What Does It Mean To Immobilise The Fracture?
To immobilise the fracture means to allow enough stability for the fracture to heal correctly. This is most commonly done by splinting the injury using a plaster cast. This is helpful for pain, for healing and for helping to decrease swelling. You may have a cast that extends half-way or all the way around the arm or leg. One covering half the limb (also known as a back-slab) allows for any swelling so that the cast is not too tight. Once this swelling settles, your cast may be exchanged for a full cast.
When the cast is being applied, cotton wool is most often used to provide some padding for the skin. Then the plaster or fiberglass is applied over it.
Why Immobilise The Fracture For So Long?
For any fracture, time is needed to allow regrowth of bone between fracture ends. This ensures that when the cast or brace comes off, that the fragments are stable enough not to slip apart. The time given for healing can be a balance between fracture stability and the resultant joint stiffness. This is why rehabilitation after the cast comes off is so important.