Osteoarthritis as a common disease

Osteoarthritis is one of the most common degenerative joint diseases worldwide. The hip joint is particularly frequently affected, as it is exposed to high mechanical stress in everyday life. But what exactly happens in osteoarthritis of the hip joint? How does the disease progress, and what signs of osteoarthritis can be identified in the various stages? This article examines the individual stages of coxarthrosis and discusses the respective changes visible on X-ray.

Healthy cartilage and its protective function

The cartilage plays a crucial role in the function and longevity of the hip joint. It acts as a shock absorber and ensures smooth movement of the joint partners. Its smooth surface reduces friction and distributes the load evenly on the underlying bone.

Properties of healthy cartilage:

• High water content for elasticity and pressure distribution
• Collagen fibers for stability
• No blood vessels or nerves, therefore insensitive to pain

Once this cartilage is damaged, the degenerative process of osteoarthritis begins.

First phase of osteoarthritis: cartilage changes and reduction in cartilage thickness

In the initial phase of coxarthrosis, there are usually no severe symptoms. However, changes are already taking place in the joint:

• The cartilage loses water content and becomes less elastic.
• First fine cracks appear in the cartilage layer.
• The cartilage thickness decreases, leading to uneven stress.

Signs of osteoarthritis in the early stage:

• Morning stiffness of the hip joint
• Slight limitation of movement
• Load-related pain that subsides after rest periods

Second phase of osteoarthritis: Sclerosis of the bone and osteophyte formation

As the cartilage becomes increasingly worn, it leads to a higher load on the underlying bone. The body reacts to this with a so-called sclerosis, i.e. a densification of the bone, to make it more resistant.

At the same time, the body tries to enlarge the joint surface to distribute the load more evenly. This leads to the formation of osteophytes (bone spurs).

Symptoms of osteoarthritis in this phase:

• Pain during everyday movements
• Limitations in hip mobility
• Noticeable change in joint shape

X-ray signs of osteoarthritis:

• Joint space narrowing
• Sclerosis of the bone under the cartilage (subchondral sclerosis)
• First osteophytes at the joint margins

Third phase of osteoarthritis: formation of bone cysts

With increasing osteoarthritis, in the deeper bone layer, so-called bone cysts. These are cavities filled with fluid or dead tissue. They arise from micro‑fractures that the body can no longer properly repair.

Consequences of the bone cysts:

• The bone loses stability
• The joint becomes increasingly unstable
• The pain continues to increase

End stage of osteoarthritis: collapse of the joint surface and femoral head necrosis

In the far advanced stage of coxarthrosis, the Geröllzysten threaten to collapse. This can lead to the femoral head sinking and becoming deformed. In some cases, a femoral head necrosis, in which the bone is no longer sufficiently perfused and dies.

Symptoms of osteoarthritis in the final stage:

• Severe pain, even at rest
• Significant limitation of movement
• Gait disturbance up to limping

X-ray signs of osteoarthritis:

• Severe deformation of the femoral head
• Almost complete loss of the joint space
• Large bone cysts in the bone

Treatment options for coxarthrosis

Depending on the stage of osteoarthritis, there are different treatment approaches:

Conservative treatment of osteoarthritis of the hip:

• Physical therapy to improve mobility
• Medications for pain and inflammation inhibition
• Hyaluronic acid injections
• Weight reduction to relieve joint stress

Surgical treatment of hip arthrosis:

If the conservative Maßnahmen are no longer sufficient, an artificial hip joint (hip-THR) may be required. In this procedure, the damaged joint surfaces are replaced by a prosthesis that restores the original function of the joint.

Conclusion: Recognizing and treating hip arthrosis

Hip arthrosis is a gradual process that develops over years. The first signs of arthrosis are often nonspecific, making early diagnosis crucial. Hip arthrosis is a progressive condition that can lead to severe pain and significant mobility restrictions if left untreated. Typical signs of arthrosis, such as cartilage wear, bone sclerosis, osteophyte formation, and cysts, are clearly visible on X-rays and reflect the progression of the disease. While conservative measures like physiotherapy, weight reduction, and pain medication can help in the early stages, advanced cases often require hip replacement surgery as a permanent solution.

Because the progression of osteoarthritis varies from person to person and different factors need to be considered, early consultation with a hip specialist is crucial. An experienced specialist can not only make a precise diagnosis but also develop an individually tailored treatment strategy - whether through joint-preserving measures or determining the optimal time for a hip prosthesis. Those suffering from hip pain should not wait too long but seek advice at a specialized center to find the best possible therapy for a pain-free future.