Approach to extremity injury: Clinical sciences

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Introduction 0:00–0:32

Extremity injury is often caused by blunt trauma, including falls, crush injuries, and high-speed motor vehicle crashes.
It can also result from penetrating trauma, such as gunshot or stab wounds. While many of these injuries are treated nonoperatively, some can be life- or limb-threatening and are considered surgical emergencies.
When evaluating a patient with extremity injury, start with a primary survey by assessing their ABCDE. First, secure the Airway by endotracheal intubation if necessary and keep the cervical spine immobilized with a c-collar.

Acute Management 0:32–1:53

Then comes Breathing, so ensure adequate ventilation and provide supplemental oxygen. Next is Circulation, so obtain two large bore IVs, making sure to avoid placing the IV on the injured limb.
If you’re unable to obtain IV access, obtain intraosseous access instead. Continuously monitor patient’s vitals while starting appropriate resuscitative measures including crystalloid bolus and sometimes blood product transfusions.
Then, assess for Disability by evaluating the patient’s neurologic status using the Glasgow Coma Scale. Also, quickly check for spinal cord injury by asking your patient if they can feel or move all four extremities.
Finally, Expose the patient by removing all clothing and bandages to ensure no injuries are missed. After examining the patient, place a warm blanket over them to avoid hypothermia.
Okay, if your patient is unstable, move on to a secondary survey. This includes history and a detailed head-to-toe physical exam to assess for life- or limb-threatening injuries.

Unstable Patient 1:53–2:28

Keep in mind, limb-threatening injuries that are left untreated can quickly become life-threatening by hemorrhagic shock or sepsis.
Here’s a clinical pearl! In trauma, the visible injury might not be the cause of instability, so always be sure to assess for internal injuries as well.
Alright, let’s dive into our first case, traumatic amputation or mangled extremity. History typically reveals high-force penetrating trauma like a stab or gunshot wound; industrial injury with an object such as heavy machinery; or a motor vehicle crash.

Traumatic amputation or mangled extremity 2:28–3:25

On physical exam, you’ll find a severed or mangled extremity, as well as ecchymoses and pallor. There may be absent distal pulses with sluggish capillary refill indicating inadequate blood flow to the distal limb.
Some patients may also have soft tissue loss. In this case, you are dealing with traumatic amputation or mangled extremity, which need emergent surgical intervention.
Be sure to send for urinalysis and CMP because they have a high risk of rhabdomyolysis. Next is arterial injury.
This can result externally from penetrating trauma, or internally from a severe joint dislocation or long bone fracture.

Arterial injury 3:25–5:01

Depending on the size of the injured artery and the amount of blood loss, the patient can be hypotensive and tachycardic.
Distal pulses are typically absent on palpation, and there is a bruit on auscultation or a thrill over the injured vessel.
If the skin is intact, you may notice an active pulsatile hemorrhage or a pulsatile expanding hematoma. If these are your findings, that’s an arterial injury.
These patients should go to the OR right away to gain control of the bleeding. Here’s a high-yield fact!
Certain fractures might be associated with specific arterial injuries. For example, a fracture of the lower third of the femur can cause a femoral artery injury.
A supracondylar fracture of the femur can lead to a popliteal artery injury, while a tibial fracture can injure the posterior tibial artery.
On the upper extremity, humeral fractures may cause brachial artery injuries, while a fracture-dislocation of the shoulder can cause an axillary artery injury.
While injuries to any of these arteries can cause limb-threatening ischemia of the affected extremity, pay close attention to femur fractures because they can cause life-threatening exsanguination.
Next up is compartment syndrome. History usually reveals crush injury, major fracture, or extensive burns.

Compartment syndrome 5:01–5:50

On examination, you’ll find a swollen extremity that feels tense or “wood-like” and is extremely painful with passive stretching.
The extremity might be pale with absent distal pulses, and neurologic exam can reveal paresthesia, motor deficits, or paralysis.
These findings support your diagnosis of compartment syndrome. Management involves emergent fasciotomy to release the pressure within the muscle compartment and allow adequate blood flow to the rest of the limb.
If left untreated, worsening muscular edema and pressure will lead to limb ischemia and even necrosis. Okay, let’s move on to stable patients.

Stable patient 5:50–6:14

As before, your next step is to perform a secondary survey, which includes a focused history and physical exam, and obtain adjunctive tests like an x-ray.
Keep in mind that, unlike life- or limb-threatening conditions, isolated extremity injuries might not be obvious on initial examination.
Let’s start with vascular injuries. The mechanism of injury is similar as with unstable patients, but these are typically less severe.

Vascular injuries 6:14–6:57

Most patients sustain a localized blunt or penetrating trauma to the limb. Exam often reveals injury near major vasculature with diminished or absent distal pulses, and pallor of the affected extremity.
You may observe external bleeding or hematoma. With this presentation, consider a vascular injury.
Next, order a CTA. If it reveals contrast extravasation or cutoff, that’s vascular injury.
Moving on to nerve injuries. History often reveals hyperextension stretch injuries, penetrating transection injuries, or crush injuries; with diminished sensation and motor function.

Nerve injuries 6:57–9:10

Keep in mind, symptoms might start after an operation, indicating that the nerve damage occurred during surgery. Exam reveals focal neurologic deficits like numbness, pain, paresthesia, sensory and motor deficits, and muscle weakness.
If these are your findings, that’s a nerve injury. Here’s a high-yield fact!
Injury to the peripheral nerve root or the nerve itself can cause motor or sensory deficits, which can be identified based on the affected myotome or dermatome.
When there’s a motor deficit on one side of the extremity, the opposite action takes over. Now, certain nerve injuries will elicit specific signs.
For example, ulnar nerve injury presents with a “claw hand” where the patient can’t extend 4th and 5th digits at the interphalangeal joints, resulting in permanent flexion.
In lower extremities, injury to the common peroneal nerve can present as a “foot drop”, which results from the inability to dorsiflex the foot at the ankle joint.
Median nerve injury is associated with the “hand of benediction” or “bishop’s hand”. Usually, there is wasting of the anterior forearm and thenar eminence, as well as the inability to flex at the MCP and interphalangeal joints of the middle and index fingers.
Radial nerve injury can elicit a “wrist drop”, which presents as an inability to extend the hand and fully extend the forearm.
Obturator nerve injury can lead to the “Howship-Romberg sign”, or pain and paresthesia over the inner aspect of the thigh.
Lastly, lateral femoral cutaneous nerve injury presents as meralgia paresthetica, which refers to pain and paresthesia over the lateral aspect of the anterior thigh, or the “pants pocket” area, that can be improved by losing weight or wearing loose-fitting clothing.
Now its time to discuss musculoskeletal or MSK injuries. MSK injuries are the most common type of extremity injury in stable patients.

MSK injuries 9:10–12:47

Presentations differ based on the injured structure, but many patients report a sports injury, such as twisting or hyperextension, or a fall on an outstretched hand.
On physical exam, you’ll usually notice an obvious limb deformity and soft tissue swelling. At this point, consider an MSK injury.
Let’s start with bone fractures. Typically, patients report a fall or trauma.
Some may have a history of predisposing factors like malnutrition, such as those with an eating disorder; certain malignancies; and osteoporosis, which is more common in elderly biological females.
Physical exam may reveal point tenderness, obvious limb deformity, bone crepitus, palpable step-off or gap, or redness and swelling of the extremity.
With these findings, consider a bone fracture. Next, order x-rays of the affected extremity in multiple views.
Visualization of the fracture confirms your diagnosis. If the x-ray is unclear, a CT scan or MRI can sometimes be obtained.
Next are joint dislocations. The most common mechanisms of injury include contact injury and falls.
History might reveal a prior dislocation. Patients typically experience pain radiating distally, such as from the injured hip to the knee.
Physical exam may give some additional clues. If the upper extremity is involved, the patient may have their arm held in abduction and external rotation, indicating anterior dislocation; or adduction and internal rotation for posterior dislocation.
You might also find flattening of the anterior shoulder. If the lower extremity is injured, the leg is externally rotated and lengthened in anterior hip dislocation; or internally rotated and shortened in posterior hip dislocation.
If you see these findings, consider a joint dislocation. Next, obtain a joint x-ray.
If you see that the joint is displaced from its socket, you can confirm the diagnosis of joint dislocation. Our last MSK injury is ligamentous injury, including strains and sprains.
The most common mechanisms of injury include sports injuries from direct contact or running; falls; or wearing high heels for a prolonged period of time.
Patients typically report hearing a popping sound followed by sudden pain and decreased range of motion of the affected joint.
On exam, you’ll notice joint swelling and tenderness, limited range of motion, inability to bear weight on the affected extremity, or laxity of the involved joint.
In this case, consider a ligamentous injury. Next, order an extremity x-ray, and consider an MRI.
X-ray will help rule out a fracture or dislocation, and will show soft tissue swelling; while on MRI, the injured ligament will appear thickened, or may show partial or full-thickness tearing.
With these findings, diagnose a ligamentous injury. Finally, let’s go back and discuss superficial soft tissue injuries.

Superficial soft tissue injuries 12:47–13:46

These typically include burns; superficial blunt trauma; or penetrating injuries, such as gunshot or stab wounds that missed major neurovascular structures.
Physical exam differs based on the mechanism of injury. You can find ecchymoses, point tenderness, and soft tissue swelling, with or without signs of vascular compromise or neurologic deficits.
At this point, consider a superficial soft tissue injury. Although these injuries are often clinical diagnoses, consider getting an extremity x-ray.
The x-ray will rule out fractures or dislocations and reveal soft tissue swelling, and sometimes foreign bodies embedded within the wound.
These findings confirm your diagnosis of superficial soft tissue injury. Alright, as a quick recap… For an extremity injury, in unstable patients, look for life- and limb-threatening injuries, including amputation, mangled extremities, arterial injuries, and compartment syndrome.

Review 13:46–14:09

In a stable patient, differential diagnoses include vascular injuries, nerve injuries, MSK injuries, and soft tissue injuries.