A 6-year-old boy sustains a transverse midshaft femur fracture with 2 cm of overriding of the fragments. While planning closed reduction, the surgeon deliberately accepts residual shortening instead of restoring exact length. The physiological basis for this decision is:

• A Overriding fragments unite faster by primary cortical healing than reduced ones
• B Shortening stimulates premature closure of the distal femoral physis, halting further inequality
• C Femoral overgrowth following fracture in children averages 1 to 1.5 cm, correcting the discrepancy ✓
• D Children remodel length discrepancies only after skeletal maturity

Explanation

Fracture of a long bone in a growing child produces a hyperemic stimulus to the adjacent physes, causing accelerated longitudinal growth. For the femur this overgrowth averages about 1 to 1.5 cm and continues for roughly 18 months to 2 years. Accepting up to about 2 cm of shortening at reduction therefore anticipates spontaneous equalization of limb lengths. Physeal closure is not stimulated by shortening, and remodelling of angular deformity is greatest when close to the physis, but length correction here depends on overgrowth itself.

Reference: Rockwood and Wilkins' Fractures in Children, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.