Rhizarthrosis is arthritis of the base of the thumb. This pathology is very common. In most cases, medication and immobilization of the thumb are sufficient to relieve it. If this is not the case or if a deformity of the thumb appears, surgery may be performed.

Definition 

Rhizarthrosis or trapeziometacarpal arthritis is arthritis of the base of the thumb. It corresponds to the chronic wear and tear of the cartilage between the trapezius (wrist bone) and the first metacarpal (thumb bone). It is often a bilateral condition (it affects both thumbs). 

Causes 

Most often the exact cause of osteoarthritis is not known. Sometimes osteoarthritis is the result of a fracture, rheumatism or infection. 

Diagnostic 

The clinical diagnosis is confirmed by basic and lateral x-rays of the thumb. These examinations also make it possible to see the importance of the destruction of the cartilage and the conservation of a certain bone volume. 

The people concerned 

Rhizarthrosis is common. It represents 10% of osteoarthritis of the limbs. It mainly affects women between 50 and 60 years old. 

Risk factors 

An endocrine factor is mentioned because rhizarthrosis often occurs in postmenopausal women. Certain professions requiring in an exaggerated way the pollicidigitale clamp (seamstress…) would be more at risk. The traumatic factor is rarer.

Pain, the first symptom 

Pain is the first symptom, whether spontaneous or in everyday gestures that mobilize the pollici-digital forceps, or the thumb with another finger (turn a key, open a jar, peel a fruit, etc.) The pain may be accompanied by difficulty in using the thumb. 

Deformation of the thumb 

After 7 to 10 years of painful attacks, the thumb characteristically deforms: the column of the thumb takes the shape of an M (bump at the base of the thumb). When the thumb is deformed, the pain is replaced by stiffness.

The first treatment for rhizarthrosis is medical. It aims to relieve pain and maintain range of motion. This treatment combines rest, anti-inflammatory drugs and the wearing of a custom-made thermoformable splint at night (rest orthosis). Corticosteroid infiltrations can relieve pain during attacks.

If after 6 months to a year, this treatment has not been sufficient to calm the pain or if a deformity of the thumb spine appears, surgical treatment may be considered. In the early stages of artrosis three interventions can be proposed: stabilization of the joint (ligamentoplasty), reorientation of the joint surfaces (osteomy) or removal of the nerves intended for the joint (denervation). 

When osteoarthritis is more advanced, two types of intervention can be proposed: trapezectomy which consists of removing the diseased trapezius or a total trapeziometacarpal prosthesis which replaces the two components of the joint and includes a cup fixed in the trapezius and metacarpal head. 

These two interventions are followed by rehabilitation. 

Natural treatments for rhizarthrosis 

Herbal medicine is effective against osteoarthritis. Examples of plants that can relieve osteoarthritis: ginger, which has anti-inflammatory properties, Devil’s Claw or Harpagophytum, turmeric, blackcurrant buds.

Omega-3 fatty acids are also a natural treatment for osteoarthritis. They have the effect of blocking the production of inflammatory substances.

To prevent rhizarthrosis, it is advisable to spare the joints of the fingers and hand in daily activities such as cooking, cleaning and gardening. There are useful tools: electric can opener, bottle opener, jar opener …

Stopping smoking is also recommended in the prevention of osteoarthritis, nicotine would indeed disrupt the supply of nutrients to the cartilage.