Commonly Missed Orthopedic Injuries: Lower Extremity

Authored by: Blake Bauer, MD

• Missed orthopedic injuries account for 8% of all litigated cases from emergency department visits (Brown, 2010)
  • 28-36% of the time, decision is if favor of plaintiff
  • Not just emergency physicians, includes all specialties sued secondary to patient’s emergency department visit
  • EM physicians 19% off the study data
• When evaluating all litigated cases against emergency medicine physicians specifically, it is suggested orthopedic injuries account for 19% of litigated cases (Kachalla, 2007)
  • 96% of cases could be attributed to not ordering the right plain film, or incorrect interpretation
• As 3rd year residents are getting ready to depart on their own to community ED’s where orthopedics rarely comes into the hospital, it’s important to know what subtle fractures are frequently missed, both for patients’ and pocketbooks benefit

The Foot

• Basic Bony Anatomy

• Lisfranc injury is commonly misnomer-ed as a “Lisfranc Fracture”, incorrectly reassuring the EM physician who sees no cortical defect on plain film
  • In general, this is any sort of injury, fracture or ligamentous, that leads to midfoot instability
  • This is typically axial loading on a hyper-plantar-flexed foot
  • Most commonly seen in MVCs, falls from height onto feet, or in wide receivers/basketball players

• Important to obtain oblique ankle films to evaluate for metatarsal-cuneiform alignment
• In the AP view, alignment of 2nd and 1st metatarsals most easily visualized, and 3rd/4th most easily visualized on oblique
• Lateral view can help identify dorsal misalignment
• Important to obtain weight-bearing films if you suspect subtle articular widening; this will identify any instability and subsequent need for surgical intervention
• From EM perspective, this patient will need a short leg splint and non-weight-bearing status with Ortho follow up for surgery

• Calcaneal fractures can be blatantly obvious or obscenely subtle. Reassuringly, the tradition surgical fractures are obvious
• The subtle fractures can mean the difference between walker boot and weight bearing as tolerated, and a cast for up to 6 weeks
• Stress fractures, posterior facet compression fractures, and anterior process fractures are classically missed
• Stress fractures are subtle fracture patterns in the posterior aspect of the calcaneus, difficult to truly identify a clean fracture line
• Key for diagnosis is a keen eye, a good lateral, and a good story (runner, pain getting worse, etc.)

• For the posterior facet compression, this is the classic utility of Bohler’s angle.
• If the fracture is occult, flattening of this angle can be your only clue; it is made by creating an imaginary line from anterior process through tip of posterior facet. This line should create and angle 20-40 degrees with another imaginary line between posterior facet and insertion of Achilles tendon
• This is technically an intraarticular fracture, so severity will delineate management; typically, the subtle fractures are Sanders I (not displaced), and not managed surgically
• Remember to evaluate the spine if there is a calcaneal compression fracture!

• Anterior process fractures are very difficult to identify due to many overlapping osseous structures in the area
• This makes identifying an abnormal fracture line difficult to separate from articular surfaces
• This fracture is typically from a rotational ankle injury, as opposed to axial force like the previous fractures
• Remember to get the foot film on the patient with an “ankle” injury! This fracture is easy to miss if you aren’t actively looking!

• Calcaneal fractures as mentioned above typically are not surgical, but be sure to identify them for appropriate casting and weight-bearing status
  • Short leg cast and non-weight-bearing for 6(stress)-12(anterior/posterior) weeks

​The Ankle and Lower Leg

• The majority of ankle fractures are very visible, but the two “French” injury complexes of the ankle and lower leg can be missed if not suspected
• Maisonneuve fracture is a torsional fracture of the proximal fibula with an associated ankle instability from a syndesmosis injury + a medial malleolus fracture or deltoid ligament injury

• In general, either the ankle instability is missed while the fibular fracture is found, or vice versa
• Patient may have twisted ankle and only be complaining of knee pain, or only notice their ankle pain without noting tenderness at their proximal fibula
• Remember to always exam a bone/joint above and below area of concern/complaint
• Measure the syndesmosis (tibiofibular clear space) 1cm above the ankle mortise; the distance between tibia and fibular here should be less than 6mm if syndesmosis intact
• Similarly, if no medial malleolus fracture is noted, obtain weight bearing films to make sure medial clear space does not widen, suggesting a deltoid ligament injury
• This requires a short leg splint (fibula does not need stabilizing typically), with Ortho follow up for operative fixation of ankle + fibula

• Tillaux fracture is a fracture of adolescents, typically an external rotational injury of the ankle leading to avulsion of the lateral distal tibia
  • This is a Salter Harris III fracture, as it is the physis and epiphysis that are avulsed by the talofibular ligament

• The anterolateral tibia is the last portion for growth plate closure, leading to vulnerability of this injury as an adolescent
• The fracture fragment can sometime be subtle and “hide” behind the fibula, making it difficult to identify
• Keys to identification are high suspicion and diligence; adolescent with external rotational force to ankle/foot (i.e. foot stuck with forced internal rotation of lower leg)
• Management is typically a long leg splint in the emergency department, and likely outpatient operative fixation
• If the story is good, child will not bear weight, but you do not see a fracture, CT scan can be utilized to rule out/rule in fracture, and serves as preoperative planning if present

​The Knee

• Similar to the ankle, most knee fractures that we see are not subtle. However, some tibial plateau fractures can be small and fracture line can be difficult to distinguish.

• As with all fractures, scrutinize the cortex for any irregularities
• Tibial plateau fractures are intraarticular fractures, leading to lipohemarthrosis
• Evaluate the lateral film for the “FBI” or fat-blood-interface, where the blood displaces the fat pad anteriorly
• Fractures can be split predominate, compression predominate, or a combination
• Subtle compression fractures can “push” the tibia more laterally as it is flattened.

• If you draw an imaginary line, in a true AP, down the lateral condyle and the medial fibular cortex, there should be less than 5mm of tibia lateral to this line
• Tibial plateau fractures are intraarticular fractures, leading to lipohemarthrosis
• Evaluate the lateral film for the “FBI” or fat-blood- interface, where the blood displaces the fat pad anteriorly
• Treatment is a hinged knee brace for stability and crutch for partial weight bearing
• If you can evaluate joint for instability, do so, but patient will likely need follow up outpatient with orthopedics to determine joint stability and need for surgery after swelling decreased

​The Hip

• Occult femoral neck fractures are very frequent in the emergency department setting. Anywhere from 2-10% of femoral neck fractures that present to the emergency department are occult on initial plain film imaging

• This is dangerous because a previously nondisplaced femoral neck fracture can subsequently move, leading to AVN, malunion, and increased morbidity/mortality
• Initial step can be an extra set of eyeballs; when patient has hip pain and will not bear weight (or even difficulty bearing weight), the search needs to continue
• This is especially true in the elderly population, who can have very deceiving exam; have a heightened suspicion for occult fracture
• Traditionally, gold standard was MRI, with CT reported as missing up to 33% of occult fractures
• Newer studies with newer CT scanners show near equivalence with MRI in sensitivity, but many are not satisfied with study design and MRI remains gold standard in the literature
• This can obviously be an issue in the flow of an emergency department, so other methods can be considered before waiting hours for an MRI
• Judet and “Bristol” views can give you more angles of the femoral neck for better visualization. Quick plain films, if they show the fracture, can save plenty of time and further testing
• Further consideration on disposition of patient can then play into CT vs MRI if plain films do not show the fracture. Vast majority of EM providers are confident with modern day CT imaging
• Treatment is hemiarthroplasty versus pinning, depending on patient’s clinical status and comorbidities