Clinical Experience Treating Vertebral Osteomyelitis at University of Louisville Hospital

Abstract

Background. At University of Louisville (UofL) we implemented a multidisciplinary Bone and Joint (B&J) Infection Service. The primary objective of this study was to review our experience treating adult patients with vertebral osteomyelitis and compare findings to the IDSA Practice Guidelines. A secondary objective evaluated annual trends in IVDU and incidence of vertebral osteomyelitis. Methods. This was a retrospective, observational study of patients managed by the B&J service at UofL Hospital from January 2011 to May 2016. For clinical outcomes, patients who deteriorated during antibiotic therapy or relapsed after completing therapy requiring surgical intervention were considered failures. Outcomes were assessed at end-of-treatment, 30-days, and 12-months. Results. A total of 91 patients were reviewed; the median age was 56 years (range 19-82), and 55 were male. Relevant history and comorbid conditions include diabetes (35), IVDU (23), hepatitis C (20) with cirrhosis (5), and smoking (42). Documentation of IVDU increased from 10% to 50% of patients annually from 2011 to 2015. Infection was most common in the lumbar vertebrae (46). Staphylococcus aureus was the infecting pathogen in 52 (57%) patients, 28 were MRSA. Fifty-two (57%) patients had concurrent bacteremia, and 10 (11%) were diagnosed with endocarditis. Epidural abscess was present in 51 (56%) cases. Sixty-six (73%) underwent surgical intervention; hardware was added in 24. At end-of-treatment, 22 patients were lost to follow-up. Sixtyone (88%) were considered clinical success and 30 continued long term suppressive treatment for retained hardware. Seventy-eight patients were eligible for 12-month outcomes, but 38 were lost to follow-up. Of the remaining 40 cases, 10 died, and twenty-eight (70%) were considered clinical success. Conclusion. Our study suggests that vertebral osteomyelitis is highly curable, IVDU is a primary risk factor, and Staphylococcus aureus is the most common pathogen; which is consistent with the IDSA Practice Guidelines. However, presence of epidural abscess was much more prevalent in our patient population. Empiric antimicrobial selection, while waiting on imaging and culture results, should utilize intravenous agents that penetrate into the epidural space.