Eligible for inclusion were randomised and non-randomised controlled trials that compared ultrasound-guided versus landmark-guided corticosteroid injections to the shoulder in adults.
The primary outcome of interest was pain, measured by a visual analogue scale at six weeks after the intervention. Secondary outcome measures included the Oxford Shoulder Score, the Shoulder Function Assessment questionnaire, the Constant score, and shoulder range of movement (flexion, abduction, internal and external rotation, and night pain at one and six weeks after the intervention).
The included steroid drugs were triamcinolone, betamethasone, and depo-medrone (dosages varied). Some studies also included a local anaesthetic agent. The frequency of ultrasound transducer probes ranged from 4 to 10MHz and 6 to 18MHz (where reported). There were more women than men. All patients suffered from shoulder pain from various underlying pathologies (patient characteristics were reported in the paper).
Two reviewers independently selected the studies for inclusion.