Do I need an MRI for a sports injury?

Your exam answers the first questions

They'll check swelling, motion, strength, and balance. You'll raise your arm or bend the sore joint. With knee soreness, the doctor will watch you walk. These checks show which movements cause trouble.

The exam can also find danger.

A numb foot or weak pulse needs fast care. So does a joint that looks bent. Those warning signs matter before any routine scan. You won't need to wait for an MRI.

Each scan shows something different

X-rays show bones, breaks, and some joint wear. Ultrasound can show a tendon while it moves. MRI shows muscles, tendons, and cartilage, the smooth covering at a bone's end.

More detail isn't always useful.

An MRI will often find older changes that don't hurt. They'll compare those changes with your exam. Ask what choice the scan will help make. If care won't change, you may not need it yet.

A later exam can show more

Fresh swelling can hide how well a joint moves. Sore muscles may tighten and limit the exam. If an ankle still looks straight and holds you, another exam four to five days later may tell more.

Warning signs make waiting unsafe.

Get prompt care for fast swelling or lost feeling. Seek help if you can't stand on the foot. If you're improving, watch your motion and strength. If progress stops, another exam may lead to a scan.

Sources

1. This review of imaging in tendinopathy makes the central point that there is NO direct link between tendon structural disorganisation on ultrasound or MRI and clinical symptoms, so imaging findings can create a confusing clinical picture rather than clarify it. It also examines whether imaging predicts onset of pain or clinical outcome, and whether tendon structure has to improve for the patient to get better.

   Docking SI, et al. — Tendinopathy: Is Imaging Telling Us the Entire Story?. J Orthop Sports Phys Ther, 2015. DOI: 10.2519/jospt.2015.5880.

2. The American Medical Society for Sports Medicine's position statement on interventional musculoskeletal ultrasound reviews the accuracy, efficacy and cost-effectiveness of ultrasound-guided injections across major, intermediate and small joints and soft tissues, noting that the large growth in ultrasound use has come mostly from non-radiologists and that in sports medicine it is used to guide aspirations, diagnostic and therapeutic injections, tenotomies, releases and hydrodissections.

   Finnoff JT, et al. — American Medical Society for Sports Medicine position statement: interventional musculoskeletal ultrasound in sports medicine.. Clin J Sport Med, 2015. DOI: 10.1097/JSM.0000000000000175.

3. The updated evidence-based ankle sprain guideline states that ligament damage severity is assessed most reliably by DELAYED physical examination 4-5 days after the injury; that after a short period of immobilisation the patient benefits most from tape or a brace combined with an exercise programme; that NSAIDs may reduce pain and swelling but are not without complications and MAY SUPPRESS THE NATURAL HEALING PROCESS; that supervised exercise-based programmes are preferred over passive modalities; that surgery should be reserved for cases not responding to comprehensive exercise-based treatment; and that ankle braces are efficacious for preventing recurrence.

   Vuurberg G, et al. — Diagnosis, treatment and prevention of ankle sprains: update of an evidence-based clinical guideline.. Br J Sports Med, 2018. DOI: 10.1136/bjsports-2017-098106.

4. The Munich consensus statement on muscle injuries was written because a survey of 30 English-speaking team doctors and scientists confirmed marked inconsistency in terminology - most obviously for the word 'strain'. It defines four types: functional muscle disorders (type 1 overexertion-related, type 2 neuromuscular) with no macroscopic fibre tear, and structural muscle injuries (type 3 partial tears, type 4 subtotal or total tears and tendinous avulsions).

   Mueller-Wohlfahrt HW, et al. — Terminology and classification of muscle injuries in sport: the Munich consensus statement.. Br J Sports Med, 2013. DOI: 10.1136/bjsports-2012-091448.