Clinical Characteristics and Surgical Outcomes of Spinal Infection Caused by Methicillin-resistant Staphylococcus aureus.

Background context: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major causative organisms of spinal infections, and its incidence of spinal infection caused by MRSA has been increasing in recent years. However, limited studies have assessed surgical outcomes and complications focusing specifically on MRSA spinal infections.

Purpose: To evaluate the characteristics, surgical outcomes, and complications of spinal infection caused by MRSA.

Study design: Retrospective observational cohort.

Patient sample: Patients who underwent surgery for spinal infection, including discitis, osteomyelitis, epidural abscess, and/or septic facet arthritis. Patients with a history of spine surgery within the preceding 90 days or culture-negative spondylodiscitis were excluded.

Outcome measures: Recurrence and postoperative complications within one year METHODS: We retrospectively reviewed 205 patients who underwent surgery for spinal infection. Clinical characteristics and postoperative complications within one year were compared between patients with spinal infection caused by MRSA (MRSA) and those with infections caused by other organisms (Non-MRSA). Multiple logistic analysis was performed to determine independent factors associated with recurrence.

Results: MRSA was identified in 89 patients (43%). Compared to Non-MRSA patients, MRSA patients had a significantly higher incidence of current smoking (57% vs 40%, p=0.021), intravenous drug use (49% vs 33%, p=0.021), thoracic spine involvement (43% vs 28%, p=0.039), epidural abscess (65% vs 45%, p=0.005), concomitant bone and joint infections (30% vs 16%, p=0.027), and positive blood culture (63% vs 46%, p=0.017). They also had significantly higher rates of readmission after 30 days postoperatively (48% vs 34%, p=0.044) and recurrence (20% vs. 7.8%, p=0.012). MRSA was an independent risk factor for recurrence following surgical treatment of spinal infection (MRSA: OR 2.60, 95% CI 1.10-6.52, p =0.033).

Conclusion: Spinal infections caused by MRSA were associated with a higher prevalence of current smoking, intravenous drug use, thoracic spine involvement, epidural abscesses, concomitant bone or joint infections, and bacteremia. Moreover, MRSA was identified as an independent risk factor for recurrence following surgical treatment of spinal infection.