Arthrosis is a disease that causes inflammation, stiffness and destruction of joints. In a normal joint the cartilage covers the bony extremities allowing them to move smoothly and painlessly. The base of the thumb joint is formed by one of the carpal bones (trapezius) and the first of the 3 thumb bones (metacarpal). This (Trapezius-Metacarpal) joint allows the thumb to move and grasp with the other fingers. In osteoarthritis the cartilage layer deteriorates and the bones rub against each other. It often affects the joint at the base of the thumb, also called the trapezius-metacarpal joint. Trapezio-metacarpal arthrosis (rizartrosis) slowly destroys the joint.

Trapezio-metacarpal arthrosis (Rizartrose) is more common in women over 40, but anyone can have it. It usually affects both thumbs.

Joint Destruction by Arthrosis

The tops of the bones are covered by cartilage. This cover acts as a cushion, allowing bones to move smoothly. Arthrosis destroys the cartilage and the bones move against each other as it moves the thumb, making the joint inflamed and painful. Over time the bones may collapse, dislocate causing deformation and stiffness not allowing the finger to stretch.


Trapezio-metacarpal arthrosis results from joint wear. It is more frequent, and at a younger age, if there was trauma with ligament injury or thumb fracture. Repetitive movements of tweezers, twisting or rolling objects between the thumb and fingers can aggravate arthrosis.


The most common symptom is pain at the base of the thumb. You may feel pain when you grasp anything between your thumb and fingers, when you try to open a door or turn a lock. You can find yourself dropping things. Time can also aggravate the pain. The joint may become inflamed and over time stiff or deformed.

Your doctor can diagnose a trapezius-metacarpal arthrosis by deforming and moving your thumb. Your doctor may need to order a radiograph to see the degree of joint destruction. Treatment will depend on pain and the degree of joint involvement.

Non Surgical Treatment

If arthritis is diagnosed at an early stage of the disease, it may respond favorably to non-surgical treatment. Your doctor may apply a thumb splint for a period of 3 to 6 weeks. This limits movement and reduces inflammation. It may be associated with an oral anti-inflammatory drug such as aspirin or Voltaren. If your symptoms do not improve, your doctor may offer you a joint injection of an anti-inflammatory drug such as cortisone.

If non-surgical treatment does not relieve pain and stiffness, or if arthritis is already at a later stage with joint destruction, your doctor may advise you to consult a hand surgery specialist to assess the surgical indication and which the right technique for you.

Surgical treatment

If the hand surgery specialist advises you to have surgery, the diseased joint will be removed, usually with the removal of the base of the 1st metacarpal and trapezius and reconstruction is performed with a prosthesis or with a tendon graft removed from the forearm and wrist. . This type of surgery can be performed under general anesthesia (which implies 24 hours of hospitalization) or under local regional anesthesia of the branchial plexus, where only the arm is anesthetized (which does not require hospitalization).

The recovery

Initially the hand has a relatively bulky dressing and a splint. After removing the stitches you will only have a thumb splint for a total of 6 weeks from the date of surgery. This splint will keep the thumb stable while healing. As soon as the splint is removed, the surgeon will advise you of the movements to be made and will send you to a physiotherapist to assist with mobility, making the new joint more flexible and the muscles stronger and more elastic. It will take some time to regain full use of your thumb.

Once recovered, you will have little or no pain – as long as you don’t overdo the activities with your thumb. Make sure you continue to do the exercises prescribed by your surgeon or hand therapist to improve new joint activity. Your thumb may never fully recover, like a new finger, but you can resume most of your daily activities with virtually no complaints.