[17-year-old male patient with open radius fracture treated with ORIF at outside hospital. Pain in distal ulna consistent with infection.] [Evaluation of the distal radius and surrounding soft tissues is limited due to metallic susceptibility artifact from orthopedic fixation of the distal radius.The distal 5 to 6 cm of the ulna is replaced with abnormal signal intensity which is isointense to skeletal muscle on T1-weighted images and hyperintense on T2-weighted images compatible with osteomyelitis, and likely intra-osseous abscess formation. There is heterogeneous enhancement of the distal ulna and surrounding soft tissues following contrast administration with a small rim-enhancing fluid collection anterior to the distal end of the ulna representing a small abscess. Additional mild edema is noted within the distal ulnar diaphysis. Portions of the cortex of the distal ulna appear completely destroyed. The soft tissue inflammatory component along the distal end of the ulna measures approximately 3 cm in greatest transverse dimension. The inflammatory process extends to the sigmoid notch of the distal radius and there is underlying edema within the marrow of the distal radial metaphysis which could represent reactive osteitis or osteomyelitis. There is mild edema within the pronator quadratus, but we see no discrete abscess within the musculature of the forearm and visualized proximal hand. We see no findings to suggest osteomyelitis of the proximal carpal row.
[Osteomyelitis of the distal ulna with surrounding soft tissue inflammatory changes as described above which abuts the sigmoid notch of the distal radius. Edema within the distal radial metaphysis may reflect reactive osteitis or osteomyelitis. On the basis of accompanying outside hospital radiographs, the diagnosis of osteomyelitis of the distal radius is favored.