Lateral deviation of the radius results from which condition?

Lateral deviation of the radius results from which condition?

• A. Premature distal ulna physeal closure
• B. Premature proximal radius physeal closure
• C. Carpal hyperextension
• D. Ulna fracture

Answer: (A)

Growth imbalance between the radius and ulna during development can produce angular deformities of the forelimb. If the distal ulna stops growing early (premature closure of its growth plate), the ulna becomes relatively short distally while the radius continues to lengthen. That mismatch causes the radius to bend laterally as the limb grows, leading to lateral deviation of the radius. The other scenarios affect different parts or stages of the limb and don’t produce this specific growth-related bowing of the radius.

Growth imbalance between the radius and ulna during development can produce angular deformities of the forelimb. If the distal ulna stops growing early (premature closure of its growth plate), the ulna becomes relatively short distally while the radius continues to lengthen. That mismatch causes the radius to bend laterally as the limb grows, leading to lateral deviation of the radius. The other scenarios affect different parts or stages of the limb and don’t produce this specific growth-related bowing of the radius.