rhizarthrosis

Rhizarthrosis: General

In case of a rhizarthrosis the thumb saddle joint is worn. This joint sits at the base of the thumb near the wrist. It connects the Great Polygonail (a carpal bones) to the first metacarpal bone. This metacarpal bone is then connected via a joint to the first of the two finger bones of the thumb.

Rhizarthrosis is the most common arthritis in the hand. At the same time often also other joints wear out, for example other finger joints. Physicians then speak of a polyarthrosis.

If you want to know more about joint wear, please read the article Osteoarthritis.

Rhizarthrosis: symptoms

The arthrosis in the thumb saddle joint causes the affected person pain in the joint area. The complaints occur especially in gripping and rotating movements. Such movements are necessary, for example, to turn a key in the lock or to open the lid of a screw jar. With an “arthrosis thumb” this is hardly possible in severe cases because of the pain. In addition, the thumb is increasingly limited in its mobility.

Many sufferers also report pressure pain in the region of the thumb saddle joint. A loss of power and a feeling of instability in the thumb saddle joint are also often stated.

Rhizarthrosis: causes

The cause of a rhizarthrosis remains unclear in most cases. Physicians then speak of a 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 “arthrosis thumb” can be seen (secondary arthrosis). For example, a rhizarthrosis sometimes develops as a result of a fractured bone in the region of the thumb saddle joint: if such a Rolando fracture or Bennet fracture heals badly, the thumb saddle joint can become excessively worn. Then a Rhizarthrose arises.

Even diseases such as rheumatoid arthritis or mechanical overload can trigger a rhizarthrosis.

Rhizarthrosis: diagnosis

The symptoms described by the patient usually arouse the physician’s suspicion of a rhizarthrosis. The doctor will then examine and palpate the area of ​​the thumb saddle joint. In arthrosis in the thumb saddle joint, the area is tender painful.

In the next step, the doctor carries out the Grind test: he grips the thumb and in a certain way exercises rotating movements in the thumb saddle joint. If there are pain as well as rubbing or grinding noises, this indicates a rhizarthrosis.

The diagnosis is confirmed by an x-ray examination: On the X-ray image, typical signs of joint wear can be recognized by an “arthrosis thumb”. These include a narrowed joint space and densities of the bone tissue below the articular cartilage (subchondral sclerosis).

Watch out: The X-ray findings says nothing about the extent of the complaints! Sometimes only a few arthritis signs are visible on the radiograph, but the patient still has significant pain. In other cases, clear signs of wear in the thumb saddle joint can be detected by X-ray, but the patient has hardly any complaints.

Rhizarthrosis: therapy

First you try to treat the rhizarthrosis with conservative measures. If that does not help, then surgery may be considered.

Rhizarthrosis: conservative therapy

The doctor will plan the therapy individually. Among other things, it takes into account the extent of joint wear and the severity of the complaints.

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

Painkillers from the group of non-steroidal anti-inflammatory drugs (NSAIDs) are often given as pain relief for arthritis in the thumb saddle joint. It can be used locally (for example as an ointment) or as a tablet. Which analgesic is best for each individual case and how long it should be used is discussed by patients with their doctor.

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

In addition, there are other options for conservative treatment of rhizarthrosis such as occupational therapy and electrotherapy.

More about conservative therapies for joint wear and tear in the article Osteoarthritis.

Rhizarthrosis: surgery

In advanced stages of rhizarthrosis, conservative therapies sometimes do not help. Then sometimes only one operation can eliminate the pain and make the thumb functional again.

The doctor will decide individually which surgical procedure is best for a patient. In most cases, a so-called trapezium resection with suspension plastic is performed:

The surgeon first removes the large polygon bone (Os trapezium). In the resulting defect he uses a sinew strip of an adjacent tendon for stabilization. This can be, for example, the thumb string.

Sometimes only the big polygonal bone is removed – without hanging on a tendon strip. Then it’s a pure trapezium resection.

In addition, there are other surgical procedures that are applicable to an “arthrosis thumb”: For example, the thumb saddle joint can be stiffened (arthrodesis). This helps against the pain, but also makes the thumb less mobile.

There is also more pronounced rhizarthrosis the possibility of using an artificial joint (endoprosthesis).

Further information about various surgical procedures for joint wear can be found in the article Osteoarthritis.