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Question 15#

A 60-year-old male patient complains of low back pain, which has intensified over the past 3 months. He had experienced some fever at the onset of the pain. He was treated for acute pyelonephritis about 4 months ago. Physical examination shows tenderness over the L2-3 vertebra and paraspinal muscle spasm. Laboratory data show an erythrocyte sedimentation rate of 80 mm/h and elevated C-reactive protein. Which of the following statements is correct? 

A. Hematogenous osteomyelitis rarely involves the vertebra in adults
B. The most likely initial focus of infection was soft tissue
C. Blood cultures will be positive in most patients with this process
D. An MRI scan is both sensitive and specific in defining the process
E. Surgery will be necessary if the patient has osteomyelitis

Correct Answer is D

Comment:

The presentation strongly suggests vertebral osteomyelitis. MRI is sensitive and specific for the diagnosis of vertebral osteomyelitis and is the diagnostic procedure of choice. MRI will reveal the extent of contiguous disc and soft tissue involvement and will help assess for pending neurological compromise. The vertebrae are a common site for hematogenous osteomyelitis. Prior urinary tract infection is often the primary mechanism for bacteremia and vertebral seeding. Blood cultures at the time of presentation are positive in fewer than half of all cases. Treatment requires 6 to 8 weeks of antibiotics, but surgery is rarely required for cure.