The musculoskeletal system is composed of bones attached to joints, joints connected by ligaments, muscles supported by tendons, and cartilaginous tissues. The function of this system is to provide a skeletal framework to support the body, protect vital organs, and provide movement. It also supplies a storage space for the blood cell production and minerals responsible for regulating resorption and reformation of itself, as well as regulation of mineral and hormonal imbalances in the body (Porth, 2011).

ossifies through osteogenesis. There are two distinct types of ossification: intramembranous and endochondral ossification. Intramembranous ossification is the process in which osteoblasts form bone without the cartilaginous stage (Staheli, 2008). Endochondral ossification occurs when the mesenchyme differentiates to cartilage, and cartilage then transforms into bone within primary and secondary ossification centers. Primary ossification occurs in the diaphysis (center of the bone), whereas secondary ossification occurs at the epiphysis (end of the bones). The physis, or growth plate, is formed between the primary and secondary ossification center and allows for longitudinal growth of long bones (Staheli, 2008; Texas Scottish Rite Hospital for Children [TSRHC], 2008). The growth plate absorbs shock and protects the joint surfaces from serious fractures. The metaphysis (above the growth plate) is composed mostly of cartilage and is the area that grows between the diaphysis and epiphysis to form solid bone in adulthood. It is imperative to know the location and the function of these sites of the bone, as these are often the primary sites where infection, neoplasm, fractures, and metabolic and endocrine disorders are identified (Staheli, 2008).

The periosteum is a vascular connective tissue that lines the outer surface of all bones. It has receptor nerve endings, making it sensitive to manipulation (TSRHC, 2008). The periosteum contributes to bone development by appositional bone growth and has the capability to heal fractures and regenerate bone rapidly in children.

There are five classifications of bones: long bones, such as the femur; short bones, such as the carpals; irregular bones, such as the vertebrae; flat bones, such as the ribs; and sesamoid (sometimes classified as short) bones, such as the patella. There are also two major divisions to the skeletal system: the axial skeleton, which forms longitudinally and includes the vertebral column and the skull; and the appendicular system, which is attached to the axial and encompasses the pelvis, pectoral girdle, and upper and lower extremities (Porth, 2011).

Joints, which are composed of connective tissue and cartilage, connect two or more bones to one another and enable movement. Joints are classified by structure, function, and movement. In general, joints are identified as synarthrotic or immovable (e.g., the skull), or synovial (diarthrotic), which are freely movable (e.g., the hip) (Porth, 2011).

Alterations in joint movement and swelling require further evaluation. Defective joints are often seen in children with

neuromuscular disorders, such as spina bifida and arthrogryposis (Staheli, 2008; TSRHC, 2008). Alterations in joint movement and swelling can also be indicative of trauma, infection, or arthritis.

Muscles help stabilize joints and maintain contact between articular surfaces. Skeletal muscles are attached by tendons to bones. Ligaments bind one bone firmly to another, and the joints are further stabilized by the overlying tendons and muscles. The shape of the two ends of each muscle and of the joint determines the extent of movement or articulation. Skeletal muscles, which are composed of elongated fibers, function voluntarily and produce movement by contraction. Muscle disease in children presents as muscle weakness, spasticity, myoclonus, and myalgia (Staheli, 2008).

Cartilage is dense connective tissue that develops at the epiphysis and is capable of withstanding considerable tension. During early fetal development, the skeletal structure is composed mostly of cartilage. In time it will largely convert to bone by ossification. Connective tissue is made up of collagen and proteoglycans (Staheli, 2008). Deficiencies in connective tissues are associated with Marfan syndrome and osteogenesis imperfecta (TSRHC, 2008).

Knowledge of normal growth and development is essential when assessing, caring for, and evaluating the pediatric patient’s musculoskeletal system. Infants experience the greatest growth rate. During childhood, growth slows and then increases rapidly again in adolescence with peak height velocity. Peak height velocity is the maximum growth that occurs during puberty. Growth in the length of the long bones continues at the epiphysis until adult height is reached (see Chapter 9).

Children should be weighed and measured for length or stature with each visit. The results of these measurements should consistently and correctly be plotted on appropriate growth and development graphs in order to be aware of any variations in height or weight (see Chapter 33). Extreme variations in height and weight can impact the child’s overall state of health. Childhood obesity, for example, can have a direct effect on children with musculoskeletal problems, such as tibia vara, Blount disease, and slipped capital femoral epiphysis (TSRHC, 2008).

A basic understanding of when children meet their major developmental milestones, especially for gross motor development, is crucial when assessing and treating the child with an alteration of the musculoskeletal system. Failure to meet these milestones in a timely manner may be indicative of hypotonia, cerebral palsy (hemiplegic), or a neuromuscular disorder. See Chapters 6 through 9 for developmental milestones in children of various developmental levels.

Radiographs are the mainstay of an orthopedic evaluation. They provide important diagnostic evaluation after a clinical assessment when there is concern of a musculoskeletal abnormality. Studies have shown risks of cancer with radiation exposure in a growing child (Brody, Frush, Huda, et al., 2007; Gacca, 2008). Several recommendations have been formulated to protect the child. Radiologists and technicians are to use the least and most diagnostically effective radiation exposure on children. In addition, care needs to be taken to shield the gonads, make sure the patient is placed in the correct anatomic position, avoid routine opposite-side radiographs, take single radiographs instead of multiple views, and consult as needed with the provider ordering the x-rays (Brody et al., 2007; Gacca, 2008). It is important to note the pediatric differences in plain films as compared to adults, because the differences can lead to misinterpretation and over- or undertreatment. For example, children have open growth plates at the proximal and distal aspects of the long bones that can easily be confused for fractures. Furthermore, a periosteal reaction in the diaphysis after trauma or infection can be misinterpreted as normal (Staheli, 2008).

The hematology workup in orthopedics includes a complete blood count with a differential, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) for musculoskeletal conditions such as growing pains, bone pain, stress fractures, hip pain, back pain, and infection (Staheli, 2008; TSRHC, 2008). CRP is a protein that appears in blood during an inflammatory process and is not seen in healthy people. The measurement is nonspecific, merely indicating the presence of inflammation. ESR is the rate at which erythrocytes settle out of unclotted blood, measured in millimeters per hour. Inflammation and necrotic problems cause an elevation in ESR levels.

Chemistry labs assist in the evaluation for metabolic conditions, such as rickets (TSRHC, 2008). These labs include studies of calcium, alkaline phosphatase (ALP), and phosphorus. ALP is an enzyme found mainly in bone, liver, placenta, and kidney. Levels may be elevated in bone disease, fractures, trauma, or liver disease and during periods of rapid growth. Determinations may be ordered to differentiate between bone and liver problems.

Enzyme studies such as creatine phosphokinase (CPK) may be ordered. CPK is an enzyme found in heart and skeletal muscle; the CPK assay is a specific test for assessing cardiac and muscle damage. Levels are elevated in trauma, myocardial infarction, and muscular dystrophy. Determinations may be ordered to differentiate between cardiac (MB) and skeletal (MM) CPK.

Rheumatoid factor (RF) and a hematology workup are used to evaluate juvenile idiopathic arthritis (Staheli, 2008). RFs are antibodies that may be responsible for the destructive changes associated with rheumatoid arthritis. A positive RF with an elevated CRP and ESR can be indicative of arthritis in children; however, RF is positive in only 5% of these cases (Staheli, 2008).

Musculoskeletal problems affect muscles, bones, joints, and tendons, all of which are necessary for movement and therefore are critical to a child’s development. Many musculoskeletal problems occur because of vigorous motor activities that are part of a child’s daily life, but the rapid growth of the skeletal system also plays a significant role. Most musculoskeletal problems are short term, but a number of chronic musculoskeletal conditions require long-term treatment and nursing assistance.

The child with a musculoskeletal alteration presents a unique opportunity for nursing care. A general knowledge of the structure and function of the system is required to understand the rationale for the alteration. An awareness of normal versus abnormal growth and development patterns is necessary in order to recognize delays, variations, and medical conditions. An appreciation of the musculoskeletal differences exhibited in the pediatric patient in comparison to the adult is also essential. Nurses should be familiar with the various diagnostic imaging procedures used to assist in the evaluation of patients with musculoskeletal alterations in order to implement nursing considerations. Knowledge of normal laboratory values commonly ordered for patients with musculoskeletal conditions is vital for providing prudent, good-quality, and effective nursing care.

Splints are used to stabilize and protect or rest an affected area, increase range of motion and function, and decrease pain (TSRHC, 2008). Splints are fabricated of fiberglass, plaster of Paris, metal, or thermoplastic polymers. Splint materials are chosen for drapability, durability, softness, setup time, thickness, capacity for remolding, and color. Splinting may be a safe, effective, and cost-saving alternative to casting for some conditions (Firmin & Crouch, 2009).

Casts are made of synthetic materials, such as fiberglass, semirigid nonfiberglass (soft cast), or plaster of Paris (Bakody, 2009). Casting material comes in varied colors and patterns; casts can be wrapped and decorated to appeal to young children. The following equipment is needed for cast application:

Cast application is usually done by the physician and another trained person, one to hold the extremity in correct alignment and one to apply the cast. It is very important not to move the affected area to be casted while applying the cast. Waterproof liner or stockinette is applied if desired. Waterproof linings for casts have been shown to be as effective as cotton lining for immobilization (Robert, Jiang, & Khoury, 2011). A thin layer of Webril is then applied over the initial lining. The material is rolled in a spiral fashion around the affected area, overlapping each layer by approximately 50%. Additional padding may be placed over bony prominences, making sure there are no wrinkles in any layer. Any wrinkles in the cast padding or cast material become “set” into the cast and may cause skin breakdown. Next, the casting material is dipped in water and applied over the cotton padding, making sure to leave a cotton edge at the top and bottom of the cast for patient comfort and to maintain skin integrity. A chemical reaction between casting material and water makes it feel warm and causes it to harden. The cast should not be covered while warm to prevent a possible burn.

Rough edges of casts must be trimmed to prevent injury. Petaling of cast edges with moleskin or latex-free tape decreases irritation and breakdown of adjacent skin and protects the edges of the cast from excessive wear.

Fiberglass casts dry quickly, usually set within 30 minutes of application. Fiberglass should be rolled on the affected body part without stretching the fiberglass. Fiberglass is less forgiving when swelling is expected, and if the fiberglass is pulled “tight” or stretched during application, neurovascular status may be compromised (TSRHC, 2008).

Fiberglass casts are lighter weight and more durable than plaster (TSRHC, 2008) (Figure 50-1). Fiberglass casts are water-resistant, so the hard outer shell will not break down in water; however, the padding underneath the cast material is likely cotton and will absorb and hold water. Therefore, if a fiberglass cast becomes wet, inadequate airflow under the cast will prevent thorough drying of the padding and skin. Damp skin is more susceptible to skin breakdown and infection.

Plaster casts may be used when the physician wants to “mold” the cast to apply corrective forces to a body part, such as in the treatment of a clubfoot or early onset scoliosis (TSRHC, 2008). Plaster casts will set within 10 to 15 minutes, but will not fully dry for 24 to 48 hours. Plaster is not water resistant and will break down if it gets wet.

The disadvantages of traction include prolonged immobility and the potential need for hospitalization. Currently, early casting and percutaneous pinning are replacing the use of traction for some musculoskeletal conditions (Gosselin, Heitto, & Zirkle, 2009; Hsu, Diaz, Penaranda, et al., 2009).

Skin Traction

Skin traction (Box 50-1) is noninvasive and well tolerated, and application does not require anesthesia (TSRHC, 2008). Skin traction is most effective with children who weigh less than 15 kg (33 lb) or are younger than 2 to 3 years. It can be applied to the pelvis, spine, or extremities (usually the long bones). Skin traction is preferred for conditions in which invasive procedures are contraindicated, such as hemarthrosis (collection of blood in the joint) as a result of hemophilia. Foam rubber straps, adhesive moleskin, elastic bandages, or cloth belts are applied to the skin and then attached to the weights and pulleys. If skin traction to the lower leg is needed, a foam rubber or fabric boot may be used; the fit should be secure.

BOX 50-1

TYPES OF SKIN TRACTION

Buck

• Purpose: Used to treat some fractures, hip disorders, contractures, and muscle spasms.

• Description: Continuous or intermittent boot or circular wrap is applied to the skin. Traction is applied to boot or wrap. Rolled towels are placed on the external surface of the knee to prevent external rotation of the affected leg. Unless otherwise ordered, the mattress should be flexed at the knee (20 to 30 degrees).

Bryant

• Purpose: Used to treat very young children (younger than 2 years of age) with femur fractures or developmental dysplasia of the hip.

• Description: The child’s affected lower extremity or extremities are wrapped. The child lies in bed (or crib) with hips flexed 90 degrees and the knees extended. Traction is applied overhead with just enough weight to elevate the buttock off the surface of the mattress.

• Is continuous for femur fractures, but may be intermittent for children with developmental dysplasia of the hip. Traction may be used for 2 to 4 weeks to loosen muscles before a child goes to the operating room for closed or open reduction for the displaced hip.

Skin traction is not appropriate if the child has a skin infection, an open wound, or extensive tissue damage. Skin breakdown may develop as a result of skin traction. Applying tincture of benzoin to the intact skin before the traction is applied may protect against skin irritation.

If the traction has not been set up correctly, neurovascular impairment may occur. Therefore, skin traction is not appropriate for patients with abnormal sensation in the lower extremities (TSRHC, 2008). Hyperextension of the knee and elastic bandages that have been wrapped too tightly are the most common causes of traction-related neurovascular impairment. A thorough assessment of the traction apparatus and the extremity should be conducted at least once each shift.

Skeletal Traction

Skeletal traction (Box 50-2 and Figure 50-2) exerts greater force than skin traction and can be physiologically tolerated for longer periods. Skeletal traction helps maintain correct alignment of the bony fragments and assists in proper healing. Traction is maintained by a metal device inserted into the bone. The fracture site determines the insertion site of the stainless steel wires, pins, or tongs. Common sites for skeletal traction include the skull, the proximal end of the ulna, and the distal end of the femur, as well as the tibia and heel. General anesthesia is necessary for skeletal traction placement and removal.

BOX 50-2

TYPES OF SKELETAL TRACTION

Halo

• Purpose: To stabilize fractures or displaced vertebrae in cervical and thoracic areas. Also used to prepare the spine (muscles, vertebrae, and spinal cord) before spinal fusion, casting, or bracing in younger patients.

• Description: The halo is fitted with pins drilled directly into the skull. The halo is then attached by a rope to weights or pulley above the head or to a special vest connected to the halo with rods. When the halo is attached to weights, the center of the curved metal bar over the halo must extend along the same planes as the spinal cord. Traction pull is always along the axis of the spine. The child must maintain straight body alignment.

90/90 Femoral

• Purpose: Most commonly used traction for complicated fractures of the femur; most effective in children older than 6 years. Within 2 to 3 weeks, callus formation is sufficient to allow application of a spica cast.

• Description: A pin or wire is inserted through the distal femur.

The most serious complication associated with skeletal traction is osteomyelitis, an infection involving the bone. Organisms gain access to the bone systemically or through the opening created by the metal pins or wires used for traction. Clinical manifestations include localized pain, swelling, warmth, tenderness, unusual odor, fever, and irritability or lethargy in young children. To decrease the risk of infection, pin site care is required at least once per day. Pin care protocols involve inspecting each site for signs of infection (e.g., tenting or pulling around the pin, redness at the site, purulent drainage) and cleaning the skin around pin sites with one of various cleansing solutions (e.g., chlorhexidine gluconate, plain normal saline, soap and water), A recent evidence-based practice review of pin site care protocols was inconclusive as to the best method for preventing infection at pin sites (Lethaby, Temple, & Santy, 2008).

External fixation devices may also be used in the treatment of complex fractures, to lengthen bones, and to correct angular deformities that involve bone and soft tissue. These devices provide distraction, keeping the bone ends separated and in alignment so healing can occur. External fixators also allow periodic changes in alignment and bone length. External fixation devices, such as the Ilizarov external fixator (Figure 50-3), consist of pins or wires inserted through skin, soft tissue, and bone and secured on the outer limb surface to a rigid metal frame. General anesthesia is necessary for placement and removal of external fixation devices.

Because pins or wires of the external fixator pass through the skin to anchor in the bone, meticulous assessment of entry sites for signs of inflammation, infection, or loose pins is necessary. Pin tract infection occurs in approximately 50% of cases (TSRHC, 2008). Pin site care, similar to pin site care for children in traction, is recommended. To prevent injury to the other limb or to others, sharp protrusions from the fixator need to be adequately covered.

Many biochemical and physiologic properties of pediatric bones differ from those of adults. Three essential differences contribute to the understanding of injury, fracture patterns, healing, and treatment (Firmin & Crouch, 2009). First, children’s bones are less brittle with a higher collagen-to-bone ratio. This difference is protective, making incomplete fractures more likely. Secondly, children have a stronger periosteum. This also makes complete fractures less likely or at least limits fracture displacement. The third essential pediatric bone difference is the epiphyseal plate or growth plate. The epiphyseal plate is the weakest part of the growing bone, but often bears the brunt of children’s bone injuries.

An understanding of growth and development is helpful when assessing trauma in specific age-groups. For example, fractures in infancy are generally rare because of the cartilaginous quality of the skeleton. Fractures in infants are usually the result of trauma during birth or nonaccidental trauma. Therefore, fractures that occur after the birthing process warrant further investigation to rule out the possibility of child abuse.

Clavicle fractures can occur at any age. Lack of movement or a pseudoparalysis of the upper extremity may be the only sign in an infant who has sustained a fractured clavicle during birth. It is important to assess the infant with clavicle fracture for brachial plexus palsy because the two may be associated. An older child will report pain and show swelling on the clavicle at the site of the fracture. A common mechanism of clavicle injury in older children is blunt trauma from contact sports.

Another major cause of children’s fractures is falls. The outstretched arm often receives the full force of the fall, even

though this action is the result of the child’s protective reflexes (Figure 50-4). Although this force of impact can involve any part of the arm (wrist, elbow, shoulder), the supracondylar humeral fracture of the elbow is most commonly seen with this type of fall. Secondary complications of this injury include circulatory impairment, cellular necrosis, neurovascular damage, ischemic contracture (Volkmann contracture), or compartment syndrome.

Pediatric trauma is the leading cause of death and disability in children and one of the largest challenges to their health (Vitale, 2010). The United States has the highest incidence of pediatric trauma among developing nations; musculoskeletal trauma makes up the largest portion of pediatric injuries, with 25% of children sustaining an injury annually and 10% to 25% of those injuries being fractures (Vitale, 2010).

Fractures are common in children and adolescents because numerous gross motor activities place them at risk for injury. Young children are acquiring new motor skills, whereas older children and adolescents are participating in risk-taking behaviors as part of their normal growth and development. It is estimated that 40% of boys and 25% of girls will sustain a fracture by 16 years of age (Vitale, 2010). The distal forearm is the most common site to be fractured in children; the clavicle is second.

Rising participation in sports has been associated with an increase in sports-related injury in young children (Table 50-3). It has been estimated that 3.5 million children age 14 years or younger have received medical treatment for a sports-related injury each year (Andrews, Baker, Bergfeld, et al., 2010).

The primary goal in managing a soft tissue injury is to control swelling and prevent further injury. External pressure (compression) is most beneficial before edema has accumulated (Draper & Knight, 2010). Swelling can inhibit healing by keeping the ligament ends separated and increasing fibrous scarring. The earlier treatment is initiated, the less severe the swelling and immobility.

The injured area should be immediately wrapped with a compression bandage to support the joint and control the swelling. Ice should be applied to the injured area to reduce swelling for no longer than 20 minutes at a time. The effects of the ice can last as long as 5 to 6 hours, and ice should be used repeatedly for several days. Nonsteroidal antiinflammatory drugs (NSAIDs) help to alleviate pain and reduce inflammation.

For more severe soft tissue injuries, the child should avoid weight bearing for 3 days. Crutches may be necessary to ensure that the child does not bear weight. An air cast, which is a plastic, air-filled pressure cuff, may be used over the elastic wrap to support the joint and reduce swelling. The air cast or compression bandage should be worn for several weeks while the joint is healing. The child can begin stretching and isometric exercises to improve joint stability after the swelling and pain have diminished.

Immobilization of the injured joint and cold application are generally effective in the treatment of incomplete ligament tears. A complete rupture could require surgery to prevent excessive scar formation and long-term joint stability problems. Application of a cast or splint for 4 to 5 weeks may also be necessary, especially for knee injuries.