Interpretation of radiologic abnormalities in patients with chronically infected ingrown toenails with regard to a possible exogenic osteomyelitis

Background

Chronic infection of ingrown toenails may lead to exogenous osteomyelitis. Therefore, plain x-rays are commonly taken in children with significant inflammation. We evaluated the preoperative radiologic findings and their clinical significance, especially with regard to exogenic osteomyelitis.

Patients and methods

We retrospectively evaluated all patients who underwent surgery for infected ingrown toenails during a 5-year period. Data collection included the history of infection, preoperative laboratory tests, preoperative x-rays, and intraoperative presentation.

Findings

One hundred thirty-four patients with infected ingrown nails of the hallux underwent 161 surgical procedures. Mean age at surgery was 14.1 years. Preoperative x-rays were taken in 113 (70.2%) cases. The treating surgeon classified 76 (67.2%) x-rays as negative (no bone affection), 16 (14.2%) as positive (definite bone affection), and 21 (18.6%) as suspicious for bone affection. Only 11 (30%) of 37 children with positive or suspicious x-rays showed bone affection during surgery, which presented as a softening of the cortical bone. None of the children had significantly elevated inflammation markers in the preoperative laboratory tests. Children with positive or suspicious x-rays had a significant longer history of infection compared to those without radiologic abnormalities (8 vs 4.5 weeks mean; P = .024). A reevaluation of the x-rays by an experienced radiologist was undertaken and revealed no case of definite osteolysis.

Conclusion

In about one third of all infected ingrown toenails, radiologic changes of the distal phalanx occur. These changes primarily represent periostal reactions. A typical osteomyelitis as a complication of chronically infected ingrown toenails is rare.