Ankle and Foot 47 - Department of Radiology - University of ...

2298 VII Imaging of the Musculoskeletal System
D
E
Figure 47-102, cont’d Coronal oblique T1- (D) and
fat-suppressed T2-weighted (E) images show that this
is an incomplete fracture, beginning from the dorsal
cortex (arrowhead) and extending inferiorly in the
sagittal plane, but not extending completely to the
plantar cortex. A CT scan obtained 2 months later,
reformatted using a 6-cm field of view in the oblique
coronal (F) and oblique axial (G) planes, reveals that
the fracture remains nonunited (arrowhead) and the
bones are diffusely osteopenic from the patient’s
being non–weight bearing.
F
G
• Calcaneal Stress Fractures
Calcaneal stress fractures occur in a characteristic location,
arising from the posterior third of the calcaneal tuberosity
beginning at the superior cortex a few centimeters anterior
to the Achilles insertion, and extending inferiorly and
slightly anteriorly, running perpendicular to the trabeculae.
When radiographically apparent, these fractures are seen as
a white sclerotic line on the lateral view (Fig. 47-104A). On
MRI, calcaneal stress fractures are seen as a black line on
sagittal T1-weighted images (Fig. 47-104B) surrounded by
bone marrow edema on fat-suppressed T2-weighted (Fig.
47-104C) and inversion recovery (Fig. 47-104D) images.
Figure 47-105 is a an example of a calcaneal stress fracture
that was subtle on initial radiographs and was ultimately
imaged using CT, a nuclear medicine bone scan, and MRI.
• Plantar Fasciitis
Plantar fasciitis is a stress reaction occurring at the origin
of the plantar aponeurosis from the calcaneus, typically at
the medial calcaneal tubercle. Degenerative changes from
repetitive microtrauma in the origin of the plantar fascia
cause traction periostitis and microtears, resulting in pain
and inflammation. Plantar fasciitis is the most common
cause of pain in the inferior aspect of the heel, and the
diagnosis is typically made based on clinical symptoms
and physical examination revealing tenderness along the
medial calcaneal tuberosity. The relationship between
plantar fasciitis and heel spurs has never been firmly established.
Most patients with plantar fasciitis respond to conservative
treatments that include calf stretching, orthoses,
nonsteroidal anti-inflammatory medication, ultrasonic
therapy, and occasionally casting. Patients with atypical
clinical presentations or who fail conservative therapies
may benefit from MRI to determine if their pain is indeed
related to the plantar fascia or to some other etiology such
as a tarsal stress fracture. An MRI of plantar fasciitis reveals
edema around the origin of the aponeurosis. The plantar
fascia itself may be abnormally thickened, and there may
be edema in the underlying calcaneal bone marrow (Fig.
47-106; see Fig. 47-53).
• Metatarsal Stress Fractures
Metatarsal stress fractures occur at such characteristic locations
that some carry eponyms.
Jones Fracture. The Jones fracture occurs at the proximal
metadiaphysis of the fifth metatarsal and is seen radiographically
as a transverse lucency (see Fig. 47-41C).
Although Jones fractures can be caused by a single traumatic
injury, they are commonly seen as the result of repet-
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