In people with frozen shoulder, steroid injections reduce pain and improve shoulder mobility for up to 6 months

Sun Y, Zhang P, Liu S, et al. Intra-articular Steroid Injection for Frozen Shoulder: A Systematic Review and Meta-analysis of Randomized Controlled Trials With Trial Sequential Analysis. Am J Sports Med. 2017;45:2171-9.

Review question

In people with frozen shoulder (adhesive capsulitis), do steroid injections into the joint reduce pain or improve functioning?

Background

Frozen shoulder is common and is caused by thickening of the connective tissue around the shoulder joint. It causes pain and stiffness in the joint and limits shoulder movement. It develops slowly and has 3 stages. In the initial freezing stage, moving your shoulder will be painful and you won’t be able to move it as far as before. In the frozen stage, you may have less pain but more stiffness and difficulty moving your shoulder. In the final thawing stage, your shoulder movement improves. Frozen shoulder generally resolves within 3 years.

Treatment for frozen shoulder includes steroid injections into the shoulder joint, drugs to relieve pain or reduce inflammation, physical therapy including range-of-motion exercises, and shoulder manipulation. Surgery is rarely done for frozen shoulder. This review assessed how well steroid injections work.

How the review was done

The researchers did a systematic review of studies available up to December 2015. They found 8 randomized controlled trials with 416 people.

The key features of the studies were:

• people had a painful frozen shoulder and most had pain for at least 1 month;
• treatment was steroids (triamcinolone, hydrocortisone, or methylprednisolone), 20 to 40 mg, injected into the shoulder joint;
• some people also received pain-relieving drugs, and everyone was given exercises for stretching and to improve shoulder mobility;
• steroid injections were compared with placebo (sham injection) or no injection; and
• people were followed for up to 6 months after the injection.

What the researchers found

Compared with placebo or no injections, steroid injections:

• reduced pain for 3 to 6 months; and
• improved most shoulder mobility measures and pain and function scores for up to 6 months.

There wasn’t much information reported about the adverse effects of steroid injections.

Conclusion

In people with frozen shoulder, steroid injections into the shoulder joint reduce pain and improve mobility for up to 6 months.

Steroid injections vs control (placebo or no injection) in people with frozen shoulder*

*Only outcomes assessed in more than 1 trial are reported in the Table.

†Shoulder movement includes lifting arms up and down in a forward direction (shoulder flexion) and at the sides (shoulder abduction) and external rotation of shoulders.