Thumb arthritis overview
Thumb arthritis is common with aging and occurs when cartilage wears away from the ends of the bones that form the joint at the base of your thumb — also known as the carpometacarpal (CMC) joint.
Thumb arthritis can cause severe pain, swelling, and decreased strength and range of motion, making it difficult to do simple tasks, such as turning doorknobs and opening jars. Treatment generally involves a combination of medication and splints. Severe thumb arthritis might require surgery.
Symptoms of thumb arthritis
Pain is the first and most common symptom of thumb arthritis. Pain can occur at the base of your thumb when you grip, grasp or pinch an object, or use your thumb to apply force.
Other signs and symptoms might include:
- Swelling, stiffness and tenderness at the base of your thumb
- Decreased strength when pinching or grasping objects
- Decreased range of motion
- Enlarged or bony appearance of the joint at the base of your thumb
Causes of thumb arthritis
Thumb arthritis commonly occurs with aging. Previous trauma or injury to the thumb joint also can cause thumb arthritis.
In a normal thumb joint, cartilage covers the ends of the bones — acting as a cushion and allowing the bones to glide smoothly against each other. With thumb arthritis, the cartilage that covers the ends of the bones deteriorates, and its smooth surface roughens. The bones then rub against each other, resulting in friction and joint damage.
The damage to the joint might result in growth of new bone along the sides of the existing bone (bone spurs), which can produce noticeable lumps on your thumb joint.
Risk factors for thumb arthritis: Factors that can increase your risk include:
- Female sex
- Age above 40 years
- Certain hereditary conditions, such as joint ligament laxity and malformed joints
- Injuries to your thumb joint, such as fractures and sprains
- Diseases that change the normal structure and function of cartilage, such as rheumatoid arthritis. Although osteoarthritis is the most common cause of thumb arthritis, rheumatoid arthritis can also affect the CMC joint, usually to a lesser extent than other joints of the hand.
- Activities and jobs that put high stress on the thumb joint
Diagnosis of thumb arthritis
During a physical exam, I will ask about your symptoms and look for swelling over your thumb joint.
I will hold your joint while moving your thumb, with pressure, against your wrist bone. If this movement produces a grinding sound or feeling with pain, the cartilage has worn down, and the bones are rubbing against each other.
Imaging techniques, usually X-rays, can reveal signs of thumb arthritis, including:
- Bone spurs
- Worn-down cartilage
- Loss of joint space
Treatment of thumb arthritis
In the early stages of thumb arthritis, treatment usually involves a combination of non-surgical therapies. If your thumb arthritis is severe, surgery might be necessary.
Medication: To relieve pain, I might recommend:
- Topical medications applied to the skin over the joint, such as capsaicin or diclofenac
- Over-the-counter pain relievers, such as acetaminophen (Tylenol, others), ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve)
- Prescription pain relievers, such as celecoxib (Celebrex) or indomethacin (Indocin)
Splinting: A splint can support your joint and limit the movement of your thumb and wrist. You might wear a splint just at night or throughout the day and night. Splints can help:
- Decrease pain
- Encourage proper positioning of your joint while you complete tasks
- Rest your joint
Injections: If pain relievers and a splint aren’t effective, I might recommend injecting a long-acting corticosteroid into your thumb joint. Corticosteroid injections can offer temporary pain relief and reduce inflammation.
Surgery: If you don’t respond to other treatments or if you’re barely able to bend and twist your thumb, I might recommend seeing an orthopedist to consider surgery. Options include:
- Joint fusion (arthrodesis). The bones in the affected joint are permanently fused. The fused joint can bear weight without pain but has no flexibility.
- Osteotomy. The bones in the affected joint are repositioned to help correct deformities.
- Trapeziectomy. One of the bones in your thumb joint (trapezium) is removed.
- Joint replacement (arthroplasty). All or part of the affected joint is removed and replaced with a graft from one of your tendons.
These surgeries can all be done on an outpatient basis. After surgery, you can expect to wear a cast or splint over your thumb and wrist for up to six weeks. Once the cast is removed, you undergo physical therapy to help you regain hand strength and movement.