Msk -- Foot And Ankle

Front 1

1. What are two most common locations of tarsal coalition?
2. Of the three subtalar joints which one is more likely to undergo coalition?
3. What is the radiographic sign of calcaneonavicular coalition seen on the lateral view?
4. What are the imaging findings of talcalcaneal coalition seen on the lateral view?

Back 1

1. Talocalcaneal and calcaneonavicular
2. Middle facet of the talcalcaneal joint.
3. Anteater sign
4. Premature osteoarthritis at the talonavicular joint (talar beaking), "c shaped" ossification on the lateral view.

C sign may be present on lateral vies when a middle facet coalition is present. The dome of the talus forms the top of the c, the coalition forms the middle, and the sustentaculum forms the bottom.

Front 2

1. What is the mechanism of Lisfranc injury?
2. What is the anatomy at the tarsometatarsal joints?
3. What are the different types of tarsometatarsal dislocation patterns?
4. How can a lateral view be helpful?
5. What measurement is important?

Back 2

1. Forced plantar flexion of the forefoot.
2. Transverse metatarsal ligaments connect the bases of the second through fifth metatarsal bones, but this ligament does not exist between the first and second metatarsal bones. Instead, the base of the second metatarsal bone is attached to the medial cuneiform by an oblique ligament (Lisfranc's ligament). You can have avulsion fractures of the second metatarsal base at the enthesis of the ligament.
3.
HOMOLATERAL:
- lateral displacement of all 5 metatarsal bases.
PARTIAL INCONGRUITY:
- fracture of the 1st metatarsal base wtih displacement of the shaft medially and/or lateral displacement of the 2nd-5th metatarsals.
DIVERGENT:
- first metatarsal base displaces medially WITHOUT a fracture and the 2nd-5th MT displace laterally.
4. Because there is greater support on the plantar surface of the foot by the plantar ligaments and tendons, most Lisfranc dislocations occur dorsally which can be seen on the lateral view of the foot.
5. If displacement is greater than 2mm, then open reduction and internal fixation are required.

Front 3

1. What is the ddx of Lucent lesion in the calcaneus?
2. How do you differentiate a pseudocyst from a lipoma and solitary bone cyst?
3. What finding clinches the diagnosis of calcaneal lipoma?

Back 3

1. Intraosseous lipoma, simple bone cyst, and normal trabecular variation (pseudocyst). Note: chondroblastoma can occasionally present in the calcaneus as it is a epiphyseal equivalent.
2. A calcaneal pseudocyst is generally less prominent and less well defined than the other two kinds of lesions.
3. A central nidus of dystrophic calcification is nearly pathognomonic for intraosseous lipoma.

Front 4

1. How many plantar compartments are there, and why is it important to inspect all of them?
2. Does enhancement discriminate between edematous marrow and osteomyelitis?
3. What are radiographic features of osteomyelitis?

Back 4

1. Three main compartments—medial, intermediate, and lateral. An infection may be contained by the intermuscular septa and spread proximally.
2. The use of gadolinium improves delineation of soft-tissue inflammatory masses but does not distinguish osteomyelitis from edema. It is therefore important to identify concomitant abnormalities such as an abscess, sinus tract, or skin ulceration.
3. The radiographic features of osteomyelitis include osseous destruction, focal bone lysis, sclerosis, and periostitis, in addition to surrounding soft tissue swelling or ulceration.

Front 5

1. What is the ddx of fusiform shaped mass in kager's fat pad?
2. What kind of symptoms can an accessory soleus produce?

Back 5

1. Accessory soleus.
2. Patients present with a mass, soft-tissue swelling, or claudication.

Front 6

1. What are tendons in the lateral ankle compartment?
2. What accessory tendon can occasionally be present?
3. What is the relationship of the peroneus brevis to the peroneus longus?
4. What is the most common type of tear that affects the peroneal tendons?
5. Where are most tears located?

Back 6

1. Peroneus brevis and peroneus longus.
2. Peroneus quartus
3. Proximally, the peroneus brevis is located medial to the peroneus longus. Distally, the peroneus brevis is located anterior to the peroneus longus.
4. The majority of peroneal tendon tears are partial and oriented in the long axis of the tendon, splitting the tendon into two or more bundles.
5. Most tears are located distal to the fibular tip.

Front 7

1. What is the most common tendon to be injured in the medial aspect of the ankle? What sign does it produce on physical exam when it is disrupted?
2. What is the normal relationship of the PTT to the FDL?
3. What is the sequelae of injury to the PTT?
4. Who is most commonly affected?
5. What is the difference between os-tibiale externum and os naviculare?
6. Where does the PT tendon insert?
7. What are different types of PTT tears?

Back 7

1. Posterior tibialis tendon is the most frequently injured tendon in the medial aspect of the foot. Too many toes sign.
2. Normally, it is 2-3x as thick as the FDL.
3. Injury to the Spring ligament (calcaneonavicular ligament), progressive pes planus deformity, and weakened inversion.
4. Middle aged women.
5. Os tibiale externum is small, round ossicle separate from the navicular and is encompassed by the PT tendon. An accessory navicular is in continuity with the navicular by a synchondrosis, triangular in shape, and may be the site of insertion of the PT tendon.
6. Navicular, medial and intermediate cuneiform, and base of the 2-4 MT.
7.
- Type 1: longitudinal splitting of the tendon producing a thickened morphology owing to hemorrhage and fibrous tissue.
- Type 2: thinning or attenuation
- Type 3: complete tendon rupture with retraction and gap.

Front 8

1. What processes result in erosions of the calcaneus?
2. What are the common sites of involvement of Reactive and psoriatic arthritis in the foot.

Back 8

1.
- Seronegative spondyloarthropathies
- Retrocalcaneal bursitis
- RA
2.
- Calcaneus is a pimary target: fluffy periostitis at the at the enthesis of the plantar aponeurosis and Achilles' tendon. Poorly defined erosion can develop as well.
- MTP and IP joints are commonly affected demonstrating asymmetrical involvement with soft tissue swelling and fluffy periostitis.

Front 9

1. What is a triplane fracture?
2. Describe the physeal closure of the distal tibia.
3. How many fracture fragments are produced?
4. What is a Tillaux fracture?

Back 9

1. Fracture of the distal tibia that occurs in children.
- fracture of the lateral half of the distal tibial epiphysis in the the sagittal plane.
- fracture through the lateral aspect of the growth plate in the axial plane.
- fracture through the distal tibial metaphysis in the coronal oblique plane.
2. The distal tibial growth plate begins to close centrally, then medially, and finally laterally.
3. Depending on how much the medial growth plate has fused, you may get two or three fracture fragments. If there is no fusion of the medial growth plate, you will get 3 fracture fragments. If there is fusion of the medial growth, you will get 2 fracture fragments.
4. Tillaux fracture is a Salter type 3 fracture of the anterolateral tibial epiphysis which is avulsed by tension from the tibiofibular ligaments.

Front 10

1. What is the most common location for Achilles tendon rupture?
2. Does the Achilles tendon has a tendon sheath?
3. What muscles form the Achilles tendon?

Back 10

1. 2-6 cm above its insertion onto the calcaneus as it represents a vascular watershed area.
2. No. The Achilles tendon has a paratenon. NOTE: the patellar tendon also lacks a tendon sheath.
3. It forms from the union of the gastrocnemius and soleus muscles.

Front 11

1. What is Kohler's disease?
2. What are the radiographic findings of Kohler's disease?

Back 11

1. Idiopathic osteonecrosis of the tarsal navicular
2.
- fragmentation
- increased density
- flattening
- morphology of the bone may return to normal, or the deformity may persist throughout a patient's life.

Front 12

1. Talar neck fractures are at increased risk for what complication?
2. What classification system is used to classify talar neck fractures?
3. What is the Hawkins sign?

Back 12

1. AVN
2. Hawkins classification. The higher type, the greater the likelihood of AVN.
3. Subchondral lucidity in the talar dome from disuse osteoporosis, which indicates an intact vascular supply.

Front 13

1. What are the sites of stress fracture in the foot?
2. What is stress reaction?

Back 13

1.
- Second and third metatatarsals
- Calcaneus
- Talus
- Navicular: stress fxs occur in the sagittal plane and involve the middle and medial thirds of the bone.
- Cuneiforms: rare; cuneiform stress fractures are usually subchondral in location.
- Sesamoids
(note: cuboid is not in this list)
2. Stress reaction occurs before development of a fracture line. If the offending activity is continued, a stress reaction will progress to a stress fracture.

Front 14

1. What are some causes of plantar heel pain?
2. How many cords make up the plantar fascia and what cord is usually affected in acute plantar fasciitis?
3. What are the findings of acute plantar fasciitis?
4. What are the findings of chronic plantar fasciitis?

Back 14

1. Acute plantar fasciitis, tarsal tunnel syndrome, stress fractures, and plantar fascia rupture.
2. Medial, central, and lateral cords. The central cord is nearly always affected by plantar fascitis, but the lateral cord may be involved as well.
3.
- Marked thickening (typically a twofold to threefold increase) of the calcaneal attachment of the central cord of the plantar aponeurosis.
- Increased SI within the plantar fascia.
- Edema in the subcutaneous fat
4. The majority of patients with chronic plantar fasciitis enthesophytes will develop at the enthesis of the plantar fascia.

Front 15

1. What is the sinus tarsi?
2. What are the imaging findings of sinus tarsi syndrome?
3. What is the etiology?

Back 15

1. Funnel-shaped space between the talus and the calcaneus that is best seen on the lateral view (located posterior to the anterior process of the calcaneus).
2. Effacement of fat.
3. In nearly 75% of cases, this syndrome is caused by disruption of the interosseous and/or cervical ligaments. It is acquired during an inversion injury. It may also be seen with flatfoot deformity and inflammatory arthropathies.

Front 16

1. What is the tarsal tunnel?
2. What is tarsal tunnel syndrome?
3. What are some causes of tarsal tunnel syndrome?

Back 16

1. The tarsal tunnel is a space in the foot that contains the medial tendons of the ankle, the posterior tibial nerve, and the medial vascular structures.
2. Entrapment neuropathy of the posterior tibial nerve or one of its branches.
3. Trauma, neoplasms, ganglions or other cysts, varicose veins, muscle anomalies, taut flexor retinaculum, tenosynovitis, mass or hypertrophy of abductor hallucis muscle, and neuroarthropathy.

Front 17

1. What are the most common sites of coalition in the foot?
2. What types of coalition exist?
3. Which coalition is easier to see on radiographs?
4. What subtalar joint is more likely to undergo coalition?
5. What are the common radiographic features of coalition?
6. What findings are seen with fibrocartilaginous coalitions?

Back 17

1. Talocalcaneal (subtalar joints) and Calcaneonavicular.
2. Osseous, Cartilaginous, and Fibrous.
3. Calcaneonavicular coalition is easy to see on oblique radiographs of the foot.
4. Middle facet
5. Talar beaking and C-shape seen with talocalcaneal coalition; Anteater sign (seen with calcaneonavicular coalition)
6. Joint space narrowing wtih cortical irregularity.

NOTE: Coalition may be bilateral and at muliple sites in the same foot.

Front 18

1. Describe the findings of clubfoot?
2. How common is bilateral involvement?
3. What is risk of clubfoot if there is history of clubfoot in a first degree relative?
4. What is the relationship between forefoot and hindfoot abnormalities in congenital foot diseases?

Back 18

1. The findings of clubfoot include:
- hind foot varus
- forefoot varus
- hind foot equinovarus
- inversion
2. 50%
3. There is 30x increased risk.
4. In congenital foot diseases, forefoot and hindfoot abnormalities go together (i.e. if there is hindfoot valgus, there will be forefoot valgus). If hindfoot and forefoot are in opposite direction, then it is a spastic foot.

Front 19

How can you determine forefoot varus/valgus abnormality on a foot radiograph?

Back 19

On the AP view, draw a line through the midtalus, it should pass through the base of the first metatarsal.

In forefoot varus, the line passes LATERAL to the 1st metatarsal.
In forefoot valgus, the line passes MEDIAL to the 1st metatarsal.

Front 20

What are the imaging findings in hindfoot varus/valgus?

Back 20

The talocalcaneal angle is important to determine hindfoot varus/valgus.
Normally on an AP view, the talocalcaneal angle is 20-40 degrees. Normally on a lateral view, the talocalcaneal angle is 25-50 degrees.
In hindfoot varus, the TC angle on both AP and lateral views is less than 20 (usually around 10).
In hindfoot valgus, the TC angle is greater than 40 degrees.

Front 21

What are the imaging findings in hindfoot equinus?

Back 21

- Normally, the tibio-calcaneal angle is between 60-90 degrees.
- In clubfoot, the tibio-calcaneal angle is greater than 90 degrees.

Front 22

How do you determine if the foot is in inversion or eversion on a radiograph?

Back 22

In inversion, the base of the metatarsals converge.
In eversion, the base of the metatarsals converge.

Front 23

Subtalar dislocation

Back 23

Refers to simultaneous dislocation of the talocalcaneal and talonavicular joints.
The ligamentous support around the talus (talocalcaneal and talonavicular ligaments) is weaker than the calcaneonavicular and ankle ligaments so the entire mid foot and calcaneus may dislocate as a single unit.

Front 24

Congenital vertical talus

Back 24

- hind foot vagus (talocalcaneal angle > 40 on the ap view, >50 on the lateral view.
- forefoot valgus

Front 25

1. What are the abnormalities that can be seen in the sesamoid bone?
2. Describe the anatomy in the region of the sesamoid bones.
3. What is turf toe?
4. Which is more common: stress or post-traumatic fx of the sesamoids?

Back 25

1.
- Post-traumatic sesamoid fracture (turf toe)
- Stress fracture
- Sesamoiditis
- Osteonecrosis
- OSM
- Arthritis
- Bursitis
2. The medial and lateral sesamoid bones are located in the medial and lateral heads of the flexor hallucis brevis which attaches to the plantar capsule of the proximal phalanx of the great toe.
3. Turf toe refers to post-traumatic fracture 2/2 force applied to a dorsiflexed great toe resulting in a transverse fx of the sesamoid.
4. Stress fractures of the sesamoid are more common than traumatic fractures. Stress fx is more common in the medial sesamoid, whereas traumatic fractures are more common in the lateral sesamoid.

Front 26

Fracture-dislocations in the foot

Back 26

a Lisfranc fracture-dislocation is a Tarsometatarsal dislocation
A Chopart fracture-dislocation involves the hindfoot-midfoot joint, i.e., tarsonavicular and calcaneocuboid joints

Front 27

Erosive arthropathy involving the foot

Back 27

RA
- bilateral symmetric distribution
- unifrom joint space narrowing, periarticular osteopenia, marginal erosions, and joint subluxation.
- **lateral aspect of the 5th MT is the earliest site involved.
- retrocalcaneal bursitis with erosions and Achilles tendinitis
GOUT
- **punched out lytic lesions with sclerotic borders and overhanging edges.
- soft tissue tophi
- normal bone mineralization
REACTIVE ARTHRITIS
- uniform joint space narrowing, marginal erosions, and adjacent bone proliferation.
- ankylosis with chronic disease (not as frequent as psoriatic arthritis)
- **fluffy periostitis and erosions along the posterosuperior aspect of the calcaneus.
INFECTION
- usually monoarticular.
PSORIATIC ARTHRITIS
- proliferative erosions
- sausage digits
- *Ankylosis occurs frequently
- *fluffy periostitis and erosions along the posterosuperior aspect of the calcaneus.

Front 28

Jones vs. Pseudo-Jones fractures

Back 28

Pseudo-Jones fracture
- avulsion fracture occuring at the base of the 5th MT.
- involves the joint surface.
- surgery is not required.

Jones Fx
- occurs ~1.5 cm from base of the 5th MT.
- Does not involve the articular surface.
- High rate of non-union, therefore, surgery is usually required.