Hydrodilatation for frozen shoulder (also called hydrodistension) stretches the tight joint capsule by filling it with fluid, usually saline with a steroid and local anesthetic. Most people go home the same day. The shoulder is often sore for 1 to 3 days. The first 2 to 6 weeks of regular movement matter most, because that is when range gained from the procedure is either kept or lost. Improvement usually builds over several weeks to a few months.
Hydrodilatation is usually offered when frozen shoulder (adhesive capsulitis) pain and stiffness are limiting sleep and daily tasks and have not eased enough with exercise, pain relief or a steroid shot. It does not shorten the condition on its own. It is meant to make the exercises possible.
Key takeaways
- What it does: a volume of fluid is injected into the shoulder joint to stretch the thickened, tight capsule.
- Same-day procedure: it is usually done under ultrasound or X-ray guidance with local anesthetic.
- Soreness: an ache or a feeling of fullness for 1 to 3 days is common.
- Movement starts early: most protocols start gentle range-of-motion exercises the same day or the next day.
- Timeline: gains usually build over 6 to 12 weeks, and the overall course of frozen shoulder can still run for many months.
What the procedure is and why it is used
In frozen shoulder, the capsule around the ball-and-socket joint becomes inflamed, thickened and tight. The joint holds less fluid than a normal shoulder, and turning the arm outward or reaching behind your back becomes hard.
During hydrodilatation, a doctor guides a needle into the joint and injects fluid until the capsule stretches. The volume varies by clinic, often somewhere around 20 to 40 mL. Some people feel pressure or a deep ache as the capsule fills. Many clinics add a corticosteroid to calm inflammation, plus a local anesthetic so the shoulder can move more freely in the first hours.
Research suggests hydrodilatation can reduce pain and improve movement in the short to medium term, especially when it is followed by an exercise program. Results vary between people and between studies.
Day by day: the first week
- Day 0: the shoulder may feel numb and move more easily than it has in months. Many protocols ask you to do gentle movements that afternoon, while the anesthetic is still working, to use the new range.
- Days 1 to 3: an ache, fullness or a short flare of pain is common as the anesthetic wears off. Keep doing the gentle exercises several times a day, within a tolerable ache. A cold pack for 10 to 15 minutes can help.
- Days 3 to 7: soreness usually eases. Most people start or continue physical therapy within the first week. Daily movement is the main task.
- If you have diabetes: when a steroid is included, blood sugar often runs higher for about 3 to 5 days. Check more often during that time.
Weeks 2 to 6: why the first weeks of movement matter
A stretched capsule can tighten again if it is not moved through its new range. That is why most protocols ask for short, frequent sessions, often 3 to 5 times a day, over the first several weeks.
- Weeks 1 to 2: gentle assisted movements: lifting the arm forward with the other hand helping, turning the forearm outward with the elbow at your side, sliding the hand up your back. Aim for a stretch you can feel without sharp pain.
- Weeks 2 to 6: range usually keeps improving with daily work. Light strengthening for the rotator cuff and shoulder blade muscles is often added as pain allows.
- Weeks 6 to 12: the steroid effect, if one was used, often fades. Range already gained tends to hold better if the movements continue.
The procedure opens the door. Daily movement in the weeks after keeps it open.
How long the effect usually lasts
Pain relief from the steroid part, if one is used, typically lasts weeks to a few months. Range gained from stretching the capsule can last longer if you keep moving the shoulder. Frozen shoulder itself often takes one to three years to run its full course. Hydrodilatation is a step within that course, not the end of it.
How many procedures are usually considered
Many people have one. Some are offered a second, usually several weeks to a few months later, if the first gave a partial result. If two procedures and a steady exercise program have not helped enough, the options often discussed next are manipulation under anesthesia or a keyhole capsular release.
Is this normal?
- The shoulder felt loose on day 0, then stiff again on day 2: common. The anesthetic hides stiffness and pain for a few hours. Keep up the daily movement.
- A feeling of fullness or swelling: the injected fluid is absorbed over a day or two.
- Night pain still there in week 1: night pain often lags behind daytime improvement and eases over several weeks.
- Gains that feel small: many people gain a modest amount of range rather than a full return. Small gains held over weeks still count.
Call your local emergency number or go to the emergency department if
- Signs of a serious allergic reaction: swelling of the face, lips or throat, or trouble breathing.
- Chest symptoms: chest pain or pressure, breathlessness or sweating along with shoulder or arm pain, especially on the left.
See a doctor today if
- Signs of infection: the shoulder becomes hot, red and swollen, or pain keeps climbing after day 3 instead of easing.
- Fever: 100.4°F (38°C) or higher, or chills, in the days after the procedure.
- Severe new pain: pain far worse than before the procedure that pain relief does not settle.
- Blood sugar out of range: if you have diabetes and readings stay above your target for more than a few days, or you feel very thirsty or unwell.
Get it checked soon if
- Range slipping back: movement gained in week 1 is lost by week 3 despite daily exercise.
- New weakness: trouble lifting the arm that was not there before.
- Numbness or tingling down the arm: symptoms past the elbow may come from the neck.
More on this area: injections for neck and shoulder pain.
Hydrodilatation gives the capsule room. The weeks of movement after it decide how much of that room you keep.
Written by Louise Yow, Neck & Shoulder Physio.