The shoulder joint is made up of a ball and a socket for ball to rest in. Because the socket is shallow compared to the large ball, there is an elastic capsule that goes around the joint with additional ligaments attaching to this to keep the shoulder in place.
The shoulder joint has a lot of movement and therefore the capsule needs to be elastic and stretch when the arm is lifted up high. When the arm is be its side, the excess capsule forms folds at the bottom of the shoulder.
A Frozen shoulder, also known as Adhesive Capsulitis, typically starts without an obvious cause or with only a mild injury. It is often very painful and hurts even at rest. One of the key features is a limited range of movement of the shoulder as the capsule becomes inflamed and less elastic and the folds stick together
The 3 stages
At first the shoulder becomes progressively more painful. The pain is quite diffuse and spreads across the shoulder and down the upper arm. Sleep is often disturbed.
With time the shoulder starts to become less mobile. At this stage it is often the pain that limits the movement .
This stage can last 2-9 months
Frozen or stiff
The pain starts to reduce but the shoulder movement reduces further. Patients often say that is feels like the joint is too tight as the capsule doesn't stretch as it should do.
Lack of movement is the main issue at this stage
This can last from 4 - 12 months
Recovery or thawing
The shoulder starts to move more and pain resolves. The shoulder can regain full movement but this iften requires some regular stretching by the patient. Getting their hand behind their back is often one of the last movements to come back fully.
This can last for 12-42 months
Its exact cause of Frozen Shoulder is unclear. It has been thought that the inflamed capsule is an exaggerated healing response to a small injury in the shoulder. It is most common between the age of 40 and 60, and women more commonly having it than men.
The following can increase the risk of developing a Frozen Shoulder:
Previous shoulder injury
Dupuytrens - scar tissue in the palm of your hand
Frozen Shoulder is a self limiting problem. This means that it will recover on its own but this may take 2 years or more. Treatment options are there to try and speed this process up, reduce pain and increase range of movement of the shoulder.
Physiotherapy helps to increase the shoulder range of movement by gradually stretching the capsule. It has been shown that regular stretches into a little bit of pain is most effective compared to very hard stretches associated with significant pain after.
There are 2 main types of injection:
Steroid injection - also know as hydrocortisone, this is an anti-inflammatory drug that helps to reduce inflammation of the shoulder capsule. It can be very effective at reducing pain but does not effect the restriction in the capsule and therefore range of movement does not immediately change. However, if the shoulder is less painful because it is less inflamed then it is easier for the patient to stretch the capsule themselves with exercises.
Hydrodilatation - a fluid (normal saline and steroid) is injected into the shoulder capsule to stretch it from inside. This is thought to break up sticky adhesions of the capsule to the humeral head (ball at top of arm bone).
There are 2 main types of surgery:
Manipulation under Anesthesia (MUA) - whilst under general or local anaesthetic, the shoulder is manipulated by the surgeon to stretch the capsule and increase range of motion
Capsular release - a small camera and a special probe is inserted into your shoulder. The probe emits a high frequency radio wave and cuts or divides the thickened and scarred part of the shoulder capsule