A retrospective database analysis among Medicare beneficiaries
The aim of this study was to determine the effect of chronic steroid use and chronic methicillin-resistant Staphylococcus aureus (MRSA) infection on rates of surgical site infection (SSI) and mortality in patients 65 years of age and older who were treated with lumbar spine fusion.
Systemic immunosuppression and infection focus elsewhere in the body are considered risk factors for SSI. Chronic steroid use and previous MRSA infection have been associated with an increased risk of SSI in some surgical procedures, but their impact on the risk of infection and mortality after lumbar fusion surgery has not been studied in detail.
The PearlDiver insurance-based database (2005–2012) was queried to identify 360,005 patients over 65 years of age who had undergone lumbar spine fusion. Of these patients, those who had been taking oral glucocorticoids chronically and those with a history of chronic MRSA infection were identified. The rates of SSI and mortality in these two cohorts were compared with an age- and risk-factor matched control cohort and odds ratio (OR) was calculated.
Chronic oral steroid use was associated with a significantly increased risk of 1-year mortality [OR = 2.06, 95% confidence interval (95% CI) 1.13–3.78, P = 0.018] and significantly increased risk of SSI at 90 days (OR = 1.74, 95% CI 1.33–1.92, P < 0.001) and 1 year (OR = 1.88, 95% CI 1.41–2.01, P < 0.001). Chronic MRSA infection was associated with a significantly increased risk of SSI at 90 days (OR = 6.99, 95% CI 5.61–9.91, P < 0.001) and 1 year (OR = 24.0, 95%CI 22.20–28.46, P < 0.001) but did not significantly impact mortality.
Patients over 65 years of age who are on chronic oral steroids or have a history of chronic MRSA infection are at a significantly increased risk of SSI following lumbar spine fusion.
Level of Evidence: 3
Chronic steroid usage was associated with increased risk of 1 year mortality and 90 day and 1 year surgical site infection, while chronic MRSA infection was associated with increased risk of infection at both 90 day and 1 year in this nationwide database analysis of lumbar fusion.
∗Department of Orthopedic Surgery, University of Virginia Health System, Charlottesville, VA
†Department of Orthopedic Surgery, University of Missouri, Columbia, MO.
Address correspondence and reprint requests to Anuj Singla, MD, Department of Orthopedics, 400 Ray C Hunt Drive, Charlottesville, VA 22903; E-mail: Anujrajsingla@gmail.com
Received 30 May, 2018
Revised 3 August, 2018
Accepted 14 August, 2018
The manuscript submitted does not contain information about medical device(s)/drug(s).
No funds were received in support of this work.
Relevant financial activities outside the submitted work: board membership, grants, payment for lecture.