflammation. Choice D reason: While PDB does involve abnormal bone remodeling, it does not lead to decreased skeletal mass. Instead, it results in structurally unsound bone that may be enlarged but weakened.