Tibial Osteomyelitis Caused by Morganella morganii After External Fixation for Limb Length Discrepancy in a Pediatric Patient: A Case Report and Literature Review

Morganella morganii is a facultative, anaerobic rod Gram-negative enteric bacterium. Few cases are documented of musculoskeletal infection. We present a case of a 9-year-old boy with osteomyelitis 1 year after index external fixation for leg length discrepancy. Our patient initially presented with wound drainage at his distal medial tibia fixation site but had negative radiographs. Initial antibiotic treatment failed after 1-month follow-up, and cultures revealed M. morganii. He underwent incision and drainage with external fixator removal, and the antibiotic regimen changed after a susceptibility panel. Symptoms were alleviated after 30 days with the new antibiotic regimen, and the patient was put back on his original schedule for limb lengthening through external fixation. A new methicillin-sensitive Staphylococcus aureus occurred at the same site 2.5 years later but was easily treated, and the 3-year follow-up showed no other recurrences or complications.