# Osteomyelitis of the Third Metatarsal Mimicking a Neoplastic Lesion Due to a Retained Wooden Foreign Body

## TL;DR

A child's chronic foot pain was caused by a wooden foreign body missed on initial imaging, leading to osteomyelitis and requiring surgery.

## Contribution

Highlights the importance of advanced imaging for detecting radiolucent foreign bodies in foot injuries.

## Key findings

- Plain radiographs and ultrasound failed to detect a retained wooden foreign body in a child's foot.
- CT and MRI successfully identified the wooden foreign body eroding into the third metatarsal medullary canal.
- Surgical removal of the foreign body resolved the osteomyelitis symptoms.

## Abstract

Plantar puncture wounds are a common entity among children, particularly in areas where walking barefoot is common, but the detection of radiolucent foreign bodies (FBs), like those made of wood, remains elusive, with the risk of delayed diagnosis. The patient was a four-year-old girl who presented with chronic foot pain, limping, and a localized dorsal mass six months following a plantar puncture injury. Initial management at another facility consisted of exploration for a suspected FB and abscess, guided by an ultrasound report and an attempt at removal guided by ultrasound; however, her symptoms persisted. Plain radiographs showed osteolysis and sclerosis of the third metatarsal, which would be suspicious for osteomyelitis or a neoplastic process. Computed tomography (CT) and magnetic resonance imaging (MRI) subsequently provided a clear identification of a 2-cm retained wooden FB eroding into the medullary canal of the third metatarsal. The FB was successfully removed via surgical exploration through a dorsal approach, followed by debridement and curettage. This case underlines the limitations of plain radiographs and ultrasound in detecting radiolucent FBs. Early application of advanced cross-sectional imaging studies, such as CT and MRI, is indispensable in penetrating trauma with organic material in order to avoid delayed diagnosis and grave complications such as osteomyelitis.