Plantar Fasciitis

Radiographic findings may include:

  • thickening of plantar fascia at proximal enthesis
  • ill-defined increased soft tissue density

Differential Diagnosis:

  • enthesopathy (inferior calcaneal spur - medial tubercle)
  • fractured spur or tubercle
  • fascial tear or rupture
  • inflammatory arthritis (rheumatoid, seronegative) (subcalcaneal erosion, ill-defined spur)
  • myositis ossificans (ossification of fascia)
  • HADD (calcification of fascia)
  • bursitis (calcification of subcalcaneal bursa, erosion)
  • calcaneal stress fracture (ill-defined increased density in posteroinferior calcaneus)
  • calcaneal bone tumor (unicameral bone cyst, chondromyxoid fibroma, fibrosarcoma, etc.)

Here are examples:

  • Case 1
  • *Case 1
  • Case 2
  • *Case 2
  • Case 3
  • *Case 3
  • Case 4
  • *Case 4
  • Case 5
  • *Case 5
  • Case 6
  • *Case 6
  • Case 7
  • *Case 7
spur
spur

Lateral view. Findings include a well-defined spur (arrow) along the anterior aspect of the calcaneal medial tubercle. Additionally, there is posterior calcaneal spurring at the Achilles tendon enthesis (arrowhead). Diagnosis: enthesopathy.

thick fascia
thick fascia

Lateral view. Findings include an inferior calcaneal spur and thickening of the plantar fascia (arrows). Diagnosis: plantar fasciitis.

HADD
HADD

Lateral view. Findings include curvilinear calcifications (arrows) inferior to a calcaneal medial tubercle spur. Diagnosis: HADD (hydroxyapatite dihydrate deposition disease).

FractureFracture LOB
FractureFracture LOB

Lateral and lateral oblique views. Findings include a curvilinear, ill-defined decreased density mixed with increased density (arrows) running through the calcaneal medial tubercle. Diagnosis: fracture.

UBC
UBC

Lateral view. A geographic decreased density presents within the calcaneal neutral triangle, bordered by a thin sclerotic margin. Diagnosis: unicameral bone cyst.

Myo Oss
Myo Oss

Lateral view. Findings include ossification (arrows; note that there are trabeculations) just anterior and inferior to the medial tubercle. (There was a history of direct trauma). Diagnosis: myositis ossificans traumatica.

stress fx
stress fx

Lateral view. Findings include an ill-defined increased density (white arrows) within the posterosuperior aspect of the calcaneus. Diagnosis: stress fracture. (The black arrow points to a well-defined, curvilinear increased density just above the medial tubercle; this is the inferior border of the lateral tubercle, a normal finding.)

Should a radiographic study be ordered for suspicion of plantar fasciitis?

Not initially, if the patient presents with the classic signs and symptoms of plantar fasciitis. However, if the patient does not improve with conservative treatment over the first few weeks, radiographs should be obtained to rule out other possibilities.

What are the best views to order?

At a minimum, order lateral and lateral oblique views; dorsoplantar view should be added when considering inflammatory arthritis; include the calcaneal axial view for suspected fracture or tumor.

When should additional imaging studies be ordered?

If plain films are unremarkable, ultrasound and MRI are valuable in assessing plantar fasciitis, fascial tear or rupture, and fibroma.

MRI would additionally be useful for stress fracture.

Other information

Unicameral bone cyst may be an incidental finding and not related to the symptomatology.

References:

  1. Resnick, D: Bone and Joint Imaging, 2nd edition, WB Saunders, 1996.
  2. Christman RA: Foot and Ankle Radiology, 2nd edition, Lippincott Williams & Wilkins, 2015.