STAGES OF FRACTURE HEALING WITH DIAGRAMS

                                              FRACTURE HEALING

FRACTURE:- A fracture is a break in the continuity of a bone. The healing of bone fracture is almost similar to the healing of soft-tissue wounds, except that the end result is mineralised mesenchymal tissues. A fracture begins to heal as soon as the bone is broken. In order to heal the fracture correctly, the bones must be held in correct position.

STAGES OF FRACTURE HEALING  

1. Stage of haematoma

2. Stage of granulation tissue

3. Stage of callus

4. Stage of remodelling

5. Stage of modelling                                                                                                                 

                           1. STAGE OF HAEMATOMA   

 This stage lasts up to 7 days. When a bone is fractured, blood leaks out through torn vessels which forms a haematoma between and around the fracture site. There is ischemic necrosis of the fracture ends which results in either death of the fracture ends or sensitisation of these cells to differentiate into daughter cells.

                

                            2.STAGE OF GRANULATION TISSUE    This stage lasts up to 2-3 weeks. In this stage, the sensitised cells(daughter cells) produce cells which differentiate to blood vessels, fibroblasts, osteoblasts etc. This eventually gives a soft-tissue anchorage to the fracture, but it does not give any structural rigidity. The blood clot will serve as a framework for ingrowth of fibroblasts and new capillaries.

               *FROM THIS STAGE, THE HEALING OF BONE DIFFERS FROM THAT OF SOFT-TISSUE, THAT IS, WHEREAS IN SOFT-TISSUE HEALING THE GRANULATION TISSUE IS REPLACED BY FIBROUS TISSUE, WHILE IN BONE HEALING THE GRANULATION TISSUE DIFFERENTIATES TO CREATE OSTEOBLASTS (BONE FORMING CELLS).

                          3. STAGE OF CALLUS 

 This stage lasts for about 4-12 weeks. In this stage, the granulation tissue differentiates further and creates osteoblasts. Theses cells are impregnated with calcium salts. This will results in CALLUS formation.Callus is also known as WOVEN BONE. 

                             *THE CALLUS IS THE FIRST SIGN OF UNION VISIBLE O X-RAYS, USUALLY 3 WEEKS AFTER THE FRACTURE.

                    4. STAGE OF REMODELLING                                           

  In this stage, the woven bone is replaced by mature bone with a typical lamellar structure. It is a slow process and takes around one to four years.

                                  5.STAGE OF MODELLING                                          

 In this stage, the bone is gradually strengthened and takes normal shape. This process of strengthening and shaping comes from local bone strains, i.e., weight-bearing stresses.

                   FACTORS AFFECTING FRACTURE HEALING

 a) Age of the patient:- Fractures unite faster in children. On an average, bones in children unite in half the time compared to adults.

 b) Sex of the patient:- There is no differences between fracture healing in males and females.

 c) Type of bone:- Flat and cancellous bones unite faster than tubular and cortical bones.    

   d) Pattern of fracture:- Spiral fractures unite faster than oblique fractures, which in turn unite faster than transverse fractures. This is because of the greater area of fracture site.

   e) Types of reduction:- Good apposition of the fracture ends results in faster union. 

   f) Immobilisation:- Immobilisation keeps the fractured parts in place, but it is not necessary to immobilise all the fractures like scapula, ribs,etc.