1
 Radiologic evaluation of the foot is often a
complex task given the relatively small size
of structures, detailed intric...
3
Primary centers
 Within the fetal period, ossification commences first in the
metatarsals, followed closely by the dista...
 The primary centres of ossification for the proximal
phalanges appear in the 4th prenatal month, around
14-16 prenatal w...
6The Juvenile Skeleton, By Louise Scheuer, Sue Black
7The Juvenile Skeleton, By Louise Scheuer, Sue Black
 The foot is divided into the
 Hindfoot
 Calcaneus
 Talus
 Midfoot
 Cuboid
 Navicular
 Three cuneiforms
 Forefoot...
9
 There are three distinct groups or compartments of lower leg
musculature:
 posterior,
 lateral,
 and anterior.
 The ...
 The Achilles tendon is not surrounded by a tendon sheath as are other
ankle tendons, but does have a peritenon covering....
 The deep group of posterior muscles consists
of the flexor hallucis longus, flexor digitorum
longus, and tibialis poster...
16
 The anterior compartment contains the
tibialis anterior, extensor hallucis longus,
extensor digitorum longus, and perone...
 Radiograph
 USG
 CT
 MRI
 A multimodality approach is often necessary for
complete radiologic assessment.
 Radiogra...
 Plain radiographs are instrumental in the
initial evaluation of foot disorders.
 Weight-bearing views should be obtaine...
20
 Sonography readily demonstrates the tendons
and peritendinous pathologies,
 Dynamic examination during flexion and
exte...
22
23
•No thickening
•Homogeneous
echogenicity
•No hypoechoic or
hyperechoic foci
•Nil neovascularisation
24
Neovascularization in the distal third
of tendon
Thickened – ‘Spindle Shape’
Abnormal Diagnosed by 1 or more of
the fol...
 CT has become an invaluable additional tool, particularly
for visualizing complex anatomic regions such as the
midfoot a...
 Helical CT is useful in the trauma setting due
to difficulty positioning caused by pain,
splints and concomitant injurie...
 Magnetic resonance (MR) imaging has opened
new horizons in the diagnosis and treatment
of many musculoskeletal diseases ...
 Congenital variants and abnormalities
 Tendon abnormalities
 Impingement syndromes
 Infections
 Arthritis
28
29
 Accessory ossicles of the feet are
common developmental variants with almost 40
having been described. The more common o...
 Secondary ossification centers are sometimes confused for
fractures.
 The os trigonum may be mistaken for the much less...
 Accessory ossicles may be painful. CT features that have been
associated with pain include degenerative sclerosis and
ir...
33
Os peroneum - “An os peroneum is
a small accessory bone located just
proximal to the base of the
5thmetatarsal and loca...
34
Os tibiale externum
(accessory navicular) is a
large ossicle adjacent to
the medial side of the
navicular bone. The
tib...
35
Os trigonum - “An os
trigonum is one of
the bony ossicles of the
foot and can be mistaken
for a fracture. it sits
poste...
 Pes cavus
 Congenital talipes equinovarus (idiopathic
club-foot)
 Rocker bottom foot.
 Tarsal coalition
36
 Pes cavus refers to a descriptive term for a type
of foot deformity with an abnormally high
longitudinal arch of the foo...
 A lateral view is the key to assessment as the
dorso-plantar view can sometimes be normal
unless there an associated abn...
 The calcaneal inclination
angle is drawn on
a weightbearing lateral foot
radiograph between
the calcaneal inclination
ax...
 The angle of the
longitudinal arch is one
of the angles drawn on
the weightbearing
lateral foot radiograph.
The angle is...
41
The mid-talar axis represents a line
drawn down the longitudinal axis of
the talus and can be drawn on
lateral and DP r...
 Hibb's angle is formed between the line
representing the long axes of the calcaneum
and the first metatarsal. The inters...
43
Pes cavus
 It is a congenital deformity comprising four
elements:
(a) an equinus position of the heel;
(b) a varus position of the ...
 Relatively common; the incidence is 1 or 2
/1000 births
 Boys are affected twice as often as girls.
 The condition is ...
 There can be an immense number (estimated at 200) of associations
which include:
 chromosomal anomalies
 18q deletion ...
47
 In the clubfoot deformity,
 the Kite anteroposterior talocalcaneal angle is
less than 20 degrees,
 the lateral angle i...
49
Lateral radiograph of the right foot shows
that the long axes of the talus and calcaneus
are nearly parallel. The longi...
50
 It’s a rare neonatal condition usually affects
both feet.
 The foot is turned outwards (valgus) and the
medial arch is ...
 Associations
 aneuploidic syndromic
 trisomy 13
 trisomy 18
 18q deletion syndrome
 non aneuploidic non syndromic
...
53
 Radiographic features are characteristic:
 The calcaneum is in equinus and the talus points
into the sole of the foot, ...
 Tarsal coalition refers to the fusion of two or
more tarsal bones to form a single structure.
 This fusion may be compl...
 The vast majority (90%) of tarsal coalitions are
either:
 calcaneonavicular (~ 45%)
 usually involves the anterior pro...
57
The anteater nose sign refers to an anterior tubular prolongation of the
superior calcaneus which approaches or overlap...
58
59
60
A continuous C shaped arc is seen on lateral radiograph of ankle which is
formed by medial outline of dome of talus and...
 The talar beak sign is seen in cases of tarsal
coalition, and refers to a superior projection
of the distal aspect of th...
62
(A) Harris view shows bulbous sustentaculum tali, with rounded inferior
contour and overgrowth in expected region of mi...
 Achilles tendon: occur in atheletes esp
runners.
 Tibialis posterior: in middle age obese
women
 Peroneal tendons: pat...
 Tendinosis(collagen degeneration and vascular
ingrowth)
 Paratendinosis(inflamation of the paratenon)
 Tenosynovitis(i...
 The MR imaging characteristics of tendinosis
include
 a fusiform shape
 focal areas of increased tendon girth
 associ...
Tendonosis-Neovascularisation
66
67
 Caused by inflammation or mechanical irritation
of the tendon sheath and peritenon,
respectively.
 MR images reveal flu...
69
fluid is noted within the tendon sheath of the tibialis posterior tendon. The
tendon itself is of normal echotexture wi...
PERITENDINOSIS
70
Tenosynovitis
71
Tenosynovitis
72
73
Peritendinitis & chronic tendinosis TA
Peritendinitis & chronic tendinosis TA
74
 Ultrasonography :
75
76
 MRI Findings:
 Partial rupture manifests on T1-weighted and
proton-density–weighted images and occasionally
 on T2-wei...
Partial tear
78
79
 Achilles tendon injuries may be classified as
noninsertional or insertional.
 The former group includes diffuse acute a...
 Weinstabi et al classified Achilles tendon
lesions into four types on the basis of MR
imaging findings.
 Type I represe...
 A patient with isolated paratendinitis
demonstrates a normal intratendinous
structure,
 whereas peritendinous effusion,...
PERITENDINITIS
83
 Achilles tendinosis is demonstrated as
 tendon swelling, which is often bilateral, and
textural heterogeneity with intr...
 Achilles peritendinosis manifests at MR
imaging as linear or irregular areas of altered
signal intensity in the pre–Achi...
86
 At MR imaging, partial Achilles tendon tears
demonstrate heterogeneous signal intensity and
thickening of the tendon wit...
 Complete Achilles tendon rupture manifests
as discontinuity with fraying and retraction
of the torn edges of the tendon....
89
 Haglund's deformity represents insertional
tendinitis with a posterosuperior calcaneal
bony prominence and retrocalcanea...
91
92
93
94Chronic partial rupture with extensve scar formation and bursitis
 The Haglund syndrome refers to the triad of
 insertional achilles tendinopathy
 retrocalcaneal bursitis and
 and retr...
96
 The Achilles tendon is the tendon most frequently involved in
metabolic disorders
 In gout, deposition of urate tophi m...
Xanthoma of the Achilles tendon in a patient with
familial hypercholesterolemia
98
99
 Acute or chronic dysfunction of the posterior
tibial tendon encompasses a spectrum of
abnormalities ranging from tenosyn...
 Chronic posterior tibial tendon rupture
typically develops in women during the 5th
and 6th decades of life and is associ...
 MR imaging classification of chronic posterior
tibial tendon ruptures divides these injuries into
three types.
 Type I ...
Type 1
Type 2
Type 3 103
 Osteoarthritis
 Crystal artropathy(gout)
 Rheumatoid arthritis
 Seronegative arthropathies
 Septic arthritis
 Charc...
 Trauma is the most common predisposing factor,
including injuries such as lateral ligament tear
with resultant instabili...
106
 Gout is a metabolic disorder characterized by
recurrent episodes of arthritis associated with the
presence of monosodium...
 Erosions, which are usually sharply marginated, are initially
periarticular in location and are later seen to extend int...
109
 In the foot, rheumatoid arthritis has a predilection
for the metatarsophalangeal joints, especially the
fifth.
 Periart...
111
112
 seronegative arthropathy and enthesopathy, where
erosions and bone proliferation occurs.
 In the foot, this typically a...
114
115
 Septic arthritis of the foot and ankle, like
any other region,may occur secondary to
penetrating trauma/direct implantat...
 Osteomyelitis of the foot and ankle is usually
seen in susceptible populations, particularly
diabetic or paralyzed patie...
diabetic patient
118
 Neuropathic osteoarthropathy is an arthritic
process that is often aggressive, resulting from
repetitive micro- and macr...
 Radiographically in the early stage diffuse soft tissue
swelling and occasionally mild offset of a joint.
 The disease ...
121
 MR imaging has been shown to be highly sensitive in the
detection and staging of a number of musculoskeletal
infections ...
 The most common compressive neuropathies
of the ankle and foot are tarsal tunnel
syndrome and Morton neuroma
123
 Tarsal tunnel syndrome is characterized by
pain and paresthesia in the plantar aspect of
the foot and toes.
 This syndr...
 Intrinsic and extrinsic causes of posterior tibial nerve
compression have been identified.
 Intrinsic lesions that ofte...
126
 Morton neuroma (interdigital neuroma) is
actually a fibrosing degenerative process
produced by compression of a plantar ...
 MR imaging has proved highly accurate in the
diagnosis of Morton neuroma,
 manifests as a dumbbell shaped mass located
...
Morton’s neuroma
Morton’s neuroma
Transverse view: Hypoechoic focus between 3rd and 4th interspace.
132
 Osteonecrosis of the ankle and foot typically occurs in the
talus as a consequence of talar neck fractures with
vascular...
134
135
Freiberg disease. (A) T2 image shows extensive bone marrow edema and
subchondral impaction (arrow) and effusion sugges...
 Pigmented villonodular synovitis (PVNS) is
characterized by inflammatory proliferation of
the synovium associated with d...
 PVNS can occur at age 20–50 years and may
manifest as a focal mass or as a generalized
lesion involving the entire joint...
 characteristic MR
imaging features due
to the paramagnetic
effect of
hemosiderin, which
produces focal areas
of hypointe...
139
140
141
 Plantar fasciitis is a painful condition caused by
repetitive injury to the proximal plantar fascia,
at or near its orig...
143
 MR imaging is useful in distinguishing plantar fasciitis from
other causes of heel pain and in excluding plantar fascia
...
 The sinus tarsi is a lateral space located between the talus and the
calcaneus.
 It contains the cervical and interosse...
 Sinus tarsi syndrome (STS) is a clinical finding that
mainly consists of pain and tenderness of the lateral
side of the ...
Plain film
 Osteoarthritis of the subtalar joint and intraosseous
cysts may be present in advanced cases.
CT
 Shows seco...
148
149
Diffuse fluid signal or oedema around the interosseous ligaments in the
sinus tarsi.
 The initial evaluation should always
commence with plain radiographic
assessment.
 MR imaging is the modality of choice...
151
Imaging of foot in non trauma and non neoplastic diseases
Imaging of foot in non trauma and non neoplastic diseases
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Imaging of foot in non trauma and non neoplastic diseases

  1. 1. 1
  2. 2.  Radiologic evaluation of the foot is often a complex task given the relatively small size of structures, detailed intricacy of anatomy, multifaceted relationships and mechanism of the anatomic structures, and wide range of pathologic entities. 2
  3. 3. 3
  4. 4. Primary centers  Within the fetal period, ossification commences first in the metatarsals, followed closely by the distal phalanges, proximal and finally the middle phalanges.  this is a different order from that found in the hand, where the distal phalanges are the first to commence ossification.  The primary centres for the shafts of the metatarsals appear between 8-10 prenatal weeks, which is at a similar time to that for the metacarpals.  Metatarsals 2 -4 tend to appear before metatarsal 5, while the first metatarsal may not appear until 12 prenatal weeks.  The distal phalanges appear around the end of the 2nd and throughout the 3rd month of intra-uterine life and so may appear- before the shaft of the first metatarsal. 4The Juvenile Skeleton, By Louise Scheuer, Sue Black
  5. 5.  The primary centres of ossification for the proximal phalanges appear in the 4th prenatal month, around 14-16 prenatal weeks.  The centres for the first to the third toes tend to appear in advance of those for the fourth and fifth toe.  As with the hand, the middle phalanges of the foot are the last of the long bones to commence ossification.  In summary, therefore, the primary centres of ossification for the metatarsals and phalanges are all present (with the probable exception of the middle phalanges of the lateral toes) by the end of the 5th prenatal month.  The normal sequence of appearance for the tarsal bones is relatively constant and well documented.  The calcaneus appears first, followed closely by the talus and then the cuboid. The remainder of the tarsal bones always appear after birth and the sequence begins with the lateral cuneiform and is followed by the medial and then the intermediate cuneiform, with the navicular being the last to commence ossification. 5The Juvenile Skeleton, By Louise Scheuer, Sue Black
  6. 6. 6The Juvenile Skeleton, By Louise Scheuer, Sue Black
  7. 7. 7The Juvenile Skeleton, By Louise Scheuer, Sue Black
  8. 8.  The foot is divided into the  Hindfoot  Calcaneus  Talus  Midfoot  Cuboid  Navicular  Three cuneiforms  Forefoot  Metatarsals  Phalanges  The articulation between the hindfoot and the midfoot (midtarsal joint) is frequently referred to as Chopart’s joint  Named after surgeon who performed amputations at the calcaneocuboid, talonavicular joint  The articulation between the midfoot and the forefoot is referred to as the Lisfranc joint  Named after French surgeon Francois Chopart (1743–1795) who performed amputations of the foot at this level 8
  9. 9. 9
  10. 10.  There are three distinct groups or compartments of lower leg musculature:  posterior,  lateral,  and anterior.  The posterior muscles are divided into superficial and deep groups.  The superficial group consists of gastrocnemius, soleus, and plantaris.  The gastrocnemius and soleus unite to form the Achilles tendon that inserts into the tuberosity of the calcaneus. 10
  11. 11.  The Achilles tendon is not surrounded by a tendon sheath as are other ankle tendons, but does have a peritenon covering.  The fibers of achilles tendon are homogeneous and low signal on all MR pulse sequences.  On axial images the tendon has a flat or concave anterior surface. Anterior to the tendon is a fat-containing space known as Kager’s fat pad.  Between the distal Achilles tendon and the posterior calcaneal tuberosity lies the retrocalcaneal bursa.  The plantaris is a small muscle between the gastrocnemius and soleus; this muscle is rudimentary and may be absent in 10% of the population. Its long tendon runs along the medial border of the Achilles and inserts into the calcaneus, the Achilles tendon itself, or the flexor retinaculum 13
  12. 12.  The deep group of posterior muscles consists of the flexor hallucis longus, flexor digitorum longus, and tibialis posterior.  All three muscles arise from the posterior tibia, fibula, and/or interosseous membrane.  The tendons begin above the level of the ankle and all three pass beneath the flexor retinaculum. 14
  13. 13. 16
  14. 14.  The anterior compartment contains the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius muscles.  The lateral compartment muscles include the peroneus longus and brevis. 17
  15. 15.  Radiograph  USG  CT  MRI  A multimodality approach is often necessary for complete radiologic assessment.  Radiography, sonography, and computed tomography all play important roles in the radiologic assessment of the foot and ankle.  However, magnetic resonance imaging (MRI) is often the imaging modality of choice attributable to the superior soft tissue contrast resolution, multiplanar capability, lack of ionizing radiation, and ability to do post contrast imaging. 18
  16. 16.  Plain radiographs are instrumental in the initial evaluation of foot disorders.  Weight-bearing views should be obtained when possible.  Dorsal-Plantar (DP) and Oblique - are standard projections of the forefoot.  Comparison views of the contralateral foot is not routinely ordered but can be helpful in difficult cases 19
  17. 17. 20
  18. 18.  Sonography readily demonstrates the tendons and peritendinous pathologies,  Dynamic examination during flexion and extension maneuvers  Synovial pathologies can be evaluated  Small amount of fluid along the posterior tibial and common peroneal tendons in normal subjects. 21
  19. 19. 22
  20. 20. 23 •No thickening •Homogeneous echogenicity •No hypoechoic or hyperechoic foci •Nil neovascularisation
  21. 21. 24 Neovascularization in the distal third of tendon Thickened – ‘Spindle Shape’ Abnormal Diagnosed by 1 or more of the following findings 1.Tendon thickening with heterogeneous echogenicity 2.Hypoechoic foci representing intrasubstance tears (defined as linear hypoechoic foci associated with discontinuity of tendon fibres) 3.Calcifications and enthesiophytes at the tendon attachment 4.Neovascularization
  22. 22.  CT has become an invaluable additional tool, particularly for visualizing complex anatomic regions such as the midfoot and for judging articular surface integrity.  The foot and ankle are usually imaged with 2- to 3-mm thick sections obtained in the axial plane (axial with respect to the long axis of the body) with the patient supine and the foot in neutral position.  Imaging of only the affected extremity is recommended, with the contralateral extremity removed from the scan plane when possible, to minimize streak artifact and optimize field of view and positioning for the area of interest.  When possible, direct coronal oblique sections are also obtained. With the knee flexed and the foot flat on the scan table, the gantry is tilted towards the knee as far as possible to place the tibia nearly parallel with the plane of section. 25
  23. 23.  Helical CT is useful in the trauma setting due to difficulty positioning caused by pain, splints and concomitant injuries.  Helical 1-mm images are obtained in the axial plane with 1:1 pitch, yielding essentially isotropic images and high-quality multiplanar reconstructions. 26
  24. 24.  Magnetic resonance (MR) imaging has opened new horizons in the diagnosis and treatment of many musculoskeletal diseases of the foot.  It demonstrates abnormalities in the bones and soft tissues before they become evident at other imaging modalities. 27
  25. 25.  Congenital variants and abnormalities  Tendon abnormalities  Impingement syndromes  Infections  Arthritis 28
  26. 26. 29
  27. 27.  Accessory ossicles of the feet are common developmental variants with almost 40 having been described. The more common ones include:  os peroneum  os subfibulare  os subtibiale  os tibiale externum (accessory navicular)  os trigonum  os calcaneus secundaris  os intermetatarseum  os supratalare  bipartite hallux sesamoid  os supranaviculare  Knowledge of their presence is helpful so that they are not misdiagnosed as fractures. 30
  28. 28.  Secondary ossification centers are sometimes confused for fractures.  The os trigonum may be mistaken for the much less common Shepherd fracture of the posterior process of talus.  Os trigonum syndrome is a mechanical tenosynovitis caused by tethering of the flexor hallucis longus tendon by the os trigonum.  An os supranaviculare can simulate a navicular fracture. 31
  29. 29.  Accessory ossicles may be painful. CT features that have been associated with pain include degenerative sclerosis and irregularity, subchondral cyst-like changes and vacuum phenomenon at the synchondrosis .  A bipartite medial cuneiform is an uncommon variant that is occasionally symptomatic and can be involved in trauma .  The corticated nature of sesamoids in the forefoot distinguishes them from acute fracture fragments and is usually readily apparent on CT.  Less noticed are the pathologic and potentially symptomatic entities of these normal structures, including fracture, osteonecrosis and degenerative change. 32
  30. 30. 33 Os peroneum - “An os peroneum is a small accessory bone located just proximal to the base of the 5thmetatarsal and located within the substance of peroneus longus...”
  31. 31. 34 Os tibiale externum (accessory navicular) is a large ossicle adjacent to the medial side of the navicular bone. The tibialis posterior tendon often inserts with a broad attachment onto the ossicle, which may cause a painful tendinosis due traction between the ossicle and the navicular.
  32. 32. 35 Os trigonum - “An os trigonum is one of the bony ossicles of the foot and can be mistaken for a fracture. it sits posterior to talus on the lateral foot radiograph.”
  33. 33.  Pes cavus  Congenital talipes equinovarus (idiopathic club-foot)  Rocker bottom foot.  Tarsal coalition 36
  34. 34.  Pes cavus refers to a descriptive term for a type of foot deformity with an abnormally high longitudinal arch of the foot (caved in foot).  It can be associated with certain neuromuscular disorders such as  Charcot-Marie-Tooth disease : considered one of the commonest associations in the western world  conditions that cause spastic paralysis  spinal anomalies  spinal dysraphisms  spina bifida 37
  35. 35.  A lateral view is the key to assessment as the dorso-plantar view can sometimes be normal unless there an associated abnormality 2.  On a lateral view there is:  increase in the calcaneal inclination angle  angle of the longitudinal arch greater than 170 degrees  the mid-talar axis either extends above the 1st metatarsal or intersects the shaft distal to its midpoint  Hibb's angle less than 150 degrees. 38
  36. 36.  The calcaneal inclination angle is drawn on a weightbearing lateral foot radiograph between the calcaneal inclination axis and the supporting surface.  It is a measurement that reflects the height of the foot framework, but is affected by abnormal pronation or supination of the foot:  low: 10-20 degrees  medium: 20-30 degrees  high: 30+ degrees 39
  37. 37.  The angle of the longitudinal arch is one of the angles drawn on the weightbearing lateral foot radiograph. The angle is formed between the calcaneal inclination axis and a line drawn along the inferior edge of the 5th metatarsal.  The normal angle is 150-170 degrees. 40
  38. 38. 41 The mid-talar axis represents a line drawn down the longitudinal axis of the talus and can be drawn on lateral and DP radiographs. lateral view: line should bisect the shaft of the first metatarsal DP view: line should intersect (or pass just medial to) the base of the first metatarsal
  39. 39.  Hibb's angle is formed between the line representing the long axes of the calcaneum and the first metatarsal. The intersection of the lines represents apex of the deformity.  Normally Hibb's angle is greater than 150 degrees .  Hibb's angle less than 150 degrees indicates pes cavus. 42
  40. 40. 43 Pes cavus
  41. 41.  It is a congenital deformity comprising four elements: (a) an equinus position of the heel; (b) a varus position of the hindfoot; (c) adduction and a varus deformity of the forefoot; (d) talonavicular subluxation.  Before the ossification of the navicular bone at 2 to 3 years of age, only the first three elements can be verified radiographically. 44
  42. 42.  Relatively common; the incidence is 1 or 2 /1000 births  Boys are affected twice as often as girls.  The condition is bilateral in one-third of cases.  Similar deformities are seen in neurological disorders, e.g. myelomeningocele, and in arthrogryposis.  It’s mostly a problem passed from parents to children (genetic), and it may run in families. 45
  43. 43.  There can be an immense number (estimated at 200) of associations which include:  chromosomal anomalies  18q deletion syndrome  trisomy 18  Wolf-Hirschhorn syndrome  other syndromic conditions  Freeman Sheldon syndrome  Meckel Gruber syndrome  Roberts syndrome  renal anomalies  prune belly syndrome  renal agenesis  connective tissue disorders  Marfan syndrome  Ehlers-Danlos syndrome  spinal anomalies  caudal regression syndrome  diastematomyelia  spina bifida  skeletal dysplasias  diastrophic dysplasia 46
  44. 44. 47
  45. 45.  In the clubfoot deformity,  the Kite anteroposterior talocalcaneal angle is less than 20 degrees,  the lateral angle is less than 35 degrees,  and the TFM angle is greater than 15 degrees  In the determination of the Kite anteroposterior talocalcaneal angle, the lines of the angle normally intersect the first and fourth metatarsals; in the clubfoot anomaly, these lines fall lateral to the normal points. 48
  46. 46. 49 Lateral radiograph of the right foot shows that the long axes of the talus and calcaneus are nearly parallel. The longitudinal arch is abnormally high. AP radiograph of the right foot shows abnormally narrow talocalcaneal angle, with severe adduction and supination of the forefoot.
  47. 47. 50
  48. 48.  It’s a rare neonatal condition usually affects both feet.  The foot is turned outwards (valgus) and the medial arch is not only flat, it actually curves the opposite way from the normal, producing the appearance of a “rocker-bottom” foot.  Passive correction is impossible  The only effective treatment is by operation, ideally before the age of 2 years. 51
  49. 49.  Associations  aneuploidic syndromic  trisomy 13  trisomy 18  18q deletion syndrome  non aneuploidic non syndromic  spina bifida  arthrogryposis 52
  50. 50. 53
  51. 51.  Radiographic features are characteristic:  The calcaneum is in equinus and the talus points into the sole of the foot, with the navicular dislocated dorsally onto the neck of the talus. 54
  52. 52.  Tarsal coalition refers to the fusion of two or more tarsal bones to form a single structure.  This fusion may be complete or incomplete, and the bridge may be fibrous (syndesmosis), cartilaginous (synchondrosis), or osseous (synostosis).  Various bones may be affected, but most commonly the coalition occurs between the calcaneus and navicular bone.  Pain, particularly associated with prolonged walking or standing, is a typical presenting symptom.  On physical examination, peroneal muscular spasm and restricted joint mobility (the so- called peroneal spastic foot) are revealed. 55
  53. 53.  The vast majority (90%) of tarsal coalitions are either:  calcaneonavicular (~ 45%)  usually involves the anterior process of the calcaneus  the anteater nose sign may sometimes be seen  best seen on an oblique film  talocalcaneal (~ 45%)  usually involves the middle facet  best seen on the lateral view  C-sign - complete posterior ring around the talus and sustentaculum tali  talar beak sign due to impaired subtalar movement  The remainder of the coalitions (calcaneocuboid, talonavicular, cubonavicular) are much less common . 56
  54. 54. 57 The anteater nose sign refers to an anterior tubular prolongation of the superior calcaneus which approaches or overlaps the navicular on a lateral radiograph of the foot. This fancifully resembles the nose of an anteater and is an indication of calcaneonavicular coalition .
  55. 55. 58
  56. 56. 59
  57. 57. 60 A continuous C shaped arc is seen on lateral radiograph of ankle which is formed by medial outline of dome of talus and posteroinferior aspect of sustentaculum tali .
  58. 58.  The talar beak sign is seen in cases of tarsal coalition, and refers to a superior projection of the distal aspect of the talus. It is most frequently encountered in talocalcaneal coalition . It is thought to result from abnormal biomechanic stresses at the talonavicular joint. 61
  59. 59. 62 (A) Harris view shows bulbous sustentaculum tali, with rounded inferior contour and overgrowth in expected region of middle subtalar facet. (B) Lateral radiograph shows dysmorphic sustentaculum tali, with bony overgrowth and rounding of its inferior contour. Continuity of sustentaculum tali contour with that of medial talus is the C-sign (C) Lateral radiograph shows talar beak arising at talonavicular joint and curving away from joint and dysmorphic sustentaculum tali and C-sign (D) Lateral radiograph shows rounded lateral process of talus and dysmorphic sustentaculum tali Bony prominence at dorsal margin of talar head has features of both osteophyte and beak, perhaps because this is an older patient who has developed osteoarthritis
  60. 60.  Achilles tendon: occur in atheletes esp runners.  Tibialis posterior: in middle age obese women  Peroneal tendons: pateints with previous lateral ankle sprains  Other tendons are rarely injured. 63
  61. 61.  Tendinosis(collagen degeneration and vascular ingrowth)  Paratendinosis(inflamation of the paratenon)  Tenosynovitis(inflamation of the tendon sheath)  Partial tear  Complete tear( tendon rupture)  Tendon dislocation and entrapment  These conditions often coexist, and overlap in their clinical,gross, and histologic manifestations can make them indistinguishable at MR imaging 64
  62. 62.  The MR imaging characteristics of tendinosis include  a fusiform shape  focal areas of increased tendon girth  associated with increased signal intensity within the tendon on T1-weighted and protondensity– weighted images.  T2 signal intensity alterations are noted when significant intrasubstance degeneration is present. 65
  63. 63. Tendonosis-Neovascularisation 66
  64. 64. 67
  65. 65.  Caused by inflammation or mechanical irritation of the tendon sheath and peritenon, respectively.  MR images reveal fluid accumulation, synovial proliferation, or scarring within the tendon sheath or adjacent soft tissues.  Stenosing tenosynovitis occurs when synovial proliferation and fibrosis surround the tendon, causing entrapment and even rupture.  It manifests as areas of intermediate to low signal intensity in the soft tissues around the tendon with all MR imaging sequences. 68
  66. 66. 69 fluid is noted within the tendon sheath of the tibialis posterior tendon. The tendon itself is of normal echotexture with no evidence of tendinopathy. Tenosynovitis
  67. 67. PERITENDINOSIS 70
  68. 68. Tenosynovitis 71
  69. 69. Tenosynovitis 72
  70. 70. 73
  71. 71. Peritendinitis & chronic tendinosis TA Peritendinitis & chronic tendinosis TA 74
  72. 72.  Ultrasonography : 75
  73. 73. 76
  74. 74.  MRI Findings:  Partial rupture manifests on T1-weighted and proton-density–weighted images and occasionally  on T2-weighted images as an area within the substance of the tendon having a signal intensity similar to that seen in advanced tendinosis. 77
  75. 75. Partial tear 78
  76. 76. 79
  77. 77.  Achilles tendon injuries may be classified as noninsertional or insertional.  The former group includes diffuse acute and chronic peritendinosis, tendinosis, and a rupture 2–6 cm above the insertion of the tendon on the calcaneus.  The latter group includes insertional Achilles tendinosis, which may be associated with Haglund deformity of the calcaneus. 80
  78. 78.  Weinstabi et al classified Achilles tendon lesions into four types on the basis of MR imaging findings.  Type I represents inflammatory reaction;  Type II, degenerative changes;  Type III, partial rupture;  Type IV, complete rupture. 81
  79. 79.  A patient with isolated paratendinitis demonstrates a normal intratendinous structure,  whereas peritendinous effusion,  irregularities of tendon margins and  adhesions related to scarring of the paratenon,  heterogeneous appearance of the pre- Achilles tendon fat pad, are the main findings 82
  80. 80. PERITENDINITIS 83
  81. 81.  Achilles tendinosis is demonstrated as  tendon swelling, which is often bilateral, and textural heterogeneity with intratendinous focal hypoechoic areas  US can reveal subtle changes in the fibrillar pattern, including thickening, fragmentation and disappearance of specular echoes 84
  82. 82.  Achilles peritendinosis manifests at MR imaging as linear or irregular areas of altered signal intensity in the pre–Achilles tendon fat pad, a finding that indicates the presence of edema or scarring of the peritenon. The tendon itself is normal.  Achilles tendinosis manifests on axial MR images as loss of the anterior concave or flat surface of the Achilles tendon and on sagittal images as fusiform thickening of the tendon.  Areas of increased signal intensity within the tendon are also noted. 85
  83. 83. 86
  84. 84.  At MR imaging, partial Achilles tendon tears demonstrate heterogeneous signal intensity and thickening of the tendon without complete interruption.  Differentiation between partial tear and severe chronic Achilles tendinosis may be difficult apart from clinical history.  Acute partial tears are often associated with subcutaneous edema, hemorrhage within the Kager fat pad, and intratendinous hemorrhage at MR imaging, whereas chronic tendinosis does not usually demonstrate increased subcutaneous or intratendinous signal intensity on T2-weighted images. 87
  85. 85.  Complete Achilles tendon rupture manifests as discontinuity with fraying and retraction of the torn edges of the tendon.  In acute rupture, the tendon gap demonstrates intermediate signal intensity on T1-weighted images and high signal intensity on T2-weighted images, findings that are consistent with edema and hemorrhage,  In chronic ruptures, scar or fat may replace the tendon 88
  86. 86. 89
  87. 87.  Haglund's deformity represents insertional tendinitis with a posterosuperior calcaneal bony prominence and retrocalcaneal tendo Achilles bursitis 90
  88. 88. 91
  89. 89. 92
  90. 90. 93
  91. 91. 94Chronic partial rupture with extensve scar formation and bursitis
  92. 92.  The Haglund syndrome refers to the triad of  insertional achilles tendinopathy  retrocalcaneal bursitis and  and retro tendo-achilles bursitis  This results in pain at the back of the heel.  It is associated with calcaneal spurs, and the wearing of high heels (thus the colloquial term "pump-bump") or stiff backed shoes in general. 95
  93. 93. 96
  94. 94.  The Achilles tendon is the tendon most frequently involved in metabolic disorders  In gout, deposition of urate tophi may result in intratendinous nodules or diffuse thickening of the tendon,  Heterozygous familial hypercholesterolemia, an inherited disorder leading to premature atherosclerosis,  US can depict striking bilateral tendon swelling and a high-grade textural heterogeneity and disappearance of the fibrillar pattern with focal or diffuse hypoechoic areas, the intratendinous xanthomas, before these become clinically apparent  On MR Fusiform thickening of the Achilles tendon associated with intrasubstance heterogeneity and stippling are consistent with the presence of xanthoma. 97
  95. 95. Xanthoma of the Achilles tendon in a patient with familial hypercholesterolemia 98
  96. 96. 99
  97. 97.  Acute or chronic dysfunction of the posterior tibial tendon encompasses a spectrum of abnormalities ranging from tenosynovitis and tendinosis to partial or complete rupture of the tendon.  Acute tenosynovitis is related to overuse and is usually encountered in young, athletic individuals. At MR imaging, fluid is seen within the tendon sheath 100
  98. 98.  Chronic posterior tibial tendon rupture typically develops in women during the 5th and 6th decades of life and is associated with progressive flat foot deformity.  The tear is commonly noted behind the medial malleolus, where the tendon is subjected to a significant amount of friction.  Acute partial or complete rupture of the posterior tibial tendon in young, athletic individuals is less common and is usually seen at the insertion of the tendon on the navicular bone. 101
  99. 99.  MR imaging classification of chronic posterior tibial tendon ruptures divides these injuries into three types.  Type I partial tear consists of an incomplete tear with fusiform enlargement, intra-substance degeneration, and longitudinal splits  Type II partial tear of the posterior tibial tendon. On axial images, a decrease in the diameter of the tendon, usually without signal intensity alterations. The caliber of the tendon may be equal to or less than that of the adjacent flexor digitorum longus tendon  Type III posterior tibial tendon tears there is complete disruption of the tendon fibers 102
  100. 100. Type 1 Type 2 Type 3 103
  101. 101.  Osteoarthritis  Crystal artropathy(gout)  Rheumatoid arthritis  Seronegative arthropathies  Septic arthritis  Charcot arthropathy(neuroarthropathy) 104
  102. 102.  Trauma is the most common predisposing factor, including injuries such as lateral ligament tear with resultant instability and/or osteochondral injury, as well as intraarticular fracture,Degenerative arthropathy, or osteoarthritis, commonly affects the ankle.  Classic signs include joint space narrowing,marginal osteophytes, intraarticular body formation, subchondral cysts, and subchondral sclerosis.  Osteoarthritis is also quite common at the midfoot, typically resulting in dorsal spurring at multiple articulations (also called “dorsal proliferative change”). 105
  103. 103. 106
  104. 104.  Gout is a metabolic disorder characterized by recurrent episodes of arthritis associated with the presence of monosodium urate monohydrate crystals in the synovial fluid leukocytes and, in many cases, gross deposits of sodium urate (tophi) in periarticular soft tissues.  Serum uric acid concentrations are elevated.  The great toe is the most common site of involvement in gouty arthritis;  the condition known as podagra, which involves the first metatarsophalangeal joint, occurs in approximately 75% of patients.  Other frequently affected sites include the ankle, knee, elbow, and wrist.  Most patients are men, but gouty arthritis is seen in postmenopausal women as well. 107
  105. 105.  Erosions, which are usually sharply marginated, are initially periarticular in location and are later seen to extend into the joint  an “overhanging edge” of erosion is a frequent identifying feature  Intraosseous defects are present secondary to formation of intraosseous tophi .  Lack of osteoporosis, helps differentiate this condition from rheumatoid arthritis.  If erosion involves the articular end of the bone and extends into the joint, part of the joint is usually preserved.  In chronic tophaceous gout, sodium urate deposits in and around the joint are seen, creating a dense mass in the soft tissues called a tophus, which frequently exhibits calcifications  Characteristically, tophi are randomly distributed and are usually asymmetric; if they occur in the hands or feet, they are more often seen on the dorsal aspect 108
  106. 106. 109
  107. 107.  In the foot, rheumatoid arthritis has a predilection for the metatarsophalangeal joints, especially the fifth.  Periarticular osteopenia is variably present.  Although the intertarsal, subtalar, and ankle joints may be involved.  Involvement at the ankle can create a characteristic erosion of the synovial recess at the distal tibiofibular joint.  Joint destruction and capsular distension can result in deformities including subluxation/ dislocation  Chronic inflammatory tenosynovitis can result in tendon tear and dysfunction, causing additional deformity; posterior tibial tendon dysfunction is particularly common. 110
  108. 108. 111
  109. 109. 112
  110. 110.  seronegative arthropathy and enthesopathy, where erosions and bone proliferation occurs.  In the foot, this typically affects the metatarsophalangeal and interphalangeal joints.  Interphalangeal erosions may result in the pathognomonic “pencil-in-cup” appearance.  Acro-osteolysis can occur along with nail involvement.  Proliferative bone formation manifests as periostitis and in areas of bone erosion fluffy bone production occurs.  Occasionally, if severe, erosions may result in ankylosis or joint destruction (arthritis mutilans).  Enthesial involvement resulting in erosions or “fuzzy spurs” may occur at the plantar fascia or other tendon, ligament, or fascial attachment sites.  Bursitis may also occur with focal soft-tissue swelling. 113
  111. 111. 114
  112. 112. 115
  113. 113.  Septic arthritis of the foot and ankle, like any other region,may occur secondary to penetrating trauma/direct implantation, postoperatively, due to contiguous spread, or hematogenous spread.  The imaging features consist of a joint effusion, with loss of the sharp cortical margins of the subarticular bone.  Joint space loss is rapid in acute septic arthritis, and marginal erosions may develop mimicking an inflammatory arthropathy 116
  114. 114.  Osteomyelitis of the foot and ankle is usually seen in susceptible populations, particularly diabetic or paralyzed patients.  In these patients, contiguous spread is by far the most common mode of infection, arising via skin ulceration. 117
  115. 115. diabetic patient 118
  116. 116.  Neuropathic osteoarthropathy is an arthritic process that is often aggressive, resulting from repetitive micro- and macrotrauma that heals ineffectively due to ischemia and reduced nociception.  Disease may be seen in various neurological conditions involving the foot/ ankle such as leprosy, common in diabetics with peripheral neuropathy.  In diabetic population, the Lisfranc joint and intertarsal joints are most commonly involved, followed by the Chopart joint, subtalar and tibiotalar joint, and the metatarsophalangeal joints. 119
  117. 117.  Radiographically in the early stage diffuse soft tissue swelling and occasionally mild offset of a joint.  The disease progress rapidly, with erosions and even frank joint destruction.  Often in the late stage there is excessive bone production (sclerosis and spurring), and subchondral cystic change which in addition to deformity leads to the classic appearance of chronic neuropathic osteoarthropathy.  Articular surfaces degenerate over time and may fragment, becoming distorted, incongruent, and generally disorganized, with debris and body formation.  Neuropathic osteoarthropathy has been characterized radiographically as dislocation, debris, disorganization, deformity, and increased density. 120
  118. 118. 121
  119. 119.  MR imaging has been shown to be highly sensitive in the detection and staging of a number of musculoskeletal infections including cellulitis, soft-tissue abscesses, and osteomyelitis.  MR imaging has greater specificity and better spatial resolution than bone scintigraphy and also has the capacity to provide a quicker diagnosis.  Differentiation between neuroarthropathy and infection may be difficult with any imaging technique.  At MR imaging, neuroarthropathy exhibits characteristic findings including bone fragmentation, dislocations, cortical and periosteal thickening, joint effusion, and soft- tissue swelling. In most cases, the bone marrow appears hypointense on both T1- and T2-weighted images.  In osteomyelitis, on the other hand, the bone marrow appears hypointense on T1- weighted images and hyperintense on T2-weighted images. 122
  120. 120.  The most common compressive neuropathies of the ankle and foot are tarsal tunnel syndrome and Morton neuroma 123
  121. 121.  Tarsal tunnel syndrome is characterized by pain and paresthesia in the plantar aspect of the foot and toes.  This syndrome is most frequently unilateral, as opposed to carpal tunnel syndrome, which is typically bilateral.  Nerve entrapment or compression can occur at the level of the posterior tibial nerve or its branches producing different symptoms depending on the site of compression 124
  122. 122.  Intrinsic and extrinsic causes of posterior tibial nerve compression have been identified.  Intrinsic lesions that often produce tarsal tunnel syndrome include  Accessory muscles,  Ganglion cysts,  Neurogenic tumors,  Varicose veins,  lipomas,  synovial hypertrophy, and scar tissue.  Extrinsic causes  Foot deformities,  Hypertrophic and accessory muscles,  accessory ossicle (os trigonum), and excessive pronation  In about 50% of cases, the cause of tarsal tunnel syndrome cannot be identified.  Relief of symptoms following retinacular release is frequently seen in these idiopathic cases. 125
  123. 123. 126
  124. 124.  Morton neuroma (interdigital neuroma) is actually a fibrosing degenerative process produced by compression of a plantar digital nerve.  The condition has a female predilection and is frequently seen between the heads of the third and fourth metatarsals, although all web spaces may be involved.  The nerve becomes thickened, and associated bursitis is often present.  Exquisite tenderness is elicited on lateral compression of the metatarsals.  The pain can radiate to the toes and may be accompanied by numbness 127
  125. 125.  MR imaging has proved highly accurate in the diagnosis of Morton neuroma,  manifests as a dumbbell shaped mass located between the metatarsal heads and having intermediate to low signal intensity on both T1- and T2-weighted images.  T1- weighted sequences are probably more helpful because the hypointense neuroma is made more conspicuous by the surrounding hyperintense fat.  The low signal intensity of Morton neuroma is attributed to the presence of fibrous tissue. 128
  126. 126. Morton’s neuroma
  127. 127. Morton’s neuroma
  128. 128. Transverse view: Hypoechoic focus between 3rd and 4th interspace.
  129. 129. 132
  130. 130.  Osteonecrosis of the ankle and foot typically occurs in the talus as a consequence of talar neck fractures with vascular compromise of the bone at the level of the sinus tarsi.  Osteonecrosis of the tarsal navicular bone can occur in children (Kohler disease)  Manifests radiographically as sclerosis, irregularity, and fragmentation of the bone.  A form of osteonecrosis of the tarsal navicular bone has also been described in adults (Mueller-Weiss syndrome).  Osteonecrosis of the ankle and foot region is also frequently seen in the second metatarsal head (Freiberg disease), with sclerosis and flattening of the metatarsal head seen at conventional radiography, and in the first metatarsal sesamoid bone 133
  131. 131. 134
  132. 132. 135 Freiberg disease. (A) T2 image shows extensive bone marrow edema and subchondral impaction (arrow) and effusion suggesting more acute changes. (B) Proton density images show subchondral fracture with impaction of cortex and subchondral bone plate (arrow). (C) Axial, (D) sagittal images of late-stage Freiberg disease with secondary osteoarthritis and subchondral cyst (arrow). Collapsed subchondral bone with a low-grade stress response.
  133. 133.  Pigmented villonodular synovitis (PVNS) is characterized by inflammatory proliferation of the synovium associated with deposits of hemosiderin.  It can be present in any joint, tendon sheath, or bursa but is most frequently seen in the knee, hip, ankle, and elbow.  When it originates in the tendon sheaths, the term giant cell tumor of the tendon sheaths is often used.  In the foot, this lesion predominantly involves the peroneal and flexor tendon sheaths 136
  134. 134.  PVNS can occur at age 20–50 years and may manifest as a focal mass or as a generalized lesion involving the entire joint space.  Pressure erosions may be present in the diffuse form.  These lesions manifest clinically as joint pain and swelling of long duration, and most are slowly progressive.  At pathologic analysis, PVNS is characterized by synovial inflammation with giant cell proliferation, collagen, and lipid-laden macrophages.  Treatment of PVNS often consists of resection of the lesion. 137
  135. 135.  characteristic MR imaging features due to the paramagnetic effect of hemosiderin, which produces focal areas of hypointensity with all pulse sequences,  mixed with hypointense areas on T1-weighted images and hyperintense areas on T2-weighted images. 138
  136. 136. 139
  137. 137. 140
  138. 138. 141
  139. 139.  Plantar fasciitis is a painful condition caused by repetitive injury to the proximal plantar fascia, at or near its origin from the calcaneus.  Individuals with pes planus and overpronation are predisposed.  Although spur formation at the inferior calcaneus is often implicated in this process, it actually has little association with pain;  Although plantar fascial thickening may be suggested on the lateral radiograph, this finding is not necessarily related to acute, symptomatic fasciitis 142
  140. 140. 143
  141. 141.  MR imaging is useful in distinguishing plantar fasciitis from other causes of heel pain and in excluding plantar fascia tears.  On sagittal and coronal MR images, the normal plantar fascia appears as a thin, hypointense structure extending anteriorly from the calcaneal tuberosity.  The plantar fascia has a normal thickness of 3.22 mm ± 0.53 and flares slightly at the calcaneal insertion.  When inflammatory changes take place, it becomes thickened (up to 7–8 mm) and demonstrates intermediate signal intensity on T1-weighted and proton-density– weighted images and hyperintensity on T2- weighted images .  These changes are most prominent in the proximal portion of the plantar fascia at or near its insertion on the calcaneus.  Signal intensity changes may also be present in the subcutaneous fat, in the deep soft tissues, and in the calcaneus near the fascial insertion. 144
  142. 142.  The sinus tarsi is a lateral space located between the talus and the calcaneus.  It contains the cervical and interosseous talocalcaneal ligaments, the medial roots of the inferior extensor retinaculum, neurovascular structures, and fat.  Sinus tarsi syndrome is caused by hemorrhage or inflammation of the synovial recesses of the sinus tarsi with or without tears of the associated ligaments.  This disease entity commonly occurs following an inversion injury and is often associated with tears of the lateral collateral ligaments.  It may also be related to rheumatologic disorders and abnormal biomechanics such as flat foot deformity secondary to posterior tibial tendon tear.  Patients with sinus tarsi syndrome present with hindfoot instability and pain along the lateral aspect of the foot.  The MR imaging characteristics of sinus tarsi syndrome include the obliteration of fat in the sinus tarsi space. The space itself is replaced by either fluid or scar tissue, and the ligaments may be disrupted.  Osteoarthritis of the subtalar joint and subchondral cysts may be present in advanced cases. 145
  143. 143.  Sinus tarsi syndrome (STS) is a clinical finding that mainly consists of pain and tenderness of the lateral side of the hindfoot, between the ankle and the heel. Aetiology  STS probably occurs following one single or a series of ankle sprains that also result in significant injuries to the talocrural interosseous and cervical ligaments.  This causes instability of the subtalar joint in supination and pronation movements.  In summary, STS can be primarily described as an instability of the subtalar joint due to ligamentous injuries that result in synovitis and scar tissue formation in the sinus tarsi. Haemorrhage or inflammation of the synovial recesses of the sinus tarsi can also cause scarring without tears of the associated ligaments. 146
  144. 144. Plain film  Osteoarthritis of the subtalar joint and intraosseous cysts may be present in advanced cases. CT  Shows secondary bony changes earlier than plain films. Bone scan - scintigraphy  Inflammatory changes may be attributed to the sinus tarsi / subtalar region. MRI  Probably the best test to show changes in the tissues of the sinus tarsi including inflammation, scar tissue formation or ligamentous injuries.The T1-hyperintense fat in the sinus tarsi space is replaced by either fluid or scar tissue, and the ligaments may be disrupted. Ganglion cysts in the region of the sinus tarsi may compress the posterior tibial nerve. 147
  145. 145. 148
  146. 146. 149 Diffuse fluid signal or oedema around the interosseous ligaments in the sinus tarsi.
  147. 147.  The initial evaluation should always commence with plain radiographic assessment.  MR imaging is the modality of choice for optimal detection of most soft-tissue disorders of the tendons,ligaments, and other soft-tissue structures of the ankle and foot. 150
  148. 148. 151

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