Shoulder Embolization vs. Surgery: MUA and Capsular Release Compared

When frozen shoulder does not improve after months of therapy and injections, the next step has traditionally been a surgical option: manipulation under anesthesia, arthroscopic capsular release, or both. Shoulder embolization is a newer, non-surgical alternative that works in a different way. This article compares the three so you can have an informed conversation with your doctors. The right choice depends on whether pain or stiffness is your bigger problem, your health, and how much evidence you want behind a treatment.

How each option works

Manipulation under anesthesia (MUA)

While you are under general anesthesia, the surgeon moves your arm firmly through its range of motion to stretch and tear the tight joint capsule. In the large UK FROST trial, MUA was combined with a steroid injection and followed by physical therapy.

Arthroscopic capsular release

Also done under general anesthesia, this keyhole surgery uses small instruments through tiny incisions to cut the thickened, contracted capsule. It is often followed by manipulation and then physical therapy.

Shoulder embolization

A thin catheter is passed from an artery, usually at the wrist, to the small vessels around the shoulder. An embolic agent reduces blood flow in abnormal vessels linked to inflammation. Nothing is cut or stretched in the shoulder itself. Published studies describe it being done under local anesthesia, sometimes with light sedation. The goal is to calm pain and inflammation so that motion can return, usually with therapy.

Side-by-side comparison

What the surgical evidence shows

The UK FROST trial, published in The Lancet in 2020, is the most important study of frozen shoulder surgery. It randomly assigned 503 adults at 35 hospitals to MUA, arthroscopic capsular release, or early structured physiotherapy combined with a steroid injection. At 12 months, average Oxford Shoulder Scores (0 to 48, higher is better) were 38.3 after MUA, 40.3 after capsular release, and 37.2 after physiotherapy. None of the differences reached the size the researchers had defined as clinically meaningful. There were 8 serious adverse events after capsular release and 2 after MUA. MUA was the most cost-effective option.

It is also worth knowing that frozen shoulder often improves with time. The American Academy of Orthopaedic Surgeons notes that it generally gets better without surgery, although recovery may take up to 3 years. That background matters when weighing any procedure.

The takeaway: surgery works, but in this trial it did not clearly outperform a well-structured non-surgical program, and capsular release carried more risk.

What the embolization evidence shows

Shoulder embolization has not been tested in a randomized trial against surgery. The closest evidence:

• A direct comparison. A 2026 retrospective study from Taiwan compared 21 patients treated with embolization with 19 who had arthroscopic capsular release. Both groups improved significantly in pain, motion, and function. At 3 months, the embolization group had lower pain (2.6 versus 4.7 out of 10) and more patients reached clinically meaningful improvement. By 6 months, there was no significant difference in any outcome. Because patients were not randomly assigned, the results could reflect differences between the groups.
• A cost-effectiveness model. A 2026 analysis combined results from separate studies of each treatment. When success meant having only mild pain at 3 months, estimated success was 73.3% for embolization, 61.4% for capsular release, and 55.5% for MUA. But when success meant recovering range of motion, MUA and capsular release produced more benefit at lower cost. The authors concluded embolization may be a cost-effective option for pain-predominant frozen shoulder, while MUA and capsular release may be preferred when stiffness is the main problem. Several authors reported consulting relationships with device companies.
• Single-arm studies. A 2026 meta-analysis of 12 studies with 329 shoulders found large average improvements and no severe complications, but called for randomized trials.

For the details of each study, see shoulder embolization research and success rates.

This article is part of our Embolization Guide.

Pain-predominant or stiffness-predominant?

This may be the single most useful question when choosing.

• If pain, especially night pain, is your main problem and you have some motion left, embolization's target, inflammation, lines up with your symptoms. Studies have reported early relief of night pain.
• If your shoulder is mechanically locked but no longer very painful, procedures that physically release the capsule are designed for that problem.
• If you have both, your doctors may discuss doing things in sequence, for example treating pain first so therapy becomes possible.

Recovery and risk differences

MUA and capsular release require general anesthesia and a recovery period from surgery, followed by physical therapy. Embolization avoids general anesthesia and incisions in the shoulder. Its common side effects in studies were mild and temporary, such as a few days of shoulder ache, skin color changes over the shoulder, and wrist bruising. Rare serious events, such as a reported case of temporary vision loss, have been described. Every option has risks, and the FROST trial is a reminder that surgery does too. Our article on shoulder embolization risks covers this in detail.

Who should consider surgery first

• People with a significant rotator cuff tear or another structural problem that needs repair
• People whose main problem is stiffness rather than pain
• People with artery disease in the arm, severe contrast allergy, or kidney problems that make embolization less safe
• People who prefer a treatment backed by large randomized trials

Before either route, many patients will also be offered a steroid injection or hydrodilatation, which are compared in shoulder embolization versus cortisone injections.

Questions to ask both doctors

• Is my main problem pain, stiffness, or both, based on my exam?
• What did my imaging show about the rotator cuff and the joint surface?
• If I choose surgery, how long will I need physical therapy, and when can I expect to sleep through the night?
• If I choose embolization and it only partly helps, what would the next step be, and how long should I wait?
• How does my diabetes or other health condition change the risks of each option?
• What does each option involve in time off work?
• Which option is my insurance likely to cover, and what would I owe?

Hearing both specialists answer the same questions makes the trade-offs much clearer.

Making the decision

Ideally, decisions like this involve both a shoulder specialist and the physician who would perform the embolization. Bring your imaging, a list of everything you have tried, and a clear sense of what matters most to you, whether that is sleep, return to work, or getting your full reach back. Learn more on our shoulder embolization page or in the embolization guide.

Frequently Asked Questions

Is shoulder embolization an alternative to frozen shoulder surgery?

It is a non-surgical option for some patients whose frozen shoulder has not improved with conservative care, particularly when pain is the main problem. It has not been tested against surgery in a randomized trial.

Which works faster, embolization or capsular release?

In one small 2026 retrospective study, embolization patients had less pain at 3 months, but the two groups were similar by 6 months. More rigorous trials are needed.

Can I still have surgery if embolization does not work?

Yes. Embolization does not remove the option of MUA or arthroscopic capsular release later. Discuss timing with your surgeon.

Is manipulation under anesthesia risky?

In the 503-patient UK FROST trial, 2 serious adverse events were reported after MUA and 8 after capsular release. Your surgeon can explain the specific risks for you.

Keep Reading

• Shoulder Embolization in Manhattan
• Frozen Shoulder: Causes, Symptoms, and Stages Explained
• Frozen Shoulder Embolization: Am I a Candidate?
• How Long Does Shoulder Embolization Last?
• Is Shoulder Embolization Covered by Insurance?
• Is Shoulder Embolization Painful? What to Expect Before, During, and After
• Embolization Guide: knee, heel, shoulder, elbow and hip

Sources

1. Rangan et al., Lancet, 2020 — UK FROST randomized trial: MUA vs capsular release vs early physiotherapy (503 patients)
2. Wang et al., J Shoulder Elbow Surg, 2026 — arthroscopic capsular release vs embolization for adhesive capsulitis (40 patients)
3. Khabaz et al., Cardiovasc Intervent Radiol, 2026 — cost-effectiveness of embolization vs MUA vs capsular release
4. Allaw et al., J Vasc Interv Radiol, 2026 — systematic review and meta-analysis of embolization for adhesive capsulitis (12 studies, 329 shoulders)
5. Liang et al., Korean J Radiol, 2025 — clinical and MRI outcomes of embolization for adhesive capsulitis (25 patients)
6. Liang et al., J Vasc Interv Radiol, 2024 — transient cortical blindness after shoulder embolization (case report)
7. American Academy of Orthopaedic Surgeons, OrthoInfo — Frozen Shoulder

Medically reviewed by David Fox, MD, FACS, RPVI. This article is general information, not a substitute for a medical evaluation.

Living with joint or tendon pain that hasn’t improved? Schedule a consultation with Dr. David Fox at Fox Vein & Vascular in Manhattan to find out whether embolization is right for you. Call (212) 362-3470 or request an appointment online.