Figure 5.1
Lateral radiographs of a high grade spondylolisthesis, both pre and post-op
Spondylolysis – A defect in the pars interarticularis (the area of bone between the superior and inferior articular processes).
Scoliosis – Lateral curvature of the spine with an associated rotational element.
Epidemiology/Aetiology
Under the age of 12, back pain is rare and commonly associated with either a tumour or infection. There must be a high index of suspicion – look for red flags clinically, biochemically and radiographically. After the age of 12, pain is more commonly non-specific and less likely to be due to significant pathology.
Assessment
Assessing a younger child with back pain is difficult as symptoms and signs are subtle, but may include:
A limp.
Reluctance to weight bear.
Localised spinal pain/tenderness.
Constitutional symptoms such as fever, pyrexia and raised inflammatory markers.
Examination
Younger children may have to be examined supine to assess for alignment, spinal stiffness, muscle wasting or spasm.
Older children can be examined standing, with deformities exaggerated when flexed forward.
Spondylolysis and Spondylolisthesis
Spondylolisthesis is the movement of one vertebra relative to another, and is, more precisely, the forward translation of a vertebra relative to its caudal segment. The main causes in the paediatric population include:
Congenital or dysplastic.
Dysplastic or congenital abnormality at the L5/S1 facet, with forward translation of the L5 vertebra on S1.
More common in girls.
Can present following growth spurts in adolescence.
Isthmic.
This is due to a spondylolytic lesion, i.e. an anatomic defect of the pars interarticularis.
The lesion is present in around 5% of children, half of which go on to develop spondylolisthesis.
Repeated trauma leads to repeated micro-fractures, which may not heal or may heal with an elongated pars.
Risk factors for spondylolysthesis include vigorous exercise, participation in competitive sports involving repetitive lumbar extension, and Scheuermann’s disease. The incidence may be as high as 47% in young divers and gymnasts. There is a strong genetic element with boys being affected twice as much as girls.
Symptoms and Signs
Patients tend to experience low back, buttock or thigh pain, which is exacerbated by activity. In patients with isthmic type spondylolysthesis, radicular symptoms are rare but may be due to either hypertrophic callus formation at a pars defect or due to stretching of the nerve in high grade slips. Sciatica is reported by around 50% of patients. In patients with the congenital type, neurological symptoms are more common due to anterior translation of the L5 vertebral body with intact posterior elements, leading to compression of the L5 and sacral nerve roots.
Examination
The examination findings may be the result of localised pain, compensatory muscle or skeletal imbalance, and due to neurological abnormalities. The patient may experience pain on deep palpation of the lesion. There may be an increase in lumbar lordosis – the hamstring, iliopsoas and paraspinal muscles may contract, rotating the pelvis to arch the thoracolumbar spine into maximum lordosis with an exaggerated kyphosis at the sacrum.
Investigations
Plain radiographs – taken with patients standing to exaggerate any deformity.
45° oblique X-rays may be useful in identifying pars defects.
AP and lateral views of the whole spine may identify a secondary scoliosis caused by muscle imbalance.
CT scan – the bony architecture can be visualised more readily on CT however the defect can be missed as it may be in the plane of the images. The images should be re-formatted into a different plane (“reverse gantry angle”).
MRI – is invaluable in visualizing the neural structures in cases of spinal stenosis and for assessing the corresponding discs. An MRI is indicated in the presence of abnormal neurology.
Classification
The Meyerding classification is most commonly used.
Grade I – 0–25% slip.
Grade II – 26–50% slip.
Grade III – 51–75% slip.
Grade IV – 76–99% slip.
Grade V – 100% slip (spondyloptosis).
Treatment
Non-operative Treatment
Asymptomatic slip – monitor over 3–6 months with serial radiographs to ensure the slip is not progressing.
Symptomatic Slip
Most patients with low grade slips will respond to non operative treatment.
Activity modification with physiotherapy.
Immobilisation in a brace for 6–12 weeks may aid symptom control.
Monitor with serial radiographs to ensure the slip is not progressing.
Surgical Options
Low grade spondylolisthesis (<50% slip) or spondylosis.
Surgery is indicated in patients in whom there is.
Failure of non-operative management.
Progressive slip on serial X-rays.
Neurological deficit for >6 months.
An L5/S1 slip is generally fused, although more proximal lesions can be treated with repair of the pars defects so long as the lesion is reducible and the vertebral disc is intact.
High grade spondylolisthesis (>50%).
Operative stabilisation: fusion with or without instrumentation.
Complications
Complications following surgery include:
Neurological injury.
Cauda equina syndrome must always be excluded through a thorough neurological evaluation.Related posts:
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