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Chapter 28

Orthopedics

Vincent D. Pellegrini Jr.

John T. Ruth

Andrew H. Borom

I Orthopedic Patient Evaluation

A History

Pain. A thorough description of the patient's pain should be obtained, including the onset, location, duration, exacerbating factors, and character (e.g., aching, sharp, burning). What causes and alleviates the pain? Is it constant, present at rest, or only associated with activity?

Mechanism of injury. Many orthopedic complaints are related to an injury. A thorough description of the event that produced the patient's symptoms may often lead to the diagnosis. Specifically, the direction of force that acted upon a knee often gives insight into which ligaments might be injured (i.e., a patient who feels a “pop” during a twisting injury to the knee, which is followed by a large intra -articular knee effusion, often represents an acute anterior ligament rupture).

B Examination

Trauma patients. All trauma patients require a thorough palpation of all joints and bones. Specifically, the hands and feet should be inspected because fractures in these locations are often missed. The patient should always be log rolled to inspect and palpate the spine.

Regional or problem -oriented complaints. Patients with complaints about specific joints (e.g., the knee) deserve a thorough examination of that part, in addition to the joints both proximal and distal to it. The low back should also be examined because pain originating in the low back may produce symptoms more distally; this is called “referred pain.”

Patients with musculoskeletal tumors. These patients deserve a complete and thorough examination to rule out the possibility of metastases.

Neurovascular examination. All orthopedic examinations should include a thorough neurovascular examination, particularly for patients who have fractures or extensive lacerations of the extremities.

C Imaging studies

Plain radiographs should include views in at least two planes and always include the joints immediately above and below the presumed area of interest. Occasionally, oblique views are necessary. These views are most useful for fracture evaluation and should afford the examiner the ability to give a thorough description of the fracture to consultants.

Computed tomography (CT) scans are useful in orthopedics to evaluate complex articular fractures as well as fractures of the spine and pelvis.

Magnetic resonance imaging (MRI) is helpful for the evaluation of meniscal tears around the knee and rotator cuff tears at the shoulder, for diagnosing and defining the extent of osteomyelitis, for evaluating avascular necrosis of the femoral head, and for determining the intraosseous and extraosseous extent of primary bone tumors or metastases. Occult fractures, not apparent on plain x-rays, such as of the scaphoid or femoral neck, are most expediently diagnosed by MRI.

Bone scans are helpful for identifying occult fractures and for localizing sites of osteomyelitis. It is important to remember that although bone scans are very sensitive, they are often not very specific.

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Ultrasound has become popular in the evaluation of the hip in infants and children. It is also used to define and diagnose rotator cuff tears.

II Trauma

A Overview

Orthopedic injuries with few exceptions are rarely acutely life threatening but can be limb threatening.

In the management of trauma patients, it is important to remember the guidelines of advanced trauma life support (ATLS) with strict adherence to the ABCs (airway, breathing, circulation; see Chapter 21).

The extent of injury to the musculoskeletal system varies according to the patient's age, the direction of the energy causing the trauma, and the magnitude of the trauma.

The patient's age suggests the weak link in the musculoskeletal system.

In skeletally immature patients , the weak link is the growth plate at the ends of the long bones.

Young but skeletally mature patients (16–50 years of age) may be more likely to sustain ligamentous injuries because the relative strength of the mature bone exceeds the strength of the soft tissues supporting the joints.

In late middle-aged or elderly patients with significant osteopenia, injuries to the ligaments are uncommon. Instead, in this age group, fractures of the metaphyseal portions of long bones are prevalent (i.e., distal radius, hip). The metaphyseal area is at risk because the likelihood of osteopenia is much greater in this metabolically active area.

The direction of the trauma may determine which structures are injured. An example is the typical knee -dash injury that occurs in motor vehicle accidents. These injuries frequently cause fractures of the patella and femur as well as posterior hip fractures or dislocations.

The magnitude of the trauma is related to the energy imparted (E = ½ mv2 ), where m = mass and v = velocity.

High-energy injuries (e.g., in motor vehicle accidents) tend to cause shattered or “comminuted,” complex skeletal injuries, which may be open fractures.

Low-energy injuries, which frequently occur in sports, are more likely to cause simple, isolated injuries of ligaments, muscles, or bones.

Fracture

The radiographic appearance of a particular fracture may give insight into the type of trauma that produced it.

Description

Location may be the diaphysis (shaft), the metaphysis (juxta -articular), or through the joint surface (articular).

Orientation may be transverse, oblique, spiral, segmental, comminuted, or incomplete

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FIGURE 28-2 Fracture patterns in children. (Redrawn with permission from Rang M. Children's Fractures, 2nd ed. Philadelphia: JB Lippincott; 1983:2.

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TABLE 28-1 Classification of Open Fractures (Gustillo)

Grade 1: -Skin opening of 1 cm or less, quite clean; most likely from inside to outside; minimal muscle contusion; simple transverse or short oblique fractures

Grade 2: -Laceration more than 1 cm long, with extensive soft tissue damage, flaps, or avulsion; minimal to moderate crushing components; simple transverse or short oblique fractures with minimal comminution

Grade 3: -Extensive soft tissue damage including muscles, skin, and neurovascular structures; often a high-velocity injury with a severe crushing component

3A: -Extensive soft tissue laceration, adequate bone coverage; segmental fractures, gunshot injuries

3B: -Extensive soft tissue injury with periosteal stripping and bone exposure; usually associated with massive contamination

3C: -Vascular injury requiring repair

Reprinted with permission from Behrens F. Fractures with soft tissue injuries. In: Browrer BD, Jupiter JB, Levine AM, Trafton PG, eds. Skeletal Trauma Philadelphia: WB Saunders; 1992:313.

Diagnosis

Plain radiographs are helpful if reactive healing has occurred.

Bone scans are quite sensitive but not specific.

MRI is very sensitive and has increased specificity if a linear signal change is present. The T2 image will most commonly demonstrate edema in the area of fracture.

Pathologic fractures sometimes overlap with insufficiency fractures, specifically those fractures that occur in osteopenic bone. More frequently, pathologic fractures refer to a fracture occurring in a bone weakened by a tumorous condition (i.e., a primary bone malignancy, myeloma, or metastatic disease).

Impending pathologic fractures refers to a lytic defect in bone, usually secondary to a metastasis, which is precariously large and weakens the bone to a worrisome degree requiring prophylactic stabilization to prevent a fracture.

This can occur with a lytic lesion greater than 2.5 cm in diameter.

Criteria include a lytic lesion that occupies 50% or more of the cortex on any radiographic view.

Also includes a lytic lesion that continues to produce pain despite radiation therapy.

B

Orthopedic urgencies require the initiation of definitive care within 6 hours of the injury.

Hip dislocations. A reduction delayed more than 12 hours may increase the likelihood of development of avascular necrosis of the femoral head.

Open fractures

Early debridement of contaminating material and devitalized tissue with stabilization has been shown to reduce the infection rate.

Management

Splinting is done in the field or emergency department with removal of gross contamination and placement of sterile dressings. (Once this is done, the dressings should remain intact until the patient reaches the operating room.)

Administration of a first-generation cephalosporin (vancomycin in patients who are allergic to penicillin) should be performed in the emergency department. Use of an aminoglycoside and penicillin should be considered for patients with large wounds or for those with soil or farm contamination.

Tetanus prophylaxis is administered.

Definitive irrigation and debridement are performed in the operating room with stabilization.

Penetrating injuries to joints

Because of the excellent bacterial growth media provided by joint fluid, all open-joint penetrations require formal irrigation and debridement either via arthrotomy or arthroscopy.

Outcome. The amputation rate approaches 100% if warm ischemia time exceeds 6 hours.

Some types of pelvic ring injuries can be life threatening because of exsanguinating hemorrhage.

Types

Injuries that disrupt the sacroiliac joint are secondary to anteroposterior compression, vertical shearing, or combined forces.

Occasionally, fractures that enter the greater sciatic notch can lacerate the superior gluteal artery.

Diagnosis is confirmed by the following:

An initial trauma anteroposterior radiograph can show a suspicious pattern.

Pelvic instability can occur with gentle pressure over the anterior iliac crests.

Management

Field and early emergency department management

Aggressive fluid resuscitation is undertaken.

A pneumatic antishock garment is applied with use of an abdominal binder.

An intra -abdominal source of hemorrhage is ruled out.

Emergent stabilization of a hemodynamically unstable patient includes:

External pelvic fixation to decrease:

Bleeding can start again from bony surfaces, and the patient can be in pain.

Pelvic volume is decreased and, therefore, space into which bleeding can occur is decreased, thus allowing tamponade.

A pelvic angiogram is taken with embolization of bleeding vessels if external fixation and aggressive fluid replacement fail to achieve hemodynamic stabilization.

Definitive stabilization

Closed or open reduction of the sacroiliac joint, sacrum, or posterior ilium is undertaken with internal fixation.

Open reduction and internal fixation of the anterior ring or continued external fixation is achieved.

D Fractures in children

Overview

Growth plate fractures. The growth plate is cartilaginous and, therefore, represents a weak point at