Pediatric Fracture

Question 1

Background

Answer 1

In growing children, sprains and strains often result in potentially serious growth plate fractures and physeal fractures (see the image below). These same sprains and strains in active adults are relatively benign injuries. This article discusses some of the important orthopedic history relative to the physes, relevant anatomy, classification systems, and some details of physeal fractures in specific areas of the body.

Question 2

Growth plate (physeal) fractures

Answer 2

Growth plate (physeal) fractures are typically believed to occur through the zone of provisional calcification but may traverse several zones, depending on the type of external load application. For instance, with application of compression-type loads, the histologic zone of failure is typically the provisional calcification portion of the hypertrophic zone. Shear forces may also cause failure in the hypertrophic zone. Tension forces lead to failure of the proliferative zone.

Question 3

Salter-Harris Fracture Imaging

Answer 3

Salter-Harris fractures are fractures through a growth plate; therefore, they are unique to pediatric patients. These fractures (radiographs of which are presented below) are categorized according to the involvement of the physis, metaphysis, and epiphysis. The classification of the injuries is important, because it affects patient treatment and provides clues to possible long-term complications.

When all types of Salter-Harris fractures are considered, the rate of growth disturbance they cause is approximately 30%. However, only 2% of Salter-Harris fractures result in a significant functional disturbance.

Question 4

The basic Salter-Harris fractures include the following

Answer 4

Type I
A type 1 fracture (illustrated below) is a transverse fracture through the hypertrophic zone of the physis. In this injury, the width of the physis is increased. The growing zone of the physis usually is not injured, and growth disturbance is uncommon.

On clinical examination, the child has point tenderness at the epiphyseal plate, which is suggestive of a type I fracture

Type II
The most common type of Salter-Harris fracture, a type II fracture (illustrated below) occurs through the physis and metaphysis; the epiphysis is not involved in the injury.

These fractures may cause minimal shortening; however, the injuries rarely result in functional limitations.

Type III
A type III fracture (illustrated below) is a fracture through the physis and epiphysis. This fracture passes through the hypertrophic layer of the physis and extends to split the epiphysis, inevitably damaging the reproductive layer of the physis.

This type of fracture is prone to chronic disability, because by crossing the physis, the fracture extends into the articular surface of the bone.
However, type III fractures rarely result in significant deformity; therefore, they have a relatively favorable prognosis.
An ankle fracture termed a Tillaux fracture is a type of Salter-Harris type III fracture that is prone to disability.
The treatment for type III fractures is often surgical.

Type IV
A Type IV fracture involves all 3 elements of the bone, passing through the epiphysis, physis, and metaphysis

Similar to a type III fracture, a type IV fracture is an intra-articular fracture; thus, it can result in chronic disability.

By interfering with the growing layer of cartilage cells, these fractures can cause premature focal fusion of the involved bone. Therefore, these injuries can cause deformity of the joint.

Type V
A type V injury (illustrated below) is a compression or crush injury of the epiphyseal plate, with no associated epiphyseal or metaphyseal fracture.

Question 5

Salter-Harris Fracture Imaging

Preferred examination

Answer 5

Radiography always is the preferred examination in a suspected fracture. The use of another modality should not be considered until appropriate plain film radiography has been performed.

In cases of severe injury in which the patient has acute pain, appropriate radiographic examination of the involved area may be difficult because of inadequate patient positioning. In these cases, computed tomography (CT) scanning may be beneficial in evaluating the injury after a radiologist has evaluated the plain radiographs.

However, the cost of CT may prohibit its use in all cases in which the area of interest is suboptimally evaluated. CT should be considered only when radiographic findings are insufficient. Typically, an orthopedic surgeon and a radiologist make the decision to perform CT.

If an additional study is performed, its purpose is to determine the appropriate management and to assist in surgical planning. Thus, the surgeon performing the operation is best suited to request the imaging study.

Currently, 2 radiologic examinations can be performed to further evaluate fractures:

(1) CT scanning with multiplanar reconstruction and
(2) magnetic resonance imaging (MRI). MRI depicts marrow edema, whereas CT shows cross-sectional bone detail and tomographic multiplanar information. At the present time, MRI is not the standard of care. CT is used more commonly; typically, it is used for planning surgery.

The disadvantages of MRI that limit its routine use include the modality’s expense, time requirement, and availability. In children, particularly very young children, sedation and even general anesthesia may be required to perform MRI scans.

Question 6

Legg-Calve-Perthes Disease

Answer 6

Legg-Calvé-Perthes disease is the eponym given to idiopathic osteonecrosis of the femoral head. It was described approximately 100 years ago as a unique disease entity affecting the pediatric population. [1] Legg-Calvé-Perthes disease can lead to hip deformities and severe degenerative arthritis.

Question 7

Legg-Calve-Perthes Pathophysiology

Answer 7

The pathophysiology and temporal sequence of events in Legg-Calvé-Perthes disease remains unclear; however, the following scenario is generally accepted:

1. The blood supply to the femoral head is interrupted.
2. Bone infarction and necrosis affects the articular cartilage, subchondral bone, and the bony epiphysis.
3. Revascularization occurs and new bone ossification starts. In some cases, patients may have normal bone growth and development.
4. With progression of the disease, bone resorption, delayed bone formation, and subchondral fracture occurs. This microdamage is usually the result of normal physical activity, not direct trauma.
5. This may result in deformities in the femoral head, epiphyseal growth plate, and possible lesions in the metaphysis.

Question 8

Legg-Calve-Perthes Epidemiology

Answer 8

One in 1200 children younger than 15 years is affected by Legg-Calvé-Perthes disease. Legg-Calvé-Perthes disease most commonly is seen in persons aged 3-12 years, with a median age of 7 years.The disease is familial approximately 10% of the time.

Legg-Calvé-Perthes disease is a self-limited disease if not treated. Outcome widely varies. In 15-20% of patients with Legg-Calvé-Perthes disease, involvement is bilateral.

Whites are affected more frequently than persons of other races. Males are affected 4-5 times more often than females.

In a study of girls with Legg-Calvé-Perthes disease, of the 451 patients who presented at a single large urban children’s hospital from 1990-2014 with a diagnosis of Legg-Calvé-Perthes disease, 82 (18.2%) were female. The average age at presentation for girls was 6.58 years

Question 9

Legg-Calve-Perthes

Answer 9

Symptoms of Legg-Calvé-Perthes disease usually have been present for weeks because the child often does not complain. Radiographs of the hip should always be considered for a child complaining of thigh or knee pain.

History may reveal the following:

• Hip or groin pain, which may be referred to the thigh
• Mild or intermittent pain in anterior thigh or knee
• Limp
• Usually no history of trauma
• Progressively increased pain with physical activity, usually relieved by rest

Question 10

Physical Findings of Legg-Calve-Perthes

Answer 10

Some physical examination findings and symptoms may include the following:

i. Decreased range of motion (ROM), particularly with internal rotation and abduction
ii. Painful gait
iii. Muscle spasm
iv. Limp
v. Leg length inequality due to collapse of the femoral head
vi. Thigh, calf, and buttocks muscle atrophy: vii. Circumferences on the involved side may be smaller than on the unaffected side, secondary to disuse.
viii. Short stature: This result from deformity of the femoral head.

ix. Roll test: With patient lying in the supine position, the examiner rolls the hip of the affected extremity into external and internal rotation. This test should invoke guarding or spasm, especially with internal rotation.
x. Trendelenburg sign: While standing, the patient lifts one leg up at a time; owing to muscle weakness on the affected side, the pelvis drops to the opposite side

Question 11

Legg-Calvé-Perthes cause

Answer 11

The exact etiology of Legg-Calvé-Perthes disease remains unclear, but it is likely multifactorial and may include genetic predisposition, environmental exposures, and/or socioeconomic factors.

Some specific suggested causes include trauma, an inflammatory process, a disorder of the epiphyseal cartilage, abnormalities in the vasculature, increased blood viscosity such as thrombophilia, abnormalities in growth hormone, maternal smoking, and second-hand smoke exposure.

Question 12

Legg-Calvé-Perthes Treatment

Answer 12

Goals of treatment of Legg-Calvé-Perthes disease include the following:
1. Containment of the femoral epiphysis within the confines of the acetabulum

2. Maintenance or improvement in range of motion
3. Relief of weight bearing
4. Provision of traction
5. Prevention of deformity and growth disturbances
6. Prevention of degenerative arthritis

Once the diagnosis of Legg-Calvé-Perthes disease is suspected, an orthopedic surgeon or a pediatric orthopedic surgeon should be contacted for further management decisions.
An orthopedic consultant may choose to order more specialized tests (eg, bone scintigraphy, arthrography, MRI), usually in an outpatient setting, to better determine the extent of the disease.

Management is based on the age of onset and is divided into patients younger than 6 years, patients aged 6-8 years, and patients older than 8 years.

Ultimately, patients can be managed either conservatively or operatively. This is decided on a case-by-case basis by the orthopedic specialist.

Question 13

Legg-Calvé-Perthes (LCPD)

Overview

Answer 13

Legg-Calvé-Perthes (LCPD) disease is a childhood hip disorder that results in infarction of the bony epiphysis of the femoral head. LCPD represents idiopathic avascular necrosis of the femoral head. The disease is bilateral in 10-20% of patients and usually affects children aged 4-8 years. When both hips are involved, they are usually affected successively, not simultaneously. A family history is present in 6% of patients. In adults, the corresponding condition is termed Chandler disease.

Although the etiology is unclear, certain risk factors have been identified in children, including sex, socioeconomic group, and the presence of an inguinal hernia and genitourinary tract anomalies. More specifically, boys are affected 3 to 5 times more often than girls, and the incidence increases in low socioeconomic groups and in children with low birth weight. Determining the prognosis is important at the time of presentation, because more than 50% of patients with LCPD do not require treatment.

Question 14

Legg-Calvé-Perthes (LCPD)

Imaging

Answer 14

Plain radiography remains the major modality for the evaluation of LCPD. Staging of the disease is based on plain radiographic findings.

Scintigraphy is a useful technique in early disease when plain radiographic findings may be normal; with scintigraphy, abnormalities become apparent earlier in the course of disease than they do with plain radiography.
Computed tomography (CT) scans allow early diagnosis of bone collapse and curvilinear zones of sclerosis early in the disease process when plain radiography is less sensitive. CT scans can also demonstrate subtle changes in the bone trabecular pattern.

Ultrasonography is useful in the preliminary diagnosis of transient synovitis of the hip and the onset of LCPD. [7] Hip effusion with capsular distension is well depicted on sonographic images.

Magnetic resonance imaging (MRI) is as sensitive as isotopic bone scanning and allows more precise localization of involvement than conventional radiography.

Question 15

Slipped Capital Femoral Epiphysis

Background

Answer 15

Slipped capital femoral epiphysis (SCFE) is one of the most important pediatric and adolescent hip disorders encountered in medical practice. Although SCFE is a rare condition, an accurate diagnosis combined with immediate treatment is critical.

Despite the fact that the underlying defect may be multifactorial (eg, mechanical and constitutional factors), SCFE represents a unique type of instability of the proximal femoral growth plate. Clinically, the patient may report hip pain, medial thigh pain, and/or knee pain; an acute or insidious onset of a limp; and decreased range of motion of the hip.

On plain radiographs, the femoral head is seen displaced, posteriorly and inferiorly in relation to the femoral neck and within the confines of the acetabulum.

Treatment is primarily operative internal fixation. The goal is to prevent complications such as avascular necrosis (AVN).

Question 16

Slipped Capital Femoral Epiphysis

Functional Anatomy

Answer 16

SCFE results from a Salter-Harris type physeal fracture. In patients with SCFE, the epiphyseal growth plate is unusually widened, primarily due to expansion of the zone of hypertrophy. The hypertrophic zone, which constitutes 15-30% of the normal physis, can account for up to 80% of the width of the physeal plate in affected patients. Histologically, abnormal cartilage maturation, endochondral ossification, and perichondral ring instability occur. This leads to less organization of the normal cartilaginous columnar architecture. Slippage occurs through this weakened area.

The position of the proximal physis normally changes from horizontal to oblique during preadolescence and adolescence, redirecting hip forces from compression forces to shear forces. There is an association between femoral neck retroversion and a reduced neck-shaft angle with SCFE. These changes can increase the shear forces across the hip, leading to SCFE. [19] Other concomitant findings in the hip include inflammatory synovitis and disorganized collagen fibrils with accumulations of proteoglycans and glycoproteins within the growth plate; however, whether these changes are a cause or a result of SCFE remains undetermined.

Question 17

Slipped Capital Femoral Epiphysis

Clinical Presentation

Answer 17

History
See the list below:
Slipped capital femoral epiphysis (SCFE) is most common in the adolescent period (ie, boys aged 10-16 y, girls aged 12-14 y). Males have 2.4 times the risk compared with females.

The left hip is affected more commonly than the right.

Obesity is a risk factor because it places more shear forces around the proximal growth plate in the hip at risk.

The duration, location, and radiation of pain are important, as is the ability to bear weight.
Genetics may play a role in SCFE because the rate of familial involvement is 5-7%, with a large variability in penetrance.

In patients younger than 10 years, SCFE is associated with metabolic endocrine disorders (eg, hypothyroidism, panhypopituitarism, hypogonadism, renal osteodystrophy, growth hormone abnormalities). Bilaterality is more common in these younger patients.

The chronicity of the condition should be determined.

i. Prodromal symptoms (eg, hip or knee pain, limp, decreased range of motion) for less than 3 weeks are deemed acute.
ii. Prodromal symptoms for longer than 3 weeks are deemed chronic.
iii. If a patient reports symptoms of greater than 3 weeks’ duration but presents with an acute exacerbation of pain, limp, inability to bear weight, or decreased range of motion with or without an associated traumatic episode, the SCFE is categorized as acute on chronic.
iv. Determine if a traumatic episode occurred.

It is important to determine if the lesion is stable or unstable.

i. “Stable” SCFEs allow the patient to ambulate with or without crutches. [7]
ii. “Unstable” SCFEs do not allow the patient to ambulate at all; these cases carry a higher rate of complication, particularly of AVN.

Question 18

Slipped Capital Femoral Epiphysis

Physical Exam

Answer 18

If a patient reports knee pain, always examine the hip, because knee pain may be referred pain from the hip via the obturator nerve.

Obesity increases a clinician’s index of suspicion for SCFE.

Patients often hold their affected hip in passive external rotation.

Determine the patient’s ability to bear weight (stable vs unstable).

If the patient is ambulatory, determine the his or her gait pattern:

i. Antalgic – Shortened stance phase on the affected side
ii. Out-toeing

Always examine both hips. Assess the active and passive range of motion in both hips. In patients with unilateral complaints, this comparison allows the clinician to compare the affected and unaffected sides for differences. Internal and external rotation are best tested with the patient in the prone position with the knees flexed to 90 º.

i. If SCFE is present, the lower extremity may externally rotate and abduct with gentle passive hip flexion.
ii. Internal rotation is decreased in nearly all hips with SCFE. Internal rotation is often painful.

Question 19

Slipped Capital Femoral Epiphysis

Treatment & Management

Answer 19

Treatment of slipped capital femoral epiphysis (SCFE) is emergent; therefore, early and accurate diagnosis is paramount. There is no role for observation or attempts at closed reduction.

Classification schemes are as follows:

i. Determine whether the SCFE is acute (< 3 weeks), chronic (3+ weeks), or acute on chronic (3+ weeks of symptoms with acute exacerbation or change).
ii. Determine whether the SCFE stable (able to bear weight) or unstable (non-weight bearing). This determination has become more important than acute versus chronic due to the fact that unstable patients have been found to have a high complication rate.
iii. Determine the radiographic classification. This is determined by the percentage of displacement of the hip in relation to the neck. Type I is less than 33% displacement, type II is 33-50% displacement, and type III is greater than 50% displacement.

Prophylactic treatment of the asymptomatic hip remains controversial. In Europe, the majority of patients receive prophylactic fixation of the contralateral hip. Each case should be approached individually, and the benefits and risks should be weighed when contemplating surgery on the unaffected hip.

In a review of the literature, prophylactic treatment may be considered in patients younger than 10 years or patients affected by various endocrinopathies because these individuals have higher relative risks for bilateral involvement. Prophylactic treatment should also be considered in a patient or family that is unreliable. In a typical patient who presents with unilateral SCFE, the parents should be warned of possible sequential bilateral involvement. The need for close follow-up and early operative intervention if the other hip becomes symptomatic must be understood by the family.

Delays in diagnosis or treatment can be very detrimental to the patient’s outcome. The slip may progress, and increased severity of SCFE leads to early degenerative arthritis. With a diagnostic or treatment delay, stable slips may become unstable, which leads to higher rates of AVN.

Surgical Intervention
At this time, immediate internal fixation in-situ using a single cannulated screw is the treatment of choice of SCFE. Fixation allows early stabilization of the slippage, enhancement of physeal closure, prevention of further slippage, and amelioration of symptoms with minimal morbidity.

Unstable or grade III slips may require gentle repositioning to improve alignment. Revision of the screw fixation may be needed if the child “outgrows” the screw, placing the child at risk for a repeat slip.