Meniscus Tears

Ultrasound or MRI: what question are we trying to answer?

An ultrasound demonstration can show a striking abnormality in a selected case. It cannot establish that ultrasound and MRI are interchangeable for every patient. The useful question is which investigation can resolve the uncertainty in your knee.

What to discuss before imaging

• Location: is the suspected problem inside the joint, or in a nearby tendon, bursa or ligament?
• Purpose: are we checking a suspected tear, investigating swelling, assessing associated damage or planning surgery?
• Limitations: which areas cannot be assessed reliably with the chosen method?
• Consequence: what will change if the result is normal, abnormal or inconclusive?

MRI is the preferred imaging test for an acute isolated meniscal tear in the AAOS guideline. Ultrasound can be an alternative in selected circumstances, including when MRI is unavailable or contraindicated. Its findings depend on the structures accessible to examination and the examiner. A negative ultrasound does not automatically exclude every important knee injury.

Bring useful information, not just more tests

Bring the actual previous images, reports, operation details if applicable and a timeline of symptoms. Explain whether pain started suddenly, follows a particular movement or is accompanied by persistent locking. Tell the clinician about a pacemaker or other implanted device before MRI screening; the imaging service determines whether and how scanning can proceed.

After the examination, ask for the finding in plain language and its relevance to your symptoms. Agree on the next step if imaging and clinical examination do not match. Do not interpret the word “tear” as an automatic instruction to remove tissue.

Reference: AAOS recommendations on imaging and meniscal preservation.