Scoliosis, leg length discrepancy, or both?

Scoliosis and limb length discrepancy (LLD) are frequent findings in pediatric orthopedic practice. Because both conditions can alter posture and spinal alignment, distinguishing between a compensatory spinal curvature due to LLD and a true structural scoliosis is crucial. This review explores the relationship between scoliosis and LLD in children, emphasizing recent evidence and clinical strategies for accurate diagnosis and management.

Minor limb length discrepancies are common in the general population. However, significant LLD (defined as >2 cm) can produce pelvic tilt and a functional scoliosis, which typically resolve when the LLD is corrected. Even smaller discrepancies (<2 cm) may contribute to spinal curvature in growing children, and correcting these differences may reduce the Cobb angle of a functional scoliosis. Additionally, after surgical correction of structural scoliosis, compensatory LLD often improves, reflecting the complex biomechanical relationship between the spine and lower limbs.

LLD and scoliosis can mimic or exacerbate one another, making careful evaluation essential in pediatric patients. True structural scoliosis must be differentiated from a functional scoliosis secondary to LLD. An accurate assessment of leg lengths should be part of the routine evaluation for any child with scoliosis. When a significant LLD is identified as the cause of spinal curvature, appropriate treatment, such as shoe lifts or surgical correction of the limb inequality, might correct the spinal curvature in the coronal plane. In contrast, in idiopathic scoliosis with a minor coexisting LLD, treatment should primarily address the spinal deformity.