What is hydrodilatation for frozen shoulder?

Hydrodilatation (capsular distension) is an ultrasound-guided injection that uses fluid to stretch and expand the tight joint capsule of a frozen shoulder, relieving pain and stiffness — especially when paired with physical therapy.

How do I prepare for capsular distension (hydrodilatation)?

Hold NSAIDs/blood thinners only if advised, and plan to begin or continue physical therapy afterward — the injection works best paired with therapy. The procedure is done in the office under ultrasound guidance.

What should I do after capsular distension?

Expect rapid relief of pain and improved motion, though some temporary soreness or fullness is normal as the fluid is absorbed. Start gentle range-of-motion exercises and physical therapy promptly to take advantage of the improved mobility. Dr. Gruner outlines your therapy plan.

Capsular Distension (Hydrodilatation) for Frozen Shoulder

The short answer

Capsular distension — also called hydrodilatation — is an ultrasound-guided injection of saline, anesthetic, and steroid that expands (stretches) the thickened, tight capsule of a frozen shoulder. It can provide rapid relief of pain and stiffness, and works best combined with physical therapy to restore range of motion.

Medically reviewed by Marc Gruner, DO, MBA, RMSK
Sports medicine physician, Mayo Clinic fellowship. Last reviewed June 2026

Treating Frozen Shoulder with Capsular Distension — Dr. Marc Gruner

How it works

In frozen shoulder (adhesive capsulitis), the capsule surrounding the joint thickens and contracts, sharply restricting movement. Capsular distension uses an ultrasound-guided injection of fluid — saline plus anesthetic and steroid — to physically expand and stretch the capsule from the inside, breaking up the restriction.

The procedure is performed in the office and can provide rapid relief of pain and improved motion. Dr. Gruner pairs it with a physical therapy program to restore range of motion during the recovery window.

Why patients choose it

Ultrasound-guided for precise capsule targeting
Can provide rapid pain relief and improved motion
Office-based, non-surgical
Most effective combined with physical therapy

What to expect at your visit

1.
A focused conversation
Dr. Gruner reviews your history, prior imaging, and goals — what you want to get back to doing.
2.
Point-of-care ultrasound
When useful, a diagnostic musculoskeletal ultrasound evaluates the injury in real time, with no radiation.
3.
A clear, individualized plan
You leave understanding the diagnosis, the non-surgical options, and the expected timeline — in plain language.

Before and after your procedure

How do I prepare for capsular distension (hydrodilatation)?: Hold NSAIDs/blood thinners only if advised, and plan to begin or continue physical therapy afterward — the injection works best paired with therapy. The procedure is done in the office under ultrasound guidance.
What should I do after capsular distension?: Expect rapid relief of pain and improved motion, though some temporary soreness or fullness is normal as the fluid is absorbed. Start gentle range-of-motion exercises and physical therapy promptly to take advantage of the improved mobility. Dr. Gruner outlines your therapy plan.

Frequently asked questions

What is hydrodilatation for frozen shoulder?: Hydrodilatation (capsular distension) is an ultrasound-guided injection that uses fluid to stretch and expand the tight joint capsule of a frozen shoulder, relieving pain and stiffness — especially when paired with physical therapy.