What is it I here you ask!
Its fundamentally a treatment for persistent contracted frozen shoulders. Also known as Arthrographic Distension it was first reported back in 1965 but has been generally poorly researched. It’s basically an injection of a local anaesthetic, cortisone and saline (enough to try and stretch the joint capsule) into the shoulder joint with a contrast, which allows the procedure to show up on an imaging device. The injected fluid can be seen to expand the joint which is thought to disrupt adhesions of the shoulder capsule or even burst it.
How does this improve your pain and movement?
It is proposed that its benefits are derived from a combination of the anti‐inflammatory effect of cortisone with the mechanical effect of joint distension, thereby reducing the stretch on pain receptors in the glenohumeral joint capsule and its attachements.
The great thing about this procedure is it takes 15-20 minutes to perform and is very little risk.
Whats the evidence for this procedure.
Leonard Funk (consultant physiotherapist) reports the following outcomes from one of his studies:
- 75% patients report a good or excellent overall response and 95% report reduced pain scores and improved movement.
- 100% reduced medication use and15% have the injection repeated depending on the symptoms
Most of the research is of a poor standard with small sample size, poor methodology and significant heterogeneity.
Cochrane Review 2008 included 5 RCTs and concluded that…
- Hydrodilatation does no harm
- At best it reduces disability over the short term and might improve pain levels
- However, lower quality evidence does provide support for this technique
Initial conservative treatment is definitely recommended prior to such an injection. This includes physiotherapy (exercises and manual therapy) analgesia and a steroid injection (if pain is significant). If your symptoms of pain and stiffness persist then a hydrodistention injection might be an option for you to consider.