When is a backache not just a backache?
We discussed a 32yom with past IVDU (none in 10 years) and type I diabetes who presented with lumbar back pain radiating down his left leg for 2 months and worse for the last few days, to the point where he couldn’t sit or lay down comfortably. He had a history of an untreated +PPD, IVDU last 10 years ago, cocaine use last 1 year ago and poorly controlled type I diabetes. His exam was notable for mild tachycardia and a systolic murmur at the L lower sternal border. He had point tenderness in the upper lumbar region and hyperesthesia in his left leg.
Remember to follow guidelines for imaging in low back pain. 2011 ACP guidelines are reviewed in Table 4 of this article. MRI of vertebral osteomyelitis is characteristically hypointense on T1 and hyperintense on T2 with involvement of the disk first and then the adjacent vertebral bodies. Imaging may lag infection by 2-4 weeks.
Bacteriologic diagnosis in vertebral osteomyelitis is useful in tailoring antibiotics. 2 blood cultures prior to antibiotic initiation is the guideline. If those do not yield a result, the recommendation is to pursue tissue diagnosis with vertebral biopsy.
This patient is diagnosed with MSSA vertebral osteomyelitis by blood culture alone. His type I diabetes and misuse of his insulin needles likely put him at risk. He also seeded his L hip and had complete destruction of the joint requiring joint resection.