Review Question - QID 109987

A 27-year-old man presents to his primary care provider with low back pain. He has not been to the physician in 6 years. He reports the gradual onset of non-radiating low back pain that started 2 years ago and has progressively worsened over that time. He denies any inciting injury. His pain is worse in the morning and is accompanied by stiffness that improves throughout the day. He has been taking ibuprofen intermittently to treat his pain. He drinks alcohol socially and has a 5 pack-year smoking history. On exam, he is well-appearing and in no acute distress. Palpation of his lumbar vertebral spines elicits no pain. Spine flexion and extension are slightly limited. A radiograph of the patient’s pelvis is shown in Figure A. This patient is at an increased risk of developing which of the following?