What are the potential complications of this fracture?
Complications are events or conditions which make the process of recovering from the fracture more complex. Although most of them are rare, much of the management of the injury is directed at avoiding complications, detecting them early and treating them if they occur. Doctors, nurses and physical therapists ask patients to do some unexpected and uncomfortable things, like moving the fingers right after an operation on the wrist. These actions help to detect complications early.
The term malunion implies that the fracture has healed but is not in the anatomic position. There are three aspects of malunion of distal radius fractures that give rise to concern - irregularity of the distal radius joint surface, tilting of the joint surface, and shortening of the radius. A gap or step in the joint surface greater than 1 mm is a cause for concern about the long term possibility of wear-and-tear arthritis of the joint.
Post-traumatic arthritis of the joint is actually quite rare and there is still no absolute certainty about the amount of irregularity that will cause it. However, most agree that an irregular joint surface should be avoided if possible. Tilt of the distal radius is even more difficult to evaluate. A severe degrees of tilt affects the distal radioulnar joint and rotation of the forearm. Although, once again, there is no consensus, many doctors prefer to avoid a high angle of tilt and would operate to prevent it.
Shortening of the radius results in impingement between the ulna and the carpal bones which is often painful. It is better to prevent malunion as the treatment is difficult. Once the bone is healed it is a major undertaking to "take down" the fracture by surgery and fix it in a better position. A "wait and see" approach is often preferred with various operations proposed for reconstruction of a painful or poorly functioning wrist.
The median and ulnar nerves are often compressed by the impact of a fall and may be damaged to the extent that their function is affected. Once this is established it may be necessary to decompress the nerve. Recovery after this surgery is usually complete but delay should be avoided. If you have numbness in your hand after a fracture you must inform the doctor about it.
Another source of nerve injury is the hardware used to treat the fractures. Pins inserted through the skin may come close to or penetrate into nerves that pass over the fracture. The radial nerve on the outer side of the wrist is quite vulnerable to this type of injury. It causes pain similar to an electric shock and may also cause numbness. Most often this resolves when the pin is removed. Damage to a nerve may leave a sensitive, tender scar.
Fractures of the distal radius cause damage to the muscles of the forearm and involve bleeding into the muscle compartments. Both these processes cause increased pressure in the muscle compartments, which may be further increased by bandages or casts. If the pressure gets too high the blood supply of the muscle tissue is impaired causing further damage and a further increase in intra-compartment pressure.
The hallmark symptom of compartment syndrome is relentlessly increasing pain made worse by active or passive finger movements. For this reason patients are encouraged to move their fingers as soon as possible. If it is only mildly uncomfortable this is evidence against a compartment syndrome. Once established compartment syndrome tends to get worse and cause muscle death with long lasting disability. The treatment is to operate to open up the muscle compartments and relieve the pressure. If this is done before any muscle dies the results are excellent although the scars on the forearm may be dramatic.
If the skin is wounded either by the accident (causing an open fracture) or by surgery there is a chance that bacteria will infect the wound. Antibiotics are often prescribed to reduce the chance of this happening. The risk of an infection following an operation with modern treatment is less than 2% (one in 50) but this is little consolation to you if you have been unlucky in this way. The wound swells up, remains red and tender and may drain pus. It is normal to have a slight fever after an operation but with an infection this tends to go up and last longer. Culture of the blood or drainage from the wound may reveal the bacteria responsible.
The mainstay of treatment is prolonged high dose bacteria specific antibiotics but further surgery is also very common. The wound may be opened and washed out to reduce the number of bacteria and give the antibiotics a fighting chance. Sometimes the wound may be packed with antibiotic beads to increase the local concentration of the drug. Once the infection is under control the fracture should heal; after that it may be necessary to remove all the metal implants as bacteria tend to grow on foreign material.
In the majority of cases the combination of early aggressive antibiotic treatment, wound washout and removal of the hardware once the fracture is healed is successful in restoring the wrist to normal.
This troublesome problem results in burning pain, swelling, and stiffness of the hand and wrist even though the fracture has healed. The blood supply is increased to an injured area as part of the body's marshaling of resources. Normally this increase only lasts a few days post-injury and the blood supply returns to normal levels. After some wrist fractures this does not happen and the increased blood supply causes prolonged swelling. This in turn makes it difficult to move the hand and wrist; everything stiffens up and attempts to move are sore.
It is not clear why this occurs although there is a connection between pain and the blood supply reflex. The condition is also know as Reflex Sympathetic Dystrophy. It is less common if you get the fingers, hand and wrist moving early and this is another reason why you are asked by the staff to move the fingers right away. The pumping action of the muscles helps to reduce swelling.
Treatment of established Complex Regional Pain Syndrome is different for different individuals but includes exercises and splints to eliminate the stiffness, medication for the pain and compression gloves to help reduce the swelling. Nerve blocks may be helpful both for diagnosis and treatment. Although it may take a long time, the outlook is good with most people recovering.
For further information see A Patient's Guide to Pain Management: Complex Regional Pain Syndrome
Most implants which are used to stabilize fractures are made of metal and therefore subject to metal fatigue. You most frequently come across metal fatigue when you want to shorten a piece of wire and repeatedly bend it until it breaks. A metal implant like a wire or a plate which crosses over an unhealed fracture also bends. Granted this is to a very small degree but "micromovement" does occur at fractures and the stress is transmitted to the implant. Once the fracture is healed this micromovement stops and there is almost no load on the hardware. It is a race between the bone healing and the implant breaking which is normally won handily by the healing process.
Under some circumstances the hardware does fatigue and fail. If you carry loads or use vibrating machinery before the fracture is healed, that greatly increases the tendency to fatigue failure. The restrictions on lifting weights or riding a motorcycle too early may seem unnecessary or overcautious when your wrist is feeling strong and comfortable and when these activities do not hurt. However, the restrictions are based on the length of time it takes the bone to heal - until that time loading the hardware may have unexpectedly serious results. The risk of fatigue failure is also increased by smaller implants, with delay in healing and with infection. If there are gaps between the bone fragments that may also increase the tendency to fatigue.
If the implant does break the bone may still heal in the current position if protected by a cast (and by stopping the activities that loaded it). Alternatively, the surgery may be repeated with bone graft used to promote healing and stabilize the fracture. In the long term this complication may be seen as a "bump in the road" as the measures to heal the fracture usually succeed in the end.
Other Hardware Problems
Pins, plates and screws are often used in the surgical treatment of distal radius fractures. The location of these items of hardware often means that the tendons that pass to the hand have to glide over the plate or the sticking out ends of the pins and screws. In a small percentage of cases the tendons are irritated and may even rupture. This was a relatively common complication of plates on the back of the wrist where there isn't much room for the tendons. The main symptom is pain in the wrist region when moving the fingers or thumb. The area is likely to be tender. If the tendon ruptures this affects a specific movement like straightening the thumb or index finger. The treatment is to remove the hardware that is causing the trouble. If the fracture is not healed some other method of treatment may be necessary. For instance the plate may be applied to a different surface or in a different position.