This is a randomized controlled trial in which patients with moderate to severe shoulder pain (Visual Analog Scale (VAS) > 40), in the setting of rotator cuff tendinopathy refractory to conservative treatment, will be enrolled.

The primary aim of the study is to estimate the effect of transcatheter arterial embolization (TAE) with physical therapy (PT) vs PT alone on the change in shoulder pain at 12-month follow up. Scientific objectives also include an assessment of safety of the intervention, assessment of changes in Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity score, Shoulder Pain and Disability Index (SPADI) scores, MRI Tendinopathy Score between the TAE + PT and PT groups.

This is a single center prospective randomized controlled study at Brigham & Women's Hospital (BWH), a teaching hospital of Harvard Medical School. Patients with clinical and MRI findings of shoulder tendinopathy, moderate to severe shoulder pain (VAS > 40), and pain refractory to at least 6 months of physician directed conservative therapy will be eligible for enrollment.At screening patient will undergo a shoulder MRI to evaluate for tendinopathy, and patients with complete full thickness tendon tears will be excluded.

Patients will be randomized to either the TAE +PT or PT group. Patients in the TAE + PT group will undergo angiography to evaluate branch shoulder arteries for hyperemia. If hyperemia is present, then embolization will be performed. This treatment will be followed by 3 months of structured PT. Patients in the PT group will undergo 3-months of structured physical therapy with isolated eccentric exercises.

Inclusion Criteria:

1. Male, female, transgender female, transgender male, non-binary
2. Moderate to severe shoulder pain (VAS > 40)
3. Pain refractory to at least 6 months of physician-directed conservative therapy (analgesics or injections or PT), including a minimum of 6 weeks of PT
4. Willing, able, and mentally competent to provide informed consent and to tolerate angiography and physical therapy

Exclusion Criteria:

1. History of peripheral arterial disease or peripheral artery disease symptoms including claudication, diminished or absent upper/lower extremity pulses, or known upper extremity arterial atherosclerosis or occlusion that would limit selective angiography
2. Known history of anaphylaxis to iodinated contrast agents or gadolinium based contrast
3. Acute kidney injury
4. Allergy to poppy seeds or lipiodol
5. Renal dysfunction as defined by serum creatinine >1.6 dl/mg or eGFR <60 obtained within 30 days of procedure.
6. Uncorrectable coagulopathy (platelet count < 50,000, international normalized ratio >1.8 within 30 days of procedure
7. Active systemic or local upper extremity infection
8. Patient pregnant, intending to become pregnant during the study.
9. Prior shoulder replacement surgery
10. Prior rotator cuff repair surgery
11. Previous history of complete full-thickness tear of the rotator cuff
12. Presence of non-MRI compatible devices (e.g., non-compatible cardiac pacemaker).