Gelenk-Klinik

We distinguish between a primary and secondary type of arthritis of the shoulder joint (omarthritis). In both cases it is due to a growing wear and tear of the joint which eventually leads to complete destruction of the cartilage in the gleno-humeral joint. Very often, this degenerative joint disease is the consequence of mechanical surcharge, of lesions in the rotator cuff, inflammations or accidents. General symptoms present are uncharacteristic shoulder pain and limited mobility.

What happens when the shoulder is affected by arthritis?

When the mechanics of the shoulder joint are disturbed, for instance due to defects of the rotator cuff, the humeral head leaves its initial position in the joint and moves upwards under the shoulder bone (the acromion). This leads to excessive strain, to growing cartilage abrasion and eventually to shoulder joint arthritis. When the humeral head becomes in contact with the shoulder bone, this is called defect arthropathy. Often, due to the cartilage degeneration, bony growth i.e. painful bone spurs also called osteophytes, form at the edges of the joint.

The signs of this condition are quite unspecific. Patients often complain of shoulder pain and joint mobility limitations. It is quite typical to observe diffuse shoulder pains, often in the rest position after straining or during activities that stress the shoulder. Lying on the affected shoulder may also be very painful. However, mobility becomes limited only at a relatively late stage of the deterioration. Over time, moving the shoulder begins to cause pain, particularly when rotating the arm. The movement radius of the shoulder joint becomes more limited, starting with the external rotation i.e. the outward turning movement of the arm. Growing degeneration signs may lead to the patient adopting a protective posture to minimise discomfort, which provokes a loss of mobility.

At the humeral head itself, the zones most commonly concerned are those with a contact angle between 60° and 90° during the abduction of the glenoid cavity, as the surface pressure is relatively strong in this position.

At the glenoid cavity, cartilage degeneration occurs mainly in the backmost area and is accompanied by growing abrasion, as the gleno-humeral contact surface shifts backwards when the arm is bent. In contrast, cases with central cartilage degeneration are much rarer.
Causes of shoulder arthritis

In most cases of primary shoulder arthritis, the origin of the condition remains unclear. Possible causes could include a family predisposition to degenerative joint diseases or long-term physical stress of the gleno-humeral joints.

The secondary omarthritis can have different origins:

• Impairment of the rotator cuff (above all the supraspinatus muscle) The cause of this is often degeneration (wear) or traumata (accidents), which lead to a loss of stability and a biomechanical defect within the shoulder joint.
• Shoulder joint surgery
If the shoulder balance is disturbed as a result of shoulder dislocation (luxation) this could give rise to shoulder arthritis. As a consequence of the anterior capsular plication, the humeral head may be pressed backwards, leading to a mechanical disorder and thus to mechanical stress of the glenoid cartilage at the back of the shoulder.
• Accidents
Injuries of the joint-forming shoulder blade or of the humeral head can lead to uneven cartilage surfaces or to a malposition of the joint. This in turn leads to growing cartilage abrasion and to shoulder joint arthritis.
• Inflammations
Bacterial shoulder joint inflammations are uncommon. They are caused either through the hematogenic spread of germs or through iatrogenic transmission, for instance after operations or injections. The bacteria themselves and the substances they release can harm the joint considerably and rapidly, however, shoulder joint inflammations and chronical polyarthritis (articular rheumatism) i.e. non bacterial irritations, are more frequent. Due to chronically inflammatory joint disorders, the mucosa proliferates into the cartilage and erodes it.
• Humeral head necrosis
• When there is a circulatory disorder of the bone, this may lead to a humeral head necrosis and subsequently to shoulder arthritis, if the cartilage containing part of the humeral head collapses.
• Rare causes
• Chondromatosis
• Gout
• Hemochromatosis
• Syringomyelia
• Diabetic osteoarthropathy

How is the diagnosis done?

An X-ray will show that the joint space is too narrow, a typical symptom of omarthritis. In many cases, the primary shoulder arthritis, exhibits the destruction of the rear parts of the joint cavity. If bone spurs (osteophytes) are apparent on the X-ray then the affliction has reached an advanced stage .This may lead to a deformation of the humeral head.
In isolated cases, an MRI may be necessary in order to assess the condition of the joint cavity, which is particularly important not only for planning the implantation of a shoulder replacement but also to exclude other diseases.

What is the treatment for shoulder arthritis?

An omarthritis cannot be healed through non-surgical treatments, however, such treatments can reduce pain, maintain or increase mobility and strengthen muscles. Thus, the shoulder's function can be preserved and the progression of the arthritis minimised. Non surgical treatment may involve:

• Anti-inflammatory, analgesic medication
• Physiotherapy
• Physical therapy (cryotherapy, microcurrent therapy)

If these measures do not bring relief, surgery, such as the arthroscopic debridement, (i.e. the removal of degenerative tissue) is an option, perhaps combined with the removal of the subacromial bursa. In cases of severe arthritis, joint replacement surgery is recommended. In this operation, the surgeon replaces the damaged parts of the humeral head and joint cavity with a shoulder replacement.

What to bear in mind when participating in sports

In general, all sports that strain the shoulder should be avoided, particularly contact or throwing sports and those activities involving strong leverage effects, such as golf and tennis. It goes without saying that sports such as rugby or American football do not belong to the recommended leisure-time activities!

One should also avoid all movements that imply strong, shear and tensile stress, and sports where one might easily fall, such as rollerblading and mountain biking.
The intensity with which a sport is performed, plays an important role. An amateur athlete climbing on his mountain bike at the weekend is in less danger than a fanatical cross country downhill biker.

Excellent sports are those which foster general fitness without jeopardizing the shoulder, for example; walking, jogging, cycling and breast-stroke swimming. If practised carefully, even golf and skiing are acceptable.