If you are an active individual and injured all you want is treatment to get back to your sport. Trouble arises when you have treatment without a clear idea of what is wrong with you. So how do you find out what’s wrong?
I frequently see people post on a blog a few of their symptoms. Quite quickly advice comes in. Often it is very helpful with sympathetic comments. Usually someone chips in with a treatment even though they really don’t have any idea what the diagnosis is. Some suggest a scan. A scan may be required but without a clinical diagnosis it may potentially cause harm and is often a complete waste of money. Why is this the case?
What is the role of a scan?
When the doctor wishes to make a diagnosis they ask you lots of questions that result in a list of possible diagnoses. An examination follows – this helps shorten the list by excluding diagnoses that don’t fit. The scan is then performed to try and whittle the list of diagnoses down to, ideally, one clear diagnosis.
So when I order a knee scan I ask the radiologist who will be reporting the scan to tell me which of my list of possible diagnoses are supported by findings on the scan. I ask for information that will tell me how severe the problem is.
Lets look at some examples.
Making a diagnosis
Let’s say I’m certain that the Anterior Cruciate Ligament (ACL) has been injured. I will ask the radiologist to confirm that the ACL is ruptured. In this situation it is important to know whether the joint surfaces and meniscii are healthy. Hence I specifically ask that question. A good radiologist will answer my questions and not just present me with a generic report that lacks detail. Joint surface damage is difficult to diagnose on the history and examination but the MRI scan is good at picking it up. Meniscus tears are normally fairly accurately diagnosed clinically but when the knee is sore, as it is after injury, it is more difficult. So the scan confirms some things I know and pick up things that I couldn’t establish from just talking to and examining you. Finally a scan helps me when I think something might be injured but my examination is difficult because the knee is sore.
As you can see the history, examination and scan all complement each other when trying to arrive at a clear diagnosis and assessing the severity of the problem. It is only by asking specific questions of the reporting radiologist that I get this clarity. If I sent you for a scan without any information given to the radiologist they would not know what to look for and there is a possibility that they would overlook subtle findings on the scan. Imagine I asked you to look at a painting of an English landscape but didn’t tell you what aspect of the painting I was interested in. After you look away I ask “how many sheep in that painting?”. Wouldn’t it have been easier to tell me the answer had I asked you to look at the painting with that question in mind? Wimbledon Clinics order thousands of scans so we can demand the best radiologists to report our scans.
Assessing the severity of a problem
Scans are particularly good at helping to assess the severity of a problem and hence prognosis. Consider this example.
A 60 year old has a history and examination compatible with a tear of the medial meniscus. It is tempting just to go ahead with an arthroscopy but a scan can be very useful in helping to decide if that is a good idea.
Asking the radiologist if there is a medial meniscus tear will help decide whether the clinical diagnosis is correct or not. However by asking additional questions we can decide whether it would be a good idea to proceed to arthroscopy. If the joint surfaces are healthy then arthroscopy will probably be successful. If the joint surfaces show signs of significant of osteoarthritis and bone bruising I would be very wary of offering the same individual an arthroscopy. Why? Because I know that knee has a higher chance of a poor outcome.
Scans are too sensitive
An MRI scan will typically produce over a hundred images. Each image contains huge detail. The MRI scan is remarkably sensitive and will pick up all sorts of things that might be irrelevant to the current problem. For example the scan may pick up a long recovered ligament sprain. The best analogy I can think of is the surveyor’s report I received when buying a Victorian house. When i read it I thought the house was falling apart. That is until the surveyor explained that most of the “problems” picked up were in keeping with the age of the house and could be ignored. Sometimes the same is true of a scan of the knee. The abnormality seen on scan is not relevant to the current problem.
MRI scans are not an electronic doctor.
Take again medial meniscus tear of the knee. Since the use of MRI scan has become widespread we now know that there are many people in their 50s who have a medial meniscus tear that is completely symptom free. If I had an asymptomatic medial meniscus tear I would not be seeking out someone to perform an arthroscopy of my knee. Now imagine the situation where you have not had anyone ask if you have pain from your meniscus and examined you to confirm whether it is tender but you have a scan that shows a tear. Before too long someone will suggest an arthroscopy all because you didn’t get a doctor to check if it was the source of pain. So a scan on its own may lead to unnecessary treatment.
There is also a tendency for some doctors to be over reliant on scans to plan treatment and in rushed consultations it is easy to see how this can happen but it is not good practice.
Occasionally a patient comes to see me having already had a scan. I make a particular point of not looking at the scan, nor report, until I have done my clinical assessment as I don’t want the scan findings to bias my clinical diagnosis- the scan must always follow the clinical assessment because scans don’t tell me what is hurting- you do.
So in conclusion an MRI scan plays a specific role in the assessment of your knee. A clinical diagnosis followed by a scan where there is a good working relationship between myself and the radiologist will most likely give better accuracy of the diagnosis, assessment of the severity of the problem and clarity on the best treatment plan. This in turn will reduce the number of unnecessary operations. Conversely relying on the scan to make a diagnosis without any helpful input from a thorough history and examination can result an incorrect diagnosis and possibly overtreatment.
For that reason we do not offer just scans through Wimbledon Clinics but we do offer affordable packages that include a consultation where the doctor will take a history and examine you. They will then as part of the package order a scan and then call you will the results. We call this our Game Ready Package and you can find out more by calling our Treatment Coordinator on 0202 8 944 0665.
You may wish to look at Why does my knee hurt when my scan is normal?