Back pain in children and adolescents — formative SAQs

SAQ 1 (10 marks) — The three-year-old who refuses to walk and holds her back

Stem: A three-year-old girl is brought to the emergency department refusing to walk and holding her lower back stiff. She is mildly febrile at 38.1 degrees Celsius and irritable, and her mother reports she has been reluctant to sit for two days. Her CRP is 42 milligrams per litre and her ESR is 48 millimetres per hour. A plain radiograph of the lumbar spine is reported as normal. Outline your assessment, investigations, and management. [1] [7]

Model answer

Assessment and red-flag screen (2 marks). This child has back pain in a pre-school child, which is itself a red flag — back pain under five years is uncommon and an organic cause is sought by default. She has two further red flags: a fever and the systemic picture of irritability. The refusal to walk in the young child is the presenting feature of discitis, the classic spinal infection of this age, and the workup is directed at the spinal infection regardless of the normal temperature. The normal plain radiograph does not exclude the diagnosis, because the early discitis is radiographically occult. [1] [7]

Investigations (3 marks). The inflammatory markers are already raised and provide the baseline for tracking the response. A blood culture is drawn before any antibiotic is given, to identify the organism. The definitive investigation is an urgent magnetic resonance imaging of the spine, which reveals the disc-space inflammation and the adjacent endplate oedema that the plain film misses, and which excludes a vertebral osteomyelitis, an epidural abscess, and a tumour. The ACR Appropriateness Criteria confirm the MRI as the modality for the suspected spinal infection in the child. The plain film is reviewed for a destructive lesion, and the MRI frames the extent and the complication. [11] [7]

Immediate management (5 marks). The blood culture and the MRI are obtained, and the child is managed with empirical intravenous antibiotics targeting Staphylococcus aureus, the commonest organism in the spinal infections of childhood. The choice of antibiotic follows local guidelines, and the duration is typically two to four weeks intravenously with a step-down to oral guided by the clinical and the inflammatory-marker response. The child is immobilised for comfort, and the analgesia is provided. The infectious-diseases team is involved for the antibiotic guidance, and the orthopaedic team is involved if an abscess, a neurological deficit, or a progressive deformity demands surgical intervention. The family is counselled on the diagnosis, the duration of therapy, and the safety-net. [7] [11]

SAQ 2 (10 marks) — The thirteen-year-old gymnast with extension-related low back pain

Stem: A thirteen-year-old female competitive gymnast presents with three weeks of low back pain that worsens with her backbend routine and eases with rest. She is afebrile, systemically well, and has no neurological symptoms. The pain is unilateral and low in the lumbar spine, and the one-legged lumbar hyperextension test reproduces it on the left. Her examination is otherwise normal. Outline your assessment, investigations, and management. [9] [1]

Model answer

Assessment and differential (3 marks). This is a school-age athlete in an extension-loading sport with a classical spondylolysis pattern — a low back pain that worsens with hyperextension, eases with rest, and is reproduced by the one-legged lumbar hyperextension test. The red-flag screen is negative: she is afebrile, has no night pain, no weight loss, no neurological deficit, and no systemic features. The differential includes a mechanical muscle strain, but the focal extension-related pain and the positive hyperextension test raise the spondylolysis to the leading diagnosis. The fellowship skill is to recognise that the athletic extension back is a spondylolysis until imaging excludes it. [9] [1]

Investigations (2 marks). The imaging strategy for the suspected spondylolysis progresses from the initial plain films to the modality that reveals the early pars lesion, chosen with the radiologist and the orthopaedic team. The plain radiograph may show an established pars defect, but the stress reaction and the early fracture are radiographically occult, and the focused lumbar imaging reveals the lesion at the lowest adequate radiation dose. No bloods are required in the absence of red flags, because the infective and the inflammatory picture is excluded by the clinical assessment. [9] [11]

Management (5 marks). The definitive management of spondylolysis is activity cessation, an anti-lordotic brace in the symptomatic or the high-grade lesion, and a core-stabilisation physiotherapy programme, with the goal of bony union of the pars before the defect becomes complete. The review of over two hundred young athletes confirms that the conservative approach achieves union or a symptom-free state in the great majority. The graded return to the gymnastics is guided by the resolution of the pain and the imaging, and the child is reviewed at six to twelve weeks. The bilateral defect with a progressive spondylolisthesis is monitored closely and fixed when the slip progresses, and the surgical repair is reserved for the refractory symptomatic lesion that fails a thorough conservative programme. The safety-net is the instruction to return if the pain persists or if any red flag emerges. [9] [11]