Wrist Injuries – having the correct initial treatment can prevent long term problems
Wrist injuries are very common and can be caused by anything from a simple trip and fall onto the hands, to a high speed road traffic accident. The injury can be to various structures and some are easier to diagnose and manage than others.
The most common fracture is to the lower end of the forearm bone called the radius. Most people with a radius fracture will be aware that they have a significant injury and will attend the accident and emergency department. An x-ray will be taken and how the fracture will then be treated will depend on whether the bone has moved out of position. If it has not then a plaster cast, backslab or a splint is usually applied and the wrist is supported in a cast while the bone heals.
If the bone has displaced out of position then the fracture will have to be treated to try and reduce the risk of leaving long term disability. The bone is usually pulled back into position in the casualty department and a plaster cast is applied. In some cases this is all that will be required but if the bone cannot be adequately realigned or if after realignment it re-displaces to an unsatisfactory position, then the opinion of a specialist is required. The challenge for the specialist is to advise whether the benefits of improving the position of the bone with an operation out way the risks. Surgery for wrist fractures is usually performed as a day case under a general anaesthetic or the patient can be awake and have the surgery done under a nerve block, where the anaesthetist numbs the arm with an injection of local anaesthetic. The actual operation performed will be determined by the nature of the fracture but for complex injuries where there is disruption of the surface of the joint or where the bone is unstable, the treatment is likely to be open reduction and internal fixation of the fracture with a metal plate.
Over the last few years the designs of these plates have improved such, that the bits of bone are held securely by the screws and following the surgery the wrist is only immobilised in a cast for two weeks and the patient then wears a removable wrist splint. This is more convenient allowing the hand to be washed but also by getting the wrist gently moving more quickly, there is less of a tendency for it to become stiff.
The second most common bone in the wrist to be fractured is called the scaphoid. This is a small bone which lies between the thumb and the side of the wrist. Scaphoid fractures can be caused by falling onto the hand, anything which forces the wrist backwards or by punching injuries. The scaphoid is a notorious bone for causing long term problems. Because of its shape it can be difficult to diagnose fractures and the bone has a poor blood supply which makes it more difficult for fractures to heal. About one in ten scaphoid fractures do not heal when treated in a cast and the likelihood of a scaphoid fracture not healing is increased if the wrist has not been immobilised in a cast. This occurs either because the patient thinks they have just sprained their wrist and does not attend hospital or they do, but the x-ray looks normal and the fracture is not diagnosed.
There has been a move towards operating on all scaphoid fractures, inserting a metal screw into the bone which can be done with keyhole surgery. The thinking behind this, was that it was thought the fractures were more likely to heal and the patient’s spend less time in a plaster cast. However a recent trial which recruited patients from a number of hospitals around the country, including Tunbridge Wells, comparing treatment in a plaster cast with fixation with a screw did not find any significant difference between the two groups one year after their injuries. My usual practice is to treat undisplaced scaphoid fractures in a plaster cast but if after six to eight weeks in plaster the fracture has not healed, then I offer them keyhole surgery.
If a scaphoid fracture does not heal and develops into a non-union then this can cause continuing pain and stiffness of the wrist and in the longer term it can lead onto osteoarthritis. The patients who I see with scaphoid non-unions either have had their fracture correctly treated at the time but it still has not healed or they did not have their fracture diagnosed at the time and in some cases cannot even remember injuring their wrist in the past. Once a patient has a non-union of the scaphoid then the treatment to try and get the bone to heal involves inserting a bone graft which is usually taken from the top of the pelvis into the fracture and then fixing it with a metal screw. After surgery of this nature the wrist is then immobilised in a cast for about six weeks. If the patient has an injury to their wrist but nothing has been fractured then there may well be injuries to the ligaments or cartilage. These will not show up on an x-ray and diagnosed on the basis of examination of the wrist by a specialist who may request an MRI scan to get more information. Various soft tissue injuries in the wrist can be treated with keyhole surgery where a small telescope is inserted into the wrist or if there are more significant ligament injuries then these ligaments may need to be repaired. If left untreated major ligament injuries to the wrist will usually result in arthritis developing a few years later.
Quite a high proportion of the work of a wrist specialist is dealing with the long term consequences of injuries sustained some time previously. If these are treated differently at
the time then this can hopefully prevent these longer term problems developing.