CHAPTER 23: Orthopedics

Musculoskeletal complaints and injuries are some of the most commonly encountered problems in pediatrics. In addition, children have immature musculoskeletal systems that pose particular challenges that are quite different than those of adults.

• Children have open growth plates, or physes, located between the epiphysis and the metaphysis

• Fractures most commonly occur near the metaphysis or physis

• An open growth plate is cartilaginous, and has not yet calcified, which makes it the weakest part of the immature bone

• Pediatric bones are less brittle than adults leading to some distinct fracture patterns

• In a buckle fracture, compression force leads to partial failure, but the fracture does not traverse the entire bone

• A greenstick fracture occurs due to tension or torsion force that leaves the cortex and periosteal sleeve intact of one side of the bone

• Angulated fractures in children have a much greater potential to remodel back to original shape than fractures in adults. Remodeling potential is greatest in: younger patients, injuries near a growing physis, and those in the plane of motion congruent to an associated joint

• Open fractures require consultation with Orthopedic Surgery

• Consider child abuse as a factor in pediatric fractures. Injuries concerning for abuse include: Bucket-handle (metaphyseal corner) fractures, multiple fractures of different ages, posterior rib or scapular fractures, and long bone fractures in children that do not walk

Management of fractures depends on the type, location, and amount of displacement present. Displacement, or loss of normal alignment of the distal fragment, is usually described in terms of translation (repositioning away from but remaining parallel to the long axis), angulation (degrees of bending from a straight line), shortening (overlap) or distraction (increased distance), and rotation (twisting).

FRACTURES OF THE PHYSIS

Physeal fractures are more common than isolated ligament or tendon injuries in skeletally immature patients because the surrounding connective tissues are stronger than the open physis. Injuries involving the physis are described with the Salter–Harris (SH) classification as shown in Figure 23-1, and described in Table 23-1.

• Physical exam findings in physeal fractures: Tenderness over long bone physis following an injury, swelling, difficulty bearing weight

• Diagnosis: Commonly made by plain radiographs

• SH-I fractures may not be visible on initial films. Look for soft tissue swelling adjacent to the physis in question

• In equivocal cases, consider imaging the contralateral joint to compare physeal widths

• Injuries to the physis should be monitored for several months after injury to monitor for growth arrest

• Injuries that result in some measure of disability, along with tenderness at a physis on exam, should be treated as SH-I fractures even if there is no abnormality demonstrated on the radiographs

UPPER EXTREMITY

Clavicle Fractures

• The most frequently fractured bone in children; most are in the midshaft

• Mechanism of injury: Trauma at birth due to difficult delivery; fall onto shoulder or outstretched arm in older children

• Physical exam: Tenderness at clavicle; patient may have visible deformity

• Shoulder range of motion (ROM) likely limited, especially forward flexion and abduction

• Assess for associated injuries, especially at the sternoclavicular (SC) joint

Diagnostic Workup:

• Plain radiographs: True anterior-posterior (AP) view of both clavicles, and AP view with beam at 30-degree cephalad angle (“serendipity view”)

Management:

• Infants: Pinning the sleeve to the body of their shirt for comfort; avoid direct pressure on the clavicle

• Older children: Sling, or figure of eight splint, typically for 3–4 weeks

• A palpable bony callus often remains after healing, but should not affect function

• Orthopedic referral required for open fractures, injuries adjacent to the SC or acromio-clavicular (AC) joint, or when significant skin tenting is present

Proximal Humerus Fractures

This is a rare injury in children, accounting for <5% of pediatric fractures. Patients with proximal humerus fractures need to be seen by Orthopedic Surgery service within 24–48 hours.

• Mechanism of injury: Backwards fall onto outstretched arm in older children and adolescents

• Children >11 years old usually have SH II pattern

• Assess neurovascular status, especially the axillary nerve (lateral shoulder sensation)

Diagnostic Workup:

• Plain radiographs: AP, lateral, and oblique views

Management:

• Consult with Orthopedic Surgery

• Infants: Nearly all do well with nonsurgical care

• Older children and adolescents: Most can be managed with sling and swathe

• Surgical indications: >50% translation, and angulation of >30–40 degrees in adolescents or >60–70 degrees in younger children

Fractures About the Elbow

All elbow fractures require consultation with Orthopedic Surgery. Elbow fractures do not remodel so alignment for healing fractures needs to be near perfect.

• The lateral epicondyle is the last ossification center to appear, around age 8–11 in girls and 9–13 in boys

• The medial epicondyle is the last to fuse, at age 14 in girls and 17 in boys

Supracondylar humerus fracture: Account for 60–80% of elbow fractures in children. Most occur in children <8 years old. Up to 15% may be associated with nerve injury, especially the anterior interosseous (Flynn). Evaluate by having patient flex thumb interphalangeal (IP) joint, and index finger distal IP joint (making the “OK” sign).

Diagnostic Workup:

• Plain radiographs: AP, lateral, oblique

• In the presence of a posterior fat pad (Figure 23-2), there is about a 75% chance of fracture

Management:

• If there is little to no posterior translation of the distal humerus, cast alone may be appropriate

• Most other fracture patterns require closed reduction and pinning

Lateral condyle fracture: The second most common elbow fracture, accounting for about 15% of elbow fractures in children. Injury is often due to varus force to the elbow during a fall.

Diagnostic Workup:

• Plain radiographs: AP, lateral, oblique

• Oblique view is paramount to properly assess for displacement

Management:

• Most are treated surgically, and the amount of displacement is a key factor

• If <2 mm displaced, consider long-arm cast for 4–6 weeks with repeat radiographs in cast at 1 and 2 weeks

• Fractures displaced >2 mm require surgical treatment

• Unlike most pediatric fractures, these can show nonunion that may lead to cubitus valgus

Medical condyle fracture: More likely in boys (nearly 80%) with peak incidence in early adolescence. The mechanism is valgus force with associated firing of forearm flexor and pronator muscles. There is an association with elbow dislocation in 50% of cases. The ulnar nerve may be compromised in rare cases.

Diagnostic Workup:

• Plain radiographs: AP, lateral, oblique

Management:

• Most surgeons accept treatment with cast for displacement 2–5 mm. Internal fixation is advised if displaced >5 mm

• May be associated with loss of terminal extension, which is more common with dislocation injuries and prolonged immobilization

Forearm Fractures

Forearm fractures account for nearly 50% of fractures in skeletally immature children, and nearly 80% involve the distal 1/3 of the forearm. Typical mechanism of injury is a fall onto an outstretched hand (“FOOSH”).

• Most fractures are buckle, greenstick, or SH-II pattern, and displacement is often dorsal

• Fractures involving both bones (radius and ulna) are more complex, as are diaphyseal and proximal injuries

• Be sure to evaluate distal vascular status

• Monteggia fractures are a proximal ulna fracture with an associated dislocation of the radial head. These require management by Orthopedic Surgery

Diagnostic Workup:

• Plain radiographs: AP and lateral views of the forearm to include both the elbow and wrist

• Assess distal and proximal articulations of the radius, ulna, and humerus

Management:

• Non-displaced injuries: Can be initially managed with volar splint (proximal forearm to metacarpal heads) (Figure 23-3B)

• Reduction attempt with sedation is warranted for displaced distal fractures, followed by long-arm splint or cast for 4 weeks

• Up to 50% translation is likely acceptable if >2 years of growth remains

• Most metaphyseal fractures are managed successfully in short-arm cast for 4 weeks

Hand Fractures

A fall onto an outstretched hand and direct blows are common mechanisms. Overall the thumb and little finger are most likely to be injured. Tendon and ligament injuries are uncommon until skeletal maturity.

• Distal phalangeal fractures are common

• Metacarpal fractures most often occur at the neck. Evaluate for rotational displacement by having patient make a fist, which should show all fingers pointing to scaphoid

• Carpal bone fractures are rare. The scaphoid is the most commonly fractured carpal bone. Patients have snuffbox tenderness, and radiographs may be negative

Diagnostic Workup:

• Plain radiographs: AP, lateral, oblique

• Consider “scaphoid view” with wrist in ulnar deviation

Management:

• Most metacarpal fractures are treated with closed reduction and splint in the “safe position” (10 degrees wrist extension, 60–70 degrees flexion at MCP joints, extension at IP joints) (Figure 23-3C)

• Displaced fractures usually require open reduction and pinning

• Snuffbox tenderness, even with negative radiographs requires thumb spica (Figure 23-3A) immobilization for 2–3 weeks then repeat evaluation with radiographs out of cast. If fracture is present then total immobilization is usually 6–12 weeks

LOWER EXTREMITY

Fractures of the lower extremity are more often seen in older children and adolescents.

Femur Fractures

• Most femur fractures are due to low energy events in middle childhood (6–10 years) with falls during play being the most common cause (Wells)

• In children less than 1 year, 80% may be due to abuse

• In adolescents most are due to motor vehicle accidents

• With a femoral shaft fracture, the patient is likely unable to bear weight, and may have visible deformity

• Distal femur physis fractures are most likely SH-I or II. Knee may be held in flexion due to hamstring spasm. Exam may reveal tenderness at the distal physis, which is just proximal to the joint line near the superior pole of the patella

Diagnostic Workup:

• Plain radiographs: AP, lateral; obtain oblique view for distal injuries. Include the ipsilateral hip and knee

• For fractures into the joint, consider CT scan to assess displacement in multiple planes

• Infants often warrant a skeletal survey to evaluate for child abuse

Management:

• Birth–5 years: Treat with spica cast or Pavlik harness for infants. Most show significant healing in 4 weeks, but may need up to 8 weeks immobilization

• 5–10 years: Consider conservative management with inpatient traction then spica casting. Surgical options include intramedullary nails, plates with screws, and external fixation devices

• >11 years: Surgery is the primary treatment; intramedullary nails are often used and facilitate early weight bearing (Wells)

• There is high risk for growth arrest with distal femur physeal fractures, and treatment of distal physeal injuries depends on fracture pattern

• SH-I injuries may be treated with long-leg or spica cast with knee at 15–20 degrees flexion

• SH-II fractures may require percutaneous pinning if unstable

• SH-III and IV require open reduction and internal fixation (ORIF) with long-leg cast postoperatively

Tibia Fractures

The tibia is the most commonly fractured bone of the lower extremity in children, and these injuries are frequently accompanied by ipsilateral fibula fracture. Most proximal tibia physeal fractures are SH-I or II, and if displaced can compromise the surrounding vascular structures.

• Tibial tubercle avulsion fractures are rare, and occur with a jumping or landing mechanism that typically produces a pop sensation and presents with significant swelling over the tubercle and an inability to do straight leg raise

• The Toddler’s fracture is a non-displaced spiral fracture of the tibial metaphysis in children 1–4 years old. It occurs with an apparently innocuous twist and fall that is often unwitnessed. Child may limp or stop weight bearing

• The Cozen fracture involves the proximal tibia metaphysis, and is seen in children 2–10 years old. It can lead to progressive valgus deformity

• Both Tillaux and triplane fractures are fractures of the distal tibia in adolescents near skeletal maturity. They most often occur due to external rotation of a planted foot and may be mistaken for an ankle sprain

• The Tillaux fracture is an SH-III injury to the anterolateral distal tibial epiphysis

• A triplane fracture involves coronal, sagittal, and transverse components at the distal tibia. It appears as an SH-II fracture on lateral radiographs and as an SH-III on anterior posterior radiographs

Diagnostic Workup:

• Plain radiographs: AP, lateral, oblique views to include the ipsilateral knee and ankle

• CT scan may be indicated for Tillaux and triplane fractures to assess the degree of displacement at the joint surface

Management:

• Most tibial shaft fractures are treated with cast; consider closed reduction as needed

• Non-displaced tibial tubercle avulsions are managed with cast above the knee; if displaced, they warrant ORIF

• Cozen fractures are treated with closed reduction and casting

• Proximal physeal fractures are treated with cast above the knee if non-displaced. If displaced they require closed reduction, often under general anesthesia

• Treat Toddler’s fracture with above the knee cast, weight bearing as tolerated, for 3 weeks (Wells)

• Closed reduction may be attempted for Tillaux and triplane fractures, but ORIF is indicated for residual joint step-off greater than 2 mm

Foot Fractures

Most metatarsal fractures are due to a direct blow. Fractures at the base of the 5th metatarsal require special attention.

• The apophysis at the 5th metatarsal base appears on radiographs as a line parallel to the shaft of the bone. A lucency perpendicular to this is consistent with a fracture

• Avulsion of the apophysis at the base of the 5th metatarsal occurs with inversion of the foot and ankle with tension from the lateral cord of the plantar aponeurosis pulling on the apophysis

• Jones’ fracture is injury at the junction of the metaphysis and diaphysis, distal to the apophysis. It occurs in adolescents, and is often seen as an acute on chronic injury

Diagnostic Workup:

• Plain radiographs: AP, lateral, oblique

• Obtain weight-bearing views if tolerated

Management:

• Most non-displaced metatarsal fractures are treated with short-leg walking cast

• Immobilization is preferred for avulsion at the base of the 5th metatarsal

• Nonoperative care can be considered with acute Jones’ fracture and consists of non-weight bearing cast for 6–8 weeks. There is a relatively high nonunion rate, and some patients will require internal fixation with a screw

COMPARTMENT SYNDROME

Compartment syndrome occurs when increased pressure within an osseofascial compartment leads to impaired blood flow with ischemia of muscle and nerve tissue.

• Most often seen in the lower leg or the forearm

• May result from trauma and hemorrhage, or postsurgically. Especially likely in the setting of a crush injury

• 75% of cases are associated with a fracture

• Pain apparently out of proportion to injury, or pains with passive stretching are hallmarks that warrant further evaluation

• Late findings include diminished pulse and pallor

Diagnostic Workup:

• For proper assessment (visualization, palpation, ROM) removal of cast or splint is necessary

• Clinical concern can be corroborated with compartment pressure measurement

Management:

• If suspected, immediate surgical consultation is advised

• Remove any restrictive dressings including cast material

• Keep affected limb at the level of the heart. Do not elevate the limb as this can decrease arterial blood flow

• Fasciotomy is the definitive intervention

SLIPPED CAPITAL FEMORAL EPIPHYSIS (SCFE)

SCFE is a disorder in which the femoral neck slides up and outward along the femoral physis, consistent with an SH-I injury. The femoral head remains in place within the acetabulum.

• Typically seen from late childhood (9–10 years) through middle adolescence (15–16 years)

• More likely in obese youth

• May be acute (symptoms <3 weeks), chronic, or a combination thereof

• Symptoms: Unilateral hip, groin, thigh or knee pain. Patients with chronic picture have more vague pain and often limp

• Up to 60% can be bilateral

• It is stable if the patient can ambulate, either with or without crutches

• Exam reveals limited internal rotation, abduction, and flexion, with pain upon hip ROM. The affected limb may be held in external rotation, and may appear slightly shortened

Diagnostic Workup:

• Plain radiographs: AP and frog-leg lateral (hips flexed and abducted) views of the pelvis with assessment of both hips

• A line (Klein’s line) drawn along superior aspect of the femoral neck should intersect the lateral capital epiphysis. As the femoral neck slips up and outward, the line will intersect progressively less of the epiphysis, until it no longer contacts it at all. This is the radiographic finding in SCFE (Figure 23-4)

Management:

• Upon diagnosis, contact Orthopedic Surgery

• Make patient non-weight bearing with either crutches, or a wheelchair for bilateral involvement. Transfer to Emergency Department, and/or hospital admission is warranted

• Definitive treatment for non-displaced lesions is in situ fixation using a pin or screw. Surgical intervention for the unaffected hip, whether symptomatic or not, may be considered, but remains controversial

TRANSIENT SYNOVITIS VERSUS SEPTIC ARTHRITIS

This remains a potential diagnostic dilemma. Both are primarily seen in the hip with unilateral pain at hip, groin, thigh, or knee, often with a limp. The affected limb may be held with hip flexed and abducted.

• Transient synovitis is the most common cause of hip pain and usually affects children 3–8 years old. It is often associated with recent or current illness. Children are nontoxic appearing, and are able to bear weight on the effected limb

• The child with septic arthritis may appear more ill, and have higher fever. (See Infectious Diseases chapter for management of septic arthritis)

Diagnostic Workup:

• History and physical, along with complete blood count (CBC) for white blood count (WBC), and erythrocyte sedimentation rate (ESR)

• The four primary criteria to consider are: Fever, inability to ambulate, WBC count >12,000/mm³, and ESR of 40 mm/h or higher

• If all four criteria are met, there is up to a 99% chance that the patient has septic arthritis. The likelihood decreases to 93% if three of four criteria are positive, 40% if two of four are positive, and down to <5% if only one of four present (Kocher criteria)

• Joint aspiration is indicated if two or more criteria are met

• An aspirate is considered indicative of bacterial infection if the fluid has >50,000 WBCs/mm³ or if bacteria are present on Gram stain

Management:

• Most transient synovitis will resolve spontaneously within 2 weeks. Weight bearing is limited for comfort, and nonsteroidal anti-inflammatory drugs (NSAIDs) are used as needed

• Despite its efficacy for pain relief, joint aspiration is reserved for diagnostic purposes as fluid often rapidly reaccumulates

• The septic joint must be explored surgically, and is a relative emergency