Mr Richard Baker – Weekly Blog
Understanding the different type of wrist injuries
This week I have seen a number of wrist injuries and I have been thinking about their natural history of and my approach to them. There are two general mechanisms of wrist injury which divide the patients into two groups.
The first group tends to be young men involved in a high energy injury such as coming off a motorcycle, coming off a bicycle at speed, falling off a skateboard, throwing a punch of falling from a height such as a ladder at work, for example.
The second group tends to apply to women and children in particular and is a lower energy injury, typically tripping over and landing on the outstretched hands.
Both of these groups of patients present with significant pain and swelling in the wrist and loss of movement, but paradoxically I find diagnosis and treatment more straightforward in the first high energy injury group than the second group.
In the high energy injuries, you can usually identify a broken bone (fracture) such as a scaphoid fracture or a specific ligament injury, although this is less common. In the case of a scaphoid fracture, around six weeks of immobilisation in a plaster cast is sufficient, although there is a minority of patients in which the bone fails to heal and require surgery.
In the second group of patients who have the low energy injury, the x-rays are often completely normal with no sign of fracture, dislocation or ligament injury. The patient’s wrist is often tender throughout and all movements are painful and there is swelling, but there is often not any specific point that is painful or a specific anatomical structure that can be identified as the cause of the pain. In most cases, it is frustrating because it is not possible to tell a patient that structure X is injured and therefore we will do treatment Y and it will take X weeks to get better. The cause of pain and swelling in these patients is likely to be a general overstretching of the many ligaments around the outside of the wrist joint – a “wrist sprain” and so the best treatment is rest, elevation, splinting of the wrist and gradual resumption of normal activities as the pain resolves. Often, though, this period takes weeks to months. Patients sometimes ask about steroid injections for these injuries, and I generally use steroid injections for long-term chronic problems such as arthritis because the underlying problem is not something that is going to get better, whereas in contrast, in a wrist sprain, I have an expectation that the pain will get better as the tissues heal. Occasionally, though, if the process does take a long time a steroid injection can help to at least break the cycle of pain and allows the patient to return to normal activities sooner.
Patients also often ask about having scans of their wrist. The scan of choice would be an MRI scan because it is better at identifying the ligaments in the wrist than a CT scan. I am very careful about which patients I request an MRI scan for, by which I mean that I have to have a specific diagnosis in mind that I want to confirm or refute. It is generally unhelpful to request an MRI scan of a wrist when you have no idea of the possible causes of pain because it may well detect symptomless abnormalities (for example painless degeneration of the triangular fibrocartilage complex ligament (TFCC) is common in middle age) that can send the unwitting patient and surgeon down the wrong path of treatment.
The final investigation is a wrist arthroscopy (keyhole surgery) to look inside the wrist. Similar to an MRI scan, I would reserve this for patients in which I suspect a specific diagnosis that I want to confirm or refute. The patient should be chosen with care; it does involve a general anaesthetic and there are risks such as damaging tendons and nerves on the back of the wrist. It is useful for identifying specific ligament or cartilage injuries, which helps me decide what I am going to do next. I suspect over the years as the resolution of MRI scans improves, there may be less need for undertaking arthroscopies of the wrist. Wrist arthritis is a different concept to wrist injury and wrist sprains but can be the result of an injury many years in the patient’s past. Treatment of wrist arthritis is very different to treatment of wrist injuries and is the subject of another blog. The good news is that most wrist injuries get better by themselves without surgery, although the timing of resolution of symptoms is very difficult to accurately predict.
In conclusion, there are two main types of wrist injury, the high energy injury and the low energy injury, and paradoxically the high energy injuries are easier to diagnose, but fortunately in the low energy injuries very rarely do the patients need surgery.