Presentation
Diabetic with swollen foot ? osteomyelitis, 51 year old female
Patient Data
Left foot.
The tarsal bones show normal density with loss of cartilage and subchondral cysts/erosions at the lesser tarsometatarsal and some of the intertarsal articulations. Bone fragments and osteophytes are best seen dorsally on the lateral projection.
Site of abnormality and the appearance in a patient with long standing diabetes is consistent with a diabetic neuroarthropathy (Charcot).
MRI Left Foot.
Extensive mild tarsal bony edema with subtle enhancement on the post contrast images.
Intertarsal and tarsometatarsal joint space narrowing, articular surface irregularity, subchondral sclerosis bone fragmentation and subcortical cyst formation with adjacent soft tissue thickening.
Flattening of the plantar arch (pes planus), particularly medially.
No significant joint effusion.
No soft tissue collection or sinus tract.
Conclusion:
Appearance is that of a Charcot arthropathy of the mid foot. There are no features to suggest infection.
Case Discussion
Articular abnormality at this site in a diabetic patient is most likely due to a neuropathic arthropathy rather than infection. With a rocker bottom foot she is at risk of infection but there is no sinus tract to the plantar surface of the foot that is likely to occur as a precurser to infection.