Fractures of the wrist are common injuries.
The most common mechanism of injury for a wrist fracture is a fall on the outstretched hand. In the elderly, falls are by far the most common reason for a wrist fracture. In younger people it takes more force to break the bone so distal radius fractures are seen following higher energy events such as motor vehicle accidents, falls from a height, industrial, and sports injuries.
What types of fractures can occur?
There are a wide variety of fracture patterns depending on the direction and amount of the injuring force, the position of the wrist when it was injured and the inherent strength of the bone. Fractures are classified according to:
- whether there is damage to the radiocarpal joint surface
- whether there is damage to the ulnar styloid
- how much splintering (multiple fragmentation) of the bone has occurred
Another very important way to classify these fractures is as stable or unstable. In unstable fractures, the fracture fragments are highly likely to move further out of position during the healing period.
Fig .1 normal appearance of the distal radius
Fig 2 Fracture of the distal radius. There is shortening of the radius and the fracture is angulated so that it is no longer adequate to leave this in its existing position
What symptoms do wrist fractures cause?
- Sensory changes
The wrist region will be x-rayed. At least two x-ray views are normally taken – AnteroPosterior (AP) with the back of the hand on the film and Lateral (from the side).
In many situations the finding of a wrist fracture will result in referral to an orthopaedic surgeon
The goals of treatment of distal radius fractures are:
- To relieve the pain of the injury
- To facilitate healing by immobilizing the fracture fragments
- To ensure that the fracture heals in a position which does not compromise wrist function
- To protect the region during the healing process
- To allow return to normal function as soon as possible
If the fracture is stable and nondisplaced then its position does not need to be improved by manipulation. These fractures can be treated in a cast.
A cast must be tight enough to hold the forearm and wrist securely but not so tight that it compresses the damaged and swollen tissues of the forearm.
Follow-up of a fracture in a cast may require frequent visits to the cast clinic.
The cast will be removed when there is evidence of healing on x-ray. At six weeks there is usually enough new bone formation (callus) to allow for removal of the cast. This new bone is still quite weak, though and you should protect the fracture for a few weeks more. Sometimes this means a removable splint.
Cast immobilisation of radial fracture
Closed Reduction & Cast
Frequently the position of the fracture is not acceptable. The angulation or the impaction is so severe that the function of the wrist would be impaired if allowed to heal in this position. In these cases, the surgeon may opt to improve the position of the fracture by manipulation
Closed Reduction & Pinning
When more control of the fracture fragments is necessary, some type of surgical intervention is usually necessary. One minimally invasive option is to perform a closed reduction and pinning of the fracture. This procedure is suggested when the fracture is considered unstable, but the fragments can be manipulated into an acceptable position. The fragments are stabilized by driving smooth sterile stainless steel pins through the skin and across the fracture. The ends of the pins are cut outside the skin and bent to prevent them migrating any deeper.
k wire fixation of distal radial fracture
Open Reduction & Internal Fixation
This technique has gained popularity and is the preferred method of treatment of unstable distal radius fractures for many surgeons. The bone is exposed by an incision on the front or back of the wrist depending on the exact anatomy of the injury. The fracture fragments are reduced into anatomical position and held there with a metal plate.
Internal fixation with plate and screws of distal radial fracture
The bone of the distal radius is cancellous (spongy) and heals very well. New bone formation is often evident on x-ray at three weeks post injury but most surgeons keep the fixation in place or the cast on for six weeks. Non-union is rare. As with most bones it takes about three months for the bone to consolidate at the fracture site and be strong enough to use normally.
Once the cast or splint has been removed physical therapy may be started to help you recover the range of movement of the wrist, fingers, and thumb; then recovery of the strength once the bone is strong enough to load and finally endurance to allow you to recover normal function and return to work and sports activity. Bone and joint function continue to improve for up to 18 months after a fracture.
Outcome and long term prognosis and medical-legal issues
Most patients will plateau around 12-18 months. Not everyone makes a 100% recover and the final outcome is often influenced by a number of factors. The most important factors are the severity of the original injury and the position that is obtained at the time of bony union.
Overall 78 % have satisfactory outcome but when dealing with just undisplaced fractures then there is a 89-100% satisfactory outcome
Residual pain- 34-75% complain of some degree of residual pain
Weakness- 18-35% complain of subjective weakness.
Risk of post traumatic arthritis- 3 to 17.8%
Nerve injury – median nerve most common – 13-23%.
Complex regional pain syndrome-10-30%
Loss of range of motion is composed of reduced flexion in 40.8%, reduced extension-14.2% and reduced pronation/supination-7-9.0 %
Post-traumatic arthritis of the joint is actually quite uncommon and there is still no absolute certainty about the amount of irregularity of the articular surface that that will cause it. However, most agree that an irregular joint surface should be avoided if possible. Gaps or steps in the articular surface more than 1mm are best avoided.
The aim of treatment is prevent more than 2mm of shortening the radius if this does occur then it results in impingement between the ulna and the carpal bones which is often painful and can result in ulnar sided pain and that will then often persist without additional intervention
The third important factor in determining future problems is the inclination of the articular surface. The normal inclination of the distal radial surface is that it face in a palmer direction, if this inclination is lost and especially if the inclination becomes dorsally placed then this will also increase the risk of future problems A dorsal tilt also affects the distal radioulnar joint and rotation of the forearm.