Case report and brief review of literature on sonographic detection of accidentally implanted wooden foreign body causing persistent sinus

Despite advances in imaging techniques, the detection of retained vegetative foreign bodies remains a difficult and challenging task and may require the use of imaging modalities for better localization. Patients may present for evaluation several months or even years after the initial injury, and consequently, clinical evaluation may fail to elicit a history of antecedent skin puncture. When a history of penetrating trauma is suggested, its severity is difficult to estimate clinically [1]. Radiographs may fail to reveal the retained radiolucent foreign bodies leading to missing the diagnosis entirely [1].A 15-year-old boy of average built presented to the orthopaedics department with a draining non-healing sinus at the lateral aspect of his right lower thigh for the last 9？months (Figure 1). Pain was minimal. The margins of the sinus were hyperpigmented and thickened with excoriation of the surrounding skin; pus was expressed out on pressure. Palpation was painful but did not reveal any mass around the sinus. Regional lymph nodes were enlarged compared to the contralateral side. Distal neurovascular status was normal. The knee joint was not swollen, and the range of motion was normal except for a mild terminal restriction of flexion due to pain. Detailed history revealed that about 9？months ago, he fell down from a tree which is approximately 15 feet in height and sustained injury from wooden branches at the right thigh. He also had transient loss of consciousness from the impact. After consciousness was regained, he noticed a small wound over the outer aspect of his right thigh. There was not much bleeding, and he considered it a minor injury. The wound, however, nearly healed. After about 3？weeks, he noticed swelling and frank pus started coming out of the wound. He sought traditional treatment and got some temporary relief. The amount of pus decreased in-between and the size also diminished, but complete healing never occurred. During the whole course, he did no