Purpose:

Surgical site infection is a significant complication in posterior spinal fusion for scoliosis in pediatric and adolescent patients. Current literature demonstrates a lack of consensus regarding best prophylactic systemic and topical antibiotic regimens for reducing infection rates. This study aims to identify which common microbes are present at particular locations in the spine, and whether these are covered by our current systemic and topical antibiotic prophylaxis regimens.

Methods:

A prospective observational study at a National Children’s Hospital was conducted on 21 consecutive patients who underwent elective surgery for spinal deformity. Swabs were taken from four layers of the spine, including the superficial skin surface at the start of the case (after surgical site preparation with povidone-iodine), the deep dermis, and the deep surgical bed at the end of exposure and again after the corrective maneuver prior to closure. At each layer, swabs were taken from the proximal, middle, and distal portion of the wound. Swabs were sent to the laboratory for culture and susceptibility testing.

Results:

Thirteen (62%) of patients had positive microbial growth. Two microbes were identified, Staphylococcus epidermidis (9.5% of patients) and Cutibacterium acnes (Propionibacterium acnes) (52% of patients). 100% of these microbes were sensitive to cefazolin and vancomycin. 3% of patients had positive growth at the skin layer, 32% positive at the dermal layer, 17% positive after exposure, and 40% positive at the conclusion of the case (p = 0.006). No difference was observed in microbial presence in the upper thoracic, lower thoracic and lumbar spine.

Conclusion:

Despite adequate surgical site preparation and sterile procedure, microbial contamination remains abundant in the dermal layer and deeper in the spinal wound throughout the case.