What is Arthritis?
It is a condition whereby the articular cartilage which lines the shoulder joint becomes worn out. This is a degenerative process and occurs more common with increasing age. It can sometimes affect young patients as well especially following injuries which have caused cartilage damage, or disruption of the blood supply to the head of the humerus, otherwise known as avascular necrosis. This is often seen following radiotherapy or long term steroid therapy

How does arthritis progress?
As sections of the cartilage are worn away, bare bone is exposed in the ball and socket joint. As the bone surfaces rub against each other, this produces friction with subsequent grating, pain and stiffness. In addition, bony spurs may form at the edge of the joint and fragments of loose bone or cartilage may appear in the joint space.

What types of arthritis are there in the shoulder?
- Osteoarthritis
- Rheumatoid arthritis
- Rotator cuff tear and arthritis
- Arthritis of the acromioclavicular joint – this is completely different from the above 3 types of arthritis and the treatment of isolated acromioclavicular arthritis is by key hole surgery which reliably produces excellent results with rapid recovery.

What are the presenting symptoms in shoulder arthritis?
Patients with shoulder arthritis usually develop pain and stiffness. The pain is often worse at night, especially when trying to sleep on the side. Subtle degree of stiffness may be noticed on a day to day basis with inability to perform tasks which involve shoulder rotation such as blow drying the hair or undoing the bra from behind.
What are the treatment options?
- Physiotherapy
- Steroid injections into the shoulder joint
- Arthroscopic debridement (Key hole surgery – washout)
- Shoulder replacement
What types of shoulder replacement are there?
The shoulder replacement can be done in the form of a surface replacement whereby the irregular humeral head is ‘smoothened’ out and a metallic ‘mushroom’ type cap placed over the humeral head. Traditionally, shoulder replacements were done using a stemmed implant that goes down the shaft of the humeral bone and is still indicated in selected cases. Finally, in patients with severe rotator cuff rupture and arthritis, and perhaps those with a previous unsuccessful shoulder replacement, a reverse shoulder replacement might be indicated. This is similar to the conventional type of replacement except that the ball and socket positions are reversed. By placing the prosthetic socket in the humerus of the upper arm and the ball in the glenoid cavity, the biomechanical function of the shoulder is greatly improved.
How long is the recovery usually following a shoulder replacement?
With advances in technology and minimally invasive techniques, most patients will stay one night in hospital although some do go home on the same day. Following surgery, you will be asked to wear a sling usually for about 2 to 3 weeks until the muscles heal. Physiotherapy will then be needed to regain the movements and build up the strength in the arm.
Types of shoulder replacements - Images
Resurfacing of humeral head (ball) Stemmed Shoulder replacement


Glenoid (this is the artificial socket for the shoulder joint)

Reverse ball and socket type of shoulder replacement

Radiograph of cuff tear arthropathy showing evidence of arthritis with deficient rotator cuff After a reverse polarity shoulder replacement – note that the ball and socket parts of the prosthesis have now been ‘switched over’


Biomechanical considerations of the normal and rotator cuff deficient shoulders and the reverse shoulder
prosthesis
Click here for link to Reverse Polarity Total Shoulder Replacement