Paediatric lumbar disc herniation presenting as pseudo flexion deformity of the hip and knee: A case report

ABSTRACT
Background: Lumbar disc herniation (LDH) in paediatric age group is rare and respond differently to treatment
measures compared to adult LDH. We present such a case with an atypical and confusing presentation. Case report: A 13-year-old boy presented with radiating low back pain for two weeks, and a pseudo flexion deformity of the hip and knee. The bowstring sign was positive, the sensory loss was present over the S1 dermatome, and an ankle jerk was absent. MRI showed disc herniation and annulus fibrosis tear at the L5-S1 level. Right interlaminar discectomy of L5-S1 provided a complete resolution of symptoms, and excellent functional outcome at two years follow up. Conclusion: A disc herniation should be considered as a differential diagnosis in children presenting with back pain. Pseudo flexion deformity of hip and knee could be an indicator of S1 nerve root compression. Paediatric LDH responds poorly to conservative management, but a good functional outcome can be achieved with prompt surgical management.