Orthosis for rhizarthrosis Push CMC protects the painful joint (TM) while leaving, unlike other orthoses, the joints essential to function free (MP and IP)
The orthosis for rhizarthrosis (arthrosis at the base of the thumb) ortho CMC
The Push CMC stabilises the base joint of the thumb (CMC-1) and places the thumb in a functional position. This ensures optimal hand function and reduces symptoms such as pain and lack of strength.
The selected material and rounded edges contribute to maximum comfort, and the simple closure system allows patients to apply the brace themselves without any effort. The product is antimicrobial, can be used in water and can be dried easily.
OSTEOARTHRITIS CMC-1 - N. KOEKEBAKKER, CERTIFIED HAND THERAPIST
CMC-1 osteoarthritis is a common condition of the carpometacarpal joint of the thumb, also known as degenerative joint disease.
The carpometacarpal joint of the thumb is formed by the first metacarpal bone and the trapezium (trapezium). Together they form the sellar joint, whose two joint surfaces do not quite match. This is because it is a non-congruent joint. If the ligament of this joint weakens, the joint can become unstable.
Joint incongruence and instability lead to an increase in the load on the joint. This chronic load on the joint can negatively influence the degenerative process.
Wear and tear affects the surface of the cartilage that covers both ends of the bones that form the joint. This affects the quality of the cartilage, which may even disappear completely. Movement then causes pain as the ends of the bones touch each other. The joint may also grow and distortions of the joint may occur in the form of bony growths, also known as "osteophytes". This wear is irreversible.
This wear process often causes a deformity in the alignment of the thumb. The carpometacarpal joint of the thumb slips and forms a separate mass; the thumb aligns with the index finger and passes over it. This is called a zigzag deformity.
> COMPLAINTS
The primary complaints are pain in the thenar eminence. The pain initially occurs with movements that require effort from the thumb, such as daily pinching or twisting movements. This may include twisting a dishcloth, opening jars, bottles or vacuum packs, turning a key, operating knobs and pulls, holding a book, writing, etc.
In a later stage, these pains may last longer and frequently occur at night. The base of the thumb may swell and the joint may produce a cracking sensation/noise during movement. Stiffness of the joint and loss of strength may occur at this stage.
> CAUSES OF OSTEOARTHRITIS
Osteoarthritis is caused by different things.
Generally, it is caused by a normal wear and tear process due to age. It affects women more than men and is most common after the age of forty. 16-25% of post-menopausal women suffer from osteoarthritis of this joint. As age advances, 1 in 4 women and 1 in 12 men aged 70 and over suffer from CMC-1 joint osteoarthritis. Specific activities involving the joint excessively, or instability of the joint can play a role in the development of osteoarthritis. Post-traumatic osteoarthritis occurs if it follows a previous injury to the joint, such as a bone fracture that has spread to the joint.
> TREATMENT
In the early stages of osteoarthritis, non-steroidal anti-inflammatory drugs (NSAIDs) can be administered, a specific orthosis can be used and exercises can be performed to control complaints.
The fundamental element of an orthosis is that it stabilises the carpometacarpal joint and places the metacarpal in a functional position. This creates what is called a "thumb arch" which reduces the stress on the carpometacarpal joint. If the other joints of the thumb and fingers remain free, this ensures optimal functioning of the hand.
The hand therapist will try to optimise the stability and strength of the thumb, train a "functional thumb arch", and provide advice on the daily use of your hand.
N. Koekebakker is active as a member of the Nederlands Gezelschap voor Handtherapie. She works at 4hands, a private clinic specialising in hand therapy in Amsterdam.
