Cause And Development Of Shoulder Arthrosis
Known causes of shoulder arthrosis include mechanical overload, damage to the rotator cuff (muscle and tendon coat that moves and stabilizes the shoulder joint), conditions after operations, inflammation and accidents. In most patients suffering from shoulder arthrosis, the cause remains unclear. In these cases one speaks of a primary shoulder arthrosis or primary omarthrosis.
The symptoms are rather uncharacteristic and manifest themselves in shoulder pain and restricted movement of the shoulder. The diagnosis is made using x-rays of the shoulder. Both conservative and surgical treatment methods (shoulder prosthesis) can be considered.
Damage to the rotator cuff as the cause of shoulder arthrosis
As a rotator cuff, several shoulder-encompassing muscles and tendons are described that move the shoulder joint and hold it in an optimal position for the joint function. Defects in the rotator cuff lead to muscular imbalance and loss of the stabilizing balance. The supraspinatus muscle under the shoulder roof is most often affected by injuries, which are mostly caused by degeneration (wear), less often by an accident.
If the supraspinatus tendon is the cause of the shoulder arthrosis, the mechanics of the shoulder joint are severely disturbed. In an extreme case, a complete tear, the humeral head leaves its original position in the joint and rises up under the shoulder roof. Wrong strain on the shoulder joint cartilage occurs, which leads to increased cartilage abrasion and ultimately to shoulder arthritis. The final stage of this development is described by the term defect arthropathy, in which the upper arm head comes into contact with the bone of the shoulder roof (acromion).
The frequency peak of wear-related rotator cuff injuries is in the 4th and 5th decades of life.
Operations on the shoulder joint as causes of shoulder arthrosis
Shoulder surgery can cause osteoarthritis of the shoulder if it disrupts shoulder balance. The most important example here is surgery for anterior stabilization of the shoulder after shoulder dislocations (shoulder dislocation). The mostly necessary fixation of the joint lip (labrum) and especially the gathering of the front shoulder capsule can cause the humerus head to be pushed backwards if the shoulder joint capsule is shortened too much. As in the previous example, there is a disruption in the shoulder joint mechanics. In this case, there is an overload of the acetabular cartilage (glenoid) in the rear shoulder area.
Accidents as causes of shoulder arthrosis
Injuries to the joint-forming shoulder blade (e.g. luxation fractures of the glenoid when the shoulder is dislocated) or the upper arm head can lead to irregularities in the cartilage surfaces or to joint misalignments. In both cases, there is increased abrasion of the cartilage, which gradually develops into osteoarthritis of the shoulder.
Inflammation as the cause of shoulder arthrosis
Bacterial inflammation of the shoulder is rare and either comes from the spread of germs via the blood path (very rare) or is caused by medical treatment measures (iatrogenic), e.g. after operations or syringes. The shoulder joint can quickly be severely damaged by the bacteria themselves and by cartilage-damaging substances that they form.
The most common form of non-bacterial shoulder inflammation is chronic polyarthritis ("rheumatoid arthritis"). The chronically inflamed synovial mucosa proliferates in the articular cartilage and progressively destroys it.
The infrequent death of the humerus due to loss of blood flow to the shoulder also leads to shoulder arthrosis if the cartilage-bearing part of the humerus collapses.
What Are The Symptoms Of Shoulder Arthrosis?
The symptoms of shoulder arthrosis usually begin with the appearance of shoulder pain after a long period of stress on the arm. The fatigue pain in the shoulder joint continues to increase and can also radiate into the rest of the arm. In addition, with osteoarthritis of the shoulder, there may be increased pain at the start of a movement. These come about because not enough synovial fluid has yet been formed in the joint space, i.e. between the bones that form the joint. The synovial fluid is responsible for ensuring that the bones glide gently past each other during a movement and do not rub against each other and thus wear out. It also provides bones and cartilage with nutrients that are important for maintaining and rebuilding.
At the beginning of a movement, the formation of synovial fluid is activated. Therefore, there is little synovial fluid between the bones at the beginning. If these are already damaged by the osteoarthritis, rubbing against each other is very painful and can last for the entire duration of the movement. For this reason, it is called permanent pain.
In the course of the disease, the pain is more and more persistent and can also occur at rest and at night. In addition, pronounced osteoarthritis is usually accompanied by restricted movement. The cause of osteoarthritis is wear and tear and no inflammation.
Nevertheless, an existing osteoarthritis of the shoulder can catch fire. This is called activated arthrosis. In addition to the pain, symptoms such as redness, swelling and warming of the shoulder joint appear here.
Pain is the most common symptom of osteoarthritis of the shoulder. The pain is most pronounced at the beginning and at the end of a load. They can occur not only in the shoulder itself, but also in the lower areas of the arm. The pain is particularly bad with movements such as spreading the arm or rotating, because here the bones are pressed against each other particularly strongly.
Restriction of movement
Restricted movement is a symptom of advanced osteoarthritis of the shoulder. In the joint, the adjacent bone surfaces are surrounded by a protective layer of cartilage. This layer of cartilage is continuously destroyed in osteoarthritis, which increases the pressure on the bones. This causes the bone to thicken below the cartilage to remain stable. However, the increased bone formation leads to stiffening and restricted movement. This is particularly noticeable when rotating the shoulder joint and spreading the arm outwards.
Conservative (non-operative) measures cannot cure shoulder arthrosis. All related treatment measures aim at:
- Pain relief
- Maintaining and improving joint mobility and
from. The aim is to maintain the function of the shoulder and to minimize the progression of the shoulder arthrosis. Therapy options include:
- Pain relievers (analgesics).
- Non-steroidal anti-rheumatics (NSAIDs) - for pain therapy in particular inflammatory disease phase (e.g. diclofenac, ibuprofen, arcoxia).
- Cortisone - injected into the joint (intra-articular) or under the shoulder roof (subacromial) for strong anti-inflammatory effects.
- Hyaluronic acid - Hyaluronic acids belong to the group of so-called chondroprotectives.
- Hyaluronic acid is a natural component of the cartilage that is lost in osteoarthritis. If hyaluronic acid is injected directly into a joint damaged by osteoarthritis, the quality of the remaining cartilage improves, which has a positive effect on pain and mobility.
- Physiotherapy - to maintain joint mobility and muscle strengthening (active and passive movement exercises, stretching, manual therapy, isometric muscle building and much more).
- Physical therapies - cooling, pain relieving power applications, iontophoresis.
- X-ray irradiation stimulus
Which medications help with the treatment?
Pain relievers can help with osteoarthritis of the shoulder. It is very important to slowly increase the dosage of the drug and to start with lighter pain medication. In this way, with increasing pain, you have the option of increasing the dosage and not already using the maximum dose at the beginning of the therapy.
In addition, permanent pain therapy due to the strong side effects should be avoided. For acute complaints, medication such as paracetamol, ibuprofen or diclofenac is started.
The latter two have the advantage that, in addition to relieving pain, they have an anti-inflammatory effect and thus prevent inflammation of the affected joint. Diclofenac can also be applied directly to the affected area in the form of a cream known under the name Voltaren®. It moves in the corresponding area and works especially there. This can reduce side effects in other parts of the body. If these drugs are no longer sufficient, stronger pain relievers such as tramadol, which belongs to the group of opiates, are used.
Shoulder Osteoarthritis Surgery
Diagnosing shoulder osteoarthritis does not necessarily mean that surgery on the shoulder joint is necessary. However, shoulder osteoarthritis is a progressive condition that cannot be cured.
In the early stages of cartilage wear, conservative therapy is recommended in most cases, in which the focus is on mobilizing the joint, removing the stiffness, releasing the narrowed (contracted) shoulder capsule, relieving pain and reducing inflammation. This is intended to slow down the progression of shoulder arthrosis and strengthen the shoulder muscles.
Only when these conservative measures do not improve the symptoms does surgical therapy have to be considered. Depending on the severity of the osteoarthritis of the shoulder, a cartilage smoothing performed during a joint mirroring can already provide relief. If this treatment approach is no longer sufficient, the implantation of an artificial joint replacement (shoulder prosthesis) may be necessary in the last step.
There are various surgical options available for treating shoulder arthrosis, which depend on the level of pain and the functional requirements of the person concerned.
In the early stages of shoulder arthrosis, joint-preserving surgery can be performed as part of a shoulder joint mirroring (arthroscopy). This measure is particularly suitable if the joint space is only slightly narrowed due to the osteoarthritis and sufficient mobility of the shoulder joint is maintained. As a rule, the cause of the pain can be eliminated with the small arthroscopic intervention; For example, using the minimally invasive keyhole technique (arthroscopic), a scarred and hardened bursa can be removed or calcified or torn tendons can be sewn. In addition, the articular cartilage can be smoothed, the shoulder roof expanded and inflamed tissue removed. This operation can be carried out on a short inpatient basis, which corresponds to a hospital stay of around two to three days.
If the osteoarthritis of the shoulder has already progressed, the joint gap is very narrow, or pronounced restrictions on movement can be determined, a shoulder joint replacement should be used surgically. Depending on the extent and cause of the osteoarthritis of the shoulder, different prosthesis models can be considered (see below).
If the prosthesis loosens, a replacement operation is usually required. Here, the loosened part is replaced; sometimes it may be necessary to use a different type of prosthesis, for example if there are soft tissue defects or poor bone quality.
What Surgical Methods Are There?
Nowadays there are several options for treating shoulder osteoarthritis surgically. Especially when conservative therapy no longer alleviates the symptoms and the osteoarthritis has advanced too much, the patient's pressure of suffering increases, so that a final solution in the form of surgery is used.
Previously, the stiffening of the shoulder joint was mainly carried out in these cases. This makes the joint completely immobile and unusable, the severe pain subsides and osteoarthritis cannot develop again. Nowadays, this surgical procedure takes a back seat as prostheses of the shoulder joint are becoming more common. For this purpose, both the articular surface of the humerus and the articular surface on the shoulder blade, the so-called "glenoid", are replaced. Both articular surfaces are often damaged by long-term shoulder arthrosis. If the joint socket on the shoulder blade is still intact, half a prosthesis can also be inserted. Here, only the part of the upper arm near the joint is replaced by the prosthesis. Nowadays, a wide variety of prostheses can be selected for different cases. In this way, the prostheses can be cemented in the bones if they do not hold well. So-called “inverse prostheses” can also be used if the shoulder muscles are inadequate and improve the overall result. In such prostheses, the upper arm forms the socket and the shoulder blade the joint head.
Types Of Shoulder Prostheses
With a very pronounced, severe shoulder arthrosis, an artificial joint replacement can be a good therapy option. The goal that is to be achieved with the artificial joint is long-term pain relief and an improvement in (usually considerably) restricted shoulder mobility. Statistically, the functionality of an artificial shoulder joint is around 15 years, but there may be individual deviations.
With the total shoulder prosthesis, better shoulder function can be expected, but risks may arise in the short or long term if the socket is also artificially implanted.
With a so-called inverse shoulder prosthesis, the durability is slightly less than 10 years. Here, the joint head (actually the humerus head) becomes the joint socket and the shoulder joint socket becomes the joint head (inverse means that the tasks are exchanged). Greater abrasion occurs on the existing bones on which the artificial, inverse joint is mounted, which is why the artificial joint can loosen more quickly and may need to be replaced earlier.
The inverse shoulder prosthesis ensures better active mobility and is stable against possible dislocations, but there is a higher risk of loosening the head component and an infection. For this reason, inverse shoulder prostheses are only used in those over 70 years of age and with very extensive tendon damage, chronic instability, massive bony destruction and with alternating operations.
The goal of the operation is to achieve freedom from pain in the shoulder and to improve mobility so that the shoulder can be fully used in everyday life. Shortly after the operation, the shoulder is immobilized with a stabilizing shoulder splint so that the healing process can begin. However, the first small and careful movements with the shoulder are practiced as quickly as possible in order to regain the mobility of the shoulder soon. Initially, the movement exercises take place passively (by a therapist or passive motor tracks), and only after two to four weeks (depending on the operation) can the person concerned actively participate in the physiotherapy exercises.
If an artificial shoulder prosthesis has been installed, it is necessary to keep the shoulder completely still for about four weeks. After that, slow and increasing movement exercises are carried out, after a further two weeks it should be possible to spread the arms by 60 degrees and bend the shoulder forward. The entire post-treatment phase usually takes around 12 to 16 weeks.
Alternatives To Surgery
Shoulder arthrosis can also be treated (conservatively) without surgery. This therapy option depends on the course of the disease, symptoms and the disease mechanism. Various physiotherapy exercises, drug therapy or other treatment methods can be considered. With shoulder arthrosis in particular, conservative treatment can often suffice to positively influence the course of the disease and alleviate symptoms. For this reason, surgery for shoulder arthrosis is only indicated in selected cases.
Non-surgical therapy for shoulder arthrosis is particularly suitable if the disease begins slowly and gradually. The earlier the individual treatment is started, the easier it is to treat the shoulder arthrosis in the long term. Healing of the shoulder arthrosis cannot be achieved with conservative therapy. However, the treatment methods can achieve pain relief, maintenance and improvement of joint mobility and muscle strengthening. This can maintain the function of the shoulder and slow the progression of shoulder arthrosis.
Treatment options include a shoulder splint (orthosis), cold therapy (cryotherapy), physical therapy, healing current applications or shock wave treatments. In addition, medication can be injected into the shoulder joint, as well as anti-inflammatory and analgesic medication. The patient should learn to regulate movements and loads on the shoulder joint and to adapt their behavior to the disease. For example, contact and throwing sports or activities with high leverage, such as golfing or playing tennis, should be avoided.