Orthopedic Injuries

Author: Shreni Zinzuwadia, MD, Department of Emergency Medicine, Rutgers-New Jersey Medical School and Newark Beth Israel Medical Center

Editor: Matthew Tews, DO, MS, Department of Emergency Medicine and Hospitalist Services, Medical College of Georgia

Objectives

Describe the mechanism and initial evaluation of orthopedic injuries of the extremities
Discuss the importance of determining neuro-vascular integrity of the injured extremity
Identify correct imaging modalities for presenting injuries
Identify common and subtle injuries to look for on plain film radiographs

Introduction

Orthopedic injuries are a common part of the practice of emergency medicine. Fractures are a leading cause for malpractice claims due to missed diagnosis, and account for 20% of malpractice claims nationally. A sound approach to the diagnosis and treatment of orthopedic injuries is important to avoid missing life or limb-threatening injuries. Table 1 lists the common orthopedic emergencies. This chapter will focus on the approach to patients with traumatic orthopedic injuries, commonly fractures and dislocations.

Table 1: Common Orthopedic Emergencies

Open Fractures

Closed fractures

Compartment syndromes

Neurovascular injuries

Dislocations

Septic joints

Initial Actions and Primary Survey

The initial evaluation of a patient with an orthopedic injury should focus on the ABCDE,’s (airway, breathing, circulation, orthopedic and/or neurologic disability, exposure) during the primary survey of a trauma evaluation. The evaluation of orthopedic injuries follows as part of a secondary survey, unless there is active hemorrhage associated with an extremity injury or a pulseless limb. In these cases, the evaluation and management should be a part of the circulation or ‘C’ part of the primary survey. Once the patient is stable and the secondary survey is being performed, there should be a focused assessment of the injured extremity. For those with isolated orthopedic injuries, the assessment of neurovascular status should take priority.

Focused Assessment

Initial Evaluation of Injured Extremity/Joint

Inspect the involved limb for active hemorrhage, obvious deformity, positioning of the limb, or hematoma. Skin changes like mottling, abrasions, or breaks are worrisome for underlying injuries.

Palpate the injured area to assess for tenderness or crepitus.

Assess for neurovascular compromise, including loss of pulses, paresthesias or weakness. Palpate distal pulses in all extremities for symmetry and check for capillary refill delays.

Evaluate for passive and active range of motion only after it is determined there is no evidence of neurovascular compromise, significant pain or deformity. In high-energy, multisystem trauma all limbs must be examined to detect injuries that may otherwise be missed.

Basic Imaging Principles

The physical examination should direct the imaging to be obtained. In skeletal injuries, plain radiographs are the imaging modality of choice. A minimum of two views at right angles to each other should be obtained to minimize missing injuries that are subtle or non-visible on one view. The AP and lateral are the basic essential views of any injury. Oblique views are typically part of the initial radiograph for visualizing extremities, but are not often possible depending on various factors such as portable imaging limitations, associated injuries and patient stability. Stress views are required in very specific scenarios to assess for severe ligamentous injury, such as with a Lis franc injury, but are not always necessary in the ED. It is important that adequate views of the injured extremity are obtained. Interpreting inadequate views can lead to a missed diagnosis. It is typically prudent to film the joint above and below the injured bone in question to rule out associated injuries.

Further study modalities such as computed tomography (CT) or Magnetic Resonance Imaging (MRI) of the extremities are typically reserved for outpatient evaluations of injuries. When there is uncertainty in the diagnosis such as when a radiograph appears unremarkable, or the patient has significant pain or difficulty with mobility, a CT may be used to further assess for an occult fracture or injury. For the assessment of a vascular injury a CT angiogram may be necessary. Further imaging may also become relevant for surgical planning when indicated.

Interpreting Plain Radiographs

Interpreting plain film radiographs is a learned skill and an important one when working in the ED. Each imaging study has its own nuances and complexities to consider, yet there are several basic principles to remember when interpreting plain film radiographs.

Determine if the radiographs are adequate to visualize what bony structures are in question and need evaluation. The degree of rotation, bone overlap, and overlying materials may obscure the view.

Use a consistent approach. One must be methodical in the approach to reading radiographs. This will limit the chances of missing injuries. See “Description of Fractures” section below.

Look past the obvious injuries. The saying goes that ‘the most commonly missed fracture is the second fracture’. When an obvious fracture is noted, there should be due diligence on focusing on a potential second fracture or more. Examine the entire radiograph for abnormalities and then refocus on the obvious injury.

Review normal bony patterns. Each bone has areas of common and subtle injuries that should be learned or looked up if there is uncertainty. Some radiographic appearances can mimic a fracture, such as the appearance of a nutrient vessel. Isolated islands of bone can be seen and adjacent bony fragments can be fracture pieces, sesamoid bones, degenerative changes or accessory ossification areas.

Correlate findings on radiographs with your clinical exam. It is common to review radiographs with findings that seem to be fractures or dislocations, but on exam the patient may have no pain or tenderness over the corresponding area. On the other hand, subtle imaging findings may be correlated with significant pain or limited mobility on exam. Diagnosis and treatment of orthopedic injuries should be based on these correlations between the clinical exam and the radiographs. The benefit of being able to perform the physical exam is an advantage of seeing the patient in the ED and being able to interpret radiographs correctly.

Look at more than just the bones on the radiographs. Radiographs can also demonstrate soft tissue swelling, joint space effusions, foreign bodies, and gas in the tissues.

Secondary findings in the absence of an obvious fracture may be present. Particularly with concern to the elbow, there can be displacement of the fat pad as an indirect sign of fracture. When there is no obvious fracture.

Determining What to Image

Choosing what to image with orthopedic injuries can seem simple, but in some cases, can be complex. Here are some typical principles to consider when choosing what to image for long bones and large joints.

Long Bone Injuries

When the injury involves a long bone from blunt trauma, such as the femur, the entire bone should be imaged as well as the joint above and below. Joints typically need a dedicated AP and lateral radiograph even if the joint is included in the femur films. Several radiographs may be needed to view the length of the bone. Remember to order and view radiographs prior to performance of a reduction, unless a delay may cause further injury, such as limb ischemia. In the era of portable radiography and digital viewing of images, a radiograph can be ordered quickly without a delay in care. This is helpful for an assessment of a potential concomitant fracture with a dislocation. It is also useful to assess how many bony structures are involved.

For injuries caused by penetrating gunshot wounds, if there is no exit wound, the radiographs should start at the site of the injury, but should not stop until the missile is found. When the missile is not found in an obvious area consider looking distally in the off chance it could have traveled distally in the blood vessel. If there are two wounds, typically a radiograph of the area of injury is enough if the history suggests and in-and-out injury (Image 1). For penetrating stabbing injuries, the radiographs are typically looking for foreign bodies, such as the blade of a knife that could have broken off in the body.

Image 1: GSW to right knee with paperclips marking an in-and-out injury

Finally, it is important to always look at the proximity of any foreign object or fracture to a blood vessel. There are soft and hard signs of vessel injury that should assessed for as part of the evaluation of the injury site and the distal neurovascular status (Table 2).

Table 2: Signs of Vascular Injury

Hard Signs	Soft Signs
Abesent pulses	Proximity of injury to vascular structures
Bruit or thrill	Major single nerve deficit (e.g. radial)
Active or pulsatile hemorrhage	Non-expanding hematoma
Signs of limb ischemia or compartment syndrome	Reduced pulses
Pulsatile or expanding hematoma	Posterior knee or anterior elbow dislocation
	Hypotension or moderate blood loss at scene

Joints

There are several joints that have unique articulations and radiographic nuances when reading them. It is important to have at least a basic understanding of the imaging of these joints. Table 3 provides a summary of imaging for these structures.

Elbow: The elbow is a joint with multiple articulations and therefore has some unique signs to look for on imaging. AP and lateral views should be obtained, as well as an oblique view. There are several areas that should be reviewed on the elbow radiographs.

Fat pad signs - There are two fat pads, anterior and posterior. These are extra-synovial fat collections within the capsule. They can be displaced by any intra-articular effusion. Sometimes this may be the only sign of an occult fracture- particularly in pediatric cases. The anterior fat pad is often seen on unremarkable radiographs, but if protruding in the classic “sail sign”, a fracture should be considered. The posterior fat pad is often only seen in cases of joint effusion and is often pathognomonic for fractures when present. (Image 2)

Image 2: Posterior Fat Pad in a Patient with Radial Head Fracture

Radiocapitellar line – A line drawn along the shaft of the radius should intersect the middle third of the capitellum, regardless of position of the elbow on the radiographs. Displacement of the radial head is suggested if the line does not intersect as expected. (Image 3)

Image 3: Radiocapitellar Line in a Patient with Radial Head Dislocation

Anterior humeral line – A line drawn down the anterior surface of the humerus on the lateral radiograph should intersect the middle third of the capitellum.Displacement of this line can suggest a distal humeral fracture, such as a supracondylar fracture. (Image 4)

Image 4: Anterior Humeral Line Showing Anterior Condylar Displacement in a Patient with a Transcondylar Fracture

Wrist: The wrist has more bony articulations that any other joints in the body. AP and lateral radiographs should be obtained, as well as an oblique view. The oblique view looks more closely at the carpal-metacarpal articulation of the thumb. Since the scaphoid is the most commonly injured carpal bone, there should be a high index of suspicion of a scaphoid injury when there is a wrist injury (Image 5). Physical exam should include palpation of the anatomic snuff box – where lies the scaphoid. The scaphoid radiograph of the wrist is an AP view of the wrist in ulnar deviation and can be added if the view of the scaphoid is inadequate on the AP view. Care should be taken to look at each carpal and metacarpal bone, as well as their articulations with the forearm bones and with each other. When viewing the lateral wrist view, the alignment of the bones should be examined closely. On this lateral view, a line should be drawn down the shaft of the radius, which should continue through and intersect longitudinally with the lunate, capitate and the third metacarpal bone. Misalignment suggests displacement or dislocation of the lunate, capitate or metacarpal bones.

Image 5: Subtle Scaphoid Fracture (green arrow)

Pelvis: For assessment of the pelvis, a plain AP radiograph of the pelvis is the initial view of choice. This looks at the articulations of the sacroiliac joints, the pubic symphysis and the hip joints. Often, if one fracture is found on the pelvic x-ray, a second fracture and/or fracture-like injury should be sought (such as SI joint disruption) as seen in Image 6. Additional views of the pelvis (inlet, outlet, Judet) can be obtained if acetabular or pelvic ring fractures are suspected.

Image 6: Left Superior and Inferior Pubic Rami Fractures Should Prompt Look for Second Fracture or Ligamentous Injury, Typically Along the SI Joint

Knee: To assess for trauma, AP, lateral, and oblique views of the knee should be obtained. A good lateral view of the knee super imposes the medial and lateral posterior epicondyles and the fibula is overshadowed by the tibia. For suspected tibial plateau fractures a specific tibial plateau view is part of the work up, but often the fracture can be seen by a depressed plateau and widening of the tibia compared to the femur (Image 7). Intraarticular fractures, extending through the joint are treated differently from long bone fractures. There is due an increased risk of complications from these injuries, such as post traumatic arthritis. Often a CT scan is necessary to further characterize these fractures.

Image 7: Tibial Plateau Fracture Medially on Tibia/Fibula View

Ankle: The ankle joint radiographs should include three standard radiographic views; AP, lateral and oblique views. The oblique view is also called the mortise view. The mortis view allows evaluation of the joint where the talus can be visualized sitting in between the medial and lateral malleoli. In this view, the space around all sides of the talus should be equal. Any one of these spaces being unequal suggests a fracture or if there is no fracture visualized, there may be a tear in the deltoid ligament (Image 8).

Image 8: Widened Medial Space Between the Talus and the Medial Malleoli without Fracture Suggests Ligamentous Injury

Table 3: Imaging of Bones

JOINTS	Plain Films	Special Considerations
Elbow	AP/ lateral	Posterior fat pad sign; large anterior fat pad sign; radiocapitellar and anterior humeral lines
Wrist	AP/lateral and Oblique views	Scaphoid views if pain and AP radiograph non-diagnostic; visualize line parallel to shaft of radius, lunate, capitate and metacarpal
Pelvis	AP	Close attention to pelvic ring fractures and acetabular fractures (Inlet/ outlet/ Judet views)
Knee	AP/lateral and oblique views	Plateau views for suspected tibial plateau fractures
Ankle	AP/lateral and oblique views; oblique view typically called the mortise view	Misalignment of the talus sitting in the mortise suggests deltoid ligament injury or fracture

Description of Fractures

It is important to be able articulate a thorough description of radiographic findings to an orthopedist. Below are some key items to include when describing a fracture. Always start your description with the patient’s name, age and a brief mechanism of injury.

Open/Closed Fracture

Open Fracture: exposed bone or puncture of the skin with underlying fracture. If the fracture is exposed to the external environment (abrasion/ puncture wound/ obvious bony fragments), it is considered an open fracture. It can be difficult to determine whether a small wound in proximity to a fracture actually communicates with the fracture. If there is doubt, then assume an open fracture is present. Open fractures are considered to be true orthopedic emergencies due to a high risk of infection. There should be no delay in treatment. The wound should be covered with clean dressings. The patient should be given a dose of empiric IV antibiotics covering skin flora and most often the patient requires surgery.

Closed Fracture: Skin and soft tissues overlying the fracture are intact.

Anatomic Location

The name of the bone should be included in the description of the fracture involved. State whether the fracture is left or right sided. Proximal and distal descriptors should be used in reference to standard reference points such as the head, neck, body, condyle, and base. Examples include: proximal humeral neck fracture, distal radial shaft, and proximal 1/3 humeral shaft. (Image 9)

Diaphysis: the shaft of the bone. Fractures are termed midshaft if they occur near the axial center of the diaphysis. All other fractures of the diaphysis are referred to as proximal third, middle third, or distal third of the diaphysis. An example is closed transverse fracture of the proximal third of the right femur.

Metaphysis: the area adjacent to the growth plate.

Epiphysis: the end of the bone adjacent to the joint. This is only relevant in the immature bones of pediatric patients while the epiphyseal growth plate is still open. These are described using the Salter-Harris Classification system (see Salter-Harris Classification below).

Image 9: Structure of a Long Bone

Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014". WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. - Own work, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=27796930

Fracture Descriptors

Accurately describing fractures over the phone or in medical documentation is an important part of communicating the type and severity of injury. Several terms are used to describe a fracture on radiograph (Table 4).

Table 4: Descriptors of Fractures

Fracture Type	Description
Transverse	Traverses the bone perpendicular to the long axis of the bone. Used mostly to describe long bone fractures. Typically, these fractures are at right angles or less than 30’ to the shaft of the long bones.
Oblique	Occurs at a plane oblige to the long axis of the bone. Looks similar to a corkscrew. Commonly used to describe long bone fractures. Typically, oblique fractures are greater than 30’ to the shaft of the long bone.
Spiral	Result from a rotational force applied to the bone, typically caused by a twisting or torque applied.
Longitudinal	Occur along or nearly to the axis of the bone. Commonly used to describe long bone fractures.
Comminuted	Multiple fragments of bone. This is not very specific and can range from 2 bony segments to multiple bony segments. Examples also include non-comminuted, mildly comminuted, or severely comminuted.
Segmental	Composed of at least two fracture lines that cause isolation of a segment of bone.

Additionally, there are several terms that are used to describe how a fracture piece is positioned compared to the proximal portion of the bone. These are commonly divided into complete and incomplete fractures.

Complete fractures - describe the direction of the fracture line(s). Fracture line goes all the way through the bone.

Displacement

The movement of fracture fragments from the normal anatomic location. Typically, one describes movement of the distal fracture fragment in relation to the proximal bone.

Angulation: dorsal/palmer; radial/ulnar. Varus/valgus refers to media angulation vs lateral angulation. This can also be described as the amount of bend a fracture fragment has in degrees.

Translation: movement of the bones away from each other; typically, a horizontal movement of long bone fragments.

Rotation: more obvious on clinical exam rather than on plain films. Rotation of the distal fragment from the proximal fragment. Rotation of a long bone may be internal or external.

Fracture length

Distraction: A fracture resulting in increased overall bone length due to widening or distraction of the bony components.
Impaction: A fracture resulting on shortening of the bone without obvious loss of alignment. One bony fragment is driven into the other.
Shortening: migration of a distal fragment in a long bone fracture results in shortening of the overall bone length. Oblique fractures are more often shortened compared with transverse fractures, unless the transverse fracture is 100% displaced where it could shorten.

Incomplete fractures - the bone is not completely broken.

Bowing: a bending of a long bone. Often occurs as an incomplete fracture in the tubular long bones of pediatric patients. Almost exclusive to children. Rare although reported in adults. Most commonly affecting the radius and ulna, followed by the fibula.

Buckle: a fracture of the concave surface of a bone; also known as Torus fractures. This is an incomplete fracture of the shaft of a long bone, characterized by bulging of the cortex. Commonly in children involving the distal radial metaphysis.

Green stick: Incomplete fracture of the long bones of young pediatric patients less than 10 years of age.

Salter-Harris Classification: fractures involving various degrees of the physeal plate also known as the growth plate. Classification is done using the ubiquitous Salter-Harris system, Types I-V, which is shown in Table 5 and Image 10.

Table 5: Salter-Harris Classification

Salter-Harris Classification	Description
Type I	Fracture across the physis with no metaphyseal or epiphyseal injury.
Type II	Fracture across the physis that extends to the metaphysis.
Type III	Fracture across the physis that extends into the epiphysis.
Type IV	Fracture through the metaphysis, physis, and epiphysis.
Type V	Crush injury to the physis that may misleadingly appear normal at brief glance.

Image 10: Salter-Harris Classification Images

Dr Frank Gaillard (MBBS, FRANZCR) (http://www.frankgaillard.com); used under Common Creative License

Special Considerations

Intra-articular fracture: involvement of the fracture through an inter-articular surface, or involving the joint. Periarticular fracture would mean a fracture near to the joint but not involving the joint.

Avulsion: injury to a bone where a tendon or ligament attaches to the bone. The tendon or ligament pulls off the piece of bone in the type of fracture. These occur more commonly in children than adults.

Depression fracture: Occur in areas where multiple fissure lines intersect. When enough force is applied there is depression away from the direction of the applied force. Typically, this occurs in the calvarium, the maxilla, or the frontal bones of the face.

Compression fractures: These fractures are similar to impaction fractures. In this case cancellous bone collapses and compresses on itself. Typically, this occurs in vertebral bodies, where a portion of the anterior portion of the vertebrae or the entire vertebra collapses due to osteoporosis or trauma leading to a compression fracture.

Pathologic fracture: the presence of bony disease such as osteoporosis, osteomalacia, Paget’s disease, osteitis, osteogenesis imperfecta, benign bony tumors or cysts, metastatic malignant disease to the bone.

Stress fracture: typically an overuse injury. The muscles become fatigued and are unable to absorb the typical shock associated with the activity. These fractures typically occur in weight bearing lower legs and feet.

Initial Management

During the initial evaluation of the patient with an orthopedic injury, the first step is to ensure that a life or limb-threatening process is not occurring. As described, an evaluation of the limb for pulses, capillary refill, sensation and the presence of displacement or an open injury is paramount. For those with injuries that result in these processes, emergent orthopedic consultation is required. In some cases, reduction may be needed prior to orthopedic arrival and should be done by the emergency physician.

Once the patient and extremity is determined not to require emergent intervention, the following should be considered:

Pain Control – orthopedic injuries are quite painful given the involvement of broken bones, ligaments, tendons or swelling. The use of intravenous pain medications is indicated, but oral medications, joint injections or hematoma blocks can also be used, depending on the injury, patient considerations and treatment necessary in the ED. To help control swelling, elevate the extremity when able and apply ice can help with comfort. For distal extremity injuries, remove watches, rings or jewelry on the affected extremity to avoid constricting of the extremity due to swelling.

Imaging – unless emergent reduction is required due to a pulseless limb, imaging should be obtained to characterize the injury and to ensure the appropriate treatment is initiated. With current technology, bedside imaging with portable machines can be expedited in most cases even when pulses are in question.

No oral intake – keep the patient NPO until it is determined that surgery or procedural sedation won’t be required.

Reduction of the fracture or dislocation – for closed fractures or dislocations, reduction takes precedence when there is any limb ischemia or lack of pulses and emergent reduction is required. It is important to reduce a fracture or dislocation to restore anatomic appearance, alleviate pain, and relieve tension on the tissues. This most often requires appropriate sedation and monitoring of the patient and can be done at the bedside in the ED with procedural sedation. After a reduction has been performed, obtain a post-reduction imaging to ensure successful alignment.

Open fractures – when a fracture is identified as being open (i.e. bone protruding through the skin or a puncture of the skin overlying a fracture), the approach and management are different. This management includes tetanus prophylaxis, antibiotics and irrigation and debridement, often in the operating room. Early administration of antibiotics is important for open fractures, typically with a first-generation cephalosporin and an aminoglycoside if the wound is severe or with a penicillin when there is contamination by plants or soil.

Splinting - used to immobilize a joint for fractures and for dislocated joints that have been reduced. This involves the use of plaster or fiberglass. Both require contact with water to initiate a chemical reaction that leads to hardening of the material. Liberal use of padding of the affected limb or joint before splinting is necessary for the comfort of the patient and protection from the exothermic reaction of the splint material. Often, the simple act of immobilizing a fracture or reduced joint with splinting significantly reduces pain. Additionally, there are numerous commercially available devices that can help immobilize a joint of fracture like a shoulder immobilizer, sling, knee immobilizer or a short-leg walking boot. All of these devices and splinting materials are variable depending on the institution, but the principles of immobilizing are still the same. While the discussion of the various types of splints are beyond the scope of this chapter, there are many good resources available to help guide the choices and application of them.

Pearls and Pitfalls

Assessing the neurovascular status needs to occur with the initial evaluation of the injured extremity. The priority to is to identify a pulseless limb.

Utilize orthopedic consultation for any injuries that will require surgery or have life or limb-threatening potential for the individual.

Description of an orthopedic injury to a consultant over the phone is important to ensure appropriate management occurs

Become proficient at the basic principles of splinting a limb or joint as these can be applied in a variety of settings.

References

Sherman, S. (2015). Simon's Emergency Orthopedics (7th ed.). China. The McGraw-Hill Companies, Inc.

Stapczynski, J. S., & Tintinalli, J. E. (2016). Tintinalli's emergency medicine: A comprehensive study guide (8th ed.). New York, N.Y.: McGraw-Hill Education LLC.