Answered: What are the four steps of bone repair?

Human Anatomy & Physiology (11th Edition)

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...

See similar textbooks

Related questions

Question

What are the four steps of bone repair?

Expert Solution

Step 1

Bone is progressively rebuilt and restored by removing old cell tissue when broken due to fracture. The replacement of old bone tissue with new bone tissue is bone remodeling. It comprises the osteoblast deposition or osteoclastic bone manufacture and osteoclastic bone absorption, which break up the old bone. Normally bone formation includes vitamins D, C, and A, plus calcium, phosphorous and magnesium minerals. Bone development and maintenance also include the use of hormones such as parathyroid hormone, growth hormone, and calcitonin.

Step 2

There are four steps in the reconstruction of a bone that is broken:

Hematoma in the rupture - Blood vessels at the fracture site are torn and hemorrhage, which leads to the formation of coagulated blood or hematoma. The fractured ends of the bone are screened through the extreme blood vessels for clotting; nutrients are deprived to the bone; cells start to die.
Fibrocartilaginous callus formation- Within days of the break, capillaries become hematoma when phagocytic cells start removing dead cells. Although blood clot fragments can still exist, fibroblasts and osteoblasts join the region and begin bone recovery. Fibroblasts produce collagen fibers, which connect the broken bones, while osteoblasts form the spongy bone. The repair tissue, the fibrocartilage callus, between the fractured ends of the bone, consists of hyaline and fibrocartilage. There may also be some bone spicules at this stage.
Bony callus formation - The fibrocartilaginous callus has been transformed into a bony spongy bone callus. The fractured bone ends up securely together after the fracture takes about two months. The endochondral formation of the bone is similar as cartilage is ossified; there may be osteoblasts, osteoclasts, and bone matrices.
Compact bone restructuring and extension - The osteoclasts and osteoblasts are then remodeled, and excess material is removed on the outside of the bone and inside the medullary cavity. Compact bone is inserted to make bone tissue identical to the original bone without interruption. It may take several months to remodel; for years, the bone may remain uneven.