Why is my physio sending me for an MRI?

As primary contact clinicians, physiotherapists are often the first port of call for clients with acute injuries. Just as equally they can be the first clinician someone seeks help from with a persistent pain problem. Either way, the days of private clients needing a referral from a medical practitioner to see a physiotherapist are in the past. Of course, that doesn’t mean a medical practitioner won’t need to be involved at some stage in the process, it just means people are walking in off the street looking for an answer to their problems and are often starting at the physio clinic.

So, if a client has sustained an acute injury, say for example on the sporting field or from an accident at home are they all being sent for an MRI? Well, the short answer is no, not all of them but a percentage of them will be sent off after the first visit to obtain a scan if it is warranted and clinically relevant. Those last two words “clinically relevant” are critically important in the decision-making process as there is no point in sending a client for a scan if it is not going to alter the outcome or the treatment plan. Also, because MRI scans are so sensitive often a scan result will come back with half a dozen findings that could be an issue but only one of them is relevant to the client’s problem and reason for seeing the clinician. As such blanket referrals for an MRI are to be avoided.

If however the scan will allow the clinician to “rule in or rule out an injury” then an MRI is an incredibly powerful tool in the armoury of the clinician. For example, if someone enters the clinic as a first-time client on crutches having been cleaned up on a football field complaining of an acutely sore and swollen knee and unable to weight bear on the limb, then the clinician will be suspicious of a serious injury. Once a thorough verbal and physical examination has been conducted, injuries such as ligament ruptures, serious or subtle fractures, meniscal tears or even dislocations need to be confirmed or denied through scans. In days past plain x rays were often used to exclude fractures, but the problem with this type of scan is that subtle joint injuries and fractures can be missed as well as ligamentous and soft tissue injuries. The other bonus of an MRI over a plain x ray, especially in children is the lack of radiation. As an MRI is a giant magnet there is no radiation at all involved, making it a much safer scan.

In reference to the client with the acute knee injury, experienced clinicians will have a pretty reasonable clinical suspicion of what injury has occurred without scans but often an MRI is required to confirm or deny the injury plus concurrent damage. Whether the injury has or has not been sustained will often make a huge difference to the rehabilitation process and time frames involved. For example, if the above footballer has ruptured an ACL the timelines and management will be totally different to a dislocated kneecap with associated chondral (cartilage) damage. If it is too difficult to obtain a clinical picture MRI can be very helpful in ruling out something like the ACL rupture as mentioned. An ACL rupture would mean a full season off football but a dislocated patella may mean only a few weeks are needed to return to play.

The other type of issue where an MRI can be extremely useful is a persistent pain issue that has been hampering a client for many months and precluding them from training or playing at their best. Injuries such as stress fractures of the lower back in fast bowlers or rowers are classic examples of these. Clients will often complain that they can still participate in sport but have high levels of pain during and also after activity. Again, after a thorough history and examination has been performed an MRI can be extremely useful in picking up this more subtle injury. Once diagnosed, the rehabilitation pathway can be much clearer for both the client and clinician and often this type of injury has been lingering because the client hasn’t reduced the amount of load. Sometimes with this type of stress injury, follow up MRI can be very useful in demonstrating improvement in the condition and giving the client a green light to get back to participation and being able to load more.

So next time you hear of a physio ordering an MRI you can be sure that they have some sound clinical reasoning for ordering such a scan and often they will be doing it to rule in or rule out a particular injury. Equally they may be ordering the scan to determine the extent of an injury which will in turn determine the length of time off sport and duration of rehabilitation. The other bonus of them ordering an MRI is that there are no harmful effects of radiation. Be confident that when a physio orders an MRI it will help both them and the client in getting the best possible plan in place for a successful recovery.

Michael Pierce

Sports Physiotherapist

Lake Health Group