If your shoulder has been stiff for months and you have hit a wall with physio and rest, you are probably already researching the next step. Frozen shoulder, or adhesive capsulitis, is one of those conditions that sounds manageable until you are living with it.
Getting dressed hurts. Sleeping is frustrating. And the standard advice to “give it time” starts feeling less helpful the longer it drags on.
Hydrodilatation is the procedure that changes that equation. At Melbourne Radiology Clinic, we perform CT-guided hydrodilatation for frozen shoulder patients across Melbourne, and this guide walks through exactly how it works, what makes CT guidance different from the alternatives, and what you can expect before, during, and after the procedure.
What Is Frozen Shoulder, and Why Does It Happen?
Frozen shoulder is not simply a sore shoulder. It is a condition where the capsule surrounding your shoulder joint thickens, tightens, and fills with scar tissue, restricting movement and often causing significant pain. Clinically, it progresses through three stages:
Stage 1: Freezing
Pain increases, particularly at night. Range of motion begins to decline. This stage can last anywhere from 2 to 9 months.
Stage 2: Frozen
Pain may begin to ease slightly, however stiffness reaches its peak. Everyday activities like reaching overhead or behind your back become very difficult. This stage typically lasts 4 to 12 months.
Stage 3: Thawing
Mobility gradually returns. Full recovery without intervention can take up to 42 months from onset.
That final figure is worth sitting with. Without targeted treatment, some patients spend three and a half years waiting for their shoulder to resolve.
Who Gets Frozen Shoulder?
Frozen shoulder is more common than most people realise, affecting roughly 2 to 5% of the general population. Certain groups are at higher risk:
- People with Type 1 or Type 2 diabetes (frozen shoulder is approximately five times more common in diabetics due to capsular thickening linked to glycation of collagen fibres)
- People aged 40 to 60
- Women more than men
- Those who have had a recent shoulder injury or surgery
- People with thyroid conditions or cardiovascular disease
What Is Hydrodilatation?
Hydrodilatation (also called distension arthrography) is a procedure where a precise volume of fluid is injected directly into the shoulder joint capsule under image guidance. The fluid physically stretches the contracted capsule, breaking the adhesions that have formed and restoring joint volume.
The injection typically contains a combination of:
- Saline solution (the primary distension agent)
- Local anaesthetic (to reduce procedural discomfort and provide a short-term mobility window post-injection)
- Corticosteroid (to reduce inflammation within the capsule)
The goal is not simply pain relief. Cortisone alone can help with pain, however does not physically stretch the capsule. The “hydro” part of the word is the critical element: the saline distension is what physically opens the joint.
Hydrodilatation requires image guidance to confirm the needle is in the correct position within the joint, and it uses a substantially higher fluid volume (typically 20 to 40 ml) than a standard cortisone injection.
Paying the additional cost for a properly image-guided hydrodilatation is what actually produces the mechanical change in the joint.
The Procedure: What to Expect at Melbourne Radiology Clinic
Before Your Appointment
You will need a referral from your GP or specialist. When requesting the referral, it helps to ask your doctor to specifically note “adhesive capsulitis” and “frozen shoulder” on the referral form.
Most patients do not require any special preparation.
If you take blood-thinning medications, let us know in advance.
If you have diabetes, please inform your GP before the procedure, as the corticosteroid component of the injection can cause a temporary blood sugar elevation lasting 48 to 72 hours.
Wear comfortable, loose-fitting clothing that allows easy access to your shoulder.
During the Procedure
The procedure itself takes approximately 5-10 minutes.
You will lie on the CT table and the area around your shoulder will be cleaned and draped. A local anaesthetic is applied first to numb the skin and deeper tissue. We use a step-up approach to local anaesthetic delivery, which significantly reduces the discomfort associated with the initial capsule stretch.
Once the local anaesthetic has taken effect, the radiologist uses CT imaging to position the needle precisely within the joint capsule. Contrast dye is then introduced to confirm correct placement before the therapeutic injection is administered.
You may feel a sensation of pressure or stretching as the saline volume is delivered. This is normal and indicates the capsule is expanding. The intensity varies between patients. For most, it is manageable. For some, it is briefly uncomfortable. The local anaesthetic within the CT-guided injection begins providing relief shortly after.
You do not need to hear or feel a “pop” for the procedure to have worked. Controlled CT-guided distension is more predictable than the audible capsule rupture that older technique descriptions focused on.
After the Procedure
Post-procedure rehabilitation is one of the most important parts of the treatment process.
Most patients are able to go home shortly after the procedure. It is common to experience temporary heaviness, mild discomfort, or a sensation of pressure in the shoulder once the local anaesthetic begins to wear off. Some patients notice an immediate improvement in movement, while for others, mobility improves more gradually over the following days and weeks.
You should avoid heavy lifting or strenuous shoulder activity for the rest of the day, but gentle movement is encouraged. The shoulder capsule has just been expanded, and maintaining that new range of motion through guided stretching and physiotherapy is an important part of the recovery process.
The corticosteroid component of the injection may take several days to reach its full anti-inflammatory effect. Mild soreness for 24 to 48 hours is normal, however severe pain, significant swelling, fever, or redness around the injection site should be reviewed promptly.
How to Get a Referral for Hydrodilatation at Melbourne Radiology Clinic
You will need a GP or specialist referral to book your procedure. When you see your GP, it helps to mention the following:
- Your diagnosis (or suspected diagnosis) of adhesive capsulitis or frozen shoulder
- The duration of your symptoms and which treatments you have already tried
- Any relevant medical history (diabetes, thyroid conditions, prior shoulder injury or surgery)
- A request for a referral for “CT-guided hydrodilatation”
Frequently Asked Questions
- How long does the procedure take?
The procedure itself takes 5 to 10 minutes. Allow approximately 20 to 30 minutes in total for preparation, the procedure, and a brief recovery period before you leave.
- Is it painful?
The local anaesthetic significantly reduces discomfort. Most patients describe a sensation of pressure during the injection rather than sharp pain. Our step-wise anaesthetic protocol further reduces the intensity of the initial stretch sensation.
- How many injections will I need?
Many patients experience meaningful improvement after a single injection. In more severe or long-standing cases, a second injection may be recommended, particularly if the first injection primarily addressed pain but range of motion gains were limited. Your radiologist will advise you based on your individual presentation.
- When can I drive home?
You should not drive immediately after the procedure. Arrange for someone to collect you, or allow time before driving if you are relying on public transport. The local anaesthetic temporarily affects shoulder and arm function.
- Can I have hydrodilatation if I have diabetes?
Yes. The procedure is well suited for diabetic patients, though it requires coordination with your GP regarding glucose monitoring in the 48 to 72 hours following the injection due to the corticosteroid component. Inform your GP before your appointment.
- Is hydrodilatation covered by Medicare?
Yes. A gap fee applies in private clinic settings.
Book a Consultation at Melbourne Radiology Clinic
If you have a GP referral or are ready to discuss whether CT-guided hydrodilatation is appropriate for your situation, contact Melbourne Radiology Clinic to book your appointment. Our team can also provide a GP referral guide if you need support with the referral wording.
Frozen shoulder does not resolve faster by waiting. The sooner the capsule is addressed, the more of that mobility window you have available to work with.
