Introduction
The shoulder joint is a ball and socket type joint composed of the head of the humerus (ball) and the glenoid (socket) – both lined by thick smooth cartilage. This allows pain free movement.
Shoulder arthritis is progressive degenerative disease of the shoulder joint in the form of cartilage loss.
Arthritis of the shoulder is less common than arthritis of the hip and knee.
Shoulder arthritis is more common in females. Primary shoulder osteoarthritis in present in approximately 1/3 of people over 60 years age.
Causes
The 2 most common causes of shoulder arthritis are primary osteoarthritis and cuff tear arthritis.
Osteoarthritis (70%)
This is the traditional age related ‘wear and tear’ degenerative arthritis. It may also be caused by trauma, such as fractures or dislocations.
Cuff tear arthritis (15-20%)
Patients with long standing large rotator cuff tears will have abnormal loading of the humerus head on the glenoid (socket) and this will cause cartilage degeneration.
Signs and symptoms
Diagnosis is based on patient symptoms, examination findings and imaging.
Pain
Pain may be at rest, at night or with activities. The pain gets worse with movement.
Stiffness
The shoulder will have restricted movement which may get worse over time.
Activity Limitation
One may have difficulty performing activities requiring shoulder movement. For example:
- Reaching for cupboards / clothesline.
- Washing hair.
- Brushing teeth.
- Doing / Undoing bra.
Weakness
Some weakness may occur.
Tests
X-ray
This will show loss of the normal joint space.
CT
This can more accurately depict abnormalities in shape of the bones due to arthritis and can be used for planning surgery.
Non-surgical treatment
Early stages of arthritis may not require surgery.
Lifestyle Modification
Avoiding aggravating / painful activities and resting the shoulder when possible
Physiotherapy
Gentle range of motion and strengthening exercises can help patients in early stages of disease.
Analgesia
These may be in the form of Paracetamol or NSAIDs.