Question

A $24$-year-old man schedules an appointment at an outpatient rheumatology clinic due to progressive, dull lower back pain over the past eight months. He describes the discomfort as insidious in onset, peaking during the early morning hours, and accompanied by severe stiffness that lasts approximately two hours. His symptoms are noticeably alleviated by engaging in physical exercise but worsen with prolonged rest. He denies any recent trauma, urethritis, psoriasis, or vision changes. Physical examination demonstrates limited lumbar flexion (positive Schober test) and bilateral tenderness upon palpation of the sacroiliac joints. Laboratory studies reveal an erythrocyte sedimentation rate (ESR) of $45 \text{ mm/h}$ and a C-reactive protein (CRP) level of $22 \text{ mg/L}$. Rheumatoid factor and anti-cyclic citrullinated peptide (anti-CCP) antibodies are negative. The physician suspects a seronegative spondyloarthropathy and begins formulating a clinical pathway to confirm the diagnosis and establish long-term management.

Arrange the following diagnostic and therapeutic interventions in the most appropriate chronological sequence based on standard medical guidelines for this suspected condition.