Draining sinus tract, calcaneal fracture Evaluation of the ankle joint is limited given metallic susceptibility artifact from prior surgical intervention.Best seen on series 13 images 20 through 22 is a sinus tract extending from the body of the calcaneus to the skin surface. A small focus of signal void is identified on the distal and of this tract which likely represents a small focus of gas. This sinus tract arises from the calcaneus where there is an ill-defined multilobulated peripherally enhancing collection. This measures approximately 4.4 x 2.6 cm in the greatest AP and craniocaudal dimensions. This extends into the body of the calcaneus with the anterior process relatively preserved. There is no joint effusion. There is fragmentation and deformity of the calcaneus which is at least posttraumatic in nature but may also reflect the sequela of chronic infection. There is intermediate T1 marrow signal of the calcaneus and slightly increased marrow edema but no discrete low T1 marrow signal intensity. There is no tibiotalar effusion.Note that the exam was not tailored for the evaluation of the ligaments and tendinous structures. The distal Achilles tendon demonstrates abnormal signal intensity and thickening representing tendinopathy. The sinus tract described above courses through the intrasubstance of the distal Achilles tendon but more proximally, the tendon appears relatively normal. There is otherwise no obvious tendinous or ligamentous disruption. Mild osteoarthritis also affects the midfoot.
1. Deformity of the calcaneal body which is at least in part posttraumatic in nature but may also represent the sequela of chronic infection and/or posttraumatic change.2. Draining sinus tract extending through the distal Achilles tendon to the skin surface which arises from an ill-defined fluid collection within the calcaneal body. Findings are concerning for an intraosseous abscess. The surrounding bone marrow demonstrates slight edema but no discrete low T1 signal intensity focus.