MSK: Trauma and Overuse, Foot Flashcards
Next step:
Lumbar spine radiographs (to look for a T12-L2 burst fracture)
Note: Bilateral calcaneal fractures tend to occur in the setting of severe axial loading (e.g. jump out the window, which is why these are called Casanova fractures).
Casanova fracture (calcaneal fracture due to axial loading)
What tendons often become entrapped within this type of fracture?
Peroneal tendons
What is the most common tarsal bone fracture?
Calcaneus (60%)
What are the two major types of calcaneal fracture?
- Extra-articular
- Intra-articular
Note: This depends on whether the subtler joint is involved.
How can you check for an occult calcaneal fracture on radiographs?
Measure Bohler’s angle
Note: If less than 20 degrees, this is suspicious for an occult calcaneal fracture.
What is the normal Bohler’s angle?
20-40
Note: Less than 20 is suspicious for an occult calcaneal fracture.
What is the normal range for this angle?
The critical angle of Gissane is normally 100-130 degrees
Note: This can be used to evaluate the severity of a calcaneal fracture. Intra-articular fractures will have a fracture line extending through this Gissane angle.
5th metatarsal stress fracture
Note: These are high risk (hard to heal).
Jones fracture (base of the 5th metatarsal fracture)
Note: These are at high risk for non-union (treated with non-weight bearing cast or internal fixation).
Jones fracture (base of the 5th metatarsal fracture)
Note: These are at high risk for non-union (treated with non-weight bearing cast or internal fixation).
Normal 5th metatarsal apophysis
Note: Do not confuse this with an avulsion fracture (which should be more transverse and less longitudinal).
Avulsion fracture of the 5th metatarsal (AKA dancers fracture)
Avulsion fractures of the 5th metatarsal are commonly seen in what pt population?
Dancers (AKA dancers fracture)
Os peroneus (an accessory ossicle)
Note: This is seen in approximately 10% of the general population.
What structure is this accessory ossicle located in?
The os peroneus is located within the peroneus longus tendon
Painful Os Peroneus Syndrome (POPS)
Note: Progressive retraction of an os peroneus over time indicates repetitive injury to the peroneus longus tendon (POPS).
Painful Os Peroneus Syndrome (POPS)
Note: Edema surrounding an os peroneus just proximal to the peroneus longus tendon enters the cuboid tunnel.
What is the most common dislocation in the foot?
A lisfranc injury
What is the Lisfranc joint?
The combined tarso-metatarsal joints of the foot
Note: This joint is recessed at the 2nd digit, creating a “keystone” (arrow) locking mechanism.
What does the lisfranc ligament connect?
The medial cuneiform and the 2nd metatarsal base
Note: You can easily perform a forefoot amputation by cutting this ligament.
What radiographic view is needed to exclude a Lisfranc injury?
Weight-bearing foot radiographs
Note: You cannot exclude Lisfranc injury on non-weightbearing radiographs.
Lisfranc fracture-dislocation
Lisfranc fracture-dislocation
Lisfranc injury
Note: This is the “fleck sign” (a small bony fragment in the Lisfranc space representing avulsion fracture of the Lisfranc ligament from the 2nd metatarsal base).
What is the usual mechanism of injury in the Lisfranc fracture-dislocation?
Axial loading while in extreme ankle plantarflexion
What are the major types of Lisfranc fracture-dislocation?
- Homolateral
- Divergent
Lisfranc fracture-dislocation (homolateral)
Lisfranc fracture-dislocation (divergent)
What is the largest tendon in the body?
The Achilles tendon (fused tendons of the gastrocnemius and soles muscles)
Achilles tenosynovitis?
No, the achilles tendon does not have a tendon sheath so it cannot have tenosynovitis
Note: If there is inflammation around the tendon, call it “paratendinitis.”
Tibialis anterior (extensor tibialis) tendon
Tibialis posterior tendon
Note: This is Tom in Tom, Dick, and Harry (medial to lateral).
Flexor digitorum longus tendon
Note: This is Dick in Tom, Dick, and Harry (medial to lateral).
Flexor hallucis longus tendon
Note: This is Harry in Tom, Dick, and Harry (medial to lateral).