Radiating Low Back Pain • History of Urinary Symptoms • Past Surgery for Scoliosis • Dx?

Risk factors for spondylodiscitis include IV drug abuse, diabetes, morbid obesity, and having had a genitourinary or spinal procedure. X-ray findings for patients with spondylodiscitis will include osteolysis and end plate erosions (early) and narrowing and collapse of the disk space (late). (In TB, relative preservation of the disk spaces is seen, with significant vertebral destruction.)

MRI is the modality of choice for diagnosis and assessment of suspected spondylodiscitis because it can provide imaging of the soft tissue, neural elements, and bony changes with a high sensitivity and specificity.²³ Once infection is suspected, the diagnosis should be confirmed by fluoroscopic- or computed tomography-guided biopsy before starting antibiotic treatment.

Long-term antibiotics
 are required to prevent recurrence


IV antibiotics are the mainstay of treatment for spondylodiscitis;²⁴ the specific drug used will depend upon the organism identified. Patients typically receive 2 to 6 weeks of IV therapy. Then, once the patient improves and inflammatory markers return to normal levels, the patient receives a course of oral antibiotics for 2 to 6 more weeks. Grados et al¹⁹ found recurrence rates of 10% to 15% for patients who were treated 4 to 8 weeks compared to 3.9% in those treated for 12 weeks or longer; therefore, a total duration of 12 weeks is commonly chosen.^25-28

To minimize the risk of spondylolisthesis, kyphosis, and fractures of the infected bone, patients are advised to rest and the spine is often immobilized with a spinal brace. Surgery may be needed if antibiotics are not effective, or for patients who develop complications such as fluid collection, neurologic deficits, or deformity.

Our patient’s pain improved after 2 weeks and she became more comfortable wearing the thoracolumbar brace. Her CRP and ESR also improved and there was no radiologic evidence of fluid collection. The patient was discharged with a peripherally inserted central catheter in place and received IV ceftriaxone for 6 more weeks at home. This was followed by 4 weeks of oral ciprofloxacin 750 mg twice daily, thereby completing a 12-week course of antibiotics.

Our patient’s response to treatment was monitored clinically and the inflammatory markers were checked weekly after discharge until the end of treatment and at 6 and 12 months after start of treatment. At 12 months, our patient’s CRP was <1 mg/dL and ESR was 22 mm/h. One year later, our patient remained asymptomatic with normal inflammatory marker levels and no evidence of recurrence.

THE TAKEAWAY

Spondylodiscitis is an important differential diagnosis of lower back, flank, groin, and buttock pain. It’s important to be aware of this diagnosis, especially in patients who have risk factors such as IV drug abuse, diabetes, and morbid obesity. Although previous spinal surgery is a risk factor, spondylodiscitis should be considered in patients with persistent back pain even if they haven’t had spinal surgery. It can be present even when there is no tenderness over the spinous process or any fever.

Checking inflammatory markers is a reasonable next step if a patient’s pain does not resolve after at least 4 weeks. If levels of inflammatory markers such as CRP and ESR are elevated and symptoms continue, MRI can confirm or rule out the presence of spondylodiscitis. Treatments include orthotic support, antibiotics, and surgical intervention when complications arise.

REFERENCES

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10. Learch TJ, Sakamoto B, Ling AC, et al. Salmonella spondylodiscitis associated with a mycotic abdominal aortic aneurysm and paravertebral abscess. Emerg Radiol. 2009;16:147-150.

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