Back Pain In Children

Back pain in children is very much more likely to have a serious underlying disorder compared to adult back pain and deserves careful attention.¹
There are important differences in the aetiology, diagnosis and management of backache in children, the younger the child and the longer the history the more likely it is that a serious underlying condition is responsible for the symptoms.
Unfortunately the diagnosis of serious disease causing back pain in children is often made late or missed.^2,3
A recent study does challenge the conventional wisdom that back pain in children is very likely to herald serious pathology.⁴

• Nonspecific back pain in children is increasingly prevalent.⁵
• However back pain is much less common than in adults with fewer than 30% of children and adolescents reporting back pain and very few presenting to doctors with their pain.⁶
• Persistent back pain, unlike in adults is likely to indicate serious pathology and physical findings are likely to be found. About half will have a specific or serious cause.⁷

Older children

• Overuse and back strain or musculoligamentous injury
• Disc injuries. Disc herniation. Scheuermann disease (or juvenile disc disorder).
• Vertebral fractures
• Spondylolysis
• Spondylolisthesis

Younger children and older children

• Infection. Usually in under 10 year olds:
  • Discitis
  • Osteomyelitis
• Tumour of bone. Primary osseous neoplasms are rare. The most common are:
  • Ewing sarcoma
  • Aneurysmal bone cyst
  • Benign osteoblastoma⁸
  • Osteoid osteoma
  • Primary lymphoma - rarer still
• Tumours of spinal cord such as ependymoma
• Congenital disorders of the spine. For example scoliosis.
• Systemic disease. For example sickle cell disease.
• Pyelonephritis
• Retroperitoneal infection

An algorithmic approach to pediatric back pain has been tested.⁶ Good clinical assessment will diagnose most causes of pain.

History

It is essential to take a careful history. This should incorporate:

• History of the pain:
  • Frequency, duration and severity of pain
  • Mechanism of onset of the pain
  • Length of history. Persistent pain is very much more likely to herald a serious disorder.
  • Severity of the pain
  • Characteristics: pain that disturbs sleep or is worse at night; pain which is interfering with activities (school, play or sports).
  • Associated and exacerbating features - particularly if pain is associated with stiffness or limitation of movement.
  • It is important to identify accompanying symptoms. For example:
    • Fever
    • Weight loss
  • Radiation of pain
• Neurological symptoms:
  • Weakness
  • Numbness
  • Gait
  • Bowel and bladder dysfunction
• Past medical history. For example:
  • Arthritis
  • Trauma
• Family history. For example:
  • Arthritis
  • Scoliosis
• Social history. For example:
  • Activities (extreme sports, gymnastics,⁹ diving, bowling, asymmetric activities)
  • School bags and school activities

Examination

Physical findings are likely to be found, particularly in persistent back pain (unlike in adults).¹⁰This should incorporate:

• Localisation and evaluation of pain
• Tenderness (site of maximal tenderness)
• Inspection (to detect deformity, wasting, kyphosis and scoliosis)
• Gait
• Flexibility
• Neurological examination (including power, tone, reflexes, sensation)

Symptoms and signs likely to indicate serious pathology

These include:⁷

• Age under 4 years
• Symptoms persisting for more than 4 weeks
• Interference with function
• Systemic features (fever, weight loss)
• Worsening pain
• Neurological features
• Recent onset of scoliosis
• Stiffness

Persistent back pain in children is serious. It can be diagnosed by history, examination and relatively simple tests (blood tests, plain radiography, bone scans).^4,11 In the absence of indications for urgent referral it can be diagnosed in general practice.

• Blood investigations might include:
  • FBC, ESR and CRP.
  • Rheumatoid factor and other rheumatological tests may be indicated if arthritis suspected
  • Urea and electrolytes
  • Liver function tests
  • Amylase
• Imaging:
  • Plain X-rays. Including PA and lateral
  • CT scanning
  • MRI
  • Radionucleotide imaging studies: including planar bone scanning and single-photon emission computed tomography scanning (SPECT).
  • SPECT bone scanning - for example in young at risk athletes with persistent symptoms, to uncover stress fractures.¹²

It is important to pursue a diagnosis. As indicated it is more usual to make a diagnosis in children. Non-specific back pain is likely to be a diagnosis of exclusion and represents a much smaller proportion of children, as compared to adults, with back pain. When considering the aetiology and diagnosis of back pain consider:

• Scheuermann' disease (juvenile kyphosis):¹³
  • Boys more often affected than girls.
  • It is rare under age 10 and most common between age 13 and 16 years.
  • Usually intermittent low back pain (dull and aching character) in adolescents made worse with bending forward and activity. Improves when resting.
  • If it affects the upper thoracic spine it often presents with kyphosis.
  • There is often decreased flexibility with tenderness on palpation above and below the apex of kyphosis.
  • Associated hamstring tightness often found.
• Vertebral fractures. Worthy of special mention is lumbar spondylolysis (a unilateral or even bilateral stress fracture of the narrow bridge between upper and lower pars interarticularis).
  • This causes low back pain quite commonly in adolescent athletes.
  • Consider especially age 11- 17 years.
  • Occurs in sports with repetitive flexion and extension. Sports include: gymnastics, diving, weight lifting, rowing, tennis, cricket and football.
  • In some cases spondylosis persists to become spondylolisthesis (25% of cases). This occurs particularly in adolescent athletes.
  • There is also an association with spina bifida occulta (5-10% of the population).
  • It is often asymptomatic, but symptoms typically occur at the time of the growth spurt.
  • Usually causes focal pain aggravated by certain activities (particularly spinal extension and to a lesser degree rotation).
  • Rest improves pain. Pain is sharp, mild to moderate in intensity and can radiate to the buttock.
  • On examination patients may have a waddling gait associated with hamstring tightness and a lordotic posture. The classic Phalen-Dickson sign (knee-flexed, hip-flexed gait) may occur especially if there is associated spondylolisthesis.
  • Most memorable test for spondylolysis is the stork test (stand on one leg and bring back into lumbar extension illicits pain on side ipsilateral to pars interarticularis lesion).
  • SPECT scanning is the most sensitive imaging test to detect spondylolysis.
• Infection:
  • Pyogenic vertebral osteomyelitis is the most common form of vertebral infection.
  • Children usually present with abrupt onset of malaise, fever and back pain with stiffness, restricted movement, guarded walking and spine tenderness.
  • Leucocytosis, raised ESR and CRP are usual findings.
  • CT scanning detects earlier than plain radiographs and MRI is better still.
  • Radionucleotide scanning, especially technetium combined with gallium demonstrates virtually all pyogenic vertebral infections.
• Ankylosing spondylitis:
  • Peak age of onset is 15 years to 30 years and a juvenile form also exists which starts younger.
  • Pain is of gradual onset, worse in the morning and improving during the day.
  • Pain is better with activity and worse with rest unlike mechanical low back pain.
• Tumours. Bone tumours may present with pain and can be demonstrated on plain radiographs.
• Overuse, non-specific back pain and musculoligamentous injury. This settles quickly with rest but caution is due particularly with respect to the diagnosis of spondylolysis.

About half of adolescent patients will have self limiting, shortlived pain caused by overuse or strain. Management should incorporate:

• Confirmation of diagnosis and exclusion of serious pathology.
• Simple analgesia.
• Preventive measures with:
  • Advice and education
  • Physiotherapy
  • Exercise

For those patients more likely to have a serious pathology early assessment to establish a differential diagnosis and hence urgency of referral is important. All will require referral and subsequent management will vary according to the underlying diagnosis.

Referral

Urgent referral is indicated if:¹⁴

• Pain is persistent. Particularly if under 11 years old and for several weeks.
• Pain is worsening
• Persistent fever
• Neurological deficit
• Pain is accompanied by stiffness¹⁵

A variety of complications can arise depending on the diagnosis. In general terms complications may be reduced or prevented by timely diagnosis.¹⁶

This is determined by the underlying diagnosis.

Posture and psychosocial factors are important in back pain.¹⁷ Back education programmes are effective at improving posture but whether there is an effect on back pain in later life requires further investigation.^5,18

• Back packs.¹⁹ If these are too heavy or the weight is carried unevenly (over one shoulder) they can cause back pain. There is little evidence of risk of permanent injury. Recommendations include:
  • Limiting weight to 10-15% of body weight (no evidence base for this and recommendations differ - from 5-20% of body weight between different physical therapy professional bodies).
  • Limit weight to avoid:
    • Leaning or bending forward
    • Distorting natural curves of middle and lower back
    • Causing rounding of shoulders
  • Avoid habitually carrying over one shoulder
  • Choose good back pack design:
    • Lightweight material
    • Padded adjustable side straps (2 inches wide)
    • Padded back
    • Hip strap to distribute weight from shoulders to pelvis
    • Wheeled varieties (to pull rather than carry)
  • Educate child on correct loading and wearing:
    • Use both shoulder straps
    • Pack heavy items low in the backpack
    • Use compartments to prevent suddens shifting of weight distribution
    • Correct adjustment of backpack
    • Advice on lifting backpack (bend legs not back)
    • Avoid overloading (which causes leaning and postural changes likely to cause strain and pain)
  • Vigilance:
    • Reduce weight if pain
    • Encourage other strategies to avoid excess weight (unnecessary books, clear out bag regularly)
  • Proactive parenting:
    • Enquire after pain
    • Help with above strategy
    • Lobby to help school procedures to reduce back pain (lockers, vigilance, classroom routines etc).
• Discourage high risk or extreme sports, particularly in at risk children (age, build etc)
• Beware of certain sports in younger children (rowing, diving, gymnastics,⁹ cricket bowling). Advice from sporting bodies and sports medicine specialists should be sought by schools, sporting bodies and clubs.¹⁶ Individual children may need to consult.¹²
• Encourage sports which improve isometric muscle endurance as high isometric muscle endurance is associated with less back pain.²⁰

Screening programmes for scoliosis are indicated but otherwise back pain in children requires vigilance and opportunistic diagnosis.