The wrist joint actually contains two separate joints. One of these moves the wrist up and down (extending and flexing) whilst the other allows the forearm to twist to place the palm up or down (pronation and supination). Fractures of the wrist can involve none, one, or both of these joints.
If the bone breaks distant from the joint surface, the risks of long term stiffness and early arthritis are much less than if the break involves the smooth surface of either joint, in which case attempts will be made by your doctor to ensure the surface heals as smoothly as possible to reduce these risks to a minimum.
Wrist fractures usually occur after a fall onto the outstretched hand. When they occur in younger people, the bone quality is much harder, so the bone tends to shatter into fragments and requires significant energy to do so. In older people, the softer bone bends and squashes, causing deformity with sometimes only a minor force from a stumble or trip. These two broad categories of wrist fractures are handled differently by doctors.
The common low energy bending fracture (so frequently seen in elderly women) usually requires a plaster cast for 6 weeks until healing has occurred. Sometimes, the pieces of bone may not be where they should be (displaced). In these circumstances, a manipulation will be performed, where the limb will be gripped and pulled by the doctor to 're-set' the bone into a better position. Very occasionally, even this process is not sufficient to hold the pieces of bone in place whilst they heal and an operation involving the insertion of smooth pins (approximately 1mm in diameter) is performed. These are called K-wires. A plaster cast will still need to be worn for 6 weeks and the pins will then be removed.
The high energy fracture in the young adult requires a more accurate rebuilding of the bone fragments (reduction). If the fragments are sitting in a good position on the x-ray, a simple plaster cast will be worn for 6 weeks. If the fragments require reduction, they will need to be held in position (stabilisation) with either K-wires or a metal plate and screws, inserted through a 6-7cm scar.
The injury that causes a wrist fracture can also tear ligaments and cartilage, as well as break the bone. Surgeons will assess each individual for all components of these injuries, and may sometimes arrange a scan as well as x-rays.
After the wrist fracture has healed (usually around 6 weeks) the plaster cast is removed and exercises are begun. Some people will need help from a Physiotherapist to regain movement and strength, but this treatment is useless without motivation and co-operation from each patient. If a wrist fracture has been treated by surgical insertion of a metal plate and screws (open reduction and internal fixation - ORIF), physiotherapy can begin at an earlier stage - usually around 2 weeks after surgery.
Recovery from wrist fractures will take many months. It is generally thought that improvement in function will continue for up to 18 months.
More detailed information about wrist fractures is available here