Medically reviewed by Dr James Thing, MBBS, BSc, MRCGP, FFSEM — Sport and Exercise Medicine Consultant
Hydrodilatation (also called hydrodistension or high volume injection) is an ultrasound-guided injection procedure used to treat frozen shoulder (adhesive capsulitis). A sterile mixture of saline, local anaesthetic and corticosteroid is injected into the shoulder joint capsule under direct ultrasound vision. The volume of fluid gently stretches the tight, thickened capsule that causes the pain and stiffness of frozen shoulder, while the steroid settles the underlying inflammation.
In frozen shoulder, the capsule surrounding the ball-and-socket joint becomes inflamed, thickened and contracted. Hydrodilatation addresses both problems at once: the injected volume mechanically expands the contracted capsule to restore range of movement, and the corticosteroid reduces the capsular inflammation that drives night pain. Because the injection is performed under ultrasound guidance, the needle position within the joint is confirmed throughout, which maximises accuracy and comfort.
Hydrodilatation is most effective for frozen shoulder in the painful and early stiff phases. It may be recommended if night pain is disturbing your sleep, movement is significantly restricted, or a previous steroid injection alone has given only partial relief. Left untreated, frozen shoulder can take one to three years to resolve; clinical studies suggest hydrodilatation can shorten this course considerably, with many patients regaining comfort and movement within weeks of the procedure.
The appointment takes around 30 minutes. Your consultant first scans the shoulder to confirm the diagnosis and plan the safest needle path. The skin is cleaned and numbed with local anaesthetic. Under continuous ultrasound guidance, a fine needle is placed into the joint and the saline/anaesthetic/steroid mixture is injected slowly — you may feel a sensation of pressure or fullness as the capsule stretches. The needle is then removed and a small dressing applied. You can walk out of the clinic and go home straight away.
Your shoulder may feel full or achy for 24–48 hours; simple painkillers and an ice pack are usually sufficient. We advise avoiding heavy lifting for 48 hours. Gentle range-of-movement exercises — and physiotherapy where recommended — should begin within a few days of the procedure, as this is when the capsule is most amenable to stretching. Most patients notice meaningful improvement in pain within one to two weeks, with range of movement continuing to improve over the following weeks.
Hydrodilatation is a safe, well-established procedure. Common, short-lived effects include post-injection soreness and a temporary flare of pain. Uncommon effects include facial flushing and, in people with diabetes, a temporary rise in blood sugar. Serious complications such as infection are rare (well under 1 in 10,000 for ultrasound-guided joint injections). Your consultant will discuss the risks and answer any questions before you decide to proceed.
Hydrodilatation costs £650 (or £750 for two sites). An initial consultation including diagnostic ultrasound is £405 — see our full fee guide.
Joint Care London provides this treatment at our clinics in Notting Hill (The Portobello Clinic, 12 Raddington Road, W10) and Golders Green (The Brook Surgery, NW11), with appointments usually available within a week. Call 0333 011 1885 or book a consultation.
At Joint Care London, hydrodilatation for a frozen shoulder costs £650 for one site. An initial consultation with diagnostic ultrasound (£405) is needed first to confirm the diagnosis. Please see our Prices page for full details.
Hydrodilatation, also called a high-volume injection, treats frozen shoulder by injecting sterile fluid together with steroid under ultrasound guidance. This gently stretches and releases the tight shoulder capsule, easing pain and helping to restore movement.
Hydrodilatation is available on the NHS in some areas, but waiting lists are long. At Joint Care London it is offered privately, usually within 0–1 weeks, at our Notting Hill and Golders Green clinics.
The skin and joint are numbed with local anaesthetic first. Most patients describe a feeling of pressure or stretching rather than sharp pain as the fluid is introduced. Any post-procedure ache typically settles within a day or two.
Pain relief from the steroid usually begins within a few days. Improvement in stiffness is often noticeable within one to two weeks and continues to build, particularly when combined with stretching exercises or physiotherapy.
Most patients need only one procedure. If symptoms improve but plateau, a second injection can be considered after review with your consultant.
Both are effective treatments. Research suggests hydrodilatation may restore movement faster than steroid injection alone, because it combines the anti-inflammatory effect of the steroid with a mechanical stretch of the tight capsule. Your consultant will advise which option suits the stage of your frozen shoulder.
