Paget's disease of bone presenting as bowing deformity of the tibia (saber tibia) with a 'banana fracture' risk. The incomplete stress fractures typically occur on which cortex, and what is the implication for prophylactic management?

• A Lateral (convex) cortex; propagate to complete transverse fracture (banana fracture) and prophylactic intramedullary nailing should be considered ✓
• B Medial cortex; protective medullary nailing not indicated as they heal spontaneously
• C Posterior cortex; external fixation prevents completion
• D Anterior cortex; bisphosphonates alone prevent propagation

Explanation

In Paget's disease of the tibia, the bowing creates tension on the convex (lateral/anterior) cortex. Stress fractures (fissure fractures, 'crack fractures') form on the tension (convex) cortex and can propagate transversely through the osteoporotic pagetic bone, producing a 'banana fracture' (complete transverse fracture). Because pagetic bone heals poorly and these fractures can be sudden and complete, prophylactic intramedullary nailing of a structurally compromised bowed tibia with multiple stress fractures is considered. Bisphosphonates can treat the metabolic disease but do not adequately prevent mechanical fracture propagation.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.