“How is a torn tendon diagnosed?”

Tendons attach muscles to bones. A "strain" is a pulled or torn tendon. Ligaments attach bones to other bones. A "sprain" is a pulled or torn ligament. Tendons (and ligaments) are not calcified like bones are, so of course you cannot see them on an X-ray, unless the tear is so bad that it pulled off a piece of bone along with it. So, how can you tell if they are torn? Well, often we can tell if a tendon is torn "all the way through" by the physical exam. The muscle will be balled up and it won't work at all because it is pulled off of the bone. Often, if there is a partial tear of a tendon, it is hard to tell how bad it is. Normally, we just rest, ice, and do physical therapy. Most of the time it will heal up in a few weeks. If it doesn't, then it might be time to look at it with an MRI. If the tendon is really obviously torn on exam, or if it pulled a bone chip off on X-ray, then we would go ahead and send the patient to orthopedics or get an MRI right away. So, it depends on how severe the tear is, what muscle is involved, and whether or not it is likely to heal on its own versus getting sent to orthopedics. The MRI part is mostly if we are thinking about surgery in this case.

An MRI is the gold standard to diagnose a torn tendon. An ultrasound can be used in some cases, but an MRI is far superior.

High resolution ultrasound for degree of tendon damage. Microtear can be treated with ultrasound guided injections of dextrose or platelet rich plasma
Jack