Procedure protocol
SECONDARY
The subacromial corticosteroid injection was performed using a posterior approach without ultrasound guidance. The affected shoulder was prepared with a Betadine solution. In the case of high-volume corticosteroid injection, a 10 ml syringe was filled with 40 mg triamcinolone acetonide 1 ml and 1% lidocaine hydrochloride without epinephrine 9 ml, and a very-low volume corticosteroid injection, a 1 ml insulin syringe was filled with 40 mg triamcinolone acetonide 1 ml without 1% lidocaine hydrochloride. A 23-gauge needle was used for injection. The bony prominence of the posterolateral corner acromion was palpated. The injection point was 2 cm, both inferiorly, and medially to the posterolateral corner acromion by posterior approach. The needle was introduced directly into the subacromial space, and angled at about 45 degrees, following acromion tilted (Fig. Landmark of the posterior approach of subacromial corticosteroid injection with demonstrated a posterior injection point.The primary outcome was WORC at pre-injection, and 1, 3 and 6 months. The patient was informed of the WORC information recorded. The follow-up period secondary outcomes recorded included: VAS at pre-injection, 15 min post-injection, 2 weeks, and at 1, 3 and 6 months; DASH at 1, 3 and at 6 months, and ROM with forward elevation and external rotation of the arm at the side, at pre-injection, at 2 weeks and 1, 3, and at 6 months.