Review Question - QID 213405

A 25-year-old man presents to the emergency department with back pain. He states that it started yesterday and has been gradually getting worse. He states that the pain is worsened with moving and lifting and is relieved with rest and ibuprofen. He has a past medical history of smoking and IV drug abuse and states he last used IV drugs 2 days ago. He thinks his symptoms may be related to lifting a heavy box. His temperature is 99.3°F (37.4°C), blood pressure is 122/88 mmHg, pulse is 77/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam is notable for focal back pain lateral to the patient’s spine on the left. There is no midline tenderness and the rest of the patient’s exam is unremarkable. There are scars in the antecubital fossae bilaterally. Laboratory values including a C-reactive protein are unremarkable. Which of the following is the most likely diagnosis?