A 60-year-old man comes to the emergency department with a 10-day history of malaise and lower back pain. He has tried high-dose acetaminophen with no relief. His past medical history is significant for benign prostate hyperplasia and recent urinary tract infection treated with ciprofloxacin. He reports resolution of urinary symptoms. His temperature is 38.3 C (101 F), blood pressure is 120/76 mm Hg, pulse is 90/min, and respirations are 16/min. Physical examination shows exquisite tenderness over the L4-L5 vertebrae and local paravertebral muscle spasm. Neurologic examination shows 2+ deep-tendon reflexes and 5/5 muscle strength in all extremities. The straight leg raise test is negative at 60 degrees. The prostate is mildly enlarged and nontender. Laboratory results are as follows:
Plain x-rays of the lumbar spine show mild degenerative changes. What is the best next step in management of this patient?

Question

A 60-year-old man comes to the emergency department with a 10-day history of malaise and lower back pain.  He has tried high-dose acetaminophen with no relief.  His past medical history is significant for benign prostate hyperplasia and recent urinary tract infection treated with ciprofloxacin.  He reports resolution of urinary symptoms.  His temperature is 38.3 C (101 F), blood pressure is 120/76 mm Hg, pulse is 90/min, and respirations are 16/min.  Physical examination shows exquisite tenderness over the L4-L5 vertebrae and local paravertebral muscle spasm.  Neurologic examination shows 2+ deep-tendon reflexes and 5/5 muscle strength in all extremities.  The straight leg raise test is negative at 60 degrees.  The prostate is mildly enlarged and nontender. Laboratory results are as follows:
 Plain x-rays of the lumbar spine show mild degenerative changes.  What is the best next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_d465_f0c2_bc81_51ca829f845b_MD0003_00 This patient's presentation of fever, back pain, and focal spinal tenderness suggests vertebral osteomyelitis, most likely due to hematogenous spread of recent urinary tract infection. Staphylococcus aureus accounts for about 50% of cases of pyogenic spinal osteomyelitis. However, other pathogens, including Gram-negative bacilli in this patient, can also cause osteomyelitis. Patients often present with back pain that may be misdiagnosed as degenerative spine disease. Fever may or may not be present. Physical examination usually shows exquisite focal tenderness on percussion at the posterior spinous process of the affected vertebra, increased muscle spasm in the contiguous area, and decreased range of motion in the back. Epidural abscess may result if the infection extends posteriorly into the epidural space and often causes severe back pain with motor and sensory abnormalities, which can progress to paralysis. Initial workup includes complete blood count, blood cultures (positive in 50%-70% of patients), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and plain spinal x-rays. Leukocyte count may be normal, but ESR and CRP are usually markedly elevated. Plain x-rays can be normal in the first 2-3 weeks of infection. Magnetic resonance imaging (MRI) is the modality of choice for patients with suspected vertebral osteomyelitis. It can also detect epidural abscess and cord compression. Radionuclide bone scanning using gallium is an alternate for patients who cannot undergo MRI. Computed tomography (CT)-guided aspiration and culture of infected intervertebral disc space or bone are needed to confirm the diagnosis. (Choices A and E) Renal imaging with CT scan (preferred) or ultrasound is indicated in patients with suspected complications from pyelonephritis. These include renal abscess or calculi causing obstruction. This patient has no urinary symptoms, and the spinal examination findings make osteomyelitis more likely. (Choice C) Pain control and physical therapy are recommended for patients with muscle sprain or simple back pain with no fever, recent infection, focal tenderness, or other alarm features (eg, history of cancer). (Choice D) Prostate biopsy would be indicated if digital rectal examination shows prostate nodules, induration, or asymmetry. This patient's examination had no such features. (Choice F) Technetium bone scan is less specific than gallium imaging in the diagnosis of vertebral osteomyelitis as it also detects fractures and may result in false-positive findings. The study may also be negative in the early phases of infection. Educational objective: Vertebral osteomyelitis usually presents with fever, back pain, and focal spinal tenderness. Evaluation includes blood cultures and inflammatory markers (erythrocyte sedimentation rate and C-reactive protein). Magnetic resonance imaging is the modality of choice for diagnosis, followed by computed tomography-guided bone biopsy. References: Spinal infections: diagnostic tests and imaging studies. (http://www.ncbi.nlm.nih.gov/pubmed/16523124)

A 60-Year-Old Man Comes to the Emergency Department with a 10-Day