Back pain in children and adolescents is not as common as in adults, but neither is it as uncommon as previously thought. More than 50% of children experience some back pain by 15 years of age, and up to 36% of school-age children experience episodes of low back pain. However, medical attention is rarely sought for the problem, which contributes to the assumption that back pain is rare in the pediatric population. Historical teaching was that because back pain in children was less common than in adults, it was usually associated with an underlying pathologic condition.
In general, young children and toddlers are unlikely to exaggerate symptoms, and an “organic cause” can usually be found as the source of their back pain. But back pain in older children and adolescents, as is the case with adults, is often “nonspecific back pain.” This shows that not all patients must be evaluated with a full array of sophisticated imaging and laboratory studies. However, it is important that all patients with back pain have a careful examination to avoid missing or delaying the diagnosis of serious problems Findings in the history and physical examination associated with identifying an “organic cause” of back pain include constant (versus intermittent) pain, night pain, radicular pain, and an abnormal neurologic examination result.
An understanding of the potential causes of back pain will enable the orthopaedist to properly evaluate the patient and treat the problem. The first steps in differentiating patients with a true pathologic cause from those who need only symptomatic treatment and observation are a comprehensive history and physical examination.
In this chapter, the various causes of back pain are discussed in general terms. The specific entities, such as disk herniation, spondylolisthesis, arthritis, and neoplasms, are discussed in detail in the relevant chapters.
History
A thorough, detailed history provides the clinician with the most important information when evaluating children with back pain.
Nature of the Pain
First, the nature of the pain—its onset, character, and location—must be determined. Acute pain of sudden onset in the setting of preceding trauma is seen with fractures, ligamentous sprain, disk herniations, and apophyseal ring fractures. Symptoms usually appear within 24 hours. Slow-onset, insidious pain is more characteristic of Scheuermann kyphosis, benign tumors, and malignancies. Mild pain of short duration after a sports activity usually is due to muscle strain. Recurrent pain associated with specific activities is more likely caused by conditions such as spondylolysis, spondylolisthesis, Scheuermann kyphosis, or a herniated disk. Persistent, unremitting pain and night pain are more often associated with tumors and infections. Malignant tumors of the spine and spinal cord may cause persistent back pain that intensifies over time.
The site of the pain and any associated radiation are also important clues to a possible underlying cause. Localized back pain may be caused by spondylolysis or neoplasms. Pain in the lumbar region is associated with spondylolysis, whereas thoracic pain may be caused by Scheuermann kyphosis. Inflammatory processes and overuse syndromes usually result in a more diffuse or generalized pain that is felt over a fairly wide anatomic area. Pain that radiates to the buttocks or lower limb may indicate a herniated lumbar disk, vertebral apophysis fracture, epidural abscess, or intraspinal tumor.
Constitutional Symptoms
If a patient has coexisting constitutional symptoms such as fever, chills, malaise, anorexia, or weight loss, the back pain may be a sign of systemic malignancy (e.g., leukemia) or an infection. Antecedent bacterial or viral infections may cause diskitis and pain. The presence of neurologic symptoms, such as numbness, weakness, changes in balance or coordination, gait abnormalities, or bowel or bladder dysfunction, should be noted because these symptoms are rarely seen with benign conditions in children.
Aggravating and Alleviating Factors
The physician should ask about factors that exacerbate or relieve the patient’s pain. The relationship of pain to an activity is important to recognize. Sports activities that involve repetitive hyperextension of the lumbar spine (e.g., gymnastics, football, dancing, rowing) place shear forces across the lumbar spine and increase the risk of spondylolysis and spondylolisthesis. * Frequent participation at a high level of intensity in sports activity and training can lead to stress fractures or overuse syndromes. Rest usually alleviates pain caused by spondylolysis, spondylolisthesis, Scheuermann kyphosis, muscle strains, or overuse syndromes. Back pain caused by spinal neoplasms is constant and progressive and does not vary with activity; pain may be worse at night when the patient is supine and is not relieved by rest. Night pain has been linked to neoplasms, particularly in young children. Back pain caused by an osteoid osteoma often is relieved by nonsteroidal antiinflammatory drugs (NSAIDs).
* References .
Age-Related Conditions
Although no disorder is unique to a particular age group, the age of the patient can assist the clinician in making the differential diagnosis. Back pain in children younger than 4 years of age most likely is because of an infection or a neoplasm, which should be promptly diagnosed and treated. Infectious spondylitis is more common in children younger than 10 years of age, and the neoplasms seen in this age group include eosinophilic granuloma, leukemia, neuroblastoma, and astrocytoma. Patients older than 10 years of age are more likely to have back pain secondary to trauma or overuse syndromes, which can result in spondylolysis, spondylolisthesis, Scheuermann kyphosis, disk herniation, or slipped or fractured vertebral apophysis. Spondylolysis and spondylolisthesis are the most common causes of identifiable lumbar back pain in active adolescents. Spondylolysis usually is asymptomatic before the adolescent growth spurt. Scheuermann kyphosis is the most common cause of thoracic back pain in teenagers (with boys affected more often than girls). Lumbar Scheuermann disease is seen in older adolescents (onset commonly occurs during the adolescent growth spurt) and also is more frequent in boys. Neoplasms that occur with older children include osteoblastoma, osteosarcoma, and lymphoma. Tumors such as osteoid osteoma and aneurysmal bone cysts are not specific to any age group.
Assessment of General Symptoms
The history should conclude with a general systems assessment in which there is a review of other medical problems and family history. A myriad of medical conditions, ranging from the benign to the serious, can manifest with back pain. A thorough psychosocial assessment may reveal underlying conditions that are contributing to the pain.
Physical Examination
Proper physical examination requires that the patient disrobe. Socks need to be removed so that the feet can be examined because neurologic abnormalities may lead to foot deformities.
General Inspection
The clinician should start the physical examination by observing the child’s general habitus and affect. Patient posture, movement, and gait should be observed because abnormalities may suggest a neurologic disorder. The skin should be inspected for cutaneous lesions associated with intraspinal disorders, such as midline skin defects (e.g., hemangiomas, sinuses, lipomas, hair patches), café au lait spots, and cysts. Midline skin defects and cysts often communicate with deeper nerve structures, and their presence may indicate underlying problems, such as a spinal cord abnormality or dysraphism.
Assessment of the Spine
Next, the clinician should examine the spine by inspection and palpation for posture and alignment. Scoliosis can be detected by having the patient bend forward while standing. The presence of trunk lean or decompensation may indicate an underlying pathologic process, such as a herniated disk or neoplasm. Spinal flexibility should be assessed. When the child bends forward, reversal of the normal lumbar lordosis should occur. Stiffness, listing, or dysrhythmia during this maneuver is highly indicative of a pathologic cause for back pain ( Figs. 7-1 and 7-2 ). A child with diskitis will bend the knees, rather than bend over at the spine, to retrieve an object from the floor. Hyperextending the spine while the child is standing on one leg can exacerbate lumbar pain from pars interarticularis lesions (i.e., spondylolysis and spondylolisthesis). The straight-leg raise test is used to rule out herniated disks or apophyseal fractures. Children with back pain often have hamstring tightness, which may be expressed in diminished straight-leg raising or inability to touch the floor with the fingers without bending the knees. The back should be palpated for tenderness, muscle spasms, and anatomic abnormalities. Patients with spondylolisthesis may have an L5-S1 step-off or “heart-shaped” buttocks.
Neurologic Assessment
A careful neurologic examination is crucial for diagnosing spinal cord disease in patients with back pain. Motor and sensory function and deep tendon and abdominal reflexes should be tested. Asymmetric findings should be noted. The presence of long tract signs should be determined. Clonus or an abnormal Babinski reflex may indicate a central nervous system abnormality, such as a spinal cord anomaly or compression. The abdominal reflex is tested by stroking the skin in each of the four quadrants of the umbilicus and noting movement of the umbilicus toward the quadrant stroked. An abnormal abdominal reflex may indicate a pathologic process of the spinal cord. Asymmetry or absence of abdominal reflexes can be associated with syringomyelia ( Video 7-1 ). 
General Physical Assessment
Finally, a general physical examination is performed to make sure the patient’s back pain is not caused by nonorthopaedic conditions, such as urinary tract infection, hydronephrosis, ovarian cysts, pneumonia with chest wall pain, or inflammatory bowel disease.
Diagnostic Studies
The history and physical examination findings help determine which diagnostic studies are appropriate ( Box 7-1 ). Standard radiographs should be ordered for all children age 4 years or younger with back pain and in older children when the pain has lasted 2 months or longer, when the pain is severe enough to wake the child from sleep, or when the child has coexisting constitutional symptoms. Plain radiographic appearances will guide the clinician in deciding on additional diagnostic studies. At the other end of the spectrum are older children with activity-related pain of short duration and whose neurologic examinations are negative. These patients do not need additional diagnostic workup and need only be observed for at least 1 month. The extent of additional workup for children who fall between these two groups needs to be decided on an individual basis. Feldman and associates reported an algorithm for evaluation of pediatric back pain. Advanced imaging was reserved for patients with abnormal plain films, constant pain, night pain, radicular pain, or an abnormal neurologic examination. Nonspecific back pain was diagnosed in patients with intermittent pain and normal radiographs. No specific diagnoses were missed during the study period.
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Plain radiography: Best diagnostic screening test for children with back pain.
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Other imaging modalities: If plain radiographs are equivocal or nondiagnostic but the history and physical examination findings suggest a pathologic cause, more sophisticated imaging modalities should be used.
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Triphasic technetium bone scans: Used in patients with normal findings on neurologic examination. Increasingly MRI is replacing bone scans.
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Computed tomography (CT): Provides the best images of bony anatomy of areas of involvement.
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Single-photon emission computed tomography (SPECT): Used when bone scans are equivocal or nondiagnostic.
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Magnetic resonance imaging (MRI): Used in patients with abnormal findings on neurologic examination.
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Laboratory tests: Complete blood count (CBC) and erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) tests should be ordered for all young children with back pain, patients with night pain, and any child with coexisting constitutional symptoms.
Radiography
Plain radiographs are the best diagnostic screening test for children with back pain. The films should be carefully examined for vertebral alignment, disk space narrowing, vertebral end-plate irregularities, vertebral scalloping, and lytic or blastic lesions. Anteroposterior and lateral views of the spine obtained without shielding usually are sufficient for this purpose. It is important that the pelvis be adequately seen on plain radiographs because sacral and pelvic lesions can manifest with back pain. Lesions or stress reactions around the sacroiliac joint may mimic spondylolysis or spondylolisthesis, whereas lesions around the ischium and greater sciatic notch may cause radicular symptoms.
A lateral view of the spine usually shows the pars interarticularis defect in patients in whom spondylolysis or spondylolisthesis is the cause of back pain. If the film is equivocal, oblique views and a spot lateral film of the lumbosacral junction may better delineate the condition. A coned-down spot radiograph, which provides greater bony detail, may be ordered to demonstrate better any questionable lesions seen on screening views or to evaluate a specific painful area of the spine.
Although plain radiographs may demonstrate scoliosis in the patient with back pain, the deformity usually does not cause significant back pain. When questioned, up to 33% of adolescents with idiopathic scoliosis report some back pain; however, it usually is located over the rib prominence. The finding of scoliosis requires its own workup, but the cause of the back pain remains to be determined. Careful examination of the apex of the curvature on the convex side may reveal a bony lesion, with the spine deviating away from the irritating process.
When plain radiographs are equivocal or nondiagnostic, but the history and physical examination findings are highly suggestive of a pathologic cause for the patient’s pain, higher level imaging modalities are recommended.
Bone Scan
A triphasic technetium bone scan is recommended for patients whose neurologic examination results are negative. Scintigraphy is very sensitive in localizing pathologic processes that affect the bone, such as infection, benign and malignant neoplasms, and stress fractures, which appear as areas of increased uptake of the radioactive material. However, it is not specific in defining the precise nature of a lesion. Bone scans also are of value in assessing the healing process of established lesions. Pinhole collimation may be helpful in localizing increased uptake more readily and in providing better detail around a stress fracture or tumor nidus. Bone scans should cover the entire spine and, as with plain radiography, the pelvis.
Computed Tomography
Computed tomography (CT) is not used as a screening tool, but the scans provide the best images of the bony anatomy of areas of involvement. Thus when lesions such as bone tumors and fractures are observed on plain radiographs or scintigraphy, CT is the best imaging modality for further defining the status of the process. Although the lesions can be seen on magnetic resonance imaging (MRI), surrounding edema may obscure the precise site or extent of the abnormality. CT also can be used to assess spondylitic lesions in the lumbar spine and to evaluate the healing process in the pars area.
Single-Photon Emission Computed Tomography
Combining the physiologic data of a bone scan with the localizing ability of CT, single-photon emission computed tomography (SPECT) is a more precise imaging modality for localizing spinal lesions, and for diagnosing spondylolysis and stress fractures in the lumbar spine. SPECT may be used when bone scans are nondiagnostic or equivocal. SPECT has been reported to be more sensitive than scintigraphy in assessing diseases affecting the lumbar spine. SPECT scanning was performed for all patients presenting at one institution with back pain and was found to have low diagnostic sensitivity and specificity. Although 22% of patients had a positive scan result, the primary usefulness was in evaluation of spondylolisthesis and spondylolysis.
Magnetic Resonance Imaging
If the patient’s neurologic examination is positive, images of the neural axis should be obtained. In the past, CT-enhanced myelography was used for imaging the spinal cord. However, today, MRI provides more accurate images of spinal neoplasms, syringomyelia, diskitis, herniated disks, and other conditions.
Laboratory Tests
Laboratory tests should be ordered for all young children with back pain, patients with night pain, and any child with coexisting constitutional symptoms. A complete blood cell (CBC) count, with differential and peripheral smear, and erythrocyte sedimentation rate (ESR) should be obtained as an initial screening. Assessment of C-reactive protein (CRP) is used to measure an acute-phase reactant, but its specific value in patients with back pain has not been established. Urinalysis may be used to screen for urologic conditions that might be contributing to the patient’s symptoms and signs. If a rheumatologic disease is included in the differential diagnosis, the clinician should determine human leukocyte antigen (HLA)-B27, rheumatoid factor, antinuclear antibody, and Lyme titers.
Differential Diagnosis
Mechanical Disorders
Muscle Strain
Muscle strain is a relatively common cause of back pain in the adolescent athlete. The duration of the symptoms and a history of antecedent physical activity help in the diagnosis. On physical examination, the pain does not radiate, and neurologic findings are normal. Treatment includes modification of activity, application of ice first and heat later, and NSAIDs. The patient can resume athletic activities when the pain resolves, but special attention should be paid to the training regimen to ensure that the problem does not recur. Muscle strains usually resolve quickly, within several weeks. If the pain persists, radiographs should be obtained to rule out other potential disorders, such as spondylolysis.
Disk Herniation
Although less common than in adults, disk herniation occasionally is seen in children and adolescents. The patient most often presents with back pain that radiates into the legs. The onset of pain may be either acute or insidious. The pain is exacerbated by activity and sometimes by coughing or sneezing. Lumbar spasms may result in an abnormal gait.
Physical examination reveals a compromise in spinal mobility, and the patient may list on forward bending. Almost all patients have a positive straight-leg-raise test (Lasègue sign). The presence of neurologic signs (e.g., decreased or absent reflexes, numbness, weakness) is observed less frequently in children and adolescents than in adults. A high incidence of other spinal anomalies, such as transitional vertebra, spondylolisthesis, congenital spinal stenosis, and lateral recess narrowing, has been noted in children with herniated disks.
Plain radiographs usually are unremarkable but may occasionally show reactive scoliosis or asymmetric facet orientation at the level of the herniation. The herniated disk can be clearly seen on MRI ( Fig. 7-3 ), and this imaging modality is now preferred over CT myelography. MRI also is very helpful in differentiating herniation from epidural abscess, spinal cord tumor, abnormalities of the conus or cauda, and apophyseal separation. Care is advised, however, when interpreting MRI because false-positive findings, such as bulging and degenerative disk changes, have been noted in asymptomatic adolescents. MRI results need to be carefully correlated with patient symptoms and physical examination findings. CT can help identify congenital lumbar spinal stenosis.
Most patients can be initially treated conservatively with restriction of activity, a short period of rest, oral steroids or NSAIDs, and physical therapy. However, if the child or adolescent does not respond to this therapeutic approach, improvement can be achieved with surgical diskectomy. Prolonged conservative treatment of a herniated disk has been associated with persistent pain.
Apophyseal Ring Fracture/Slipped Vertebral Apophysis
Apophyseal ring fractures occur at the junction between the vertebral body and the cartilaginous ring apophysis before complete fusion has occurred. The posteroinferior apophysis avulses from the vertebral body and is displaced into the spinal canal. This injury is seen specifically in adolescents, particularly male weight lifters. It is caused either by acute trauma secondary to rapid flexion with axial compression or by repetitive microtrauma. The patient usually has sudden onset of back pain that radiates into the legs. The pain is constant and burning, and similar to that of a herniated disk, but its onset is more acute. The patient may complain of a stiff back. Neurologic signs usually are not present. Plain lateral radiographs reveal a small, triangular piece of bone that represents the avulsed vertebral apophysis next to the vertebral body. The most common site of injury is the posteroinferior apophysis of the fourth lumbar vertebra. It is often difficult to see the bony fragment on plain radiographs; CT can be helpful in identifying it. A recent study using CT scans of adolescents with lumbar disk herniation found that 28% of patients had CT evidence of ring apophysis fracture. The patients with apophyseal fracture were twice as likely (55% vs. 25%) to require surgical management.
Spinal Fracture
Fractures of the spine obviously cause back pain. If the energy of the injury or the severity of the pain is such that a fracture may have occurred, radiographs should be obtained immediately. Treatment of spinal fractures is discussed in Chapter 32 .
Developmental Disorders
Spondylolysis and Spondylolisthesis
Spondylolysis refers to a defect (stress fracture) in the pars interarticularis, usually located in the lumbar spine. Spondylolysis is most commonly caused by repetitive microtrauma during a child’s growth period. The defect is bilateral in approximately 80% of patients and unilateral in 20%, with defects found at more than one level in 4% of patients.
Spondylolisthesis occurs when the pars defects are bilateral at the same level and there is subsequent forward slippage, or subluxation, of the upper vertebral segment on the one below. This most commonly occurs when the fifth lumbar vertebra slips forward on the sacrum.
Spondylolysis and spondylolisthesis are normally caused by repetitive hyperextension of the spine, which causes shear of the posterior elements, and they are most often seen in gymnasts, divers, dancers, and football linemen.
† References .
† Over time, the continual stresses can result in fracture of the pars interarticularis, with ensuing pain or listhesis.Patients present with low back pain of mild to moderate severity that may radiate into the buttocks or legs. The pain is exacerbated by activity (particularly that involving hyperextension or twisting of the lumbar spine) and is alleviated by rest.
Physical examination may reveal postural changes, particularly flattening of the normal lumbar lordosis if spondylolisthesis has occurred. Hamstring tightness is common, and the patient may walk with a shuffling, stiff-legged gait. Hamstring tightness also limits the patient’s ability to bend forward. Palpation of the paraspinal muscles may elicit pain. In cases of spondylolisthesis where the subluxation is significant, the examiner will be able to feel a step-off at the L5-S1 level. Vertical positioning of the sacrum may result in flattened buttocks, and the patient often has a protruding abdomen with transverse abdominal creases.
Lateral radiographs may show spondylolysis, but oblique views of the lumbosacral spine can be helpful in less obvious cases. The telltale radiographic finding of spondylolysis is a lytic defect in the pars interarticularis. In isthmic defects, this appears as the collar of the “Scotty dog” sign ( Fig. 7-4 ). When plain radiographs are nondiagnostic, scintigraphy is useful in diagnosing the prefracture stage and can help demonstrate an occult pars fracture. Scintigraphy also can help in the evaluation of the healing activity of established lesions. SPECT scans provide superior images of prefractures and occult pars fractures. In the prefracture and acute stages, there is increased uptake. As the lysis becomes chronic, this increase in uptake is no longer observed. MRI has been proposed as helpful in the early detection of spondylolysis. Scoliosis may coexist with spondylolysis and spondylolisthesis; however, these curves usually are mild and may appear atypical for idiopathic scoliosis.
Treatment of spondylolysis and type 1 spondylolisthesis (<25% slip) starts with hamstring stretching. The patient is restricted from sports participation until the symptoms resolve. Athletic activities are then gradually resumed, with the individual avoiding activities that exacerbate the pain to an unacceptable level. If the spondylolysis is acute, orthotic management with a low-profile thoracolumbosacral orthosis (TLSO) can alleviate symptoms and aid healing. Surgical intervention is indicated if the pain persists despite these conservative therapies. Controversy exists, however, as to whether spondylolysis is best treated with repair of the spondylolytic defect itself or by posterolateral fusion. Surgical treatment of spondylolisthesis depends on the severity of the slip. Surgery is indicated for slips with greater than 50% translation and for the uncommon milder slip that remains symptomatic despite conservative treatment. The surgical treatment is discussed further in Chapter 14 .
Scheuermann Kyphosis
Scheuermann kyphosis is characterized by anterior wedging of three consecutive vertebrae, leading to a kyphotic deformity. Abnormalities in the vertebral end-plates and intravertebral herniation of disk material (Schmorl nodules) also are seen.
Back pain from Scheuermann kyphosis usually is localized to the midscapular region at the middle of the kyphosis. The pain, described as aching, usually is exacerbated by prolonged sitting, standing, and physical activity. Often the pain is not severe, and the primary complaint instead is poor posture. There are no associated neurologic or constitutional symptoms.
On physical examination, the clinician notes an increased thoracic kyphosis ( Fig. 7-5 ). The deformity is more obvious on forward bending and does not flatten when the patient performs hyperextension movements or lies supine. Compensatory lumbar hyperlordosis is less obvious but still notable. The patient may have hamstring tightness. The neurologic examination results usually are negative.
