Rhizarthrosis
Comprehensive information about the causes, symptoms, and prognosis of the degenerative disease affecting the trapeziometacarpal joint (the joint between the trapezium and the first metacarpal bone).
Symptoms and Causes
Rhizarthrosis is a degenerative joint disease characterized by the wear and tear of the cartilage of the trapeziometacarpal (TMC) joint, located at the base of the thumb. This joint connects the trapezium bone of the wrist to the first metacarpal bone. Also referred to as degenerative arthropathy of the trapeziometacarpal joint, it is one of the most common hand pathologies.
Thumb osteoarthritis is classified into several stages according to the degree of cartilage involvement:
- Grade 1 Rhizarthrosis: minimal articular changes:
- Synovial inflammation.
- Slight widening of the joint space.
- No evidence of bone destruction.
- Grade 2 Rhizarthrosis: mild degeneration:
- Joint space narrowing.
- Subchondral sclerosis: hardening of the bone beneath the cartilage.
- Small osteophytes (bony spurs around the joint) less than 2 mm in size.
- No subluxation, i.e., no partial dislocation of the joint.
- Grade 3 Rhizarthrosis: significant joint damage:
- Marked joint space reduction.
- Osteophytes larger than 2 mm causing stiffness.
- Joint subluxation.
- Grade 4 Rhizarthrosis: advanced articular degeneration:
- Collapse of the joint space.
- Large osteophytes (up to 4 mm).
- Complete dislocation.
- Involvement of adjacent joints.
Rhizarthrosis has no definitive cure, as it is a degenerative process. However, current treatments —including joint replacement— are highly effective in alleviating symptoms and improving quality of life.
Symptoms
The most characteristic symptoms of rhizarthrosis are:
- Pain at the base of the thumb.
- Limited motion, especially when performing pinching movements or thumb opposition.
- Joint deformity, with the thumb adopting a Z-shaped appearance.
- Swelling.
- Stiffness.
- Loss of strength.
Causes
As with other types of osteoarthritis, the etiology of rhizarthrosis remains unclear. It may result from genetic predisposition, hand anatomy, lifestyle factors, or be secondary to other conditions.
Risk Factors
Risk factors associated with rhizarthrosis include:
- Age: being a chronic degenerative disorder, it appears with joint wear, typically after the age of 50.
- Sex: women are more susceptible. Approximately 50% of women over 70 have thumb osteoarthritis.
- Obesity.
- Hormonal imbalances.
- Previous thumb injuries.
- Repetitive and sustained joint motion: occupational activity, sports, instrumental tasks, writing, or smartphone use.
Complications
When rhizarthrosis is severe or left untreated, it may cause:
- Complete loss of movement.
- Persistent pain.
- Functional limitation of the hand.
- Some degree of dependence.
Prevention
Although rhizarthrosis cannot be prevented, its onset or symptom severity can be delayed by following these recommendations:
- Limit thumb use when possible (grasp objects using the palms, avoid pinch movements, press buttons with other fingers, use both hands for large objects).
- Reduce repetitive movements.
- Use adapted kitchen utensils, such as peelers or electric devices.
- Avoid carrying heavy loads with the hands — for example, use a trolley instead of carrying bags.
- Use tools, utensils, pens, and pencils with a wider diameter for better grip.
Which Specialist Treats Rhizarthrosis?
The diagnosis and treatment of rhizarthrosis are carried out by specialists in orthopedic surgery and traumatology.
Diagnosis
Rhizarthrosis is diagnosed through the following procedures:
- Medical history: assessment of prior medical conditions, lifestyle, and current symptoms.
- Physical examination: evaluation of the joint’s condition, palpation to detect non-visible deformities, and assessment of pain during motion.
- X-ray imaging: visualization of joint changes such as bone narrowing, osteophyte formation, or cartilage degradation, allowing the clinician to determine the stage of rhizarthrosis.
Treatment
Several treatments are available for rhizarthrosis, depending on disease severity and patient needs. Conservative management is preferred, while surgical intervention is reserved for selected cases:
- Physical therapy:
- Manual therapy to relax the muscles.
- Strengthening exercises.
- Stretching routines.
- Cold therapy to reduce inflammation.
- Heat application to relieve pain.
- Ultrasound therapy: emission of high-frequency waves that generate heat and vibration, enhancing circulation, relieving pain, and decreasing inflammation.
- Medication:
- Oral analgesics and anti-inflammatory drugs.
- Intra-articular injections of corticosteroids or hyaluronic acid to improve mobility and relieve pain.
- Splints or wrist braces: stabilize the joint without limiting function, relieve pain, reduce friction, and protect against excessive motion or accidental trauma.
- Surgery: indicated when conservative treatments fail. Surgical options include:
- Arthrodesis: the standard approach; bones connecting the wrist and hand are fused to eliminate pain, though wrist mobility is lost.
- Trapeziectomy: partial or total removal of the trapezium bone, filling the residual space with tendon tissue to preserve function.
- Prosthetic arthroplasty: replacement of the joint (or part of it) with a mechanical prosthesis, usually made of titanium.
Rhizarthrosis surgery is generally safe and yields favorable outcomes, though some patients may experience residual stiffness, limited motion, persistent pain, or nerve injury.
