38-year-old woman presents with foot pain. History of infection following percutaneous pinning of a navicular fracture. Evaluate for plantar abscess. There is a band of nonenhancing signal abnormality extending through the dorsal soft tissues of the forefoot and midfoot which upon discussion with Dr. Toolan likely represents a surgical incision approximating the tract of a removed percutaneous pin. This incision extends through the soft tissues to the dorsal aspect of the base of the second metatarsal, the middle cuneiform and the navicular. There is signal abnormality and enhancement of these bones compatible with osteomyelitis as well as signal abnormality due to a comminuted fracture of the navicular. There is dorsal subluxation of the 2 larger navicular fragments relative to the head of the talus. There is a tubular focus of signal abnormality extending vertically through the medial cuneiform which represents a surgically created tract per discussion with Dr. Toolan.A second bandlike collection of nonenhancing signal abnormality is noted along the base of the first metatarsal and medial cuneiform representing a second incision along a prior pin tract.There is diffuse enhancement of the soft tissue surrounding the midfoot as well as enhancement of the articulations of the midfoot indicating inflammation. This enhancement extends proximally along the medial and lateral aspect of the hindfoot and distally to surround the bases of the first through fourth metatarsals. Although we see no discrete soft tissue abscess, there is fluid within the calcaneocuboid joint with small pockets of rim-enhancing fluid extending from the joint laterally and medially as well as a small amount of rim-enhancing fluid tracking inferiorly along the anterior plantar surface of the calcaneus. Given the degree of adjacent enhancement, this is concerning for septic arthritis that likely extends dorsally and anteriorly along the margins of the cuneiforms and fractured navicular.In addition to the signal abnormality in the aforementioned bones there is also abnormal signal within the head, neck and body of the talus, anterior tuberosity lateral marrow of the calcaneus, the cuboid, the lateral cuneiform, the medial cuneiform, and the bases of the third and fourth metatarsals. We suspect that this abnormal signal reflects osteomyelitis to at least some extent, although it could in part be due to long-standing neuropathic arthropathy. Bone marrow signal intensity of the phalanges appears normal.There is also a small amount of fluid within the tibiotalar joint with enhancing synovium which is nonspecific but we cannot exclude septic arthritis. There is also enhancement of tissue between the tip of the distal fibula and the lateral margin of the calcaneus just proximal to the calcaneofibular ligament indicating inflammation. There is enhancement of the tenosynovium of the peroneal tendons though see no frank fluid within the peroneal tendon sheaths. There is also mild enhancement of the tenosynovium of the medial tendons. There is minimal fluid within the flexor hallucis longus tendon sheath posterior to the distal tibia which may simply reflect extension of fluid from the ankle joint.There is also small amount of fluid within the subtalar joint. There is little if any enhancement of the joint following contrast administration and therefore we suspect this is noninfected.There is generalized atrophy of the musculature of the foot.There is diffuse reticulation of the subcutaneous fat of the dorsum of the foot with enhancement and thickening of the overlying skin suggesting cellulitis.
1. Bone and soft tissue infection of the foot as described above. Fluid in the calcaneocuboid joint is concerning for septic arthritis which we suspect propagates through the midfoot to the fractured and displaced navicular. A small amount of fluid and enhancement in the tibiotalar joint is nonspecific but we cannot exclude the possibility of infection. Other findings as above.