General Descriptors

Description of a fracture should begin by stating whether the fracture is closed or open (less desirable terms are simple or compound). In a closed fracture the skin and soft tissue overlying the fracture site are intact. The fracture is open if it is exposed to the outside environment in any manner. This exposure may be as obscure as a puncture wound or as gross as splintered bone protruding through the skin. It is sometimes difficult to determine whether a small wound in proximity to a fracture actually communicates with that fracture. Some physicians advocate probing such a wound with a blunt sterile swab to establish a relationship; no study has established the safety, benefit, or accuracy of this maneuver. If doubt exists, an open fracture should be assumed to be present.

The next item that should be noted in the description of a fracture is the exact anatomic location, including the name of the bone, left or right, and standard reference points along the bone, for example, the humeral neck or posterior tibial tubercle. Long bones can be divided into thirds—proximal, middle, or distal—and these thirds or the junction of any two of them (e.g., the junction of the middle and distal third of the tibia) are used to describe fractures. The most descriptive language possible should be used. It is better to say “closed fracture of the right ulnar styloid” than “closed fracture of the right distal ulna” because the former conveys more precise anatomic information.

An additional modifier describes the direction of the fracture line in relation to the long axis of the bone in question. A transverse fracture occurs at a right angle to the long axis of the bone (Fig. 49-1A), whereas an oblique fracture runs oblique to the long axis of the bone (Fig. 49-1B). A spiral fracture results from a rotational force and encircles the shaft of a long bone in a spiral fashion (Fig. 49-1C). A fracture with more than two fragments is termed comminuted (Fig. 49-1D).

The position and alignment of the fracture fragments (i.e., their relationship to one another) should be described. Fragments are described relative to their normal position, and any deviation from normal is termed displacement. By convention, the position of the distal fragment is described relative to the proximal one. Displacement may be described as a quantitative measurement (i.e., in millimeters) or as a percentage of the bone width. Figure 49-2 shows a dorsal displacement of the fractured radius, and Figure 49-3 shows lateral, or valgus, displacement of the distal tibia and fibula.

The terms valgus and varus are sometimes confusing. Valgus denotes a deformity in which the described part is angled away from the midline of the body. Conversely, varus denotes a deformity in which the angulation of the part is toward the midline. Alignment refers to the relationship of the longitudinal axis of one fragment to another; deviation from the normal alignment is termed angulation. The direction of angulation is determined by the direction of the apex of an angle formed by the two fracture fragments (Fig. 49-4). This angle is opposite to the direction of displacement of the distal fragment. The relative position or angulation of the distal fragment of a fracture may also be described with terms such as radial or ulnar, dorsal or volar, anterior or posterior, and lateral or medial. One should also be aware of rotational deformity, present when the distal fragment of a fracture is rotated to some degree along the axis of the bone itself. Especially in the digits of the hand, radial or ulnar deviation of a flexed finger can occur, and radiographs often underestimate the degree of clinical deformity and rotation present.

Descriptive Modifiers

A fracture is termed complete if it interrupts both cortices of the bone and incomplete if it involves only one. It should be noted whether a fracture extends into and involves an articular surface. Frequently the percentage of articular surface involved can only be estimated; in some cases the percentage that is actually involved dictates the need to perform a surgical reduction. In general, it is important that the articular surface be restored to anatomic integrity to prevent consequent traumatic arthropathy.

Avulsion fracture refers to a bone fragment that is pulled away from its normal position by either the forceful contraction of a muscle (Fig. 49-5A) or the resistance of a tendon or ligament to a force in the opposite direction (Fig. 49-5B). Impaction refers to the forceful collapse of one fragment of bone into or onto another. In the proximal humerus, this collapse typically occurs in a telescoping manner, particularly in elderly patients, whose bones are soft and brittle. In the tibial plateau, impaction occurs frequently in the form of a depression (Fig. 49-6A and B), and in the vertebral bodies, impaction frequently occurs in the form of compression (Fig. 49-6C).

A fracture that occurs through abnormal bone is termed pathologic. A pathologic fracture is suggested whenever a fracture occurs from seemingly trivial trauma. Diseases that cause structural weakness predisposing to injury include primary or metastatic malignancies, cysts, enchondromata, and giant-cell tumors. In addition, osteomalacia, osteogenesis imperfecta, scurvy, rickets, and Paget’s disease all weaken bones, making them susceptible to fracture. The term pathologic also is applied to fractures through osteoporotic bone when the demineralization is a result of disease, as in polio. Fractures through osteoporotic bone of the elderly usually are not described as pathologic. When fractures occur in normal bones and a history of “trivial trauma” is elicited, violence or battering should be suspected. Repeated low-intensity forces may lead to resorption of normal bone, resulting in a stress fracture. Other names for this condition are fatigue fracture and march fracture (see Table 49-1). Most stress fractures occur in the lower extremities and commonly affect individuals involved in activities such as running, basketball, aerobics, and dancing. Extrinsic factors such as training regimens, type of equipment used, and nutrition habits, as well as intrinsic factors such as anatomic variation, muscle endurance, and hormonal factors have all been associated with stress fractures. These injuries may not be recognizable on initial plain films; therefore management should be based on clinical diagnosis.¹ The tibia, fibula, metatarsals, navicular, cuneiform, calcaneus, femoral neck, or femoral shaft may be involved.^2,3

Fracture Eponyms

Many fractures were described before the advent of radiography and are described by an eponym rather than the exact bony injury. These eponyms reflect the rich history of orthopedic care and, despite the objections of some, are still commonly used to describe orthopedic injuries (see Table 49-1).

Plain Radiography

Conventional radiography is the mainstay in diagnosing fractures. In addition to confirming or excluding fractures, it can identify other pathologic conditions. With penetrating trauma, foreign bodies, air, and gas also may be detected. With minor trauma and when good follow-up monitoring is ensured, it is acceptable to delay radiography. Delay cannot be permitted, however, when the suggested injury is one that might be made worse by delayed diagnosis, such as a nondisplaced hip fracture.

Biplanar radiographs of an injured extremity should be obtained to fully delineate the bony injury. Conventional radiographic evaluation of long bones include at least two orthogonal views, and an oblique view is also usually obtained. In certain locations, such as the phalanges, oblique views are necessary. If doubt still exists, the clinician should ask for more views in various degrees of obliquity to the other films. A fracture line is most visible when it is parallel to the x-ray beam and is invisible when it is exactly 90 degrees to the beam. The clinician should never accept a study that examines the bone in only one plane. When a long bone is found to be fractured, it is imperative that the bone be viewed radiographically in its entire length.

Each film is examined to ensure that proper technique has been used and that no important area is omitted from the film. Overexposed films may fail to reveal an abnormality. Although some fine detail is lost on portable films, these are acceptable in unstable patients, in whom the risk of moving the patient does not outweigh the benefit of the more detailed study. Even with good technique, some fractures are not visible initially and do not appear until the margins of the fracture absorb. Absorption widens the radiolucent line, and a defect appears in 7 to 10 days. At that time, new bone produced beneath the periosteum at the margins of the fracture accentuates the fracture. Accordingly, if a fracture is suggested but not visible at the initial visit, the injury should be treated as a fracture and reexamined clinically and radiographically in 7 to 10 days, and the patient should be informed of the rationale for this regimen.

Stress views of joints are used in some instances to evaluate the degree of ligamentous injury. Some authors argue against the use of stress views, citing a risk of further injuring an already traumatized structure, additional radiation exposure to the patient and the technologist, and the possibility that pain may not allow sufficient stress to be applied. For these reasons, stress views should be used judiciously in circumstances when other methods of evaluating ligamentous injuries are not available. Comparison views are useful in selected situations but should not routinely be performed in all pediatric examinations.¹¹ If a fracture is definitely present on the affected side, the comparison view exposes the child to radiation and adds expense with no benefit. Similarly, an experienced physician generally is able to read a normal film with reasonable certainty. It is reasonable to use comparison views in instances when radiographs are inconclusive and when the confusion arises specifically out of the need to distinguish between a possible fracture and normal developmental anatomy. Obtaining a wide field of the affected extremity is more useful than routine comparison views for a young child because the child often does not localize the pain well; this is especially true with regard to complaints of knee pain in cases of hip injury or wrist complaints in forearm and elbow injury. Comparison views sometimes are helpful in adults when a question of accessory ossicles or nonfused bones (e.g., bipartite patella) exists because these anomalies are usually bilateral. The bleeding that inevitably accompanies fractures may produce soft tissue swelling, which may impinge on or obliterate overlying muscle planes. Fat pads, such as in the elbow, may be displaced. Another useful sign is the fat-fluid level, which may accompany fractures extending into the knee joint. The fat-fluid level is visible, however, only if the cross-table technique is used.

The bones themselves should be examined systematically. Normal adult bones possess a smooth unbroken contour. A distinct angle is highly suggestive of a fracture. In an adult the typical fracture is represented by a lucent line that interrupts the smooth contour and usually extends to the opposite side. Nutrient arteries may be confused with fractures but have different radiographic characteristics: They are fine, are sharply marginated, extend obliquely through the cortex, and are less radiolucent than fractures. Pseudofractures can be created by soft tissue folds, bandages or other overlying material, or a radiographic artifact called the Mach effect. If lucencies extend beyond the bones, the line is highly unlikely to represent a fracture. Anomalous bones and calcified soft tissue likewise may be mistaken for fractures. Avulsions and small fracture fragments have an irregular surface that lacks well-corticated margins and a defect in the adjacent bone is present, whereas anomalous ossification centers (accessory ossicles) and sesamoids are characterized by smooth cortical margins. Reference texts are useful in identifying and confirming these anomalies because they tend to occur in predictable locations.¹² Compression fractures are represented by increased density rather than a lucency. Finally, the most commonly missed fracture is the second fracture. One should be diligent in searching for additional fractures after discovering the first fracture on a study. In particular, certain paired fractures, such as the distal tibia and proximal fibula, should be sought out.

Special Imaging Techniques

Infection (Osteomyelitis)

Any fracture communicating with the surface of the skin is termed an open fracture. Open fractures are treated as true orthopedic emergencies because of the risk of infection; the dreadful nature of the complication of osteomyelitis dictates that no time should be wasted in initiating therapy (Box 49-2). Wounds should be irrigated of gross debris and covered with a sterile dressing, and parenteral antibiotics should be instituted as early as possible.²⁰

Currently, suggested therapy includes a first-generation cephalosporin, such as cefazolin, for all open fractures, with the addition of an aminoglycoside for grade II or III fractures.21,22 Early versus delayed treatment of open fractures and its subsequent effect on rates of infection has been a source of debate. Historic guidelines recommending débridement of open fracture wounds within 6 hours of injury were based on animal experiments conducted in the 1890s.²³ Current human studies suggest no clear advantage to performing surgical débridement within 6 hours of injury. The timing of débridement—less than 6 hours versus more than 6 hours after injury—had no effect on clinical or functional outcome in a prospective multicenter study of severe lower-extremity fractures.²⁴ Other retrospective studies and literature reviews advocate early débridement and irrigation of the wound within the first 24 hours of injury to prevent infection.

Certain open fractures of the finger present a notable exception to the previous recommendation. Such injuries, especially an open distal tuft fracture, are common when the phalanx of a finger is subject to crush injury (e.g., by a door) and there exists a skin defect overlying a fractured bone. In a prospective randomized, placebo-controlled study of 193 patients with open fracture of the finger, flucloxacillin or placebo was administered to randomized patients with open phalangeal fractures, and both groups were treated with aggressive surgical irrigation and débridement. No significant difference was found in the infection rate between the groups, and no patient developed osteomyelitis. The data suggest that vigorous irrigation and débridement are adequate primary treatment for open phalangeal fractures in fingers with intact digital arteries.²⁵ Such injuries might be repaired by the emergency physician without consultation.

Hemorrhage

Because of the rich blood supply to the skeleton, fractures can result in large amounts of blood loss, shock, and death from exsanguination. In particular, certain pelvic fractures can cause great blood loss as adequate tamponade is not possible. In adults, blood loss can range from 100 mL from a forearm fracture to 3 L from a pelvic fracture (Table 49-3).