Rhizarthrosis

Martina Feichter studied biology with an elective subject pharmacy in Innsbruck and also immersed herself in the world of medicinal plants. From there it was not far to other medical topics that still captivate her to this day. She trained as a journalist at the Axel Springer Academy in Hamburg and has been working for since 2007 - first as an editor and since 2012 as a freelance writer.

More about the experts All content is checked by medical journalists.

Rhizarthrosis is a joint wear and tear (arthrosis) in the thumb saddle joint. Usually both thumbs are affected. Rhizarthrosis occurs mainly in women after the age of 50. Read more about the causes, symptoms and treatment of rhizarthrosis!

Rhizarthrosis: general

With rhizarthrosis, the thumb saddle joint is worn out. This joint sits at the base of the thumb near the wrist. It connects the large polygonal bone (a wrist bone) with the first metacarpal bone. This metacarpal bone is then connected to the first of the two finger bones of the thumb via a joint.

Rhizarthrosis is the most common arthrosis in the hand. Often other joints also show wear at the same time, for example other finger joints. Doctors then speak of polyarthrosis.

If you want to know more about joint wear and tear, please read the article on osteoarthritis.

Rhizarthrosis: symptoms

Osteoarthritis in the thumb saddle joint causes pain in the joint area for those affected. The complaints mainly occur with gripping and turning movements. Such movements are necessary, for example, to turn a key in a lock or to open the lid of a jar. With an "osteoarthritis thumb" this is hardly possible in severe cases because of the pain. In addition, the thumb is increasingly restricted in its mobility.

Many sufferers also report pressure pain in the area of ​​the thumb saddle joint. Loss of strength and a feeling of instability in the thumb saddle joint are also often reported.

Rhizarthrosis: causes

The cause of a rhizarthrosis remains unexplained in most cases. Doctors then speak of primary osteoarthritis. Since osteoarthritis of the thumb occurs mainly in postmenopausal women, hormonal factors may play a role.

In some cases, a clear cause of an osteoarthritis thumb can be identified (secondary osteoarthritis). For example, rhizarthrosis sometimes develops as a result of a bone fracture in the area of ​​the thumb saddle joint: If such a Rolando or Bennet fracture heals poorly, the thumb saddle joint can be excessively worn. Then a rhizarthrosis develops.

Diseases such as rheumatoid arthritis or mechanical overload can also trigger rhizarthrosis.

Rhizarthrosis: diagnosis

The symptoms described by the patient usually arouse the doctor's suspicion of rhizarthrosis. The doctor will then examine and palpate the area of ​​the thumb saddle joint more closely. In the case of osteoarthritis of the thumb saddle joint, the area is tender on pressure.

In the next step, the doctor carries out the grind test: He takes hold of the thumb and exercises rotating movements in the thumb saddle joint in a certain way. If pain as well as rubbing or grinding noises occur, this speaks for a rhizarthrosis.

The diagnosis is confirmed by an X-ray examination: typical signs of joint wear can be seen on the X-ray image of an "arthrosis thumb". These include a narrowed joint space and compression of the bone tissue below the articular cartilage (subchondral sclerosis).

Attention: The X-ray findings say nothing about the extent of the complaints! Sometimes there are only a few signs of osteoarthritis on the X-ray, but the patient is still in significant pain. In other cases, clear signs of wear and tear in the thumb saddle joint can be demonstrated by means of X-rays, but the patient hardly has any complaints.

Rhizarthrosis: therapy

First one tries to treat the rhizarthrosis with conservative measures. If that doesn't help, surgery may be an option.

Rhizarthrosis: Conservative Therapy

The doctor will plan the therapeutic measures individually. He takes into account, among other things, the extent of joint wear and the severity of the complaints.

In order to stabilize and relieve the diseased thumb saddle joint, a splint can be worn in the case of rhizarthrosis. There are rails made of plastic or metal, for example. Some patients also wear a leather bandage that covers the wrist and thumb.

Painkillers from the group of non-steroidal anti-inflammatory drugs (NSAIDs) are often given to combat the pain associated with osteoarthritis of the thumb saddle joint. You can apply it locally (e.g. as an ointment) or take it as a tablet. Patients discuss with their doctor which pain reliever is best for each individual case and how long it should be used.

In the event of irritation and inflammatory processes in the osteoarthritis thumb, the doctor can inject a cortisone directly into the joint. It has a strong anti-inflammatory effect, but is only given for a short time.

There are also other options for conservative treatment for rhizarthrosis, such as occupational therapy and electrotherapy.

You can find out more about conservative therapies for joint wear and tear in the article on osteoarthritis.

Rhizarthrosis: surgery

In advanced stages of rhizarthrosis, conservative therapeutic measures sometimes no longer help. Then sometimes only an operation can remove the pain and make the thumb functional again.

The doctor will decide on an individual basis which surgical procedure makes the most sense for a patient. In most cases, a so-called trapezium resection with suspension plastic is performed:

The surgeon first removes the large polygonal bone (os trapezium). He inserts a tendon strip from an adjacent tendon into the resulting defect to stabilize it. This can be the tendon of the thumb, for example.

Sometimes only the large polygonal bone is removed - without hanging it on a tendon strip. Then it is a pure trapezium resection.

There are also other surgical procedures that can be used for an "arthritis thumb": For example, the thumb saddle joint can be stiffened (arthrodesis). This helps against the pain, but also makes the thumb less flexible.

In addition, there is the possibility of using an artificial joint (endoprosthesis) in the case of pronounced rhizarthrosis.

You can find more information about various surgical procedures for joint wear and tear in the article on osteoarthritis.

Tags:  healthy feet organ systems anatomy