Rhizarthrosis: thumb-base pain and ultrasound-guided injection in Milan
Rhizarthrosis is osteoarthritis of the joint at the base of the thumb, which we use to open a jar, turn a key or grip an object. Pain may begin only during gripping and later become persistent, with loss of strength and stiffness. When a brace, physiotherapy and medication are not enough, ultrasound-guided injection is a minimally invasive option for delivering treatment directly into the joint.
Do you recognise these symptoms?
- Pain at the base of the thumb during gripping or pinching
- Difficulty opening jars, turning keys or using scissors
- Reduced thumb and hand strength
- Morning stiffness and swelling at the thumb base
- Pain at rest or at night in more advanced stages
What rhizarthrosis is
Rhizarthrosis affects the trapeziometacarpal joint, between the trapezium and the base of the first metacarpal. It is a small joint exposed to high loads: it allows the thumb to oppose the fingers and perform precision gripping. Over time, cartilage becomes thinner, the joint may deform and movement becomes painful.
How it is diagnosed
Diagnosis is based on examination of the hand and the history of symptoms, usually supplemented by an X-ray. Ultrasound can show fluid, synovitis and osteophytes, and can also assess the nearby tendons and structures. It is important to distinguish rhizarthrosis from De Quervain tenosynovitis or other causes of thumb pain because the treatment is different.
How the ultrasound-guided injection is performed
After local anaesthesia of the skin, ultrasound identifies the trapeziometacarpal joint line and guides a thin needle into the joint space, avoiding tendons and neurovascular structures. A small amount of corticosteroid or, in selected cases, hyaluronic acid is injected. The procedure takes about 15 minutes, does not require admission and you go home immediately.
What to expect from treatment
Corticosteroid tends to provide faster relief, while hyaluronic acid may have a more gradual and longer-lasting effect on function in some patients. Injections reduce pain and limitation but do not rebuild cartilage: the goal is to restore hand use and make rehabilitation possible. The indication depends on the X-ray stage, symptoms and treatments already tried.
Alternatives and the role of surgery
In early stages, a brace, activity modification, exercises and medication may help. Injection can be considered when pain limits daily life despite these measures. If osteoarthritis is advanced and pain remains disabling, a hand surgeon can assess whether surgery is appropriate: the decision should be based on function and quality of life, not on the X-ray alone.
Treatments we can perform
Frequently asked questions
Is the injection painful?
It is performed under local anaesthesia. You may feel a brief sting and pressure at the thumb base, but the procedure takes only a few minutes.
How long does the benefit last?
It varies. Corticosteroid acts more quickly; hyaluronic acid may take longer. Duration depends on the stage of osteoarthritis and the individual response.
Can I use my hand immediately?
Yes for light activities. For 24–48 hours it is best to avoid forceful gripping, intensive manual work and sport that loads the thumb.
Does injection prevent surgery?
It may reduce pain and delay surgery in some cases, but it does not remove the osteoarthritis. If pain remains disabling despite treatment, a hand-specialist pathway can be considered.
Want to know if it is your case?
At the first consultation we review your clinical history and previous imaging together.
Other guides
The information on this page is for general guidance and does not replace a medical consultation. The indication for treatment must always be assessed individually.