Inclusion Criteria:  Patient with "frozen shoulder", defined as painful shoulder accompanied with a greater or lesser degree of restriction of mobility, especially in passive external rotation of at least 3 months of evolution. The diagnosis, according to the usual protocol of the unit, should include radiological images that rule out degenerative or necrotic pathology and the performance of an ultrasound or MRI to rule out associated pathology of the rotator cuff, which are already obtained in the usual clinical follow-up. Failure of conservative treatment after a period of 3 months. Acceptance and signature of informed consent.  Exclusion Criteria:  Known allergies to corticosteroids Patients with frozen shoulder secondary to previous shoulder surgery. High-risk patients in need of anticoagulant treatments. Patients with previous shoulder fracture. History of joint infection. Active neoplastic process. Associated rheumatic pathology.