What Is It?
MSK U/S is an imaging modality (like x-ray or MRI) to diagnose musculoskeletal problems and and treat those problems through needle guidance.
What Are It's Advantages?
Unlike MRI that cannot be used for patients with metal in their bodies, MSK U/S can be used on anyone. It is quick, painless, significantly cheaper than MRI or CT, and can give immediate information about where a patient's pain is likely coming from. At this point in time, insurance pre-authorization is not required, decreasing the time to diagnosis and treatment. Because it is real-time dynamic imaging, the patient can point directly to an area of pain, increasing specificity, and allow for diagnosis of certain problems that only occur with movement.
What Can It Diagnose?
MSK U/S is particularly effective in diagnosing tendon problems, with a resolution 3-5X that of MRI. Examples include tendon wear (tendinosis), partial or full thickness tears of the rotator cuff of the shoulder or hip, tennis or golfer's elbow, jumper's knee, plantar fasciitis, achilles tendon problems, or ligament tears in the ankle. It can also assess peripheral nerves in the arms or legs, looking for nerve compression or swelling. Examples include carpal tunnel syndrome or ulnar neuropathy at the elbow.
What Can't It Diagnose?
MSK U/S cannot see deep into a joint. It can see only the surface of the joint or the very edge of joint cartilage, allowing visualization of bone spurs or joint effusions (fluid). It does not accurately see ligaments or cartilage inside of a joint (ACL of the knee, labrum of the shoulder). In these cases, MRI is more sensitive.
Why Is It So Effective At Needle Guidance During Injections?
Because ultrasound is used live, meaning the needle is followed in real-time, assuring accuracy in reaching its target.
What Type of Injections Is MSK U/S Used For?
Examples include shoulder, hip, hand, and foot joint injections, knee aspirations, carpal tunnel injections, and more advanced tendon procedures like platelet-rich-plasma injections and needle tenotomy at the elbow or hip.
Learn more about MSK U/S in this article from the American Journal of Radiology:
The Top 10 Reasons Musculoskeletal Sonography Is an Important Complementary or Alternative Technique to MRI.