Risk Factors for Pseudarthrosis After Surgical Site Infection of the Spine

Abstract

Background: Pseudarthrosis following spinal fusion is a complication that frequently requires revision surgery. Reported rates of pseudarthrosis after surgical site infection (SSI) range from 30% to 85%, but few studies have identified infection as an independent risk factor for its development. The purpose of this study was to determine the incidence of clinically symptomatic pseudarthrosis in patient who developed SSI following lumbar fusion and to identify factors associated with its development. Methods: This was a retrospective review of a prospectively collected database. Patients who underwent spinal surgery and developed SSI between January 2005 and March 2015 with a minimum 2-year follow-up were included. Patient-specific and procedural characteristics were recorded. Presence of pseudarthrosis was determined clinically by the treating surgeon and was confirmed radiographically. All those in the Pseudarthrosis group required a revision procedure after the eradication of infection. Univariate and multivariate analyses were conducted as appropriate. Results: A total of 416 patients were included. Of these, 21 (5.0%) developed symptomatic pseudarthrosis following SSI. In this cohort, multivariate regression showed that age, Charlson Comorbidity Index, male sex, and surgical approach were not significant predictors of pseudarthrosis formation. However, number of levels fused was found to be the leading predictor for pseudarthrosis development (odds ratio [OR], 1.356/level, P , .001), followed by body mass index (OR, 1.083/point, P , .009) in this cohort. The number of levels fused was found to be a significant predictor of hardware removal (OR, 1.190/level, P , .001). Of the 21 pseudarthrosis cases, 85.7% found staphylococcal species, of which 27.8% exhibited methicillin-resistant Staphylococcus aureus. Conclusions: The number of spinal levels fused and body mass index are independent predictors of pseudarthrosis in patients who develop SSI after spinal fusion. Level of Evidence: Level 4 Clinical Relevance: This is the first known study to specifically identify risk factors for the development of symptomatic pseudarthrosis.

Occult infection in pseudarthrosis revision after spinal fusion

“…Occult low-grade infection in spinal revision surgery has been reported [6,[7][8][9][10][11]17,18]. Hu et al [7] found positive cultures indicating subclinical infection in 15 of 162 revision spine surgery cases (9.3%).…”

Experience With Recombinant Human Bone Morphogenetic Protein-2 in Posterior Lumbar Interbody Fusion: A Retrospective Review of 1019 Procedures

“…19 Our finding that increasing BMI predicts reoperation for nonunion concurs with previously published data associating BMI with complications after spinal surgery. 20,21 The primary endpoint used in this study was reoperation for symptomatic pseudarthrosis, which was confirmed at surgery rather than at a radiographic endpoint. While other studies have used various radiographic scoring systems for the assessment of fusion, interobserver agreement has been found to be limited.…”

Risk Factor of Postoperative Lumbar Surgical Site Infection: A Literature Review

“…This leads to risk of SSI happen. Hollern et al presented that number level of spinal fused was an independent predictor in patient with postoperative surgical site infection [39]. Other than that, epidural tear is also one of the risk factors to get SSI involved.…”