Rhizarthrosis describes arthritis, meaning joint wear, in the thumb saddle joint. The thumb saddle joint connects the first metacarpal bone to a small wrist bone and allows the many different movements of the thumb.
What happens with this form of arthritis?
Unlike other forms of arthritis, rhizarthrosis affects the saddle joint of the thumb specifically. This joint is put under a lot of strain because the thumb is involved in many everyday movements, from writing to opening a bottle to picking up small objects. Over time, the protective cartilage inside the joint wears away. When this cartilage is gone, the bones rub directly against each other. This causes pain, stiffness, and sometimes a visible misalignment of the thumb.
Many people first notice a pulling sensation or pain during certain movements, such as unscrewing a jar or gripping something firmly. As things progress, the thumb may become less mobile and grip strength can decrease. A grinding or clicking feeling in the joint is also common.
Who is most affected?
Rhizarthrosis usually develops from middle age onwards and is more common in women than in men. One reason for this is the hormonal changes during the menopause, which affect the connective tissue and joint structures. People who put a lot of strain on their hands at work or during leisure activities can also develop symptoms earlier.
Genetics play a role too. Those with a family history of arthritis or thumb saddle joint problems carry a higher risk. Injuries, such as falling onto the hand, can speed up the wear process further.
Typical complaints and symptoms
At the start, there is usually a dull ache around the base of the thumb. The discomfort becomes most noticeable when gripping, twisting, or holding objects. Many people report that the pain worsens after activity or increases in damp weather. Over time, the joint may swell. In some cases, a visible thickening forms at the base of the thumb.
Mobility suffers and gripping small things becomes harder. In advanced rhizarthrosis, the thumb can shift out of alignment and splay outwards. Grip strength in the thumb decreases, making it harder to open bottles, write, or turn a key.
How is the diagnosis made?
The diagnosis is usually made through a combination of a consultation, a physical examination, and imaging. During the consultation, the doctor asks about the exact complaints, such as when and during which activities the pain occurs. During the examination, the thumb saddle joint is tested for tenderness and range of movement.
An X-ray is often used to confirm the diagnosis. On the X-ray, typical changes such as a narrowing of the joint space, bony outgrowths, or misalignment can be seen. In rare cases, an ultrasound or MRI scan may be needed, for example to rule out other causes.
Is it serious? Should you be worried?
Many people feel worried when they first hear about rhizarthrosis. However, the diagnosis does not mean the thumb will lose its function completely. The symptoms can usually be managed well and the condition can often remain stable for many years. Although arthritis cannot be cured, severe cases with lasting restriction of movement are relatively rare.
Common worries centre on whether everyday tasks will still be possible. Most people can continue to grip well and look after themselves with targeted therapy, rest when needed, and helpful aids where appropriate.
Treatment options and what you can do yourself
Treatment depends on how severe the symptoms are. In the early stages, measures such as rest, avoiding overuse, and targeted exercises to strengthen the hand muscles are often enough. Cooling compresses, anti-inflammatory gels, or tablets can help with acute pain.
Many people benefit from special splints that take the strain off the thumb saddle joint. These are usually worn at night or during certain activities. Occupational therapy and physiotherapy can help maintain mobility and strength. In severe cases, where everyday life is significantly affected, surgery may be considered. There are several well-established methods, such as removing a small wrist bone or inserting an artificial joint. The decision for surgery is always made on an individual basis and only after all other options have been tried.
There is quite a lot you can do yourself to ease the symptoms. It helps to avoid repetitive strain and to take regular short breaks. Special hand exercises shown by an occupational therapist support the maintenance of mobility. Aids such as bottle openers or ergonomically shaped pens can also make daily life easier.
How does the condition develop?
The course of the condition varies greatly. For many people, rhizarthrosis remains stable for years and the symptoms are well controlled. For others, the wear progresses more quickly. The key is to pay attention to warning signs early and not to put the hand under constant strain. Starting targeted exercises and rest at the right time can have a positive effect on how the condition develops.
Interesting facts about the thumb saddle joint
The thumb saddle joint is one of the most mobile joints in the hand. It allows the thumb to be brought opposite the other fingers, a movement that is essential for gripping and holding. More information about the structure and function can be found in the article on the saddle joint.
When should you seek medical advice?
If the symptoms persist for several weeks or get worse, it is a good idea to see a doctor. If the thumb swells noticeably, becomes red, or movement becomes severely restricted, the joint should be examined. The earlier a diagnosis is made, the better any further damage can be prevented.
In summary
Rhizarthrosis is a common cause of thumb pain, particularly in middle and older age. Although it can sometimes limit mobility, it rarely leads to a complete loss of function. With targeted treatment and small adjustments to daily life, quality of life can usually be well maintained.
