AEMCA Practice Exam

During which stage of bone healing is fibrocartilage replaced by spongy bone?

1. Hematoma stage

2. Bony callus stage

3. Fibrocartilage stage

4. Remodeling stage

The correct answer is: Bony callus stage

The bony callus stage is critical in the bone healing process, as it is during this stage that the fibrocartilage that forms initially is gradually replaced with spongy bone. After a fracture occurs, the healing process begins with a hematoma stage, where a blood clot forms at the injury site. The fibrocartilage stage follows, during which a soft callus made of fibrocartilage is developed to stabilize the fracture site. Once this soft callus has formed, the bony callus stage kicks in, characterized by the transformation of the fibrocartilage into spongy bone. It marks a significant progress in the healing process, enabling the bone to regain some of its original strength as it continues to bridge the gap created by the fracture. Finally, after the bony callus stage, the remodeling stage occurs, refining and reshaping the new bone into its proper form, but it is specifically during the bony callus stage that the major transition from fibrocartilage to spongy bone takes place.