Emergency Care of Musculoskeletal Injuries

Chapter 20 Emergency Care of Musculoskeletal Injuries





Epidemiology of Orthopedic Injuries


Accidents continue to be a prominent cause of death and disability throughout the world. In the first 5 decades of life, trauma accounts for more deaths than any other cause. In all age groups, accidents are the fifth leading cause of death in the United States. In general, the amount of energy absorbed by a multiply injured patient corresponds to the extent of the musculoskeletal injuries. Because high energy is frequently involved, fractures and soft tissue injuries are common. Campbell et al found a 49% incidence of musculoskeletal injury among 5900 trauma patients seen at a level on trauma center from 2004–2006.1 When the disability associated with musculoskeletal injuries is tabulated, the ensuing costs are staggering; hundreds of billions of dollars are consumed by medical expenses, lost productivity, and property damage annually.


At the national and global levels, substantial improvements in transportation safety and delivery of medical care have helped address this growing pandemic. Seatbelt and helmet laws, enforcement of drunk driving laws, mandates for improved safety features in automobiles, rapid deployment of emergency medical teams, and establishment of trauma centers have decreased the number of accident scene fatalities. With more victims now likely to survive accidents that might have been fatal in the past, caregivers will be challenged with managing more complex fractures and soft tissue wounds. These realities demand that trauma teams be aware of the frequency and consequences of musculoskeletal injuries in every trauma patient. An appreciation for the unique features of skeletal injury in patients who may also have severe head, thoracic, or intra-abdominal trauma is essential. In this way, a cohesive, integrated approach to the diagnosis and treatment of musculoskeletal injuries may be used in the care of the multiply injured patient.



Terminology


Communication among collaborating specialists is central to patient care. Trauma and emergency department findings need to be relayed precisely to consulting specialists. This task is particularly challenging in view of the variety of anatomic locations, fracture patterns, and associated soft tissue injuries encountered in orthopedics. Although many injuries are identified by eponyms within the orthopedic community, the most practical and universally understood characterizations of injuries are those that adhere to basic anatomic and mechanical principles.



Fracture Types


A fracture is a disruption of the normal architecture of bone. Fractures can be acute, subacute, or chronic. Acute fractures have sharp, well-defined edges of the fragments. Subacute fractures have signs of healing present on x-ray. The edges become blunted and less well defined as bony resorption and new bone formation occur. Chronic fractures have a rounded and sclerotic appearance after resorption and remodeling of bone has occurred at the fracture ends (Fig. 20-1). This distinction can usually be made on clinical examination. Chronic fractures are often termed delayed unions or nonunions. A delayed union is defined as a fracture that is taking longer to show progression toward healing than would normally be expected. The expected healing time varies, depending on the age of the patient and anatomic location of the fracture. For example, long bones in adults typically take 6 to 8 weeks to achieve full bony union, whereas pediatric fractures and metaphyseal fractures take less time. A nonunion is a fracture that has lost the potential to progress with healing. Generally, nonunion of a long bone is a fracture that has failed to show evidence of healing over a 4- to 6-month period.2 Chronic repetitive trauma can also cause microscopic disruptions when bone is stressed beyond its failure point. These injuries are termed stress fractures and are considered overuse injuries.



Because of increased plasticity, a more substantial periosteum, and the presence of growth plates, children’s bones are at risk for a different set of fractures (Fig. 20-2). Plastic deformity of a long bone in a pediatric patient is deformation of the bone without actual disruption of the bony cortex. Diagnosis of the deformity often necessitates radiography of the contralateral extremity to confirm asymmetry. Axial loads of long bones in children can lead to buckling of the cortex without a visible fracture line, appropriately termed a buckle fracture. Incomplete disruptions of the cortex are termed greenstick fractures in children or infractions in adults. A greenstick fracture consists of a cortical disruption on one side of the bone, with a buckle fracture or plastic deformation on the opposite side. The dense periosteal layer in children can contribute stability to many of these fractures if the layer remains intact. A fracture through the cartilaginous growth plate (physis) is another fracture type unique to children. A pure physeal fracture may not be radiographically apparent. These fractures are diagnosed clinically by the presence of pain over the growth plate.



When a bone fails through an area weakened by preexisting disease, it is termed a pathologic fracture. Causes may include weakness from primary bone tumors, metastatic lesions, infection, metabolic disease, and injury to an old fracture site. Although not commonly referred to in this way, fractures in osteoporotic bone are technically pathologic. However, the term insufficiency or fragility fracture is most frequently used to describe these injuries. In distinction to acute fractures in healthy bone, fragility fractures normally result from accidents with much lower energy, such as a fall from standing height. Hip fractures, compression fractures of the vertebral bodies, and distal radius fractures in older adults are common examples.


A fracture is considered open when an overlying wound produces communication between the fracture site and the outside environment. These fractures can range from an inside to outside poke hole in the skin to severe crush injuries. High-energy fracture patterns indicate that the soft tissues, as well as the bones, have absorbed large forces. Although the skin laceration is the most obvious component, the energy of the fracture, degree of contamination, and soft tissue injury must all be taken into account when grading the severity of the injury. Final grading of open fractures cannot be accomplished until all necrotic or contaminated tissue has been removed. Contamination of bone can lead to the development of osteomyelitis and all its catastrophic consequences, and thus necessitates emergency treatment.


An intra-articular fracture extends into a joint. When there is significant cartilage damage, late degenerative changes are likely. These injuries are normally caused by a compressive, or axial, load across the joint. Displaced intra-articular fractures require urgent anatomic reduction and rigid fixation to minimize the risk of post-traumatic arthritis. Anatomic reduction can be achieved directly with open arthrotomy or by arthroscopic means. It can also be achieved indirectly with fluoroscopic guidance.


Long bone fractures are characterized by anatomic location (Fig. 20-3). The epiphysis includes the area between the physis, or physeal scar, and articular surface. The metaphysis is located between the epiphysis and shaft and includes the growth plate. The diaphysis encompasses the shaft of the bone between the proximal and distal metaphyses. The diaphysis is made up of mostly dense cortical bone, which has less vascularity than the soft cancellous bone of the metaphysis. This difference in vascularity affects the rate at which the bone heals. Fractures can be described according to location within these three sections or according to the location in the bone—proximal, middle, and distal. In addition, fractures within the diaphysis are usually divided into thirds (i.e., proximal, middle and distal thirds). Distally, the humerus and femur flare to form their articular surfaces. These flares are termed the epicondyles, and fractures in these areas are referred to as supracondylar or intracondylar. The articular surfaces distal to the epicondyles are known as condyles. Intracondylar fractures are intra-articular and may extend proximally. Such distinctions are important because these injuries present difficult treatment challenges.



A fracture may also be described by the pattern of cortical disruption (Fig. 20-4). The orientation of the primary fracture line may be transverse, oblique, or spiral. Transverse and oblique fractures occur when a bending moment is applied. Oblique fractures can be further characterized as long or short oblique. Spiral fractures generally result from a rotational force about the long axis of the bone. Comminution is the presence of multiple fragments within an individual fracture site and usually indicates a higher-energy injury or weakened bone in an older patient. A butterfly fragment is an area of comminution in one of the simple fracture patterns described earlier. Segmental fractures are fractures that occur at multiple levels in the same bone.



Displacement, if present, is described from a combination of principles. These deformities may occur in any plane. When viewed on plain radiographs, all injuries will be resolved into pure coronal or sagittal displacement. However, it is important to realize that the true displacement usually occurs in a plane that is somewhere in between. Translation, angulation, rotation, and shortening are all components of fracture displacement. Translation is the relationship of the proximal fracture fragment to the distal one. It is described in terms of percentage of overlap. A fracture with 100% translation in any plane is completely displaced. Angulation is simply the angle created by the displaced fracture fragments. It is described by the direction of the apex formed by the fracture fragments (i.e., 20-degree apex lateral). The final component is rotation. To describe rotation exactly, a full-length film of the limb segment involved, including the joints above and below, must be examined. Alternatively, rotational deformity may be assessed clinically by comparing the injured limb with the contralateral side.


Once a fracture has been identified, it must be described in a consistent, systematic manner. All descriptions begin with whether the fracture is open or closed. The amount of soft tissue involvement is described. A closed fracture is assumed if, after careful evaluation, there is no observed communication between the fracture and outside world. The presence of an intra-articular fracture is then communicated. The side of the body and injured bone are stated next. A description of the pattern, followed by its location in the bone, is indicated. The displacement of the fracture fragments is related. Finally, it is important to indicate any associated, nonorthopedic injuries that may alter the timing and type of initial orthopedic management. Adherence to this scheme allows complete understanding of the fracture.



Other Injuries


Ligamentous injuries are commonly encountered in association with traumatic injuries to bones and joints. When a ligament is damaged but is still in continuity, it is termed a sprain. Sprains can range in severity from minor injuries to significant instability about a joint. Grade I ligamentous injuries are caused by stretching of a ligament or ligament complex. They do not normally result in instability. A simple ankle sprain is a typical example of this type of injury. Partial ruptures of ligaments can result in minor instability and are considered grade II injuries. Complete ruptures, or grade III injuries, lead to significant instability at the associated joint. Avulsion fractures at the insertion of ligamentous structures also fall into this category. Ligamentous injuries cannot be overlooked because they can produce significant joint instability and endanger the surrounding soft tissue and neurovascular structures. This detail is critical when evaluating musculoskeletal injuries. A full neurovascular examination should be performed whenever there is suspicion of joint instability. Although most ligamentous injuries do not require urgent orthopedic management, stabilization or immobilization of the joint with a splint or brace is usually advisable.


A strain is an injury to a muscle or tendon. These injuries are most commonly of an overuse nature. Further loading of the already weakened structure can compound these injuries and lead to muscle or tendon rupture. Rest, ice, compression, and elevation are the mainstays of treatment for a strain; however, more urgent orthopedic management is necessary for a rupture. Although many tendon ruptures can be treated nonoperatively, proper positioning of the joint is important to ensure that the tendon scars down in a functional position. If operative management is pursued, it should occur fairly urgently. Scarring of the tendon tract and contracture of the muscle significantly complicate the operative procedure.


Joint injury without fracture is common in axial load injuries. Articular contusions, or bone bruises, usually heal with a period of rest and restricted weight bearing, but can lead to late degenerative changes in the joint. A more significant osteochondral defect (OCD) occurs when a piece of articular cartilage, along with its underlying subchondral bone, is separated from the surrounding joint surface. Small OCD lesions can be asymptomatic; however, many of these lesions can lead to chronic pain and joint degeneration. In some cases, the osteochondral fragment is large enough to see on plain radiographs. In these cases, it is important to immobilize the joint to minimize joint damage from the free-floating bony fragment. Other commonly injured joints are the intervertebral discs in the spine. These discs are made up of a viscoelastic nucleus pulposus surrounded by a dense, fibrous, annulus fibrosis. With a great enough axial load, the nucleus pulposus can herniate through the annulus, resulting in a disc herniation. This disc bulge can impinge on nerve roots, causing back and radicular pain. Disc herniations rarely need surgical intervention and often resolve with a course of physical therapy. Very rarely, severe disc bulge in the lumbar spine can cause significant impingement on the cauda equina, resulting in cauda equina syndrome. This is a surgical emergency and will be discussed in more detail later in the chapter.



Fixation Principles



External Fixation


External fixation provides stabilization of an injured limb segment through the use of pins or wires embedded in the bone. These pins are then connected to rods or rings via clamps. With the exception of the pins or wires, the rigid construct is external to the body, as the name implies. Newer designs are more complex, but easier to apply and more stable than previous designs. The addition of modularity has added to their prospective uses and has led to more adaptable and adjustable constructs.


External fixation is used for the treatment of open fractures, fractures in unstable patients who cannot tolerate significant anesthesia times or blood loss, complex fractures in which open reduction and internal fixation (ORIF) is not warranted, and fractures with associated vascular injuries requiring stabilization and urgent vascular repair. Specialized external fixation devices are also used in limb reconstruction surgery. In fractures with soft tissue injuries, placement of percutaneously inserted pins that minimize further soft tissue damage and avoid the area of contamination helps decrease the incidence of infection and delayed union. External fixators may be used for temporary stabilization or for definitive treatment in select cases. In complex fractures around joints, fixation with implanted plates or screws may not provide adequate stability. Additionally, overlying soft tissue damage makes operative exposure dangerous. In these cases, an external fixator, with the pins placed at a distance from the fracture and injured soft tissues, can provide the osseous stability necessary for fracture healing.


External frames are constructed from three components, pins, connectors, and rods or rings (Fig. 20-5). Pins are threaded or smooth and vary in length and diameter. They serve to connect the bone to the rest of the device. Pin placement is chosen to stabilize the fracture best while not compromising the viability of the fragments. Pins are never placed through compromised or infected skin. A variety of different clamps serves as connectors and secure pins to the rods that form the external frames. Most are universal joints that allow multiple degrees of freedom. Connecting clamps have advanced to the point that they now snap in place onto the pins and rods. They may be combined with rings or hinged rods and allow infinite permutations of frame constructs. Stabilizing rods are almost universally radiolucent to allow radiographic examination after application. Threaded rods, bone transport rails, motorized lengthening devices, and dynamic struts represent a small sample of the types of rods that can be used to achieve specific results.



There are a number of factors affecting the stiffness of the fixation construct. The stiffness of the pin material (usually stainless steel) and connecting bar material (titanium, stainless steel, or carbon fiber), as well as the diameter of the pins and bars, contributes to the stiffness of the frame. However, the loss of stiffness seen with more flexible materials, such as carbon fiber, or smaller diameter pins can easily be overcome by the frame configuration chosen. Increasing stiffness is seen with an increasing number of pins, increasing pin spread (distance between pins), decreasing distance between the bar and bone, increasing number of bars, and use of multiplanar constructs.


Once applied, external fixators require regular care and monitoring. Pin care is begun immediately and consists of cleansing with normal saline or half-strength peroxide solution. Drainage from pin sites must be addressed with local care, antibiotics, pin removal and replacement, or a combination of these measures. Pins are checked regularly to ensure that they have not loosened. Depending on the fracture pattern, fixator construct, and goals of treatment, the weight-bearing status is adjusted.



Internal Fixation


ORIF implies that an incision is made at or near the site of injury to facilitate reduction of the fracture under direct vision (open reduction) and rigid stabilization with plates, screws, wires, rods, or combinations thereof (internal fixation). This technique allows anatomic reduction and the creation of constructs of varying levels of stability. Different types of implants can be used to achieve these results.




Plates


Plates are used frequently for the internal fixation of fractures. They allow even distribution of force across their length and can serve various biomechanical functions. The biomechanical properties of a plate depend on the material used, usually titanium or stainless steel, dimensions of the plate (thickness, width, and length), and technique with which it is applied (Fig. 20-7).



A neutralization plate is used to protect another form of fixation from excessive force. Often used in combination with a lag screw, these plates add stability by preventing torsion and bending. The addition of a neutralization plate allows mobilization earlier than would have been possible with less stable fixation.


Buttress plates are used to counteract forces that occur with axial loading. Longitudinal and oblique fractures near joints tend to displace along the line of the fracture when subjected to axial loads. Plates placed in a longitudinal fashion can form an axilla with the intact cortex that prevents axial displacement. Some plates are specifically designed for buttressing; however, any plate can be applied in a buttress mode.


Compression plating is used to increase the stability of fixation when the two major fracture fragments can be brought into contact. This technique allows direct compression of the fracture ends. Compression plates have oval screw holes with oblique edges that allow eccentric placement of screws. When a screw is applied eccentrically, the plate (and bone fragment fixed to it) translates as the screw tightens down against the plate to create compression at the fracture. Additionally, compression can also be achieved by overbending a plate or by introducing a tensioning device.


Highly comminuted and segmental fractures may not allow anatomic reduction and direct fixation of all the fragments. In these situations, a bridge plate can be used to stabilize a long bone rigidly. The proximal and distal fragments are rigidly fixed to each other with a plate while the fracture site is bypassed. This concept has been popularized because it allows less dissection at the fracture site, which may devitalize the comminuted and segmental fragments.


Special plates have been designed for certain fracture patterns and anatomic locations. Blade plates, dynamic condylar screws, and pelvic reconstruction plates are examples of these specialized plates.



Tension Bands


When the forces across a fracture site tend to displace the fractured pieces in tension, the tension band technique can be applied to convert the displacing tensile forces on one side of a fracture into a compressive force across the entire contact area (Fig. 20-8). Traditionally, wires or cables are used to create tension bands. However, nonabsorbable suture and plates can also be used. Tension bands are used most frequently for fractures of the olecranon, where the pull of the triceps tends to distract the proximal fragment, and fractures of the patella, where the pull of the quadriceps tends to distract the superior pole. They are also commonly used for the femoral greater trochanter, humeral greater tuberosity, and medial malleolus.


image

FIGURE 20-8 Tension band principles. A, (1) An interrupted I-beam connected by two springs. (2) The I beam is loaded with a weight (Wt) placed over the central axis of the beam; there is uniform compression of both springs at the interruption. (3) When the I beam is loaded eccentrically by placing the weight at a distance from the central axis of the beam, the spring on the same side compresses, whereas the spring on the opposite side is placed in tension and stretches. (4) If a tension band is applied prior to the eccentric loading, it resists the tension that would otherwise stretch the opposite spring, thus causing uniform compression of both springs. B, The tension band principle applied to fixation of a transverse patellar fracture. (1) The AP view shows placement of the parallel Kirschner wires and anterior tension band. (2) The lateral view demonstrates antagonistic pull of the hamstrings and quadriceps, causing a bending moment of the patella over the femoral trochlea. An anterior tension band transforms this eccentric loading into compression at the fracture site. C, The tension band principle applied to fixation of a fracture of the ulna. The antagonistic pull of the triceps and brachialis causes a bending moment of the ulna over the humeral trochlea. The dorsal tension band transforms this eccentric load into compression at the fracture site. D, The tension band principle applied to fixation of a fracture of the greater trochanter. With the hip as a fulcrum, the antagonistic pull of the adductors and abductors causes a bending moment in the femur. The lateral tension band transforms this eccentric load into compression at the greater trochanteric fracture site. E, The tension band principle applied to fixation of a fracture of the greater tuberosity of the humerus. Using the glenoid as a fulcrum, the antagonistic pull of the pectoralis major and supraspinatus causes a bending moment of the humerus. The lateral tension band transforms this eccentric load into compression at the greater tuberosity fracture site.


(From Mazzocca AD, DeAngelis JD, Caputo AE, et al: Principles of internal fixation. In Browner, BD, Levine AM, Jupiter JB, et al [eds]: Skeletal trauma: Basic science, management, and reconstruction, ed 4, Philadelphia, 2008, WB Saunders.)



Intramedullary Nails


In contrast to wires, plates, and screws, intramedullary (IM) nails are placed in the medullary canal of long bones. They are used to splint or bridge a fracture and to control axial, bending, and rotational forces. IM nailing also permits fixation of a fracture through an incision distant from the fracture site. In this way, the periosteal blood supply at the fracture site is left undisturbed. Nails are made of various materials and can be fluted, smooth, solid, or cannulated (Fig. 20-9). When transverse screws are placed through the proximal and distal ends of the nail, the nail is said to be locked. Locked nails control rotation better and maintain bone length in the presence of comminution or bone loss. The locking holes in nails may be round or oval. Using a nail with an oval hole or leaving the nail unlocked at one end allows the bone fragment to slide axially along the nail and produces compression at the fracture site. Nails locked in this fashion are dynamically locked. When screws are inserted through round holes in both ends of the nail, no motion is allowed within the construct; they are statically locked (Fig. 20-10).




IM nails can be introduced in a proximal to distal or distal to proximal direction and are termed antegrade and retrograde, respectively. Nails may be inserted with or without canal preparation by reaming. Reaming involves passing a large drill down the medullary canal to remove the cancellous bone and effectively widen the canal. This increased width allows the insertion of a larger diameter nail to increase the strength and stiffness of the construct. At the same time, reaming morcellizes the cancellous and cortical bone in the canal and deposits this exceptional autogenous bone graft at the fracture site. However, reaming leads to increased pressure in the medullary canal, increased temperature in the cortical bone, and embolization of marrow contents into the vascular system. In patients with severe derangement of pulmonary function or hemodynamic instability, embolization is not well tolerated.


Unreamed nails are inserted without reaming of the canal, and destruction of the cortical blood supply from the medullary system is largely avoided. In fractures in which there is a large degree of soft tissue loss or periosteal stripping, an unreamed nail is generally used.



Patient Evaluation



History


Obtaining a detailed history of a skeletally injured patient is essential for accurate diagnosis and treatment. This can be challenging with multiply injured and older patients in the trauma setting; however, it is important to gather as much information as possible regarding the mechanism of injury. Often, trauma patients are unable to give accurate histories because of unconsciousness, intoxication, dementia, or delirium. In these cases, an account of the mechanism of injury and patient history should be obtained from family members, emergency medical response crew members, or other witnesses to the accident. Descriptions from the injury scene can be helpful because common patterns of injury follow from specific mechanisms (Table 20-1).


Table 20-1 Common Patterns and Associated Injuries

































INJURY PATTERN OR MECHANISM ASSOCIATED INJURIES
Fall from a height



Fall on outstretched hand (FOOSH)


Ejection from a vehicle

T-bone motor vehicle accident


Head-on motor vehicle accident



Posterior knee dislocation
Supracondylar humerus fracture

Anterior shoulder dislocation
Posterior hip dislocation

A general history that includes demographic information, past medical history, past surgical history, and social history are obtained. Knowledge of allergies, current medications, and time since last oral intake is useful in guiding treatment. Information about the position of the limb before and after the injury, as well as the direction of the deforming force, can help predict the resulting injuries. Ambulatory status before the injury helps determine realistic goals for functional recovery. Any transient neurologic symptoms, such as loss of consciousness, numbness, parenthesis, and spasm, must be documented. Loss of bowel or bladder control in patients with back or neck pain must also be noted. The time elapsed since injury becomes critical information in a patient with a vascular injury, open wound, or dislocation.



Trauma Room Evaluation


Examination of a multiply injured patient must first follow advanced trauma life support (ATLS) protocols in a systematic fashion and must be accompanied by appropriate treatment. The concept of life before limb demands that the ABCs (airway, breathing, and circulation) be addressed prior to evaluating for any orthopedic injuries. Hemodynamically unstable patients are assumed to be in hemorrhagic shock until proven otherwise. A search for occult hemorrhage is undertaken and may include the pleural cavities, abdomen, retroperitoneum, and pelvis. A plain chest radiograph may quickly reveal a hemothorax. Chest tubes are placed, if necessary. Pelvic instability and the need for rapid external pelvic fixation are addressed. There is debate over whether the anteroposterior (AP) pelvic film, which has traditionally been considered part of the standard trauma radiographic series, is justified with the advent of newer, ultrafast computed tomography (CT) scanners. Recent data have shown that in a stable awake patient who has no evidence of pelvic injury on physical examination, routine use of this study may not be cost-effective.3 However, in a patient with signs of pelvic injury on examination, hemodynamically unstable patient, or obtunded patient, the pelvic radiograph is essential for identifying unstable pelvic injury requiring immediate intervention in the trauma bay.4 In addition, the pelvic radiograph is necessary for preoperative planning in operative fractures and as a comparison film when following fracture healing over time. A FAST (focused assessment with sonography in trauma) scan has been shown to be a rapid and effective technique for assessing for free fluid in the abdomen.5 Positive scans have been shown to be strongly predictive of the need for laparotomy in hypotensive trauma patients. However, Gaarder and colleagues6 have found that even in the hands of experienced radiologists, the FAST scan is a relatively unreliable technique for detecting intra-abdominal bleeding in the hemodynamically unstable patient. Cha and associates7 have agreed with this conclusion and suggest that diagnostic peritoneal lavage and/or CT of the chest, abdomen, and pelvis be considered in hemodynamically unstable patients with suspected intra-abdominal injuries.


The patient’s neurologic status is noted on admission, and the Glasgow Coma Scale score is calculated. Patients with suspected head injury need to be evaluated as soon as possible by CT. Peripheral vascular injuries and musculoskeletal injuries are next in priority, followed by maxillofacial injuries.


Although the previous dictum of addressing open fractures in the operating room within 6 hours of injury may no longer hold true, open fractures still require relatively urgent operative care. More importantly, emergent trauma room management, including administration of appropriate antibiotics, tetanus prophylaxis, gross débridement, copious irrigation, splinting, and wound coverage, is imperative for preventing future infection. Sterile dressings placed in the trauma room need to be left in place until the patient reaches the operating room. This practice has led to decreased infection rates when compared with routinely redressing wounds in the trauma area.


In their landmark article, Bone and coworkers8 have shown that urgent (within the first 24 hours) versus late stabilization in the multiply injured patient reduces the incidence of adult respiratory distress syndrome (ARDS) and multisystem organ failure. In addition, with adequate stabilization of the fracture, the patient can be mobilized, avoiding convalescence. However, more recently, Morshed and colleagues9 have shown that emergent fixation—within 12 hours—of femoral shaft fractures in polytrauma leads to an increased mortality rate. They suggest that this finding is likely caused by inadequate time for patient resuscitation in those taken to surgery in the first 12 hours from the time of injury. In isolated or less severe injuries, once the patient is stabilized, the timing of repair is less significant. Operative delay allows for resolution of the soft tissue swelling that may compromise soft tissue closure.


Unstable pelvic fractures are addressed in the primary survey because of the possibility of exsanguination. Traumatic spine injuries with associated neurologic compromise also deserve immediate attention. These exceptions aside, examination and management of the extremities are deferred to the secondary survey after the airway has been controlled and hemodynamic stability has been obtained. In a team approach, these examinations and treatments take place simultaneously. One caveat to this protocol is the conscious patient who is able to follow commands, but will need intubation to protect his or her airway. In this case, a cursory neurologic examination of the extremities should be performed prior to sedation or intubation. Documentation of motor and sensory function in the upper and lower extremities is valuable information and only takes seconds to carry out. Throughout the resuscitation phase and during the remainder of the hospital course, reexamination in the form of the tertiary survey will ensure that no injury goes unrecognized.


Evidence of pelvic fractures is assessed early in the resuscitative effort. Massive flank or buttock contusions and swelling are indicative of significant bleeding. The Morel-Lavallée lesion is an ecchymotic lesion over the greater trochanter that represents a subcutaneous degloving injury. This lesion is frequently associated with acetabular fractures. Blood at the urethral meatus, signifying injury to the genitourinary tract, may be a sign of an underlying pelvic fracture. Palpation of the symphysis pubis and the sacroiliac joints can help determine the presence of disruption of these joints. Gentle rocking and lateral compression through the anterior iliac crests can provide helpful clues to the stability of the pelvic ring. Any opening or looseness signifies instability and may represent a source of hemorrhage. Rectal and vaginal examinations are performed, noting the presence of gross blood, lacerations, bony fragments, hematomas, or masses. Wounds and palpable bony fragments found on either of these examinations are diagnostic of an open pelvic fracture, which carries a poor prognosis. Rectal examination can also reveal a high-riding prostate gland, another indication of injury to the genitourinary tract.


The trauma team must always take steps to protect the patient from self-inflicted or iatrogenic spinal cord injury. Therefore, full spine precautions must be observed until it is confirmed that the patient’s vertebral column is intact, either by physical examination and clinical findings or by radiologic confirmation, when warranted. Fitting the patient with a hard cervical collar stabilizes the cervical spine. Maintaining the patient in a supine flat position at all times protects the thoracic, lumbar, and sacral segments of the spine. If the patient is to be moved, a strict log roll technique is used. At times, a patient may have to be physically restrained to prevent potential self-inflicted injury by head or lower extremity movements that could impart rotational, translational, or bending moments to the vertebral column. Special care must be taken with combative patients or those with altered mental status who may have lost the ability to protect themselves from further injury. On examination of the back, the examiner notes the presence of deformity, edema, or ecchymosis. Tenderness elicited on palpation of the spine is recorded for each level at which the patient complains of pain. Distinction is made regarding whether the pain is midline or paraspinal. Perianal sensation and rectal sphincter tone should be evaluated to test sacral nerve root function. Deep tendon reflexes and pathologic reflexes, such as the bulbocavernosus and Babinski reflexes, are tested.


Plain radiographs of the cervical spine, including AP, lateral, and open-mouth odontoid views were previously considered part of the standard trauma series of radiographs. Recently, however, Mathen and associates have shown that the standard plain films fail to identify 55.5% of clinically relevant fractures identified by multislice CT and add no clinically relevant data.10 Similarly, a CT of the thoracic, lumbar, and sacral spine is faster and more accurate than radiography at identifying traumatic injury. With most trauma patients undergoing a CT of the chest, abdomen, and pelvis, reformatting the data into spinal reconstructions adds neither time nor radiation exposure. With this data, plain films are no longer indicated.


Examination of the extremities in a patient with isolated injuries or a multitrauma patient follows a simple, systematic, and reproducible pattern. Even when an isolated extremity injury is the primary reason for evaluation, the entire skeleton must be examined. The examiner must not be distracted from the task by obvious or severe injuries. Deformity, edema, ecchymosis, crepitus, tenderness, and pain with motion are the cardinal signs of an acute fracture. Each limb segment needs to be examined for lacerations and the signs of trauma described earlier. All joints are put through passive range of motion, at a minimum. Active range of motion is tested whenever possible. Joint effusions are evidence of intra-articular pathology (e.g., ligament or cartilage damage, or an intra-articular fracture). The joints are then manually stressed to assess the integrity of the ligamentous structures. A neurovascular examination is performed and documented. Pulses are recorded and compared with the opposite uninvolved extremity when possible. Doppler signals are obtained when palpable pulses are not present or are weak. Measuring the ankle-brachial index (ABI) is important when vascular injury is suspected. Motor function and sensation must be documented for the extremity dermatomes as well as the trunk in a patient with thoracic spine pain. To avoid the complications of a missed compartment syndrome, palpation of the involved compartments is performed. Any firm or tense compartments are checked for increased pressure if time and the patient’s condition allow. Fasciotomies are performed urgently if pressures are elevated. Gross alignment and interim immobilization of long bone fractures are achieved before transportation of the patient from the trauma room. This helps prevent further damage to underlying soft tissues, reduces patient discomfort, facilitates transportation, and may help prevent further embolization of IM contents.11 Traction splints or skeletal traction are applied when indicated.



Diagnostic Imaging


Radiographic examination is used to supplement and enhance the information gathered during the primary survey, history, and physical examination. In a multiply injured patient, the ATLS protocol calls for a lateral cervical spine film and AP views of the pelvis and chest. However, as noted earlier for a stable, conscious patient with no physical examination findings of pelvic trauma, the pelvic film may be deferred for the pelvic CT. Cervical spine x-rays should be deferred for a CT of the cervical spine (if available). The secondary survey then dictates which extremity radiographs are necessary. When filming long bone injuries, it is important to verify the integrity of adjacent limb segments. Therefore, the joints above and below the level of injury are always included in the films. They are filmed separately if the cassette is not large enough to accommodate the entire view. Similarly, when pathology is suspected in a joint, the long bones above and below are also imaged. This practice helps identify commonly associated injuries to the adjacent limb segments that might otherwise be missed.


Because bone is a three-dimensional object, a single two-dimensional radiograph cannot describe a fracture. To understand the position and direction of the fracture fragments, orthogonal views (images taken at 90 degrees to one another) must be obtained. A bone may appear minimally displaced in one plane, but in another view may be significantly displaced (Fig. 20-11). All extremities with deformity need to be rotated to the anatomic position before taking radiographs to help decrease confusion when describing the fracture. When finer detail is necessary to evaluate a fracture pattern better or confirm the findings of an equivocal x-ray, a CT scan should be ordered. Magnetic resonance imaging (MRI) has become a particularly useful imaging modality. It is used to evaluate soft tissue, acute fractures, stress fractures, spinal cord injuries, and intra-articular pathology. Its role in the trauma setting has expanded as well, and it is particularly helpful in the setting of spinal cord injury. More frequently, MRI is used in the outpatient setting to evaluate soft tissue injuries and pathologic lesions. MRI is now commonly used for the diagnosis of acute fractures when plain films are negative.



Although AP and lateral views are generally adequate for most long bone fractures, there are a number of osseous structures that necessitate specific radiographs or routinely require more specialized studies, such as CT or MRI.





Pelvis and Acetabulum


The standard AP radiograph of the pelvis provides an overview to the structural integrity of the hips and pelvic ring. If pelvic pathology is noted on this film or suspected from physical examination, further views are necessary. Judet views, or 45-degree oblique views of the pelvis, are used to evaluate the acetabuli (Fig. 20-14). Because of the spatial orientation of the acetabulum, these views represent orthogonal projections when the x-ray tube is canted toward or away from the affected side. Similarly, inlet and outlet views of the pelvis allow closer examination of the sacroiliac joints and the sacrum itself, as well as identifying AP disruption in the pelvic ring. The inlet view is taken with the beam angled 60 degrees caudad, thus making the beam perpendicular to the pelvic brim. The sacral ala, displacement of the sacroiliac joints, and displacement of the pubic symphysis in the AP plane are easily seen. The outlet view is a 30-degree oblique view, with the tube angled cephalad. The sacrum is pictured en fosse, and the neural foraminae are easily evaluated. If not already obtained as part of the trauma workup, a pelvic CT should be ordered to evaluate fractures of the acetabuli and sacrum. This allows detailed evaluation of the amount of articular involvement, displacement, and presence of bony fragments within the joint. It also provides information regarding sacral displacement or neural foraminal involvement. Finally, it allows evaluation for intrapelvic hematoma. MRI has little role in acute, traumatic pelvic ring injury; however, it is the imaging modality of choice for suspected osteomyelitis or pelvic abscess.






Ankle


In the ankle, it is important to confirm maintenance of the mortise. The stability of the mortise depends on bony and ligamentous support. With AP, mortise, and lateral x-rays, disruptions in the bony anatomy can be visualized directly. Although the ligamentous structures cannot be visualized directly, assumptions about their continuity can be made by evaluating the spaces between the bones. Three main parameters are commonly used are the tibia-fibula overlap, tibia-fibula clear space, and medial clear space (Fig. 20-16). All three parameters should be measured on the AP radiograph. The medial clear space is the distance between the medial border of the talus and lateral border of the medial malleolus. A normal value is less than 4 mm. The tibia-fibula clear space is the distance between the medial border of the fibula and floor of the incisura fibularis. A normal value is less than 5 mm. The tibia-fibula overlap is the amount of the lateral tibia overlapping the medial fibula. A normal value is more than 10 mm. In an adult ankle, there should be some degree of tibia-fibula overlap in all views. Both the tibia-fibula clear space and overlap are measured 10 mm proximally to the tibial plafond. Excluding a direct blow injury, sustaining an isolated medial malleolar fracture is exceedingly rare. Most ankle injuries are caused by a twisting moment imparted to the ankle. The energy that enters through the medial malleolus must exit at some point on the lateral ankle. This may result in a lateral collateral ligament tear (rare), lateral malleolar fracture, or a more proximal fibula fracture. In some cases, the energy passes through the syndesmosis and exits at the proximal fibula. This is known as a Maisonneuve fracture. The disruption results in an unstable ankle mortise, which influences the treatment plan. Because of this, any isolated medial malleolar fracture should always get full-length AP and lateral tibia-fibula x-rays. In the case of an intra-articular fracture of the weight- bearing surface of the tibia (pilon fracture), a CT can be useful to evaluate the joint surface.




Foot


When an injury of the foot is suspected, the workup should start with a standard series of AP, lateral, and oblique x-rays. However, because of the complex three-dimensional structure of the foot, this standard series of films may not be adequate to visualize certain bones. In the case of a calcaneus fracture, a Harris axial view should be added to evaluate the varus-valgus alignment of the tuberosity, as well as any sagittal splits in the bone. Bohler’s angle—an angle formed by the bisection of a line drawn from the superior aspect of the calcaneal tuberosity to the superior aspect of the posterior facet and a line drawn from the tip of the anterior process to the superior aspect of the posterior facet—should be evaluated in the lateral view (Fig. 20-17). A normal Bohler’s angle is between 20 and 40 degrees. A decrease in this angle usually indicates fracture, with depression of the posterior facet. When in doubt, films of the uninjured foot should be taken for comparison. For fractures of the talus, the AP and lateral films should be evaluated for articular congruence at the tibiotalar, subtalar, and talonavicular joints. There are specialized views of the bone (e.g., Canale view for the talar neck and Broden’s view for evaluation of the subtalar joint); however, these views are radiology technician–dependent. In many cases, if a fracture is seen on the AP or lateral views, a CT scan is a faster and more cost-effective way to evaluate the displacement pattern. If x-rays are negative or equivocal and the patient has evidence of fracture—ecchymosis, pain out of proportion to plain film findings, significant soft tissue swelling—then a CT scan should be ordered. All but the most minimally displaced intra-articular fractures of the talus and calcaneus warrant a CT scan to define the fracture pattern and extent of articular displacement better. Except in the case of suspected osteomyelitis, MRI of the foot is of little use in the emergency setting.


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Aug 1, 2016 | Posted by in CARDIAC SURGERY | Comments Off on Emergency Care of Musculoskeletal Injuries
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