AJR 2001; 176:97-104
© American Roentgen Ray Society
Disorders of the Plantar Aponeurosis
A Spectrum of MR Imaging Findings
Daphne J. Theodorou1,
Stavroula J. Theodorou,
Shella Farooki,
Y. Kakitsubata and
Donald Resnick
1
All authors: Department of Radiology, School of Medicine, University of
California San Diego and Veterans Administration Medical Center, 3350 La Jolla
Village Dr., San Diego, CA 92161.
Received March 13, 2000;
accepted after revision June 20, 2000.
Supported by Veterans Administration grant SA-360 and the A. S. Onassis
Public Benefit Foundation Educational Stipend U-033.
Address correspondence to D. Resnick.
Introduction
The plantar aponeurosis, or plantar fascia, has received considerable
attention in the scientific literature and has been shown to be the most
important structure for dynamic longitudinal arch support in the foot
[1]. The plantar aponeurosis
comprises histologically both collagen and elastic fibers arranged in a
particular network of bundles and is a tough tendinous (rather than a fascial)
layer of the plantar aspect of the foot. This sophisticated combination of
fibers, having different biomechanical properties during stress application to
the plantar aponeurosis, affords an increased modulus of elasticity during
weight bearing [2].
Abnormalities affecting the plantar aponeurosis are well recognized.
Patients with suspected abnormality involving the aponeurosis traditionally
have been examined with conventional radiography and bone scintigraphy and
occasionally with sonography. Although conventional radiography remains
essential in the initial diagnostic approach, MR imaging is particularly well
suited for depicting the plantar aponeurosis (Fig.
1A,1B)
and for detecting the presence of a wide range of disorders. MR imaging also
may be useful in limiting the broad differential diagnosis of subcalcaneal
heel pain.
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Fig. 1A. —MR imaging configuration of normal plantar aponeurosis with
anatomic correlation. In cadaveric specimen, sagittal T1-weighted spin-echo MR
image (TR/TE, 600/20) outlines plantar aponeurosis as uniform bandlike
structure of low signal intensity (arrows).
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Fig. 1B. —MR imaging configuration of normal plantar aponeurosis with
anatomic correlation. Anatomic section, approximately 8 mm more laterally to
mid-sagittal level than MR image, delineates central component of plantar
aponeurosis (arrows).
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This pictorial review summarizes the most common abnormalities that affect
the plantar aponeurosis and addresses their characteristic MR imaging
features. Although in clinical practice plantar fasciitis is the most common
diagnosis in patients with heel pain, a spectrum of disorders may also affect
the plantar aponeurosis, including enthesopathy, traumatic and
corticosteroid-induced rupture, rheumatologic and infectious processes, and
plantar fibromatosis.
Plantar Fasciitis
Plantar fasciitis, the most common cause of heel pain in the athlete, is a
low-grade inflammation involving the plantar aponeurosis and the perifascial
structures. Affecting a wide range of age groups, it is a relatively common
disorder that is characterized by chronic deep pain in the subcalcaneal area
and along the medial aspect of the plantar surface of the foot. In general,
the factors associated with plantar fasciitis fall into three major categories
[3]: mechanical, degenerative,
and systemic. Mechanical causes of plantar fasciitis include overuse syndromes
(participation in competitive sports involving repetitive application of
tension force to the aponeurosis), various foot deformities, tight Achilles
tendon or limited dorsiflexion, increased body weight, leg length inequality,
and externally rotated lower extremity. Degenerative factors associated with
plantar fasciitis include age-related increases in foot pronation and atrophy
of the heel fat pad. Predisposing systemic factors include various rheumatoid
disorders, especially rheumatoid arthritis, seronegative
spondyloarthropathies, and gout
[3].
Repetitive trauma produces microtears of some fibers of the plantar
aponeurosis, mostly close to the site of its attachment, that are accompanied
by a local inflammatory reaction. Acute plantar fasciitis may be displayed
conspicuously with MR imaging. The inflamed plantar aponeurosis may show
abnormal high intrasubstance signal intensity on T2-weighted and short tau
inversion-recovery (STIR) MR images, with or without associated fascial
thickening (Fig.
2A,2B,2C).
The signal-intensity changes of perifascial soft-tissue edema either deep,
superficial, or both deep and superficial in relation to the plantar
aponeurosis are revealed. Marrow edema of the calcaneus also may be observed.
After administration of gadolinium-containing contrast material, ample
enhancement of the inflamed perifascial soft tissues may be seen (Fig.
3A,3B,3C).
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Fig. 2A. —Acute plantar fasciitis in 42-year-old man with subcalcaneal
pain. (Courtesy of Skaf A, Sao Paolo, Brazil) Unenhanced T1-weighted spin-echo
MR image (TR/TE, 620/25) (A) and short tau inversion-recovery (STIR) MR
image (3760/16; inversion time, 150 msec) (B) show thickening of
central component of plantar aponeurosis (large arrows). Extensive
edema infiltrates perifascial soft tissue (curved arrows). Note
abnormal foci of intrafascial high signal intensity corresponding to
intrasubstance edema because of acute inflammation evident on STIR image
(small arrows).
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Fig. 2B. —Acute plantar fasciitis in 42-year-old man with subcalcaneal
pain. (Courtesy of Skaf A, Sao Paolo, Brazil) Unenhanced T1-weighted spin-echo
MR image (TR/TE, 620/25) (A) and short tau inversion-recovery (STIR) MR
image (3760/16; inversion time, 150 msec) (B) show thickening of
central component of plantar aponeurosis (large arrows). Extensive
edema infiltrates perifascial soft tissue (curved arrows). Note
abnormal foci of intrafascial high signal intensity corresponding to
intrasubstance edema because of acute inflammation evident on STIR image
(small arrows).
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Fig. 2C. —Acute plantar fasciitis in 42-year-old man with subcalcaneal
pain. (Courtesy of Skaf A, Sao Paolo, Brazil) T2-weighted fast spin-echo MR
image (4367/86) with fat saturation shows thickening of plantar fascia
(straight arrows), extensive high signal intensity infiltrating
perifascial soft tissues (curved arrows), and abnormal intermediate
intrafascial signal intensity.
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Fig. 3A. —MR imaging findings of acute plantar fasciitis in 23-year-old
male athlete. (Courtesy of Skaf A, Sao Paolo, Brazil) Unenhanced T1-weighted
spin-echo MR image (TR/TE, 400/10) (A) and enhanced T2-weighted
fat-suppressed fast spin-echo MR image (4000/105) (B) show the
signal-intensity changes of edema in perifascial soft tissues (straight
arrows). Note foci of abnormal marrow high signal intensity at calcaneal
insertion of plantar fascia (curved arrows), evident on fast
spin-echo T2-weighted MR image (B).
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Fig. 3B. —MR imaging findings of acute plantar fasciitis in 23-year-old
male athlete. (Courtesy of Skaf A, Sao Paolo, Brazil) Unenhanced T1-weighted
spin-echo MR image (TR/TE, 400/10) (A) and enhanced T2-weighted
fat-suppressed fast spin-echo MR image (4000/105) (B) show the
signal-intensity changes of edema in perifascial soft tissues (straight
arrows). Note foci of abnormal marrow high signal intensity at calcaneal
insertion of plantar fascia (curved arrows), evident on fast
spin-echo T2-weighted MR image (B).
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Fig. 3C. —MR imaging findings of acute plantar fasciitis in 23-year-old
male athlete. (Courtesy of Skaf A, Sao Paolo, Brazil) Short tau
inversion-recovery MR image (TR/TE, 3000/48; inversion time, 150 msec) again
reveals prominent abnormal high signal intensity in perifascial soft tissues
consistent with edema (arrows).
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With chronicity, the plantar aponeurosis may show significant fusiform
thickening extending to its calcaneal origin. Erosive changes of the calcaneus
also may occur as a result of chronic inflammation at the osseotendinous
junction. Chronic inflammation of the aponeurosis and the perifascial
structures is characterized by collagen degeneration and necrosis,
angiofibroblastic hyperplasia, chondroid metaplasia, and matrix calcification.
On MR imaging, these histopathologic changes may correspond to abnormal
intrafascial intermediate signal intensity on T1-weighted MR images and high
signal intensity on T2-weighted and STIR MR images. On T2-weighted and STIR
images, however, areas of high signal intensity reflecting edema also may be
shown in the marrow of the calcaneus and in the adjacent subcutaneous tissues.
After administration of gadolinium-containing contrast material, enhancement
of the aponeurosis and the surrounding soft tissues may be evident (Fig.
4A,4B).
In almost all patients, however, fluid-sensitive sequences are sufficient, and
the use of IV gadolinium rarely is required. Because the imaging findings of
acute and chronic plantar fasciitis may be similar, accurate diagnosis
requires adequate clinical information. In the correct clinical circumstances,
MR imaging may be of particular value in differentiating plantar fasciitis
from other causes of plantar heel pain, including fascial strain or rupture,
infections, tumors, tendinosis and tenosynovitis, subcalcaneal bursitis, nerve
entrapment syndromes, and calcaneal stress fractures
[3].
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Fig. 4A. —Chronic plantar fasciitis in 42-year-old woman. (Courtesy of
Kerr R, Los Angeles, CA) Unenhanced T1-weighted spin-echo MR image (TR/TE,
720/12) (A) and enhanced T1-weighted fat-suppressed spin-echo MR image
(610/12) (B) display abnormal intermediate and high signal intensity,
respectively, in soft tissues superficial to plantar aponeurosis (solid
arrows). Contrast enhancement of soft tissues deep in relation to plantar
aponeurosis (open arrows) because of edema also can be
appreciated.
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Fig. 4B. —Chronic plantar fasciitis in 42-year-old woman. (Courtesy of
Kerr R, Los Angeles, CA) Unenhanced T1-weighted spin-echo MR image (TR/TE,
720/12) (A) and enhanced T1-weighted fat-suppressed spin-echo MR image
(610/12) (B) display abnormal intermediate and high signal intensity,
respectively, in soft tissues superficial to plantar aponeurosis (solid
arrows). Contrast enhancement of soft tissues deep in relation to plantar
aponeurosis (open arrows) because of edema also can be
appreciated.
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Calcaneal Enthesophyte
Plantar calcaneal enthesophytes originate from the medial calcaneal
tuberosity at the attachment of the flexor digitorum brevis and abductor
hallucis muscles. As with enthesophytes at other sites, calcaneal
enthesophytes may occur as a result of excessive repetitive traction by these
intrinsic muscles, causing chronic microtrauma, which in turn, leads to
periostitis and calcification. Systemic arthritis with reactive bone
proliferation and the aging process may also be associated with the formation
of calcaneal enthesophytes, which may become symptomatic in the setting of
plantar heel pad atrophy. Although calcaneal enthesophytes have been described
in association with plantar fasciitis, most publications conclude that they
rarely cause this condition as also indicated by Berkowitz et al.
[4], who found calcaneal
enthesophytes in patients with plantar fasciitis, as well as in asymptomatic
controls. MR imaging can display conspicuously calcaneal enthesophytes and may
show abnormalities at the enthesis of the plantar aponeurosis in some patients
in whom the outgrowths are associated with enthesitis
[3] (Figs.
5A,5B
and 6).
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Fig. 5B. —Calcaneal enthesophyte in asymptomatic 53-year-old man.
Unenhanced T1-weighted spin-echo MR image (TR/TE, 516/20) again shows
calcaneal enthesophyte (curved arrow). Plantar aponeurosis
(straight arrow) and adjacent soft tissues appear unremarkable.
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Fig. 6. —Calcaneal enthesophyte in 51-year-old man with chronic heel
pain. Gradient-echo MR image (TR/TE, 620/25; flip angle, 25°) shows
enthesophyte (curved arrow) and abnormal high signal intensity in
soft tissues superficial to plantar aponeurosis consistent with edema
(open arrow). (Courtesy of Roger B, Paris, France)
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Fascial Rupture
Although plantar fasciitis is common, rupture of the plantar aponeurosis,
either complete or partial, is not a commonly encountered diagnosis because it
occurs infrequently or is not recognized. Most commonly seen in competitive
athletes at the time of injury by an acceleration type of motion that leads to
forcible plantar flexion, rupture of the plantar aponeurosis also may occur as
a result of repetitive stress or repetitive minor trauma to the aponeurosis in
recreational running and jumping. Spontaneous rupture of the plantar
aponeurosis, however, may occur in patients with prior plantar fasciitis and
most commonly in those patients treated with local steroid injections (Fig.
7A,7B,7C).
Research by Acevedo and Beskin
[5] indicates a 10% plantar
aponeurosis rupture rate after corticosteroid injection for plantar
fasciitis.
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Fig. 7A. —32-year-old man with complete rupture of plantar aponeurosis
after local corticosteroid injections for chronic plantar fasciitis. Lateral
radiograph of foot shows calcaneal enthesophyte (curved arrow) with
erosion of undersurface of calcaneus (straight arrows) and small bone
fragment (open arrow).
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Fig. 7B. —32-year-old man with complete rupture of plantar aponeurosis
after local corticosteroid injections for chronic plantar fasciitis.
Unenhanced T1-weighted fast spin-echo MR image (TR/TE, 466/12.6) of foot shows
prominent pointed calcaneal enthesophyte (arrow).
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Fig. 7C. —32-year-old man with complete rupture of plantar aponeurosis
after local corticosteroid injections for chronic plantar fasciitis. Enhanced
T1-weighted fat-suppressed fast spin-echo MR image (716/13.8) shows large
osseous defect at plantar aspect of calcaneus (long arrow) and
absence of plantar aponeurosis. Note remarkable enhancement of bone caused by
marrow edema (short arrows). Soft-tissue edema also is evident
(open arrow).
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Regardless of the mechanism of rupture, MR imaging clearly reveals and
localizes the lesion and aids in distinguishing recent and longstanding
ruptures of the plantar aponeurosis. In many patients, MR imaging also may
provide additional diagnostic information with regard to inflammatory changes
of the heel fat pad, accompanying rupture. Recent rupture may be diagnosed
when the aponeurosis shows disruption of its continuity with abnormal loss of
its low signal intensity on T1-weighted MR images at the site of the complete
rupture (Fig.
8A,8B,8C)
or when it shows partial loss of its low signal intensity with partial rupture
(Fig.
9A,9B).
Typically, the aponeurosis appears thickened at the site of partial disruption
of its continuity. Soft tissues show abnormal high signal intensity on
T2-weighted MR images because of edema or hemorrhage, or both, and show
considerable enhancement after administration of gadolinium-containing
contrast material.
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Fig. 8A. —Posttraumatic acute complete rupture of plantar aponeurosis
in 48-year-old sheriff who was running after suspect. (Courtesy of Edwards J,
Savannah, GA) Unenhanced T1-weighted spin-echo (TR/TE, 760/20) (A) and
short tau inversion-recovery (STIR) (B) MR images (5830/30; inversion
time, 150 msec) display complete disruption of plantar aponeurosis with
abnormal intermediate and high signal intensity, respectively, at proximal
part of plantar aponeurosis (straight arrows). On STIR images, edema
infiltrating perifascial soft tissues (open arrows) mostly deep in
relation to plantar aponeurosis is evident. Signal-intensity changes of
minimal bone marrow edema involving calcaneal enthesophyte also are present
(curved arrows).
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Fig. 8B. —Posttraumatic acute complete rupture of plantar aponeurosis
in 48-year-old sheriff who was running after suspect. (Courtesy of Edwards J,
Savannah, GA) Unenhanced T1-weighted spin-echo (TR/TE, 760/20) (A) and
short tau inversion-recovery (STIR) (B) MR images (5830/30; inversion
time, 150 msec) display complete disruption of plantar aponeurosis with
abnormal intermediate and high signal intensity, respectively, at proximal
part of plantar aponeurosis (straight arrows). On STIR images, edema
infiltrating perifascial soft tissues (open arrows) mostly deep in
relation to plantar aponeurosis is evident. Signal-intensity changes of
minimal bone marrow edema involving calcaneal enthesophyte also are present
(curved arrows).
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Fig. 8C. —Posttraumatic acute complete rupture of plantar aponeurosis
in 48-year-old sheriff who was running after suspect. (Courtesy of Edwards J,
Savannah, GA) T2-weighted fat-suppressed fast spin-echo MR image (3901/98)
shows area of abnormal high signal intensity in central component of plantar
aponeurosis (arrows), corresponding to complete disruption of
aponeurosis.
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Fig. 9A. —MR imaging findings of acute incomplete rupture of plantar
aponeurosis in 38-year-old man. (Courtesy of Edwards J, Savannah, GA) Short
tau inversion-recovery MR image (TR/TE, 5800/30; inversion time, 150 msec)
(A) and T2-weighted fast spin-echo MR image (3901/98) (B) show
incomplete rupture of central component of plantar aponeurosis with abnormal
intrafascial signal intensity (curved arrows) at junction of proximal
and middle portion of plantar aponeurosis. Note fusiform thickening of plantar
aponeurosis (straight arrows) and perifascial soft-tissue edema
(open arrows).
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Fig. 9B. —MR imaging findings of acute incomplete rupture of plantar
aponeurosis in 38-year-old man. (Courtesy of Edwards J, Savannah, GA) Short
tau inversion-recovery MR image (TR/TE, 5800/30; inversion time, 150 msec)
(A) and T2-weighted fast spin-echo MR image (3901/98) (B) show
incomplete rupture of central component of plantar aponeurosis with abnormal
intrafascial signal intensity (curved arrows) at junction of proximal
and middle portion of plantar aponeurosis. Note fusiform thickening of plantar
aponeurosis (straight arrows) and perifascial soft-tissue edema
(open arrows).
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Chronic rupture, however, is displayed as a scar of intermediate-to-low
signal intensity on both T1- and T2-weighted MR images. This scar shows no
enhancement after contrast administration. The plantar aponeurosis appears
focally thickened, and chronic hematoma formation also may be seen (Fig.
10A,10B,10C).
On some occasions, secondary formation of a cyst is revealed as a welldefined
collection of abnormal intermediate signal intensity on T1-weighted MR images
and high signal intensity on T2-weighted images, located between the
superficial and the deep layers of the aponeurosis.
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Fig. 10A. —Chronic partial rupture of plantar aponeurosis in 42-year-old
male jogger. (Courtesy of Roger B, Paris, France) Unenhanced T1-weighted
spin-echo (TR/TE, 400/13) (A) and gradient-echo MR images (340/20; flip
angle, 25°) (B) show fusiform thickening of plantar fascia
(straight arrows) with abnormal intermediate (A) and high
(B) intrafascial signal intensity (open arrows). Extensive
edema infiltrating subcutaneous soft tissues can be seen (curved
arrows).
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Fig. 10B. —Chronic partial rupture of plantar aponeurosis in 42-year-old
male jogger. (Courtesy of Roger B, Paris, France) Unenhanced T1-weighted
spin-echo (TR/TE, 400/13) (A) and gradient-echo MR images (340/20; flip
angle, 25°) (B) show fusiform thickening of plantar fascia
(straight arrows) with abnormal intermediate (A) and high
(B) intrafascial signal intensity (open arrows). Extensive
edema infiltrating subcutaneous soft tissues can be seen (curved
arrows).
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Fig. 10C. —Chronic partial rupture of plantar aponeurosis in 42-year-old
male jogger. (Courtesy of Roger B, Paris, France) Unenhanced T1-weighted MR
image (400/13) reveals thickening of central component of plantar aponeurosis
(thin arrows) and linear regions of intrafascial abnormal high signal
intensity consistent with intrasubstance tear (arrowheads). Normal
contralateral central component of plantar aponeurosis (thick arrow)
is shown for comparison.
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Rheumatoid Nodules
Among pedal manifestations of rheumatoid arthritis, rheumatoid nodules are
considered one of the most common soft-tissue lesions, occurring in 20-30% of
instances of rheumatoid arthritis
[6]. Although rheumatoid
nodules have traditionally been associated with advanced rheumatoid arthritis
and treatment with methotrexate, they also may occur in patients with
rheumatic fever, ankylosing spondylitis, systemic lupus erythematosus, and
agammaglobulinemia. These subcutaneous lesions are commonly found in areas
that are subject to repetitive minor trauma and, specifically, in those areas
overlying osseous prominences. Typically, rheumatoid nodules are revealed as
subcutaneous focal demarcated nodular areas of fibroinflammatory reaction.
With MR imaging, rheumatoid nodules usually appear nearly isointense to
muscle in T1-weighted images and display slightly heterogeneous
intermediate-to-high signal intensity in T2-weighted images. On enhanced MR
images, rheumatoid nodules may reveal a spectrum of appearances, including
areas of heterogeneous increased signal intensity, faint peripheral
enhancement, or homogeneous enhancement in solid lesions with no central
necrosis (Fig.
11A,11B).
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Fig. 11A. —Rheumatoid nodule in 45-year-old woman with rheumatoid
arthritis and swelling over plantar aspect of calcaneus. (Courtesy of
Eilenberg S, San Diego, CA) Unenhanced T1-weighted fast spin-echo MR image
(TR/TE, 433/16) (A) and enhanced T1-weighted fat-suppressed fast
spin-echo MR image (466/17) (B) show large lobulated soft-tissue mass
of intermediate signal intensity located between skin and calcaneal tubercle
(arrow). Note that underlying bone appears unremarkable.
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Fig. 11B. —Rheumatoid nodule in 45-year-old woman with rheumatoid
arthritis and swelling over plantar aspect of calcaneus. (Courtesy of
Eilenberg S, San Diego, CA) Unenhanced T1-weighted fast spin-echo MR image
(TR/TE, 433/16) (A) and enhanced T1-weighted fat-suppressed fast
spin-echo MR image (466/17) (B) show large lobulated soft-tissue mass
of intermediate signal intensity located between skin and calcaneal tubercle
(arrow). Note that underlying bone appears unremarkable.
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Plantar Infection
As with infections at the plantar aspect of the foot in general, the
plantar aponeurosis may be contaminated by direct implantation of foreign
bodies, puncture wounds, surgical procedures, spread from a contiguous source
of infection, and, in diabetic foot disease, via plantar skin ulceration and
inoculation of infectious agents. A variety of bacteria can cause infectious
fasciitis, with Streptococci being most commonly reported. Because
fascial inflammation can cause destruction of mechanical barriers, spread of
infection along the intermuscular fascial tissue planes to adjacent soft
tissues, underlying bone, or both, may require amputation. Necrotizing
fasciitis, however, is a rare type of pedal softtissue infection limited to
the fascia only, and it is associated with generalized sepsis, endotoxic
shock, and high mortality rates.
MR imaging may be helpful in the early detection, localization, and
determination of the depth of inflammation. Infectious fasciitis may be
diagnosed when the plantar fascia and perifascial soft tissues show abnormal
high signal intensity on T2-weighted MR images. It has been suggested
[7] that high T2-weighted
signal intensity in the deep fascial planes and muscles, along with rim
enhancement after gadolinium administration, are specific findings for
necrotizing fasciitis, whereas high signal intensity on T2-weighted MR images
limited to the subcutaneous fat, with or without contrast enhancement, are
findings consistent with nonnecrotizing soft-tissue infections (Fig.
12A,12B).
However, it remains to be further investigated whether these MR imaging
findings may allow differentiation between the two entities.
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Fig. 12A. —Local infection of plantar soft tissues in 43-year-old man
with no known history of diabetes. (Courtesy of Roger B, Paris, France)
Unenhanced T1-weighted spin-echo MR image (TR/TE, 380/12) shows abnormal
intermediate signal intensity in plantar aponeurosis and adjacent plantar soft
tissues (arrows).
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Fig. 12B. —Local infection of plantar soft tissues in 43-year-old man
with no known history of diabetes. (Courtesy of Roger B, Paris, France)
Enhanced T1-weighted spin-echo MR image (390/12) at same level as (A)
shows diffuse enhancement of signal intensity in plantar aponeurosis and
perifascial soft tissues (arrows).
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Plantar Fibromatosis
Superficial plantar fibromatosis is a benign fibroblastic proliferative
disorder associated with replacement of elements of the plantar aponeurosis
with abnormal fibrous tissue. Although several etiologic factors have been
proposed [8], including trauma,
infection, neuropathy, biochemical and metabolic imbalance, faulty
development, and the patient's occupation, the precise etiology of plantar
fibromatosis remains unclear. Typically, plantar fibromatosis is multinodular
and occurs along the medial aspect of the central part of the plantar
aponeurosis. Single or multiple plantar fibromas, usually measuring less than
3 cm in diameter, are located in the plantar aponeurosis and the subcutaneous
tissues.
With MR imaging, plantar fibromas appear as well-defined nodules with
abnormal low signal intensity on T1-weighted and low-to-intermediate signal
intensity on T2-weighted MR images. In some instances associated with a more
aggressive disorder, areas of abnormal high and low signal intensity on
T2-weighted and STIR images reflect the relative proportions of cellular
elements within the mass [8]
(Fig.
13A,13B,13C).
With administration of gadolinium-containing contrast material, however, a
spectrum of enhancement patterns corresponding to the cellular portions of the
lesion may be seen, varying from heterogeneously moderate or marked contrast
enhancement to absolutely no enhancement. Local infiltrative growth associated
with poor margination of the lesion and involvement of the subcutaneous
tissue, muscles, or bones may be observed in aggressive or deep fibromatosis
[8]. In deep fibromatosis,
lesions are most commonly solitary and are characterized by a high recurrence
rate.
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Fig. 13A. —Solitary plantar fibroma in 64-year-old woman with palpable
soft-tissue mass in sole of foot. (Courtesy of Taketa R, Long Beach, CA)
Unenhanced T1-weighted spin-echo MR image (TR/TE, 600/11) reveals large
fusiform mass of intermediate signal intensity in plantar soft tissues
(arrows).
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Fig. 13B. —Solitary plantar fibroma in 64-year-old woman with palpable
soft-tissue mass in sole of foot. (Courtesy of Taketa R, Long Beach, CA)
T2-weighted fat-suppressed fast spin-echo MR image (4900/46) (B) and
enhanced T1-weighted spin-echo MR image (800/17) (C) show lobulated
mass of high signal intensity with internal septation (open arrows)
in continuity with plantar fascia (long arrows). Note distortion of
contour in plantar aspect of foot.
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|
Fig. 13C. —Solitary plantar fibroma in 64-year-old woman with palpable
soft-tissue mass in sole of foot. (Courtesy of Taketa R, Long Beach, CA)
T2-weighted fat-suppressed fast spin-echo MR image (4900/46) (B) and
enhanced T1-weighted spin-echo MR image (800/17) (C) show lobulated
mass of high signal intensity with internal septation (open arrows)
in continuity with plantar fascia (long arrows). Note distortion of
contour in plantar aspect of foot.
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In summary, subcalcaneal heel pain is a common presenting complaint
associated with a multitude of etiologic factors. The most common
abnormalities are plantar fasciitis, calcaneal enthesopathy, fascial rupture,
rheumatoid nodules, plantar infection, and plantar fibromatosis. MR imaging is
particularly helpful for the diagnosis of these entities.
References
-
Thordarson DB, Schmotzer H, Chon J, Peters J. Dynamic support of
the human longitudinal arch: a biomechanical evaluation. Clin
Orthop 1995;316:165
-172
-
Straub H. Die elastischen fasern in
Bändern des menschlichen Fußes.
Acta Anat
1950-1951;11:268
-289
-
Resnick D. Abnormalities of the plantar soft tissues. In: Resnick
D, ed. Diagnosis of bone and joint disorders.
Philadelphia: Saunders, 1995:3204
-3208
-
Berkowitz J, Kier R, Rudicel S. Plantar fasciitis: MR imaging.
Radiology
1991;179:665
-667[Abstract/Free Full Text]
-
Acevedo J, Beskin J. Complications of plantar fascia rupture
associated with corticosteroid injection. Foot Ankle
Int 1998;19:91
-97[Medline]
-
Kaye BR, Kaye PL, Bobrove A. Rheumatoid nodules. Am J
Med 1984;76:279
-292[Medline]
-
Rahmouni A. MR imaging in acute infectious cellulitis.
Radiology
1994;192:493
-496[Abstract/Free Full Text]
-
Lee TH, Wapner KL, Hecht PJ. Plantar fibromatosis: current concepts
review. J Bone Joint Surg Am
1993;75-A:1080
-1083[Free Full Text]
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Introduction
Plantar Fasciitis
