Late infection in patients with scoliosis treated with spinal instrumentation

Sixty patients were treated using a multilevel spinal instrumentation system. Spine arthrodesis was done posteriorly in all patients using a combination of two rods, hooks, screws, and cross-link plates. The Galveston technique was used in three patients. Five patients presented with late deep wound infections 1 to 5 years postoperatively. Two patients presented with a local subcutaneous abscess, whereas the remaining patients had a local drainage. Exploration revealed pus lining the instrumentation surface, at least one loose cross-link nut, and local hardware corrosion and metal infiltration of the surrounding tissues. All patients had a satisfactory bony arthrodesis, so instrumentation was removed. Intraoperative cultures revealed three coagulase-negative Staphylococci, one Acinetobacter baumani, and one Peptostreptococcus. A continuous irrigation system with antibiotics was placed for 5 days in all patients in combination with intravenous antibiotics and oral antibiotics. All patients responded to the treatment, with no recurrence of the infection after removal of the instrumentation. Although the exact nature of these infections requires additional investigation, the findings suggest a correlation between instrumentation failure and loosening and late infection. Bone involvement was not observed and removal of instrumentation was a reliable means of treatment.