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.
Terminology
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.
Fixation Principles
External Fixation
Internal Fixation
Pins and Screws
Pins and screws are the simplest implants. They can be introduced in a variety of areas and are often placed percutaneously through a poke hole in the skin. Kirschner wires may be used temporarily and frequently are used for the stabilization of small fragments. They can also be used provisionally to hold the fracture reduction while more stable fixation is applied. Screws can be used for interfragmentary compression when placed with a lag technique (Fig. 20-6). This technique involves the use of a gliding hole in one fragment to allow the screw to compress one fragment against another. Figure 20-6B shows a position screw. Without a gliding hole, a fully threaded screw will capture both fragments without compressing the far fragment to the near one, thus holding the position of the fragments.
Plates
Tension Bands
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).
Patient Evaluation
History
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 |
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.
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.
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
Hip
A hip series consists of AP and cross-table lateral x-rays. In an adult patient with acute groin pain and inability to bear weight, an occult hip fracture should be ruled out with an MRI or bone scan. In older patients with occult osteopenic hip fractures, bone scans, although accurate, are unreliable within 48 hours after injury. MRI has been shown to be at least as accurate as bone scans in the diagnosis of acute fractures. Additionally, the sensitivity and specificity of MRI were the same within 24 hours of admission as later. Earlier diagnosis can potentially lead to shorter hospital stays and, therefore, in theory offset the additional cost of MRI. In patients with femoral shaft fractures, the incidence of ipsilateral femoral neck fracture is as high as 9%. A protocol of AP internal rotation views of the hip, as well as thin cut CT (2-mm cuts) through the femoral neck in the emergency department (ED), has been shown to decrease the incidence of delayed diagnosis of this injury.12
Foot
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