Multidetector CT for thorn (wooden) foreign bodies of the knee.

Abstract

Thorn (wooden) foreign bodies of the knee present a challenge in their diagnosis. Partly because of inaccurate history and sometimes a long duration of symptoms, radiographs are negative and MRI may show synovitis without a specific pathology. We report a case of a 16-year-old male patient with a date palm thorn foreign body, which caused septic arthritis. He underwent two open surgeries. Both failed to detect the loose body. An MRI of the knee showed a high signal in the posterolateral compartment; however, the pathology could not be confirmed except by 64 Multidetector CT (MDCT) that clearly identified the thorn and its location. Arthroscopic removal and synovectomy were done by a 4-portal technique. The patient went on to complete recovery. Multidetector CT has proven very useful in identifying wooden foreign bodies, their size and location.