Foot/Ankle/Tibia Flashcards
What is the most common long bone fracture?
Tibia
What are the two types of tibia fractures?
How do they differ in …
mechanism of injury
fracture type
level of associated fibular fractures?
What are common complications of tibia fractures?
How do patients with tibia fx present?
1. Low energy
mechanism: torsion (knee in opposite direction of ankle - or fixed ankle
fracture: spiral
fibula fx: different level
2. High energy
mechanism: direct force
fracture: wedge
fibula fx: same level
Complications:
compartment syndrome
open fractures and bone loss
soft tissue injury
Presentation:
pain
deformity
inability to bear weight
Describe the following types of fractures that can occur in long bones
transverse
open/compound
oblique/oblique displaced
comminuted
segmental
avulsed
spiral
greenstick
Open/compound - innards are open to the world
comminuted - fucked
segmental - multiple fractures cause a segment separate from the rest of the bone
oblique - diagonal in one plane
spiral - torsional element, diagonal but multiple planes
avulsed - tendon or ligament is pulled and takes bony attachment with it (commonly periarticular)
greenstick - incomplete fracture typically in peds or immature bone like a new stick is hard to crack
What imaging should be ordered when assessing a tibial shaft fracture?
What special circumstances would require a CT?
Radiograph
AP and lateral or entire bone
AND knee/ankle
CT
IF intra-articular extension is noted
(on X-ray - I think why X-ray of knee/ankle required)
What criteria should the patient meet to qualify for non-operative treatment of a tibial shaft fracture?
What parameters are used to determine alignment of a fracture?
What is the non-operative treatment of a tibial shaft fx?
1. Low energy injury
2. Acceptable alignment
<5 degree angulation
>50% cortical apposition (touching)
<1 cm shortening
<10 degree rotational malalignment
Long leg cast for 6-8 weeks
would not want a cast on a soft tissue injury or open fracture - could impede healing or cause infection
What indications would cause you to treat a tibial shaft fracture with external fixation?
What indications would lead to either intramedullary (IM) nailing or open reduction internal fixation (ORIF) to treat a tibial shaft fracture?
How would you choose between the latter two and what complications accompany them?
External Fixation
- damage control: temporary fix while you tend to more life threatening issues
- open fractures: non-op would not work here because cast would impede healing of soft tissue injuries
Intramedullary Nailing and ORIF
- unacceptable alignment
- soft tissue injury
- segmental or comminuted fractures
- multiple traumas
Choosing between IM nailing and ORIF
- often surgeons preference
ORIF risks
higher risk of non-union and infection
How many tibial fractures result in compartment syndrome?
Describe compartment syndrome again. C’mon do it, it’ll be fun.
What muscle perfusion pressure (deltaP) is considered critical? What the heck is muscle perfusion pressure?
What is the treatment of compartment syndrome?
2.7-15% of tibial fx result in compartment syndrome
Compartment syndrome - osseofascial pressure rises resulting in reduced perfusion and muscular necrosis
Muscle perfusion pressure (deltaP) <30mmHg is critical.
Muscle perfusion pressure is the difference between diastolic blood pressure and compartment pressure.
Surgical emergency - tx with emergent fasciotomy
What is a tibial plafond (pilon) fracture?
What mechanism of injury typically causes this?
Plafond fracture - distal tibia extending into ankle joint
Typically high energy/axial loading
examples: motor vehicle crash (MVC) or fall from height
Complications:
articular impaction
metaphyseal comminution
extensive soft tissue damage
compartment syndrome
Presentation:
pain
inability to bear weight
deformity
What are the 3 treatment options for a tibial plafond/pilon fracture?
In what scenario?
Risks and benefits?
Non-operative
- long leg cast (not if soft tissue injury)
- stable no skin problems
- concerns for malreduction/skin problems
Temporizing spanning External Fixation
- external pins in tibia, calcaneus, and first metatarsal holding in dorsiflexion
- soft tissue or skin concerns
- allows access to skin
- CT after fixation
- leave in placed for 10 to 14 days
ORIF
- definitive fixation with periarticular plates and screws
- still risk of infection and wound slough
Ankle fractures account for what percentage of ankle injuries?
What is the age distribution of these patients?
What mechanisms of injury (MOI) can cause this?
Describe the Ottawa Ankle Rules and how this is used to determine if the pt is appropriate for X-ray.
15% of ankle injuries are fractures.
Bimodal distribution - basically young and dumb, and old and fragile
Usually inversion but can also be version
Ottawa Ankle rules
IF pain in malleolar region AND
one of the following: bony tenderness of the posterior edge of 1) medial OR 2) lateral malleolus OR 3) unable to bear weight immediately following AND in ER
Ottawa Foot rules
IF pain in midfoot AND
one of the following: bony tenderness at 1) the base of the fifth metatarsal OR 2) the navicular OR 3) unable to bear weight immediately AND in ER
What other imaging technique could be used prior to X-rays that increase specificity to 100% per SOFAR.
What radiographic studies should be ordered in every X-ray evaluating an ankle fracture?
What is a Maissoneuve type fracture? What special image should be ordered when concerned for this?
What should be ordered if concerned for syndesmotic injury? What findings are you looking for?
SOFAR (Sonographic Ottawa Foot and Ankle Rules)
US showing cortical disruption of the fibula is more specific
Always xray
AP/lateral/oblique
Maissoneuve type - involving ligamentous disruption of the ankle AND proximal fibular fracture
Order full length tibia/fibula
Syndesmotic injury - involving the compound ligament between the tibia and fibula
Order external rotation stress
clear space between tibia and fibula should be <5 mm
When treating ankle fractures who is eligible for non-operative treatment?
Who will recieve surgical treatment? What is it? What warnings need to accompany this surgery?
Non-operative
- nondisplaced medial malleolar fx
- lateral malleolar fx <3mm displaced
- not surgical candidate
ORIF
- displaced
- bimalleolar
- open fx
ORIF warnings:
up to 2 years to completely recover
no driving until 6 weeks after weight bearing
What other bones does the talus articulate with?
Describe the 3 arteries that supply the talus. Why is the dome prone to avascular necrosis?
What mechanisms typically cause talar neck fractures?
Articulates with:
- *tibia/fibula** at the ankle joint
- *calcaneus** at the subtalar joint
Arterial supply:
- *Posterior tibial** (deltoid) *
- *Anterior** tibial
- *Peroneal** artery
Prone to necrosis due to water shed area between the anterior and posterior tibial vascular supply.
Mechanism:
high energy
forced dorsiflexion with an axial load
What images are ordered when assessing talar neck fractures?
What classification system is used to assess risk of avascular necrosis?
Radiographs:
AP/lateral/”Canale” view (15degree eversion of the foot with a 75degree ankle of X-ray)
CT- more common in these to assess for displacement
Hawkins Classification
I - nondisplaced - 0 to 13% risk AVN
II - subtalar dislocation - 20 to 50% risk AVN
III - subtalar and tibiotalar dislocation - 20 to 50% risk AVN
IV - subtalar, tibiotalar, and talonavicular dislocation - 70-100% risk AVN
What is the treatment plan for non-displaced talar neck fractures?
What is the treatment plan for displaced talar neck fractures?
What positive radiographic finding is indicative that avascular necrosis of the talar dome has been avoided? Explain.
Non-displaced fractures
non-operative treatment with short leg cast for 8-12 weeks
non-weight bearing for 6 weeks
Displaced fractures
emergent reduction in ER
ORIF
Avascular necrosis:
- Positive Hawkins sign means intact vasculature
- subchondral lucency at 6 weeks
- shows that the bone is alive, although this seems counterintuitive - pt has been off feet for 6 weeks so likely some diminishing - if bright and dense that would be alarming
What anatomical structures are important when considering calcaneus fractures?
What mechanisms typically cause this injury?
What imaging should be ordered and what radiographic finding should be assessed?
What is the treatment?
Why is the complication rate high with these injuries?
Anatomy:
posterior, middle, and anterior facets (articulate with talus)
sinus tarsi
sustentaculum tali
Mechanism:
high energy
axial load
MVC or fall from height
Intra articular fractures
Imaging:
AP/lateral/oblique radiographs
Bohler angle (formed by anterior/middle/and posterior facets) should be 20-40degrees
Treatment:
ORIF
wait 10-14 days for swelling to subside
Complications:
skin is often involved
What are the 3 locations (zones) of fractures of the fifth metatarsal?
What are the treatments?
Complications?
What common complications are associated with Zone 2 Fractures?
Zones:
1 Avulsion - lateral tuberosity (good blood supply and healing)
2 Jones - metadiaphyseal junction (watershed area with poor healing)
3 Stress Fracture - proximal diaphyseal (better than jones but still kind of poor healing)
Zone 1 Treatment
protected weight bearing and activity as tolerated
Zone 2 and 3 Treatment
- short leg cast for 6 to 8 weeks with no weight bearing
-intramedullary screw if need to return to activity or if delayed/nonunion
Common Complications of Zone 2
nonunion at about 30%
refracture at about 33%
What is a Jones fracture?
What is the common mechanisms?
What populations are common?
Fracture of meta-diaphyseal junction with watershed blood supply making this concerning
Mechanisms commonly inversion and stress injury related - often building for weeks to months
Military, Laborers, athletes
What is Chronic Exertional Compartment Syndrome (CECS)?
Whos is this most common in and where does this most commonly occur?
What is the presentation typically?
What is the work up generally?
What is the diagnostic criteria?
Treatment?
CECS - reversible ischemia to muscles in a fascial compartment that is exercise induced
Most common in runners in the anterior compartment of the leg
Presentation: burning pain in legs following activity that improves with rest
Work up
- Usually a bunch of normal imaging to r/o other pathology
- Serially test compartment pressure (before, immediately after exercise, 5 minutes later)
Diagnostic:
Resting pressure over 15 mmHg
Immediate >30 mmHg and/or
5 minutes later >20mmHg
Treatment:
initially non-op: rest, NSAIDs
if not effective after 3 months: compartment release
Describe Tibial Stress syndrome.
What causes this?
What are common risk factors?
What are other differential diagnoses that could cause similar presentation?
What is the treatment?
Tibial stress syndrome (shin splints)
overuse injury characterized by pain at the distal medial aspect of tibia
can be anterior or medial (posterior)
Caused by: traction periostitis
pulling of compartment forming fascia on the periosteum
Risk Factors:
runners with bad shoes
training errors
hill training
over pronation
Differentials:
stress fractures
chronic exertional compartment syndrome
nerve or popliteal artery entrapment
lumbar radiculopathy
Treatment
reduce activity by 50%
change shoes
physical therapy
What are tibial stress fractures?
Describe the standard progression of this.
What imaging is involved in the evaluation or this and what findings would you expect?
What is the treatment?
Tibial stress fractures: overuse injury due to propagation of micro fractures due to repetitive loading with no time to heal
Often starts as tibial stress syndrome (shin splints)
Evaluation:
X-rays - AP and lateral tibia and fibula (find black line)
MRI - showing bone marrow edema
Treatment:
activity modification
bone stimulator
intramedullary tibial nail (if violates anterior cortex)
NO NSAIDs - could impede bone healing
List the 2 ligaments that stabilize the medial ankle.
The 4 that stabilize the syndesmosis.
And the 4 that stabilize the lateral ankle.
_Medial:_ deltoid ligament calcaneonavicular ligament (spring ligament)
Syndesmosis:
Anterior Inferior Tibiofibular Ligament (AITFL)
Posterior Inferior Tibiofibular Ligament (PITFL)
Transverse Tibiofibular Ligament (TTFL)
Interosseous Membrane
Lateral:
Anterior Talofibular Ligament (ATFL)
Posterior Talofibular Ligament (PTFL)
Calcaneofibular Ligament (CFL)
Lateral Talocalcaneal Ligament (LTCL)
What are accessory ossicles?
What are sesamoids?
What are the top 4 ossicles and sesamoids found in the feet?
Accessory ossicles - secondary ossification centers remain separate from rest of bone
Sesamoids - bone inside tendons
- Hallux sesamoids (100%)
- Os trigonum (10-25%)
- Os peroneum (9-20%)
- Accessory Navicular (2-12%)
What are the top 3 most common injuries of the lateral ankle sprain?
What are common risk factors to lateral ankle sprains?
How do these present?
Imaging?
- anterolateral joint capsule
- Anterior talofibular ligament (ATFL)
- Calcaneal fibular ligament (CFL)
Risk factors:
limited dorsiflexion
problems with balance
indoor-court sports
previous ankle injuries
Presentation
pain, swelling, and ecchymosis
Physical exam findings
Positive anterior drawer test
To image or not to image - ask Ottawa (pick 2)
1. Pain in malleolar zone
2. PLUS one of the following
A. Bony tenderness to posterior edge of medial mall.
B. Bony tenderness to posterior edge of lateral mall.
C. Unable to bear weight immediately and in ER
What is the normal range of motion at distal tibia-fibula joint with ankle dorsiflexion?
What mechanism of injury results in syndesmotic ankle injuries?
What physical exam tests should you perform? How reliable are these?
What imaging should be ordered?
Normal:
1.5 mm inter malleolar
15degrees rotation
2.4 mm distal migration of fibula
Mechanism:
internal rotation or tibia on fixed foot
(or external rotation of foot?)
Physical exam:
Squeeze test or External Rotation stress test
(both unreliable)
Imaging:
radiographs show widening over 6mm
MRI for subtle injuries (neg X-ray but positive physical)
What are the treatment options for a syndesmotic ankle injury?
Non-operative: RICE
Surgical fixation with obvious diastasis or big athletes
Screw versus suture buttons (tight rope)
What is the average recovery time for each grade of low level ankle sprains and high level ankle sprains treated with immobilization versus screw fixation?
Describe the locations of tarsometatarsal ligaments, intermetatarsal ligaments, and Lisfranc ligament?
What maintains stability of the 1st/2nd metatarsals and cuneiforms?
- *Tarsometatarsal** - between the metatarsals and cuneiforms/cuboids
- *Intermetatarsals** - between 2-5 metatarsals
- *Lisfranc** - between medial cuneiform and the 2nd metatarsal because there is no intermetatarsal between 1 and 2
Stability maintained by:
- Recessed 2nd metatarsal
- Arch configuration of midfoot
- Lisfranc ligament
What are mechanisms of injury that can cause a Lisfranc injury?
What injuries can occur?
What imaging should be ordered?
What are 3 findings you would expect to find on imaging?
Mechanisms:
axial load
twisting on plantarflexed foot
Injuries from sprains to dislocated fractures
Imaging
AP WEIGHT BEARING
oblique
lateral views
CT/MRI to confirm
Radiological findings:
- Medial 2nd MT and medial 2nd cuneiform
- 1 to 2 MT widening
- Fleck sign (avulsion of base of 2nd metatarsal)
What is turf toe?
What radiologic findings would you expect?
What is the treatment?
Turf toe: hyper extension of plantar plate of 1st MTP joint
X-rays may be normal but MRI will show disruption of the MTP joint space
Treatment:
initial immobilization (splint/rigid shoe)
week or 2 later early mobilization
NO INJECTIONS AND SURGERY IS RARE
What functions do sesamoid bones perform?
What disorders can occur?
What imaging can be used to confirm diagnosis?
What are the recommended treatments?
Functions:
absorb weight bearing pressure - protect FHL
fulcrum for FHB - increasing MTP flexion power
Disorders:
fracture
sesamoiditis
Avascular necrosis
osteoarthritis
~bipartite sesamoid~
Imaging:
radiographs and MRI
Treatment:
modify shoes or add pads
NSAIDS
PT
injections
boot immobilization if necessary
sesamoidectomy
What mechanism is the most likely to result in a ruptured Achilles’ tendon?
What is the specific location this is most likely to occur and why?
What physical exam test should be performed?
Treatments?
Mechanism: sharp dorsiflexion onto a tensioned tendon
More common at watershed area 4-6 cm from insertion
Thompson test
Nonoperative currently preferred
operative results in lower rerupture but higher complications
What is plantar fasciitis?
How does this present?
Risk factors?
Exam findings?
Treatment?
Inflammation at the plantar aponeurosis at its insertion at the calcaneus
Presentation: posteromedial heel pain worst with first step in the morning because sleeping in plantarflexion tightens the fascia
Risk factors:
obesity
decreased ankle dorsiflexion
endurance activities
Exam findings:
TTP at plantar fascia insertion
Treatment:
Pain control, splinting, stretching
surgical release if not better in 9 months
What is the common name for hallux valgus?
What is this?
What is the driving force?
Bunions
Deformity of the great toe resulting in progressive shifting
Adductor hallucis is the deforming force
What angles are important to look for on radiographs when assessing hallux valgus?
What is the treatment?
Hallux valgus angle (HVA) - between 1st MT and proximal phalanx
Intermetatarsal angle (IMA) - between 1st and 2nd MT
Treatments
mild - shoe modification
surgical correction - depends on severity
