The document discusses hydrodistension (hd) as a treatment for primary frozen shoulder, indicating it is effective in improving functional outcomes over the medium term, with a minimal adverse effect profile. A retrospective review of cases from 2010 to 2015 found significant improvements in patient-reported and objective outcomes after the procedure, with high rates of return to previous activities. The study supports hd as a first-line outpatient treatment for painful frozen shoulder, regardless of patient demographics or previous interventions.