Progression to Pseudomonas Osteomyelitis Following Pin Tract Infection After Percutaneous Fixation of a Pediatric Supracondylar Humerus Fracture.

Supracondylar humerus fractures are common in children, and percutaneous pinning is the standard treatment. Infection rates are low, and Pseudomonas aeruginosa osteomyelitis is rarely reported. A 4-year-old boy underwent percutaneous pinning for a supracondylar humerus fracture. Five weeks postoperatively, redness appeared at the medial pin site and that wire was removed; at six weeks the lateral site later developed granulation tissue, but no antibiotics were prescribed. At eight weeks he developed a 39°C fever. MRI on postoperative day 60 suggested osteomyelitis, and CT on day 65 demonstrated a cortical defect in the posterolateral distal humerus. Surgical debridement confirmed P. aeruginosa infection. Culture-directed therapy with intravenous cefepime plus ciprofloxacin - initiated 30 days after the first local signs and continued for five weeks - was followed by six months of oral ciprofloxacin; elbow function recovered to 0°-150° despite a residual cortical defect. This case shows that delayed antibiotics can allow a superficial pin-site infection to progress to deep osteomyelitis, and underscores that early recognition of pin-site changes with prompt antimicrobial therapy is essential to prevent deep infection and preserve function.