Key Feature 5: Identify and manage limb injuries that require urgent immobilization and/or reduction in a timely manner. 
Skill: Selectivity
Phase: Treatment, Diagnosis

Key Feature 6: In assessing patients with suspected fractures, provide analgesia that is timely (i.e., before X-rays) and adequate (ex: narcotic) analgesia. 
Skill: Clinical Reasoning
Phase: Treatment

Key Feature 7:  In patients presenting with a fracture, look for and diagnose high-risk complications (ex: an open fracture, unstable cervical spine, compartment syndrome).
Skill: Clinical Reasoning
Phase: Hypothesis generation, Diagnosis

There was a 14 year old male who presented to the pediatric ED today with acute wrist pain following trauma. He was given a dose of ibuprofen and plain radiographs were ordered that were later read by the radiologist as being negative for evidence of fracture. My attending's index of suspicion for fracture was high nonetheless, and so we immobilised the injured arm, with arrangements made for followup reassessment. What are the limb injuries that require urgent immobilization and/or reduction, and what should be done about them?

Indications for reduction (aka repositioning)

1. Joint dislocation 
2. Compromised neurovascular status of the extremity distal to a fracture

Indications for immobilization:

1. To prevent displacement of a fracture (if a fracture is displaced, it cannot heal)
2. To prevent a relocated joint from dislocating again
3. To protect the area from further injury
4. To decrease pain

Almost any fracture or dislocation may benefit from at least short-term immobilization with little harm. The choice of immobilization method, be it sling or cast, comes with inherent pros and cons. Generally speaking, slings tend to be the choice for an acute injury as they are less restricting and therefore more accommodating of swelling as tends to occur with acute bony injuries. Slings also tend not to limit the ability to apply ice to decrease swelling to the affected area, which may significantly improve pain. Furthermore, swelling in a restricted cast can lead to iatrogenic tissue damage (ex: compartment syndrome*). On the other hand, slings tend not to stabilize the affected area as much as a cast, and depending on the need for swelling vs stability, the cast may be more appropriate (ex: injuries expected to have minimal swelling, or those for which there is an increased need for stability). According to the UpToDate article, "General principles of acute fracture management" (2018), fractures that require casting as opposed to use of a sling include, "...those that required reduction, fracture dislocations, segmental or spiral fractures, and simultaneous fractures of both the ulna and radius." 

Given the pros and cons of slings vs casts, my attending physician today chose to opt to immobilize the affected wrist with a short-arm cast. There was minimal swelling, and given the time elapsed from injury, it was expected that there would not be significant further swelling to the area. Furthermore, the teenager was a seriously active person who played soccer and rugby, and without a cast was at increased risk of re-injuring the area before giving it proper time to heal. Plus, in a patient-centered way, he was kinda excited to get his very first cast, and so we made one in his favourite colour blue. 

A note on pain control: ​If pain is a concern, as it usually is when it comes to bony injuries, it is important to prioritise pain relief, because pain sucks. This is something quick and easy to do, managed with the same analgesic ladder as for any other nociceptive (tissue) pain: acetaminophen, NSAID, and/or opioids. Opioids are often unnecessary save for severe injuries, and it is worth a trial of acetaminophen +/- an NSAID first in an injury that is not seemingly too painful. Other nonpharmacological methods of managing pain can be very helpful, and these work by decreasing the pain associated with swelling. These methods include: resting the affected area, applying ice, and elevating the extremity.

*Complications that present with bony injuries include those that are evident upon initial injury assessment and those that present in a delayed fashion. Complicating factors that are evident on primary assessment include

1. A fracture that is "open" (with increased risk of infection)
   
2. A fracture with coinciding neurovascular compromise to the distal extremity (with increased risk of permanent neurological disability and tissue damage)
   
3. A fracture of the cervical spine (with increased risk of profound neurological disability and that one must have a high index of suspicion for, hence why the ABCs are sometimes called the cABCs, to consider first the need to protect the "c" spine if the patient has potentially sustained an injury to it.)

Complications that may occur after a delay from the initial assessment, as summarised in the following UpToDate table, include

As this post is much about casting, with reference to compartment syndrome as an iatrogenic complication of casting, I will elaborate briefly on what this is. Compartment syndrome occurs when there is so much swelling in an area that arterial flow is cut off. This leads to the four Ps that a clinician should always be suspicious to look for in a patient with a cast (or if there is a fracture to the regions that are more likely to host this complication because of natural tissue compartmentation)

1. Pain
2. Pallor
3. Pulselessness
4. Poikilothermia (meaning cold in Latin)

Patients should always be warned that if pain to the affected area is increasing significantly, to not delay a return to medical care as this could be a compartment syndrome and a delay in treating this could result in long-term disability.

Key Feature 3: In patients with suspected fractures that are prone to have normal X-ray findings (ex: scaphoid fractures in wrist injuries, elbow fracture, growth plate fracture in children, stress fractures), manage according to your clinical suspicion, even if X-ray 
Skill: Clinical Reasoning, Selectivity
Phase: Treatment

Key Feature 4: In assessing elderly patients with an acute change in mobility (i.e., those who can no longer walk) and equivocal X-ray findings (ex: no obvious fracture), investigate appropriately (ex: with bone scans, computed tomography) before excluding a fracture. 
Skill: Clinical Reasoning
Phase: Investigation

So that key feature is definitely not a complete sentence, and just like a suspected fracture with a negative x-ray, it leaves you hanging. X-rays are never 100% sensitive for fractures, sometimes not even approaching this depending on the fracture type, and there are fractures that have a higher risk of negative consequences if the bone/affected joint is not immobilised. Let's go through some of the more common circumstances in which having a higher index of suspicion of fracture is warranted.

1. FOOSH with wrist +/or elbow pain
   • When a patient describes having fallen on an outstretched hand (FOOSH) with the wrist in dorsiflexion, and with ongoing radial-sided wrist and/or elbow pain, they must be examined for signs of a scaphoid or radius fracture. 
     • FOOSH with radial-sided wrist pain
       • Plain radiographs to order to look for a scaphoid fracture include orthogonal PA and lateral +/- oblique and scaphoid views of the wrist. 
       • False negative rate of plain radiographs for scaphoid fractures, within 2-6 weeks of injury, hovers at around 20% (!)
       • If plain radiographs are negative and more advanced imaging is available, this would be warranted. Although many physicians may use an immobilise-and-reassess approach, opting for further imaging with MRI, CT, or bone scan is more cost-effective than empiric immobilization. Although the cost of imaging is greater up-front, the overall cost is greater with the immobilise-and-reassess approach, as accrued by costs for the supplies to immobilize, for follow-up visits, and for loss of productivity secondary to unnecessary immobilization. 
       • If advanced imaging is not available and a scaphoid fracture cannot be ruled out, the patient requires immobilization of the scaphoid using a thumb spica splint or cast for 7 to 14 days followed by reimaging 
     • FOOSH with elbow pain
       • Plain radiographs to look for a radius fracture includes orthogonal (PA and lateral) views of the wrist and elbow +/- oblique lateral view of the elbow.
       • Elevated anterior and/or posterior elbow fat pads may be the only indication of a proximal radial fracture. 
       • If there is no sign of fracture and full range of motion of the elbow joint, then no further investigation or management is necessary. If there is limited range of motion, then further imaging is warranted to detect an occult fracture, because in the setting of proximal radius fracture and decreased joint range of motion, orthopaedic surgery may be indicated. 
2. Possible growth plate fracture
   1. In pediatric patients, the growth plate is still open and at risk of being injured. There must be a high index of suspicion for a growth plate injury because if present, it can lead to growth arrest (the cells that are dividing and elongating the bone can no longer do their job). This is a bad thing. It requires a high index of suspicion not only because it's bad though, but because the fractures that are more likely to disrupt the growth plate are also the ones that are most likely to appear normal on imaging. These are classified as Type I Salter-Harris fractures. (See image at the bottom of the post.)
   2. In a pediatric patient with normal radiographs but focal tenderness over the growth plate, management should ensue as if there is a radiographically detected fracture. X-rays are then repeated 7 days after injury. 
3. Possible stress fractures
   1. ​Stress fractures occur because of repetitive use and strain on the bone, leading to cracks in the outer layer of the bone (periosteum). A high index of suspicion is warranted in patients who perform repetitive physical activity and who complain of bony pain. (See table below for stress fractures that are more commonly associated with certain sports.)
   2. Plain radiographs are typically normal until 1-2 weeks after symptom onset. A wait and reassess approach can again be taken, or further characterization with MRI may be pursued depending on available resources.
4. Hip fractures in the elderly
   
   1. ​These are so common and carry such a high burden of morbidity and mortality, they just can't afford to be missed. In an elderly patient who is complaining of new hip pain (or maybe who has decreased cognitive abilities and is unable to express this but is suddenly not willing or able to walk), there must be a high index of suspicion for hip fracture. 
      
   2. First-line imaging is to obtain 2 views: AP pelvis (to be able to compare both hips) with maximal internal rotation and lateral view of the hip. If x-rays are unremarkable, then further imaging is warranted given the clinical picture (MRI is ideal)

Key Feature 1: In a patient with multiple injuries, stabilize the patient (ex: airway, breathing, and circulation, and life-threatening injuries) before dealing with any fractures.
Skill: Clinical Reasoning
Phase: Treatment

Key Feature 2: When examining patients with a fracture, assess neurovascular status and examine the joint above and below the injury. 
Skill: Clinical Reasoning
Phase: Physical

In a patient who has sustained any trauma, as may be visible on physical exam or as may be reported by a history of injury, the clinician must begin their assessment with the ABCs. Although a fracture may be what draws attention when a patient arrives for medical care as it can be quite dramatic (think bones protruding from skin etc.), if there is this level of injury, it is also possible that the patient could  have sustained other life-threatening injuries. The order in which life-threatening injuries should be addressed to best optimise patient outcome is Airway-Breathing-Circulation-Disability-Exposure/Environment. Period. It is important not to let any fractures distract you from the basics of trauma resuscitation.

For dramatic effect, without being too gruesome, here is an example of a (weird-looking) bony injury. I can't imagine not feeling tempted to want to just start dealing with this obvious problem. But we must still bring it back to the ABCs first.

Once review of the ABCs and any life-saving resuscitation is underway, further assessment of any bony injuries is indicated. This includes palpating the entire bone in question along with palpating the entire area around any fracture sites to exclude injuries to adjacent bones, including at least one joint above and below the injury site. Then the physician should assess neurovascular status around any sites of potential bony injury. This includes assessing:

1. Motor and sensory function of the distal extremity beyond the area of injury (ex: in an injury involving the upper leg, can the patient wiggle the toes and feel when the toes are being touched)
2. Whether perfusion is intact to the distal extremity by feeling extremity temperature for coolness or warmth, and assess pulses and capillary refill time