When I start examining a joint with ultrasound, several times my patients have joked “if I see a baby in their shoulder/knee or not?” In fact, ultrasound is widely known as a test to visualize a fetus during pregnancy.
But recently, the ultrasound transducers have such great resolution that it can be used to visualize the tendons, muscles, ligaments, and joints that previously only MRI could visualize.
I personally have been doing musculoskeletal ultrasound in my office in Umpqua Orthopedics since 2013. This article discusses the background, utility and limitations of the Musculoskeletal Ultrasound in Orthopedics.
For many years, X-ray was the only tool used in diagnosing and treating a variety of musculoskeletal conditions. X-ray can visualize bones but provides very limited visualization of soft tissues. Newer technologies like MRI are being increasingly used to diagnose soft tissue injuries.
MRIs provide detailed information, but are extremely expensive and require preauthorization from insurance companies. Patients have to wait for the MRI preauthorization, schedule the test, and then return to the office for a discussion with their doctor to review the result, delaying the diagnosis even further.
Recent advances have resulted in a new tool that can be used to assess tissue health or localize injection treatments with great accuracy. The new tool is musculoskeletal ultrasound.
How is it done?
With musculoskeletal ultrasound, a probe with a water-soluble gel is placed onto the skin close to the injured area or the affected joint. This generates ultrasound waves to create real time image of a joint and the surrounding tissues.
Is the test painful?
Not at all.
Is it safe?
Yes. It does not use any radiation, but just sound waves. It is safe in pregnancy. (Remember this is routinely done for fetal evaluation).
There are some instances you might not be able to get MRI because of a pacemaker, but Ultrasound can still be done in these situations. In fact, there is practically no contraindication for an ultrasound examination.
What is it used for?
It is used to diagnose a variety of soft tissue conditions like muscle, tendons and ligaments, without having to jump through the “hoops” to get an MRI and avoiding the expense for MRI at the same time. Procedures include:
- Rotator cuff tendons issues in shoulder
- Tennis elbow and Golfer’s elbow (Lateral and Medial Epicondilitis)
- Biceps tear at the elbow
- Carpal tunnel syndrome
- De Quervain’s tendinitis (Thumb tendinitis)
- Knee ligament injuries
- Hamstring muscle/tendon injuries
- Quadriceps muscle/tendon injuries
- Ankle sprain
- Achilles tendon injuries
- Plantar Fasciitis
- Morton’s Neuroma
- Aspiration of fluid from swollen joint
- Needle guidance for accurate injections ( see below)
- And many more structures
However, there are limitations of the ultrasound and it is not suitable for all conditions, especially for deeper joint structures like glenoid labrum of the shoulder, cruciates ligaments( ACL and PCL), meniscus of the knee, TFCC and several other structures. We need MRI to visualize these structures.
Ultrasound Guided Injections/Aspirations
Ultrasound imaging is incredibly precise and the most accurate way to guide injections into just about any joint in the body. A great example of the benefit is found in patients with hip pain. Traditionally, these injections were sent to the radiology department to be done under x-ray with radiation exposure.
Now, ultrasound has made hip injections possible to do in the office and typically in the same appointment. Using ultrasound to guide an aspiration helps to make the procedure far less uncomfortable for patients. Ultrasound guided gel injections in the knee are also easier on patients (viscosupplementation).
Exciting advances in regenerative medicine use ultrasound to instill stem cells from fat or bone marrow, platelet-rich plasma (known as PRP), or for the treatment of a variety of nagging tendon and joint injuries.
At Umpqua Orthopedics, we can utilize ultrasound for conditions like:
- Ultrasound guided injections for joints (Hip, Knee, Shoulder, Elbow, Ankle, SI joints etc.).
- Ultrasound guided aspirations of joint effusion of different joints
- Ultrasound guided cyst and ganglion aspirations (like Baker’s cyst)
- Ultrasound guided gel injections in the knee (viscosupplementation).
- Ultrasound guided PRP (Platelet Rich Plasma) treatment.
- Ultrasound guided Stem cell treatment.