The pelvis is an extremely well-supported structure that generally requires a severe traumatic force to disrupt. High energy injuries resulting in complex fractures within the pelvic ring signify major trauma and carry an estimated 21% associated mortality.14 Blunt trauma from falls, side impact motor vehicle accidents, motorcycle crashes, and pedestrian versus vehicle injuries are common causes of pelvic instability.15
The strong posterior attachments of the sacroiliac, sacrospinous, and sacrotuberous ligaments provide stability between the bones of the pelvic ring (Figure 56-4).16 The pelvis protects the iliac arteries and its branches, pelvic venous plexus, and lumbar and sacral nerve roots which course through the posterior pelvis. It also houses the genitourinary system plus the descending colon, sigmoid, and rectum. Hemorrhagic shock from pelvic injury occurs via three main mechanisms: arterial or venous plexus injury, fractures, and injury to other intrapelvic organs. Hemorrhage from the pelvic venous plexus accounts for 90% of cases of pelvic hemorrhage.17
Major stabilizing ligaments of the pelvic ring. (Reprinted with permission from Tintinalli JE, Stapczynski JS, Ma OJ, Cline DM, Cydulka RK, Meckler GD, eds. Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7th ed. New York, NY: McGraw-Hill; 2011. Figure 269-1.)
Traumatic injuries to the pelvis are suspected in any patient after a high-energy injury or in any trauma patient presenting with hemodynamic compromise. There are four well-described patterns of pelvic injury based on the Young and Burgess classification system: lateral compression, anterior-posterior (AP) compression, vertical shear, and complex. Lateral compression injuries result when force applied laterally on the pelvis causes the sacroiliac joint to fracture and become disrupted with a corresponding lateral pubic ramus fracture. The hemipelvis affected rotates internally decreasing pelvic volume which may aid by tamponading bleeding, but injures pelvic vasculature and the genitourinary tract. Lateral compression fractures are the most frequent unstable pelvic fracture and are associated with side impact motor vehicle crashes, motor cycle accidents, or falls from a height onto the patient's flank. AP compression injury results from high-energy force transmitted anterior to posterior or vice versa through a patient. This pattern is often seen with pedestrian versus motor vehicle or head-on motorcycle collisions. The pubic symphysis disrupts and widens and the sacroiliac joints disrupt resulting in the “open book” injury. This pattern increases pelvic volume, allowing for large amounts of hemorrhage to occur. Vertical shear injuries often result after falls from height or motor vehicle crashes where large axial loading forces are transmitted through the femur into the pelvis. The affected hemipelvis disrupts at the sacroiliac joint and displaces vertically. Complex fractures represent a combination of any of the fracture patterns described.
Field examination for pelvic instability is conducted as part of the secondary survey after securing the ABCs and controlling major hemorrhage. Pelvic stability is assessed via a combination of approaches. In the unresponsive patient, physical examination is difficult and unreliable.
Visual examination should be conducted of the flank, perineum, and urethral meatus looking for ecchymosis, bleeding, or open fractures (Figure 56-5). Inspect and palpate the bony prominences of the iliac crests, pubic symphysis, and hips for step-offs, hematomas, or other deformities. The compression distraction maneuver is performed to assess for pelvic instability by applying gentle anterior to posterior pressure (compression) over the iliac crests as well as by applying a light outward force (distraction) assessing for any movement of the iliac crests or report of pain from the patient. Care should be used to ensure no worsening of an open-book-type injury. Indicators of sacroiliac joint disruption or an unstable compression or shearing injury to the pelvis may manifest as a rotational deformity of a leg, usually externally rotated, or as a discrepancy in leg length. Should any signs of pelvic injury be detected on physical examination, prehospital pelvic stabilization is recommended.
A vertical shear pelvic fracture presenting with scrotal edema plus perianal ecchymosis. (Photo contributor: Lawrence B. Stack, MD; Reprinted with permission from Knoop KJ, Stack LB, Storrow AB, Thurman RJ. The Atlas of Emergency Medicine. 3rd ed. McGraw-Hill; 2010. Figure 7.26.)
Examination of the pelvis alone has a poor sensitivity for the detection of pelvic fractures. A 2009 study of over 1500 patients demonstrated that the sensitivity of physical examination in detecting unstable pelvic fractures was only 8% in patients with a GCS of 13 or less.18 In contrast, a study on alert patients with a GCS of 14 or greater noted that 67% of patients with a pelvic fracture complained of pain in the pelvis or low abdomen, while only 32% and 37% had pain with pelvic compression distraction maneuvers and palpation of the pubic symphysis, respectively.19 In patients with altered mental status and hemodynamic instability, detection of unstable pelvic injuries can be very difficult to detect. Foremost, if the mechanism of injury suggests a high risk of pelvic fracture, pelvic stabilization should be considered.
Prehospital stabilization of pelvic fractures is most frequently accomplished by using a pelvic circumferential compression device (PCCD) or simple tied sheet. The use of MAST (military anti-shock trouser) trousers has fallen out of favor due to concerns of decreased venous return and difficulty obtaining access to the patients lower extremities once applied. PCCDs are generally defined as wraps or slings circumferentially placed and tightened around the pelvis, generally at the level of the femoral trochanters. A 2009 meta-analysis of 17 articles studying the effectiveness of PCCDs demonstrated their ability to reduce pelvic fractures and decrease pelvic volume, in turn leading to decreased hemorrhage.20 There is little literature available to show clear mortality improvements by use of PCCDs; however, a small trial in 2010 utilizing PCCDs did demonstrate improved mean arterial pressures and decreased heart rates after placement in a small series of patients with pelvic fractures.21
If a PCCD is unavailable, a sheet may be wrapped around the iliac crests and femoral trochanters and tied in place. In general, approximately 40 lb of force is required to reduce the adult pelvis.22 Do not overtighten such as to compromise blood flow to the lower extremities. Few complications have been reported from the use of PCCDs in the prehospital setting.
HIP FRACTURES AND DISLOCATIONS
Hip fractures encompass three subtypes of proximal femur fractures: femoral head and neck, intertrochanteric, and subtrochanteric fractures. Although important to recognize the different anatomical classifications of hip fracture, they are managed identically in the prehospital environment. Over 250,000 hip fractures occur in the United States annually with 90% occurring in a population of over 50 years of age.23 Unfortunately, there is a large amount of mortality from hip fractures. It is estimated that 14% to 36% of elderly will die within 1 year of their hip fracture.24 Most hip injuries among the elderly result from falls and may have contributing conditions such as osteoporosis, malnutrition, and muscular weakness predisposing them to this injury.25 Head-on motor vehicle collisions where axial load is transmitted up the femur are recognized for causing hip injuries and dislocations in the younger population.
Hip fractures generally present with severe pain causing inability to bear weight on the affected extremity. Patients will often localize this pain to the hip, groin, or low buttock. Classical examination findings are of a shortened and externally rotated leg. Pain is elicited at the hip by palpation at the level of the trochanter or by internal or external rotation or axial loading of the hip joint. Deformity, swelling, and ecchymosis may be present at the hip as well. Neurovascular examination should be assessed, although neurovascular complications of hip fractures are rarely reported.
Transport and immobilization of patients with suspected hip fractures focuses on patient comfort. Often, an injured patient will already have their injured extremity in a position of comfort. Transferring the patient with a scoop stretcher should be considered as logrolling onto a stretcher can be painful. Once on a stretcher, extremity immobilization with towels or pillows to support the patient in a position of comfort is recommended. Hip fractures are generally not immobilized with rigid splints and never with traction.
Hip dislocations as well as fracture dislocations require emergent evaluation. High speed motor vehicle accidents account for the majority of native hip dislocations, especially in the younger population.25 Often multiple traumatic injuries are present simultaneously with a native hip dislocation. Prosthetic hips in elderly patients may dislocate with seeming little force or trauma, even occurring with actions as simple as sitting down. There are three main types of hip dislocations: anterior, posterior, and central. Ninety percent of hip dislocations are posterior dislocations which are frequently caused when large force is applied axially through the femur, dislodging (and often fracturing) the femoral head within the pelvic acetabulum.
Patients with posterior hip dislocations classically present with severe pain at the hip with the leg shortened, internally rotated, flexed at the hip, and adducted. Deformity and bony prominence may be palpated posterior to the hip joint. A thorough neurovascular examination is essential checking specifically for sciatic nerve function. The sciatic nerve courses just posterior to the hip joint capsule and can be easily injured with posterior dislocations. Anterior dislocations frequently occur when the hip is abducted and is suddenly struck and are at high risk for vascular compromise.
Attempted hip reduction in the prehospital setting is discouraged. Radiographs should be obtained to confirm dislocation and assess for concomitant fractures prior to any attempt at reduction.
The strongest bone within the body, the femur requires high amounts of force to fracture. High-energy injuries such as head-on MVCs, pedestrian versus vehicle, and falls from greater than 20 ft are typical mechanisms.26 Pathologic fractures from low impact falls are also commonly reported in the elderly. The incidence of femur fractures is about 1:10,000 in the general population; however, a threefold increase is observed in males less than 30 years and elderly over 80 years.27 A 1986 study of MVCs demonstrated head-on collisions with an average velocity change of greater than 26 mph to have the highest incidence of femur injuries, followed by side-impact collisions with greater than 16 inches of intrusion, while rear-end collisions had no reported femur fractures.28
Femur fractures have a high incidence of reported hemodynamic compromise from associated blood loss. Examination noting pain, swelling, visible deformity, limb shortening, or a rotated extremity is common.
Large, expanding thigh hematomas may result from injury to the metaphyseal arteries which arise from various branches of the deep femoral artery and from the femur's vascular marrow supply. Weak or absent distal dorsalis pedis or posterior tibial artery pulses may identify vascular injuries early. Profuse bleeding causing upward of three units of blood loss into the thigh can result with up to 40% of isolated femur fractures requiring blood transfusions.29
Neurologic examination focuses on function of the sciatic nerve, although neurologic injuries associated with femur fractures are extremely rare.30 Additionally, a thorough examination to rule out associated injury should be conducted. Hip fractures and ligamentous knee injuries commonly are observed in association with femoral injuries.12
Two primary approaches are available for the field stabilization of femur fractures: traction splinting and rigid splinting. Traction splinting was first attributed to decreasing mortality among soldiers in World War I by Sir Robert Jones using the Thomas Splint developed in the late 1800s.31 No large trials exist to demonstrate benefit of traction splints over rigid splinting, thus benefit is based on small series and case reports. Most recently, traction splinting was attributed to decreasing morbidity among a small group of soldiers and civilians in the Gulf War.32
The primary roles of traction splints are to immobilize the extremity and prevent further soft tissue and vascular injury during transport. Secondary benefits of fracture reduction are alleviating pain, decreasing hemorrhage, lessening muscle spasm, and reducing risk of fat embolism. Decreased hemorrhage occurs with fracture reduction by minimizing the amount of elliptical free space surrounding the distracted bone fragments within the thigh.3
Important contraindications to traction splint application include nerve injury or suspected ipsilateral pelvic, hip, knee, tibia, or ankle factures. Should a contraindication for traction splinting exist, a commercially available rigid or soft splint should be used to maintain the extremity in its position of presentation. The use of traction splints for open femur fractures is in debate. There is concern that reduction of an open fracture could further contaminate the wound. If an open femur fracture is reduced with traction splinting, it is important to inform the receiving physician.
Several brands of commercial traction splints exist which can be placed within 2 to 5 minutes by two skilled providers. Examples include the Hare Splint (Figure 56-6), Sager Splint, and Kendrick Traction Device. We recommend reviewing and following the manufacturer's application instructions for each type.
Example of a Hare traction splint. (Reprinted with permission from Tintinalli JE, Stapczynski JS, Ma OJ, Cline DM, Cydulka RK, Meckler GD, eds. Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7th ed. New York, NY: McGraw-Hill; 2011. Figure 2-7.)
The knee joint is prone to many injuries including fractures, dislocations, ligamentous, and meniscal injuries. Historical information about the mechanism of injury and any associated pain, inability to ambulate, locking, or popping is often helpful in identifying injuries of the knee. Examination with pain on palpation, deformity, ecchymosis, crepitus, or decreased range of motion should be suspicious for fracture or soft tissue injury. Assess neurovascular status of the distal extremity. Physical examination should also include assessment of all joints of the affected extremity as hip and ankle injuries may commonly occur with knee injuries. Should concern for fracture exist, splint or support the patient in a position of comfort.
Knee dislocations are rare, but represent orthopedic emergencies. Dislocation is defined as complete loss of tibiofemoral articulation. There are five types of knee dislocations: anterior, posterior, lateral, medial, and rotary. Tremendous energy is usually required to dislocate the knee joint. Motor vehicle accidents are a common cause; however, low impact forces are also reported to cause knee dislocations. Vascular injury, including arterial transection, thrombus, or other disruption may occur in upward of 22% of knee dislocations.33
Physical examination to identify a knee dislocation may be challenging secondary to pain, swelling, and limited range of motion. In severe cases, there is often a very noticeable visual defect from the dislocation.
Optimally, knee reductions should be performed in hospital. Field reduction may be considered if there is a loss of distal extremity perfusion in the setting of a prolonged transport time. Reduction of knee dislocations is successfully performed using longitudinal traction the majority of the time; however, operative reduction is sometimes necessary. Once reduced, the lower extremity should be splinted in 20° of flexion.34 Serial vascular examinations of the lower extremity are required after knee reduction.
Patellar dislocation is common, representing about 2% of knee injuries, with an incidence as high as 5.8 per 100,000 and even higher among adolescents.35,36 It occurs most commonly in adolescents and young adults as a result of rapid quadriceps flexion, hyperextension injury, or direct trauma to the knee. Rapidly pivoting on the sports field is often reported as the inciting mechanism. When dislocated, the patella has been derailed from the knee's intercondylar groove, its normal sliding tract. In the majority of dislocations the patella dislocates laterally and will present with anterior knee pain and the knee in flexion with the patella often palpable lateral to the intercondylar groove.
Reduction of the patella often occurs spontaneously in the field with passive knee extension. As with all dislocations, emergency department evaluation prior to attempted reduction may be preferred; however, when seen acutely by a properly trained provider or EMS physician, an attempt at field reduction may result in acute reduction and rapid pain control. If reduction is to be attempted, the procedure for lateral patellar dislocation reduction is simple. Slowly assist the patient's knee through passive extension while simultaneously applying a lifting force over the lateral edge of the patella until it slips back into the intercondylar groove. This procedure should be relatively well tolerated, although analgesia, and sometimes mild sedation, is commonly employed. If severe pain or resistance is encountered stop as this may signify a more serious injury or underlying fracture. Once reduced, reassess neurovascular status and splint the patient's leg in extension.37
Although there are a multitude of different fracture patterns that may affect the knee, tibial plateau fractures are of particular significance for their high rate of associated neurovascular injuries. Tibial plateau fractures may occur from any combination of axial loading or varus-valgus forces. Common mechanisms include falls onto an extended leg and motor vehicle collisions. Lateral fractures of the plateau are most common and approximately 50% involve associated ligamentous or meniscal injury.38 Physical examination with pain, swelling, or deformity over the proximal tibia is suggestive of this fracture. Decreased perfusion is an orthopedic emergency. For transport, the injured extremity should be splinted with the leg in extension; however, if pain is severe, supporting the patient with soft pillows or towels in a position of comfort is also appropriate.
Lower leg fractures include injuries of the tibia and fibula. Pedestrians struck by motor vehicles, falls, and sporting injuries are common causes of trauma to the lower leg. Physical examination of the lower extremity may show evidence of fracture by eliciting pain with palpation or noting visual deformity, ecchymosis, or swelling. Particular note should be made of any lacerations or puncture wounds over the tibia and fibula as these may signify open fractures. Distal vascular assessment should include palpation of both dorsalis pedis and posterior tibial arteries. Tibia and fibula injures should be splinted to immobilize both the knee above and ankle below.
Compartment syndrome is of particular concern with lower leg fractures, although it can occur within any extremity. The calf contains four fascial compartments, all of which have limited ability to stretch to accommodate pressure. An injury such as fracture, severe contusion, or vascular injury can cause pressure to build within a compartment. Once pressure builds to a level that prevents venous return, a rapid increase in compartment pressure occurs. This will eventually impede arterial flow and cause critical muscle ischemia. Should limb threatening ischemia occur within the thigh due to compartment syndrome, the leg will need emergent operative fasciotomy. Loss of distal pulses is a very late finding in compartment syndrome and therefore presence of distal pulses is not reliable to exclude compartment syndrome. Other findings of compartment syndrome include severe pain in an extremity out of proportion to injury, significant soft tissue tightness or swelling at the injury, pain with passive motion of involved muscle groups, and distal paresthesias or weakness.39 Should a patient present with any concerns for a compartment syndrome, emergent transport to the nearest emergency facility is indicated.
Foot and ankle injuries are among the most prevalent orthopedic injuries that present to emergency departments.40 The majority of injuries represent ankle sprains; however, fractures and dislocations that are more serious may occur and may present similar to a sprain. Fractures of the lateral malleolus of the fibula are the most common and require less force to fracture than the medial malleolus. Patients with ankle fractures or dislocations will denote pain at the ankle joint and are generally nonambulatory. Deformity, swelling, and ecchymosis are all signs consistent with injury. Patient presentations concerning for ankle fracture should be immobilized to prevent movement at the ankle. Short leg posterior or sugar tong splints are ideal for field immobilization about the ankle.
EMS physicians should be aware of the Ottawa ankle and foot rules (Figure 56-7). The rules identify patients with ankle and midfoot injuries who are at high risk of fracture, and should have radiographs to evaluate for fracture. Sensitivity of the rules is demonstrated to be between 96.4% and 99.6% in repeated trials. Specificity is far lower, near 26.3% to 47.9%.41 The rules help reduce the need for radiographic evaluation of ankle injuries through their high sensitivity.
Ottawa ankle rules: Radiographs are required for any injuries of the midfoot and ankle if bony tenderness is elicited in the regions denoted in the figure. (Reprinted with permission from Tintinalli JE, Stapczynski JS, Ma OJ, Cline DM, Cydulka RK, Meckler GD, eds. Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7th ed. New York, NY: McGraw-Hill; 2011. Figure 273-4)
The Ottawa ankle and foot rules identify patients at high risk for fracture if they have any of the following: (1) Are unable to bear weight immediately after the injury or for four steps in the emergency room. (2) Have bony tenderness along the distal 6 cm of the posterior tibia or medial malleolus. (3) Have bony tenderness at the distal 6 cm of the posterior fibula or lateral malleolus. 4) Have bony tenderness at the base of the fifth metatarsal or over the navicular. Of note, the Ottawa rules are not fully validated in patients less than 6 years of age or in patients who may have altered mental status or poor recall of the injuring event.
A large amount of force is required to dislocate the ankle. This leads to significant soft tissue injury of the tendons and ligaments about the ankle and often involves a concomitant ankle fracture. Should neurovascular compromise exist in the setting of prolonged transport, reduction may be considered. Medial and lateral dislocations, with or without fracture, can typically be reduced and splinted if necessary in the field by a properly trained EMS physician. Reduction typically requires an assistant. Plantar flexion is applied to recreate the position of the initial injury followed by axial traction to the ankle. While the assistant maintains the axial traction the EMS physician grasps the distal tibia with one hand and applies lateral or medial traction (depending on the direction of dislocation), thus relocating the ankle. Neurovascular examination of the extremity must be repeated after reduction is accomplished. The ankle may be unstable and should be splinted and repeat examination for neurovascular status performed to ensure continued function after splinting.
Foot fractures can be categorized into midfoot and forefoot injuries. The midfoot comprises the cuboid, navicular, and cuneiforms, while the forefoot includes the metatarsals and phalanges. Fractures of the foot usually present with pain, swelling, ecchymosis, or deformity at the site of injury. Examination should focus on palpation and visual inspection plus assess for neurovascular compromise. Dorsalis pedis pulses should always be assessed. If any concern for foot fracture exists, immobilization is appropriate for transport.
Sprains and strains are among the most commonly encountered soft tissue injuries evaluated by prehospital providers. Joint sprains commonly occur in the ankle, knee, wrist, fingers, and toes. Most frequent are ankle sprains, accounting for an estimated 85% of all soft tissue sprains.42 Patients with sprains often present after sports-related injuries or low-energy falls. Obtaining a history of “rolling an ankle” or “twisting a knee” is a common low-energy mechanism. Ninety percent of ankle sprains occur after inversion injury. Injury after a high-energy injury, such as fall from height or motor vehicle collision, should be presumed to be a high at risk for fracture.
Differentiating sprains from fractures can be challenging without radiographs as many high-grade sprains can appear similar to fractures by examination. The Ottawa ankle rules (discussed prior) can help identify patients at highest risk for ankle and midfoot fractures. Pain, swelling, ecchymosis, and limited joint function are common examination findings.43 As a rule, any extremity that is notable for deformity or neurovascular compromise is presumed to be fractured.
Prehospital treatment of sprains should focus on minimizing further ligamentous injury and decreasing pain and swelling. The PRICE (protect, rest, ice, compression, elevation) strategy is recommended for most sprain management. Protect: If a patient has a suspected ankle sprain, a strategy of temporary immobilization by applying an air brace or splint should be used. A Cochrane review demonstrated temporary immobilization for high-grade sprains with soft or semirigid functional supports has shown modest benefit over full immobilization or use of elastic bandaging.44,45 Rest: The injured extremity should be supported and the patient should be discouraged from attempts at ambulation prior to physician evaluation. Moderate and severe sprains are often rested for a period of 1 to 3 days postinjury to allow for pain and swelling to decrease. Ice: Cold therapy is recommended by the American Academy of Orthopedic Surgeons for early management of ankle sprains.43 Cold packs or an ice bag may be applied to injured areas to decrease pain and swelling. Compression: A temporary air brace or elastic wrap can serve a dual purpose of protecting and immobilizing the sprain as well as providing mild compressive force to help reduce further swelling. Elevation: Elevating the injured extremity on towels or pillows can aid to decrease swelling. Appropriate pain control should be administered to maximize patient comfort.
Lumbosacral spine sprains and strains are very common within the United States and are estimated to be the fifth most common cause for physician visits.46 When a patient presents with low back pain, identifying the exact etiology can be very difficult without laboratory or radiographic testing. The EMS physician must recognize signs and symptoms of emergent and urgent causes of low back pain to help identify high-risk patients. The differential for low back pain is extremely broad but includes lumbosacral sprain and strain, acute disc herniation, spinal stenosis, cauda equina syndrome, traumatic or compression fracture, infection, malignancy, and aortic aneurysm. Abnormal vital signs or patient history involving systemic symptoms, trauma, fevers, weakness, sensory changes, or difficulty with bladder or bowel function is concerning for etiologies of low back pain other than lumbosacral sprain or strain.47 Acute traumatic injury resulting in back pain should be handled with the possibility of fracture and involves stabilizing the low back with a long backboard should the patient have midline lumbar tenderness. Physical examination should assess distal neurovascular.
Prehospital treatment of lumbosacral sprains and strains involves identifying and treating patient pain. Allow patients to be in a position of comfort (unless immobilization is indicated) and identifying any items on history or examination consistent with more concerning etiologies. Opioid analgesia should be administered as indicated. External warming (chemical heat packs, etc) have also been demonstrated to alleviate acute low back pain during prehospital transports.48