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 mechanisms typically cause metatarsal fractures?
What is the non-operative treatment and who qualifies for this?
What is the surgical treatment and when is this recommended?
Mechanisms:
Direct crush
Indirect twisting
Stress fractures (metabolic disorders, 2nd and 5th most common, also common in ballet dancers)
Non-operative Treatment - for nondisplaced
Stiff soled (post op) shoe
weight bearing as tolerated
Surgery
displaced 1st metatarsal
severely displaced central metatarsals
pins and plates
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)
Which lateral ligament is most commonly injured? What physical exam would confirm this?
Which lateral ligament is the strongest?
Which ligaments resist inversion in plantarflexion versus in neutral position?
What is the second most common lateral ankle sprain?
Anterior talofibular ligament is injured in 85% of ankle sprains. Anterior drawer test would confirm this.
The posterior talofibular ligament is the strongest
The anterior talofibular ligament and the Calcaneal fibular ligament both resist inversion, but the ATFL resists in plantarflexion while the CFL resists in neutral position.
CFL is the second most common sprain at 20-40% on lateral ankle sprains
