A 29-year-old man complains of back pain for several months. It takes him over 2 hours to limber up in the morning. His x-ray is shown in Figure given below. Which of the following is the most likely diagnosis?
High-Yield Explanation
The x-ray reveals typical evidence of sacroiliitis, with widening of the joints, sclerosis, and evasions. Similar findings can be seen in psoriatic and enteropathic spondyloarthropathy.