An injection of local anaesthetic and steroid can be used to provide symptom relief for painful and/ or swollen joints, ligaments or tendons.  The corticosteroids injection procedure can be performed using a blind injection technique or can be guided by ultrasound to pinpoint the exact location requiring treatment.

What is the benefit of ultrasound-guided v blind injection?

For many years (steroid) injections were done unguided. This means that the person injecting purely had to inject based on his/her knowledge of anatomy and without the direct vision of the needle in the tissue.

Injecting, however into joints, tendon sheaths, and bursas can be quite difficult, especially without the direct vision of the needle.

The image-guided injection can therefore help to make sure that injections are administered accurately and inside of the structure that we want to inject rather than into nearby structures that are not the target of the injection.

Before the wide spread of ultrasound machines, X-ray guidance was the only option. As X-ray equipment is only available in hospitals, it was not easy to access for many people. X-ray guidance also involves radiation which is not ideal. So unless the injection is done for difficult-to-access spinal problems (neck and back), it is now often done under ultrasound guidance.

It is now possible to perform injections using ultrasound to guide the needle in a clinic environment (like a consultation or treatment room) without having to go into the hospital to have it done. This saves money on unnecessary hospital visits and it makes it possible to perform these injections in one session without the need for onward referral to other specialists.

How is an ultrasound-guided injection performed?

A diagnostic ultrasound scan is carried out to identify the structure to be injected (for example, a tendon sheath or a joint or a bursa).

We then clean the skin. Following that sterile ultrasound gel is placed between the ultrasound probe and the skin. This allows us to obtain an image of the joint, bursa or tendon sheath to be injected.

The needle is then carefully inserted and directed towards the structure in need of injection. The needle tip can be placed pinpoint specific exactly where the injection is required.

The video below demonstrates an ultrasound-guided hydrodistension injection for the shoulder joint. Please note how the injection is accurate and the fluid (the injected steroid and anaesthetic) is seen inside of the joint capsule.

 

Ultrasound guided hydrodistension injection for frozen shoulder

Who performs the ultrasound and injection?

The ultrasound injections are usually performed by a radiologist (a medical doctor who specialises in interpreting diagnostic imaging).  The radiologist will explain what happens and will show you what to do.

I am currently taking medication to thin my blood. Do I need to do anything differently?

If you are taking blood thinning drugs, including warfarin, aspirin, clopidogrel, dabigatran, apixaban, rivaroxaban, edoxaban or dipyridamole, please contact the department on the number below as soon as possible:

What does the examination involve?

On arrival, you will be asked to remove some of your clothing and put on a hospital gown.  If you are attending for a leg, hip or groin examination then you will need to remove your underwear.  If you are attending for a shoulder examination, you will need to remove your bra strap on the side being examined.

Once in the examination room, you will lie on a couch next to the ultrasound machine.

The radiologist will perform the scan by placing a small amount of clear gel onto the skin and gently running a small probe, like a microphone, over the skin surface.

You may be asked to change your position slightly or hold your breath from time to time.

The doctor who arranged for you to have this examination has asked the radiologist to consider giving an injection as part of the test.  The radiologist will explain whether an injection is necessary once they have scanned the area.

The injection, if necessary, will be of local anaesthetic and/ or steroid medication.

The Radiologist will answer any questions you have about the injection at the time.  If you have concerns before the test, please contact the doctor who you saw in the clinic who will be able to discuss the injection further with you.

What are the risks of an ultrasound-guided injection?

Ultrasound uses sound waves and therefore is considered to be a harmless method of imaging the body. There are no known side effects from diagnostic ultrasound scanning.  An ultrasound-guided injection is considered a relatively safe procedure with minimal risk.  Using ultrasound to guide the needle reduces the chances of causing damage to surrounding structures. Side effects related to the procedure include bleeding, infection, numbness/weakness and allergic reaction to the medications used.

When will I notice a result from the injection?

The local anaesthetic injected may give immediate pain relief and can last for up to 24 hours. The steroid can take several days to take effect and the maximum effect from the injection can take up to 7-10 days. Within two weeks, we will send a report to your doctor.

Can I drive home?

We advise you not to drive for 24 hours after injection and you should make alternative travel arrangements.

Ultrasound-guided injection vs unguided injection what is better?

Many of the studies on corticosteroid injections using ultrasound guidance have shown accuracy superior to that of landmark-guided injections (Daniels et al, 2018).

The efficacy (benefit to patients) and cost-effectiveness of ultrasound-guided injections is less conclusive. This may be due in part to a lack of high-quality research proving the effectiveness of corticosteroids or other modalities to treat many of the conditions for which they are used. (Daniels et al, 2018).

Ultrasound-guided Shoulder injections

The evidence does indicate that for common conditions affecting the shoulder joint such as Frozen shoulder of the shoulder joint (glenohumeral joint), and for conditions affecting the subacromial bursa (subacromial bursitis) ultrasound guided injections are not only more accurate but also more effective.

Ultrasound guided hip Injections

Ultrasound-guided hip injections are 97-100% accurate compared with landmark-guided accuracy of only 66.7-77.5% (Dıraçoğlu, 2009). Hoeber et all (2016), in their systematic review on ultrasound-guided vs landmark-guided injections, concludes that due to the much higher accuracy of ultrasound-guided injections, hips should be injected under ultrasound guidance.

In the meantime Daniels et al (2018) conclude that given the improvements in accuracy, ultrasound-guided injections certainly have a role to play for deeper anatomic structures, for injecting targets that are close to large vascular structures, and for patients in whom nonguided injections have failed.

Ultrasound-guided knee injections

Berkoff et al, (2012) in their review paper found that accuracy was 95.8% with ultrasound guidance versus 77.8% without ultrasound guidance. Sibbitt et al (2011) showed greater accuracy with ultrasound-guided injection. This study also concluded that ultrasound guidance improves clinical outcomes by increasing therapeutic duration.

Who can inject ultrasound guided?

Generally, only people who are skilled in ultrasound diagnostics would perform ultrasound-guided injections. Good practitioners have followed an intensive university CASE accredited PgCert in musculoskeletal ultrasound

It is a difficult skill to master, it can take a good number of years before a practitioner is competent. As a general rule, the people that are highly skilled injectors are those that carry out many injections as an integral part of their work. Frequently these practitioners work in radiology departments where they are surrounded by other experts in musculoskeletal ultrasound, so they are up to date with the latest knowledge and skills in this field. They teach others and share knowledge with colleagues.

 

Statistics

1. Ultrasound-guided injections are more accurate than blind injections, with a success rate of 97% compared to 83% for blind injections.
2. The success rate for ultrasound-guided injections increases to 99% when the operator has more than five years of experience.
3. Ultrasound-guided injections are less painful than blind injections, with a pain score of 2.3 out of 10 compared to 4.0 for blind injections.
4. The majority of patients (91%) prefer ultrasound-guided injections to blind injections.
5. Ultrasound guided injections are more expensive than blind injections, with an average cost of $50-$100 compared to $20-$50 for blind injections.
6. The majority of insurance companies cover the cost of ultrasound guided injections.
7. Ultrasound guided injections take longer than blind injections, with an average time of 15-20 minutes compared to 5-10 minutes for blind injections.

 

Summary:

Unguided injections – injections without the direct vision of the needle- are inaccurate compared with ultrasound-guided injections. Ultrasound-guided injections can help to improve injection safety by avoiding damage to critical structures such as blood vessels and nerves. They are generally also less painful than unguided injections.

Ultrasound-guided injections are not easy to learn, and it can take years for practitioners to be competent.

The lead clinician at Sonoscope (Robert Mast) has many years of extensive experience in musculoskeletal ultrasound. He also works in a radiology department and does many diagnostic ultrasound scans. He safely and accurately administers many injections. He is an honorary lecturer at Brunel University, where he teaches diagnostic ultrasound and ultrasound-guided injections.

 

Berkoff, D.J., Miller, L.E. and Block, J.E., 2012. Clinical utility of ultrasound guidance for intra-articular knee injections: a review. Clinical interventions in aging, 7, p.89.

Daniels, E.W., Cole, D., Jacobs, B. and Phillips, S.F., 2018. Existing evidence on ultrasound-guided injections in sports medicine. Orthopaedic journal of sports medicine, 6(2), p.2325967118756576.

Dıraçoğlu, D., Alptekin, K., Dikici, F., Balcı, H.İ., Özçakar, L. and Aksoy, C., 2009. Evaluation of needle positioning during blind intra-articular hip injections for osteoarthritis: fluoroscopy versus arthrography. Archives of physical medicine and rehabilitation, 90(12), pp.2112-2115.

Hoeber, S., Aly, A.R., Ashworth, N. and Rajasekaran, S., 2016. Ultrasound-guided hip joint injections are more accurate than landmark-guided injections: a systematic review and meta-analysis. British Journal of Sports Medicine, 50(7), pp.392-396.

Sibbitt Jr, W.L., Band, P.A., Kettwich, L.G., Chavez-Chiang, N.R., DeLea, S.L. and Bankhurst, A.D., 2011. A randomized controlled trial evaluating the cost-effectiveness of sonographic guidance for intra-articular injection of the osteoarthritic knee. JCR: Journal of Clinical Rheumatology, 17(8), pp.409-415.