Surgical Infection after Posterolateral Lumbar Spine Arthrodesis: CT Analysis of Spinal Fusion

• Published in: Orthopaedic surgery 2018-05, Vol.10 (2), p.89-97
• Main Authors: Andrés‐Cano, Pablo, Cerván, Ana, Rodríguez‐Solera, Miguel, Antonio Ortega, Jose, Rebollo, Natividad, Guerado, Enrique
• Format: Article
• Language: English
• Subjects: Body mass index; Clinical; Comorbidity; Confidence intervals; Infection; Infections; Lumbar spine arthrodesis; Spinal fusion; Spinal pseudarthrosis; Surgery; Variables
• ISSN: 1757-7853; 1757-7861
• DOI: 10.1111/os.12371

Objective To determine the incidence of infection after instrumented lumbar spine surgery, the demographic and surgical variables associated with acute infection, and the influence of infection and debridement on the consolidation of spinal fusion. Methods After obtaining approval from the hospital ethics committee, an observational study was made on a prospective cohort of consecutive patients surgically treated by posterolateral lumbar spine arthrodesis (n = 139, 2005–2011). In all cases, the minimum follow‐up period was 18 months. The following bivariate analysis was conducted of demographic and surgical variables: non‐infection group (n = 123); infection group (n = 16). Fusion rates were determined by multislice CT. Logistic regression analysis was performed. Results Incidence of deep infection requiring debridement: 11.51% (95% confidence interval, 5.85–17.18]). Bivariate analysis: differences were observed in hospital stay (7.0 days [range, 4–10] vs 14.50 days [range, 5.25–33.75]; P = 0.013), surgical time (3.15 h vs 4.09 h; P = 0.004), body mass index (25.11 kg/m2 [22.58–27.0] vs 26.02 kg/m2 [24.15 to 29.38]; P = 0.043), Charlson comorbidity index (median, 0 vs 1; P = 0.027), and rate of unsuccessful consolidation according to CT (18.4% vs 72.7%; P = 0.0001). In a model of multivariate logistic regression, taking as the dependent variable unsuccessful arthrodesis after 1 year, and adjusting for the other independent variables (infection, body mass index, Charlson comorbidity index, and surgical time), the only variable that was significantly associated with an outcome of unsuccessful spinal fusion after 1 year was infection, with OR = 12.44 (95% confidence interval, 2.50–61.76). Conclusion Deep infection after instrumented lumbar spine arthrodesis is a common complication that compromises the radiographic outcome of surgery. Patients who develop a postoperative infection and require debridement surgery are 12 times less likely to achieve satisfactory radiological fusion.