Anatomical Kinesiology:  Types of Fractures, healing, and clinical advances in bone repair.
 

A. Types of fractures

1.      Complete. Bone breaks completely. Types: A. Open: Fractured (broken) bone end penetrates the skin (also called a compound fracture), B. Simple. Fractured bone end does not penetrate the skin.

2.      Comminuted.  Bone breaks into several pieces (3 or more pieces). Bone splinters at the site of impact, and smaller bone pieces lie between the two main broken pieces of bone. Older individuals who are more likely to have brittle (osteoporotic) bone are  at greater risk of a comminuted fracture.

3.      Spiral.  Ragged break occurs when excessive twisting forces are applied to the bone.

4.      Greenstick.  Partial fracture on one side of the bone as the bone bends.  Common in kids since their bones are more “flexible” (bones of children have not fully ossified)

5.      Impacted. One end of fractured bone is forced into the other bony end.

6.      Pott’s Fracture.  Fracture of distal end of fibula and injury to distal end of tibia

7.      Colles’ Fracture. Fracture of the radius, usually about 1 cm proximal to the wrist. Typically due to forceful trauma, like falling with outstretched hands.  

 

B. Stages of healing of a simple bone fracture.


1. Hematoma formation (mass of clotted blood) at fracture site.
Tissue in fracture site swells, very painful, obvious inflamation, and bone cells are dying.

2. Fibrocartilaginous callus  developes over a 3 to 4 week period.
This process involves

  -capillary growth in the hematoma
  -phagocytic cells invading and cleaning-up debri in injury site
  -fibroblasts and osteoblasts migrating into site and beginning
   reconstruction of bone
 
Note that the fibrocartilaginous callus serves to splint the fracture.

3.  Bony callus  begins forming after 3 to 4 weeks after injury and is prominent 2 to 3 months following the injury.  Continued migration and multiplying of osteoblasts and osteocytes results in the fibrocartilaginous callus turning into a bony callus.

4.  Remoldeling.  Any excess material of the bony callus is removed and compact bone is laid down in order to reconstruct the shaft. Remoldeling is the final stage.

 

C. Clinical advances in bone repair.

1. Electrical stimulation of fracture site. This process results in
   a. increased rapidity and completeness of bone healing
   b. electrical field may prevent  parathyroid hormone from activating osteoclasts at the  fracture site thereby increasing formation of bone and minimizing breakdown of bone, electrical field may also increase growth factors which promote bone formation and healing

2. Ultrasound.  Daily treatment results in decreased healing time of  fracture by about 25% to 35% in broken arms and shinbones. Stimulates cartilage cells to make bony callus.

3.  Free vascular fibular graft technique.
  a. Uses pieces of fibula to replace bone or splint two broken ends of a bone.  Fibula is a non-essential bone, meaning it does not play a role in bearing weight; however, it does help stabilize the ankle.
   b. This technique has been used in children born without a radius or long bones which have been destroyed by osteomalacia.

4.  Bone substitutes. synthetic material or crushed bones from cadavers serve as bone fillers
Can use crushed bone from a cadaver or a sea bone substitute (made from coral).