Fractures can be seen on ultrasound. Part 1
A fractured fifth metatarsal, but nothing seen on X-ray
A 24-year-old woman was referred for ultrasound, having rolled her right ankle playing netball. The injury had occurred approximately two months prior to referral, but the right ankle was still swollen, had a decreased range of motion, and was painful when tested with active-resisted movements. Ultrasound examination (Philips iU22, L12-5 MHz and 15-7 MHz Hockey Stick transducers) of the right ankle and foot were performed.
The examination indicated: “Foot: fifth metatarsal base non-displaced fracture and fourth TMT joint partial ligament tear Grade 2 injury. Ankle ATFL partial tear Grade 2 injury and CFL sprain Grade 1 injury.”
Key findings (Figures A-F) included:
The fifth metatarsal base has a cortical bone defect at the peroneus brevis tendon insertion. The tendon is mildly thickened and is reduced echogenic. No tear or vascularity. This region is tender.
The fourth tarsometatarsal joint capsule dorsal aspect cuboid attachment is thickened and has an intrasubstance tear. This region is tender.
The anterior talofibular ligament is thickened, is heterogeneous, has increased vascularity, and a partial tear (5 x 5 mm).
The calcaneofibular ligament is thickened (5 mm) and is reduced echogenic. No tear.
Figure A: the fractured fifth metatarsal bone in long view
Figure B: the fractured fifth metatarsal bone in axial view
Figure C: the thickened peroneus brevis, indicated by hashmarks
Figure D: the tear in the 4th tarsometatarsal joint capsule, indicated by hashmarks
Figure E: the thickened anterior talofibular ligament, tear indicated by hashmarks.
Figure F: the thickened calcaneofibular ligament, indicated by hashmarks.
An 18-year-old woman presented suffering from left foot pain after having her left foot stood on while playing rugby at an out of town tournament three weeks prior. Following an ultrasound examination, x-ray and a finally a CT scan she was booked for surgery.