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.