Radiographic progression of septic arthritis of the hip

A 63-year-old patient presented with a history of left low back and groin area pain. An MRI of the spine to rule it out as a cause identified a left iliopsoas abscess. The abscess was drained under CT guidance, which grew Escherichia coli and a drain sited. The patient clinically improved over the next 3 weeks with resolution of the abscess, however, the groin pain began to worsen. Subtle joint space narrowing in the hip was noted, and an MRI of the pelvis demonstrated secondary septic arthritis of the left hip. Aspirate of the hip grew the same …