Hydrodistension (high volume) injection
Hydrodistension, or ‘high volume’ injections are appropriate if you are experiencing a stiff and painful joint. They are most commonly used for a condition known as frozen shoulder, or adhesive capsulitis.
The procedure involves using an ultrasound scanner to guide a injection of combined steroid, local anaesthetic and sterile saline into the joint space, with the intention of stretching the tight tissues from the inside out. There is strong evidence to show this injection provides quicker pain relief, and the effects are maximised further when combined with physiotherapy rehabilitation.
What is the role of the different medicines in a Hydrodistension?
- Steroids: This medicine acts as an anti-inflammatory, mimicking the effect of a natural steroid which is made inside the body. This will reduce the pain an inflammation in the joint.
- Local anaesthetic: This helps to reduce discomfort during the injection, at the same time as adding some volume.
- Sterile saline: This is an inert liquid, which forms the bulk of the injection and creates the volume to stretch the tight and stiff tissues (particularly the joint capsule).
What should I expect on the day of the appointment?
Once you and your clinician have confirmed your diagnosis, they will discuss treatment options with you, including the type of medication and dosage. They will also inform you of potential risks and side effects, plus alternative treatments.
If you are happy to proceed, you will be made comfortable in either a lying or supported sitting position. The injection will be administered into the joint space using ultrasound guidance, helping it to be quick and accurate. Some people also require a small amount of extra steroid to be placed within a jelly cushion called a bursa on top of the shoulder at the same time; your clinician will discuss this with you.
What should I expect after a Hydrodistension injection?
The lidocaine/local anaesthetic part of the injection usually provides effective pain relief for a good few hours. Once this has worn off, some people feel an ache or discomfort in the injection site. This is entirely normal, and can be managed with paracetomol or cold compress. Do not take anti inflammatories (NSAIDs) such as ibuprofen or naproxen.
The steroid medication starts to take action after a few days, so it is advisable to avoid heavy loading for three to five days post injection. However, it is important to continue with the rehabilitation exercises as prescribed by your clinician.
Occasionally, someone may feel light headed or a bit unwell after the injection. Therefore, we ask for you to wait 15-20 minutes before leaving the clinic so we can monitor for adverse effects. We also suggest avoiding driving to/from your appointment, in case you have any post injection soreness.
How many injections will I need?
Most people find one high volume injection effective. However, if you require more, we recommend waiting a month between procedures and making sure you continue with your prescribed exercise programme. This is to maximise the chances of a good recovery.
What are the risks and side effects?
All injections carry risks, but they can be reduced by good clinical practice and standards of cleanliness. All of our injecting clinicians are fully qualified and well experienced.
Risk and side effects are rare but include:
- Post injection flare: A minority of people find a temporary increase in pain for 24-48 hours post injection. This is entirely normal and can be helped with paracetamol, rest and ice. We also suggest avoiding driving to/from your appointment, in case you have any post injection soreness.
- Skin depigmentation: Steroid injections can occasionally cause change to the colour of the skin, especially if the site of injection is close to the surface. Changes are often temporary but can be permanent.
- Local fat atropy: It is not common, but sometimes a steroid injection can induce a small loss of fatty tissue in the skin around the area of injection. This can lead to a small indentation in the skin. This is a rare occurrence.
- Infection: Due to the nature of the needle breaking the skin, there is a very small; chance of infection (1:50, 000). All our injections are done using sterile equipment, with the upmost attention paid to maintaining high standards of cleanliness and safety. If the injected area becomes hot/swollen/painful, you should seek urgent medical attention.
- People with diabetes are advised to monitor their blood sugars closer than usual for one to two weeks post injection. This is because steroid medication can occasionally (and temporarily) cause blood sugars to fluctuate. This is why it is important to discuss your diabetes with your clinician, and also let your GP know that you intend to have a steroid injection. For type 1 diabetes, if your HbA1C is above 8%, you will need to speak to your GP first to confirm it is safe to have the injection.
- Facial flushing: Some people find their face feels warm and flushed for a few hours post injection. You will not feel ill, and this side effect will usually wear off in the same day.
- Menstruation: there is some research to indicate a possible temporary change in menstruation, or some blood spotting, post injection. Given the relative low doses of the steroids that we use, this is unlikely, but worth knowing,
- Tendon rupture: if your injection has been near the tendon, you are advised to avoid heavy lifting/loading for two weeks, to reduce the risk of tendon rupture.
- Joint changes: multiple steroid injections into a joint such as a knee can cause damage to the internal structures. This is why alternatives may be offered if you are requiring frequent steroid injections.
Potential side effects of local anaesthetic (Rare):
Please tell the clinician if you have never had Local anaesthetic before.
- Light headedness/dizziness/fainting/drowsiness
- Blurred/double vision
- Lowering of the heart/breathing rate
Side effects specific to high volume injection:
- Post injection pain due to the physical stretching of the joint connective tissues.
- Some degree of separation of the joint capsule tissues. You may not notice this directly, but you may find your range of motion improves quickly.
What If I have another medical diagnosis or take other medications?
Hydrodistention injections are safe procedures, and do not usually interfere with other medical complaints or interact with most medications.
However due to the nature of the steroid, if you have any of the following we may need to discuss the intended procedure with your GP or specialist.
- Uncontrolled high blood pressure
- If you are taking blood thinning/anti coagulant medication such as warfarin
If you are taking medication to thin your blood, you may be asked to take a blood test via your GP, in order to ensure it is safe to have the high volume injection.
Unfortunately, this injection is not appropriate if you are pregnant, as the effects on the foetus are not fully known. If you are breast feeding, please visit this link for further information to clarify how steroid injections are safe when breastfeeding or discuss this with your clinician.