General Session: Tumor, Trauma, and Infection

Presented by: I. Lieberman - View Audio/Video Presentation (Members Only)

Author(s):

I. Lieberman(1), X. Hu(1)

(1) Texas Back Institute, Texas Health Presbyterian Hospital Plano, Scoliosis and Spine Tumor Center, Plano, TX, United States

Abstract

Introduction: Hardware removal is commonly needed in revision spine surgeries. However, the presence and significance of occult infections in removed hardware are less clear especially in those patients who have no clinical signs of infection. The purpose of this study is to examine the incidence of occult infection in a series of revision spine surgeries and to study its correlation with pre-operative inflammatory markers.

Methods: Data were retrospectively reviewed from all patients who underwent revision spine surgery and hardware removal by a senior surgeon between 2010 and 2016. Culture of the removed hardware and surrounding tissue is a routine practice of the senior surgeon. Those patients who had pre-operative clinical signs of infection were excluded from this study. The hardware and surrounding tissue culture results were obtained from medical records. The patients' diagnosis and pre-operative inflammatory marker levels (ESR, CRP, procalcitonin) were recorded.

Results: A total of 162 consecutive patients were included in this study. The patients' mean age was 61 years (range 14 - 88). One hundred and three patients (63.6%) were female. Seventy two patients (44.4%) had loose hardware and 88 patients (54.3%) had pseudarthrosis. Post-operatively, the hardware and/or surrounding tissue culture was positive in 15 patients (9.3%). The most common identified organisms were Propionibacterium acnes (7/15, 46.7%) and Staphylococcus (6/15, 40.0%). The other identified organisms were Pseudomonas aeruginosa (1/15, 6.7%) and Serratia marcescens (1/15, 6.7%). Only four patients with positive cultures had elevated pre-operative ESR and CRP levels (p>0.05). Only two patients with positive cultures had elevated pre-operative procalcitonin levels (p>0.05).

Conclusion: Our study shows that occult infections are present in 9.3% of patients who underwent revision spine surgery and hardware removal although they did not have clinical signs of infection. Our results also imply that those commonly used pre-operative inflammatory markers such as ESR, CRP and procalcitonin are not sensitive enough to detect occult infections in these patients.