Lower Extremity Fractures

FOOT

Lis-Franc Injury
= disruption of the tarsal-metatarsal (TMT) joint with or without associated fracture. The Lisfranc ligament is a major stabilizer of the TMT joint
= unstable fracture
-causes midfoot instability (may be noticeable on exam)
-may damage a branch of the dorsal pedis artery which crosses the base of the first and second metatarsal
-a fracture at the base of the second metatarsal is highly suspicious for a Lisfranc mechanism injury
-look for widening of the space between the first & second metatarsals and between the first & second cuneiform bones, look for dorsal displacement of the metatarsals on lateral view (may be only finding)
-if unsure, consider a weightbearing film, a comparison view of the other foot, or a CT scan
-consult ortho ASAP for internal fixation + NWB cast

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Base of 5th metatarsal fracture
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– <1.5cm of the styloid process = “avulsion” (pseudo-Jones) fractures
—Extra-articular tuberosity fractures will heal well requiring a walking cast or stiff shoe for approximately 2-3 weeks. Nondisplaced intraarticular fractures are treated with non-weight-bearing casting for 6-8 weeks with orthopedic evaluation one week from the ED visit. If the articular surface involved in tuberosity fractures is greater than 30% or displaced >2mm, fixation may be necessary and orthopedics should be involved early.
– >1.5cm from the end of the styloid = “metatarsal” (Jones) fractures
—consult ortho in ED

Other midfoot fractures:
-navicular: obtain reverse oblique view (tuberosity may otherwise not be visualized)
—3 types; err on managing as NWB with close ortho f/u
—if displaced >20′, consult ortho in ED – may require early OR for high risk of avascular necrosis
-fx of (distal) 5th metatarsal shaft or neck (Dancer’s fx): inversion injury
—NWB splint with routine ortho f/u unless sig displaced (then consult for ORIF as outpt)
-fxs of 3rd, 4th, 5th distal metatarsals: twist or direct force injury
—NWB splint with routine ortho f/u unless sig displaced (then consult for ORIF as outpt)

NWB stress fractures: stress fractures of the navicular, 5th metatarsal, and femoral neck. These bones have avascular centers and healing may be prolonged, so immobilization and non-weight bearing status is recommended. Stress fractures are not visible on xray until 4-6 weeks after injury, so have a high index of suspicion and f/u with ortho as outpt for MRI or bone scan

ANKLE

Calcaneus fracture:
-Bohler’s angle is formed by intersecting two lines. One is drawn from the most cephalic portion of the tuberosity (red dot) to the highest point of the posterior facet (white dot). The other line is drawn from the highest point of the posterior facet (white dot) to the most cephalic part of the anterior process (blue dot). Loss of normal angle is abnormal.
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-Normal can range from 20°- 40°, so a comparison view of the unaffected side may be helpful.
-also may see linear areas of sclerosis across trabecular lines (may be only indication of fracture)
-Management of calcaneus fractures should be decided in consultation with orthopedics because there is little true consensus on management. In general, extraarticular fractures can be managed closed, while management of intraarticular fractures varies. CT scanning is often required to aid the orthopedist’s decision. Any patient discharged from the ED with calcaneus fracture should be immobilized, non-weightbearing, and have orthopedics follow-up.

LEG

Tibial plateau fracture:
-exam should assess for associated ligamentous instability (60%), compartment syndrome, and peroneal nerve injury (foot drop, paresthesias, positive Tinel’s test over fibular head)
-obtain CT to help orthopods determine need for surgery. Indications for surgery include articular surface depression, axial malalignment, >10 degrees ligamentous instability when the knee flexed to 20 degrees
-may also see a small avulsion fracture of the lateral tibia condyle just below the joint line (Segond Fracture)
—high association of Segond fracture with anterior cruciate ligament (75%-100%) and meniscal tears (67%)
—exam reveals a painful, swollen, ecchymotic knee with limited range of motion and effusion. If the patient’s pain is controlled, classic signs of ACL or meniscal tears may be elicited

KNEE

Patellar fracture:
-usu from falling directly onto the patella (comminuted, damage to articular cartilage). The patella can also fracture from a jumping injury when the knee rapidly flexes against a fully contracted quadriceps (less comminuted and more likely to be transverse and displaced)
straight leg test – determine if the extensor mechanism of the knee is intact. Lying supine, the patient elevates the leg, keeping the knee straight. If the knee cannot remain extended, the extensor mechanism has been disrupted
-sunrise view – visualization of subtle fractures, provides the best view of the articular surface.
-Indications for surgery include: disruption of the extensor mechanism, displaced (>3mm) transverse fractures, skin compromise
-non-op pts: NWB with knee immobilizer or above-knee cast with the knee in full extension

Knee dislocation:
-look for popliteal artery injury (approximately 20%). About 50% of these injuries reportedly reduce spontaneously prior to presenting to the ED, so extra caution must be taken not to miss the diagnosis in these patients because the vascular injury risk is still present.
-check for pulse deficits and arterial pressure indices. A vascular exam should be performed before and after reduction attempts.
—typically reduced under conscious sedation by traction-countertraction
—angiogram if vascular deficit present
-check for gross instability in more than one direction which may be the only finding in a reduced injury. Other findings reported to be suspicious for a reduced knee dislocation are large posterior ecchymosis and ACL tear with large effusion
-if portable and have high suspicion, obtain lateral view

Patellar dislocation:
-usu rotational injury
-if presents dislocated, relocate quickly. Neurovascular exam before and after
-reduction: patient is positioned supine with the hip flexed 90 degrees. The physician extends the knee while simultaneously pushing the patella back medially, lifting it over the femoral condyle if necessary. This can usually be done swiftly and quickly without supplemental medication. The patient is then placed in a knee immobilizer and made NWB
-obtain xray after reduction – AP/lateral/sunrise views of the patella should be obtained, even in those that reduced spontaneously. Osteochondral fractures on the medial aspect of patella are common, occurring in up to 40% of patella dislocations

Patellar fracture:
-findings: swelling, cephalad* subluxation of patella, avulsion fracture
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unable to actively extend their knee. You can often palpate or visualize a high riding patella
-knee immoblizer, NWB, early ortho f/u for surgical repair
*vs low riding patella as seen with quadriceps tendon rupture

Fibular head fracture:
-Isolated proximal fibular fractures are uncommon and are most often associated with other injuries, such as tibia fractures, lateral collateral ligament (LCL) tears or medial ankle injuries (Maisonneuve fractures)
assess the peroneal nerve by checking ankle dorsiflexion and plantarflexion and lateral leg sensation. Medial ankle tenderness would suggest a Maisonneuve fracture. These patients will often be able to ambulate since the fibula bears little weight (only if isolated)

FEMUR

Femoral shaft fracture:
= orthopedic emergency. From high-energy forces, associated with multisystem trauma. Up to 40% of isolated femoral shaft injuries will require transfusion due to bleeding into the thigh
–look for neurovasc injury and other trauma
–watch out for respiratory compromise: DVT/PE, fat emboli
-Patients often arrive immobilized in traction devices, which should be removed while maintaining immobilization of the limb
-need traction until OR, however it is relatively contraindicated in the setting of open fractures or sciatic nerve injuries. Give abx and Tdap

HIP

Hip fractures:
-usu ring structures like the pelvix fractures in multiple areas, however an exception is low velocity falls in the elderly, in which pubic ramus fractures often occur in isolation
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  • illiopubic lines (purple line)
  • illioischial lines (brown line)
  • acetabulum (black arrow)
  • pelvic inlet (blue oval)
  • obturator foramina (green circle)
  • sacroiliac joints (yellow arrows)
  • pubic symphysis (red arrow)

Widening of SI joints > 4mm is abnormal (black arrow). Symphyseal widening > 5mm is abnormal (blue arrow).
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Hip dislocation:
-either high-energy mechanism (knee vs dashboard in MVC) in pts with native hips or minimal or no trauma in pts with prosthetic hips (weak ligaments & musculature)
—if pt is prosthetic hip suddenly has pain and is unable to bear weight, suspect dislocation
-usu posterior
-leg is shortened, internally rotated, slightly flexed at the hip, and adducted
-look for sciatic nerve injury – weakness with dorsiflexion and plantar flexion, loss of ankle deep tendon reflexes, and decreased sensation of the posterior leg and foot
-in trauma pts, obtain CT scan to screen for associated acetabular and other pelvic fractures
-reduce native hips within 6h to prevent avascular necrosis. Need procedural sedation; do not try more than 3x (further attempts increase risk of avascular necrosis)
-reducing prosthetic hips is not an emergency (no risk of avascular necrosis)

Acetabular fracture
-disruption of the iliopectinal line
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-usu high mechanism trauma, except in elderly
-soft tissue over the greater trochanter should be examined for damage which may represent a closed degloving injury (Morel Lavallee lesion), which is a contraindication to surgery
-eval sciatic nerve; look for other traumatic injuries
-call ortho in ED to determine management

Femoral neck fracture
-if displaced, shortened and externally rotated
-some pts may still bear weight on a nondisplaced fracture
-some may not be visualized on plain films – if pt in severe pain and unable to walk (high suspicion), obtain CT or MRI
-femoral head is essentially avascular from displaced fractures and will be subject to subsequent avascular necrosis and collapse without replacement

Intertrochanteric fracture
-extracapsular hip fracture of the proximal femur. The fracture line extends between the greater and lesser trochanters
-elderly pts who fall: direct axial loading of the femur with a rotational component
-leg is shortened and extremely externally rotated
-look for associated injuries and bleeding into thigh (no risk of avascular necrosis of femoral head)
-OR within 48h to prevent mortality
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Pubic Rami fractures

-elderly may have isolated pubic rami fractures (considered stable fractures) from minor fall – pain control, encouraged to bear weight
-if the fracture is near the acetabulum, obtain Judet views help to rule out acetabular involvement. Judet views are images obtained by log rolling the patient 45° to each side
-pubic rami fractures can also be occult – if high suspicion, obtain CT or MRI
-if both rami are fractured on the same side and/or the fracture fragments are significantly displaced, order CT scan to better characterize injuries
-dispo is home if pain is controlled enough to ambulate vs rehab

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