What is shoulder hydrodistension?
Hydrodistension is a special procedure used to treat frozen shoulder/adhesive capsulitis. It can be considered if simple treatments (like physiotherapy and anti-inflammatory tablets) are ineffective. It involves injecting a high volume of sterile (clean) water (approx. 20-30 mls) with steroids and numbing medications inside the shoulder joint. This aims to distend the inflamed and thickened joint capsule and reduce the inflammation via the steroid effect. Hydrodistension needs to be done under imaging guidance (either ultrasound or x-ray). Evidence is encouraging, and currently, hydrodistension is an established treatment for managing a frozen shoulder. It is important to follow the shoulder hydrodistension procedure by a specialist physiotherapy program to enhance the procedure results.
What is a Frozen shoulder?
Frozen shoulder (or adhesive capsulitis) is a condition where there is generalised inflammation of the shoulder joint capsule (the soft tissues that surround the shoulder joint). It can happen secondary to various causes, including trauma and surgery, and it is also more common in people with diabetes, but sometimes no obvious cause is found. It is more common in people over 40 years of age. To find out more, please read our article about Frozen shoulders.
What are the symptoms of a Frozen shoulder?
Patients usually experience severe pain and a significant reduction of shoulder movements, which can be limiting to simple daily activities.
The patient may also have shoulder pain at night that can disrupt sleep.
Usually, the symptoms improve without treatment, but this can take a long time (up to 2 years).
What is the best type of scan to diagnose a Frozen shoulder?
A frozen shoulder is generally a clinical diagnosis. Imaging is mainly done to rule out other causes for shoulder pain like rotator cuff tear, shoulder osteoarthritis and shoulder calcification (calcific tendonitis). An X-ray will be normal in frozen. MRI can be helpful in the diagnosis as it can show some signs suggestive of frozen shoulder changes like capsular thickening and inflammation. Ultrasound and MRI can assess the presence of rotator cuff tear or subacromial bursitis. Overall, an X-ray will be useful to assess the shoulder joint when a frozen shoulder is suspected, followed by an ultrasound examination to rule out the presence of any rotator cuff tear.
What are the medicines used in shoulder hydrodistension?
Usually, the medicines injected into the shoulder during hydrodistension include a steroid, a numbing medicine (lidocaine) and salty water (sterile normal saline) to achieve good distension. The steroid used is usually Kenalog (triamcinolone acetonide) which is a potent and long-acting type of medicine. Please read our article about a steroid injection for the shoulder joint to find out more.
How is shoulder hydrodistension done?
Your doctor will speak to you on the day of the procedure. It involves injecting a high volume of sterile (clean) water with steroids and numbing medications inside the shoulder joint. If the procedure is done under ultrasound guidance, the injection is usually done from the back of the shoulder. Your doctor will tell you about the appropriate position, but it is usually done either sitting on the couch with your back towards the doctor or lying on your side (lying on the other shoulder). In both cases, your doctor will usually ask you to put your hand across your chest to increase the space at the back of the shoulder.
We always recommend performing shoulder injections under ultrasound guidance to ensure accurate placement of the needle into the shoulder joint at the site of inflammation. Ultrasound guidance results in more accurate, less painful and faster procedures, with better outcomes than injections without guidance.
Your doctor will clean the skin and prepare the area, and numbing medication can be administered to the skin using a small needle. Then, a needle will be inserted into the shoulder joint under imaging guidance, and the medication will be injected slowly into the shoulder joint. To read a step-by-step article about the procedure, please see How is shoulder hydrodistension done?
What to expect during/after shoulder hydrodistension?
You may feel a gradual build-up of pressure inside the shoulder. This is expected as shoulder hydrodistension involves injecting a high volume of water into the joint. Your doctor will keep checking on you during the procedure. Some patients may feel gentle pressure going down the arm and the hand. When the procedure is done, your shoulder might feel heavy and tight for a few days, although some patients report immediate improvement in their symptoms.
What will happen to the fluid/medicines injected into the shoulder during hydrodistension?
These will be slowly absorbed by the shoulder joint capsule. Sometimes, a small volume of the injected fluid may leak outside the joint capsule. This is also acceptable as evidence shows that the response from the procedure is similar in both cases.
How long does a shoulder hydrodistension procedure take?
The length of the procedure depends on the difficulty of the case and the doctor's experience. Usually, 30 minutes is a reasonable time for the whole procedure (including explanation to the patient and preparation).
What are the possible complications of shoulder hydrodistension?
The complications are very rare in general. In addition to the points mentioned above, there is a small risk of infection (less than 1 in 10.000), similar to any other steroid injection. Please see our FAQs for more information.
Can a shoulder hydrodistension procedure be repeated?
The answer is yes. We can consider repeating the procedure after a few months in the case of a severe frozen shoulder when the response from one procedure is inadequate. It is important to follow the shoulder hydrodistension procedure by a specialist physiotherapy program to enhance the procedure results.
Shoulder conditions and treatments