Which condition is essential for primary (direct) cortical bone healing to occur without visible callus formation?
- A Anatomical reduction with absolute stability achieved by rigid internal fixation ✓
- B Controlled axial micromotion at the fracture site
- C Formation of a large bridging fibrocartilaginous callus
- D Immobilisation in a well-moulded plaster cast
Correct answer: A. Anatomical reduction with absolute stability achieved by rigid internal fixation
Explanation
Direct or primary bone healing occurs only when the fracture is anatomically reduced and held with absolute stability, typically by lag screws with a neutralisation plate, leaving no measurable gap. Cutting cones then cross the fracture line directly, restoring Haversian systems without callus. Micromotion and cast immobilisation produce secondary healing with callus, so a radiologically visible callus actually argues against primary healing.
Reference: Rockwood and Green's Fractures in Adults, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.