Broken Bones Healing Process

Broken Bones Healing Process
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Anatomy of a Bone

Bones are made of both living tissue and non-living tissue. The living tissue is made up of several types of cells which include osteoblasts. The bone also has a fiber matrix that contains collagen and inorganic and organic chemicals which are deposited within the matrix. These make up the nonliving portion of the bone. The chemicals are mainly composed of calcium salts; hence the importance of calcium in bone maintenance, development, and healing.

Types of Bone Breaks

The relationship between the calcium salts and collagen fibers are what give bones the ability to endure stress forces; both compressive and tensile. However, there are some cases where trauma or disease may cause a break in the bone to occur. Understanding the type of bone break helps to understand how the bone will heal and what kind of treatment or care is necessary. Breakage can be classified into groups.

  • The way the bone ends up after the break (the break the bone remains in its original position (non-displaced) or the broken bones are not aligned (displaced))
  • How complete the break is (whether the break is through the bone (complete) or not all the way through (incomplete)
  • How the break is positioned relative to the axis of the bone (parallel to the length of the bone (linear) or perpendicular (transverse)
  • Where the bone breaks the skin or not (in a compound break the broken end of the bone pierces the skin, while in a simple break the ends do not tear the skin)

Healing of a Broken Bone

The healing process depends on several factors.

  • The type of break. In breaks where there is contact between the broken ends healing begins immediately with no intermediary phases.
  • The age of the patient. Younger patients heal quicker.
  • A nutritious diet during healing can help speed up the process
  • How well the affected area is vascularized

In order for a bone to be repaired, it is important that there is some stability associated with the break and that the region is well supplied with blood. The broken bone healing process can be broken into four steps.

  1. The first involves the formation of a hematoma or a blood clot. The clot is the result of the trauma to the vessels and tissues that surround the bone. They are torn and as a result, they bleed. The blood clot serves a dual function. It helps stop the escaping blood from the damaged vessels and also serves as a building block of the forming bones infrastructure. During this phase the region surrounding the break is swollen, inflamed and painful.
  2. The second step involves the formation of a fibrocartilaginous callus. The callus is made of collagen arranged in layers that has gaps within its structure. Capillaries start connecting the tissue through the hematoma and the immune system also sends in phagocytic cells to clean out the area. Cells known as osteoblasts and fibroblasts move to the damaged area and start working. This process starts only a few days after the break. Osteoblasts produce soft callus and spongy bone while fibroblasts secret the collagen fibers which when combined lay the groundwork by forming the matrix. These structures act as splint for the damaged bone.
  3. Next is the formation of a bony callus. The osteoblasts continue to convert the callus to a boney callus. The hard callus forms three to four weeks after injury firmly binding the two bone pieces. This process continues up to four months after the injury.
  4. The final stage involves the remodeling of the boney callus. Here excess bone is removed and compact bone is added.

Reference

Mechanical Effects on Fracture Healing University of Michigan: Biomechanics BME/ME 456