Polyarthrosis Affecting Multiple Joints: Osteoarthritis, Joint Degeneration, and Modern Treatment

Osteoarthritis, also known as joint wear and tear, is a chronic condition characterized by degeneration of the cartilage and bone structures in the joints. “Arthron” is the Greek word for joint, and in medicine, the suffix “-osis” is typically used to describe chronic, non-inflammatory conditions. With approximately five million people affected in Germany, osteoarthritis is the most common chronic condition of the musculoskeletal system.

Individual joints may be affected, typically the knee or hip, as these are subject to particular stress. However, osteoarthritis can also develop following accidents and bone fractures that involve the joint area. Strictly speaking, osteoarthritis affecting a single joint should be referred to as monoarthrosis (mono = single), and osteoarthritis affecting 2 to 4 joints as oligoarthrosis (oligo = few). However, these terms are rarely used with such precision in everyday clinical practice.

In medical terminology, the term “polyarthrosis” (ICD code M15) refers to osteoarthritis that occurs simultaneously in 5 or more joints.

In humans, the joint surfaces are covered by a layer of cartilage. Although this layer is only a few millimeters thick, it plays a crucial role in joint function. This network of cartilage cells and collagen fibers reduces friction between the joint surfaces and also acts as a natural shock absorber. Cartilage is also referred to as bradytrophic (poorly nourished) tissue because it contains very few blood vessels. As the pressure on the cartilage increases, its blood supply deteriorates further, leading to osteoarthritis.

In osteoarthritis, there is a progressive breakdown of cartilage tissue—usually over the course of years or decades—which is also referred to as “cartilage wear.”

In principle, osteoarthritis can affect any of the approximately 100 joints in the human body. However, joints that are subjected to heavy daily stress are particularly susceptible. 

The most common forms of osteoarthritis therefore include:

• osteoarthritis of the hand and finger joints, particularly the thumb (rhizarthrosis)
• osteoarthritis of the shoulder joint (omarthrosis)
• osteoarthritis of the hip (coxarthrosis)
• osteoarthritis of the knee (gonarthrosis)

The progressive wear and tear of the joint cartilage can have various causes. Generally, however, cartilage damage is preceded by stress exceeding the joint’s natural capacity to withstand it. Due to its lack of blood supply, the cartilage is unable to repair and regenerate itself. Being overweight or placing an unusually high load on the joints—for example, due to physically demanding work or competitive sports—can damage the cartilage just as much as improper loading caused by joint misalignments. For example, people with bowlegs or knock-knees have a higher risk of osteoarthritis.

Metabolic disorders such as gout also contribute to cartilage damage. Injuries involving cartilage damage or bone fractures that heal in a misaligned position are also risk factors for polyarthrosis. 

Ultimately, rheumatism can also lead to polyarthrosis; in such cases, the joints of the hand are frequently affected. Typically, patients with so-called rheumatoid arthritis (i.e., osteoarthritis caused by rheumatism) exhibit increasing misalignments of the finger joints, causing the fingers to often deviate outward. This can lead to progressively limited mobility, eventually resulting in the loss of the patient’s independence. However, since rheumatism is often accompanied by inflammatory flare-ups, the condition is frequently referred to as arthritis.

In some cases, no specific cause for the cartilage damage can be identified. This is referred to as “primary osteoarthritis.” All other forms, in which the causes are known or can be identified, are referred to as “secondary forms of osteoarthritis.”

In the early stages, joint wear often causes no symptoms at all or only minor discomfort. Later on, patients complain of pain when moving the affected joints. Pain at rest is also possible, especially early in the morning after getting out of bed. If the symptoms improve after 1–2 hours, osteoarthritis is highly likely. The affected joints feel stiff and have limited range of motion. Noticeable resistance during joint movement, as well as clearly audible cracking sounds, may also occur depending on the stage of the disease. The more osteoarthritis progresses, the more likely pathological joint deformities are to develop.

Unlike arthritis, osteoarthritis is not primarily inflammatory. However, in cases of acute overuse, osteoarthritic joints can also become inflamed. Sudden joint swelling, as well as warmth and redness in the joints, may indicate such inflammation. This is referred to as “activated osteoarthritis,” which is frequently observed in the hip joint. However, activated osteoarthritis can also occur in all other joints—such as the knee—during inflammatory flare-ups and acute overload reactions.

Since damaged cartilage cannot be restored, the treatment of osteoarthritis is aimed solely at relieving symptoms. In addition, therapeutic measures are intended to halt or at least slow down the progression of joint wear and tear. In principle, osteoarthritis treatment can be divided into conservative and surgical approaches. The appropriate treatment depends on the extent and exact location of the polyarthrosis.

What does conservative therapy involve?

• The most important component of conservative therapy is exercise. Swimming and cycling help maintain joint mobility and strengthen the muscles that support the joints. Sports involving abrupt movements or high impact, such as soccer, boxing, or tennis, are less suitable.
• To relieve pressure on the joints, crutches or orthoses may be prescribed
• People who are overweight should lose weight to protect their joints
• In addition, physical therapy treatments can help alleviate the symptoms of polyarthrosis. These include mud and fango packs, as well as therapeutic baths and infrared light therapy
• Specialized physical therapy exercises and massages are also suitable for the conservative treatment of osteoarthritis
• If the pain is too severe, pain relievers containing active ingredients such as acetaminophen or ibuprofen, as well as pain-relieving ointments, can be prescribed and used. In addition, it is generally possible to administer a local anesthetic to relieve pain by injecting it into or near the painful joint. In some cases, hyaluronic acid injections are also used as part of conservative osteoarthritis treatment. Hyaluronic acid is a substance naturally produced by the body and a component of synovial fluid; it is said to improve joint mobility. However, its effectiveness has not yet been conclusively proven. Cortisone injections are also used, but they can sometimes cause unwanted side effects. 

Important: All procedures involving the injection of a substance into the joint from outside the body should be critically evaluated and carefully indicated, as there is always a risk of introducing bacteria into the joint cavity.

What does surgical treatment involve?

Surgery to correct misalignments may be beneficial for relieving pain and preventing inflammation. Drilling into the cartilage surface during arthroscopy (joint endoscopy) can stimulate the production of new cartilage tissue. If the pain cannot be relieved by any therapeutic measures, the doctor may replace the affected joint with an artificial joint (endoprosthesis). Such joint replacement is performed primarily for osteoarthritis of the knee or hip.

Osteoarthritis is therefore a progressive joint disease that is accompanied by pain during movement or even at rest. While conservative or surgical treatments can alleviate the symptoms of the disease, a cure is not possible.

Conclusion

Polyarthrosis of the hand is one of the most common forms of generalized osteoarthritis and often affects several joints at the same time, particularly the distal interphalangeal joints or, in the case of osteoarthritis, the thumb saddle joint. Causes of osteoarthritis include improper weight-bearing, cartilage degradation, genetic factors, and age-related cartilage wear, which can lead to arthritic joint changes and bone spurs.

Polyarthrosis can be diagnosed using imaging techniques, radiologically visible changes, X-rays, and blood tests, even though some patients remain asymptomatic at first. The goal of treating polyarthrosis is to relieve pain, restrictions of movement, and joint pain, and to slow the progression of the disease—for example, through conservative measures, anti-inflammatory medications, antirheumatic drugs, or support from occupational therapists.

Since polyarthrosis often affects the knees and hips, as well as joint cartilage and other joint conditions, early treatment can improve the quality of life for those affected and, where possible, help avoid joint replacement surgery in cases of limited mobility.