Overview
The joint at the base of the thumb, where the first metacarpal meets a small wrist bone called the trapezium, is shaped like a saddle. That shape lets the thumb swing across the palm, and it is also why the joint wears out: it depends on ligaments for stability, and every pinch drives the metacarpal against the trapezium with several times the force applied at the fingertip. When the cartilage thins, the metacarpal slides off the trapezium, the base of the thumb becomes prominent, and pinching hurts. This carpometacarpal (CMC) arthritis is the hand arthritis that most often brings people to a surgeon.
Treatment is decided by function rather than by the X-ray. Many people with advanced changes on film have little pain; some with early changes cannot open a jar. Dr. O'Donnell uses a brace and injection for as long as they work, and recommends reconstruction only when those no longer keep the thumb usable.
Common Symptoms
- Aching pain at the base of the thumb, at the wrist end rather than in the web space
- Sharp pain with pinch: turning a key, opening a jar, writing
- Loss of pinch strength, and dropping small objects
- In later stages, a thumb that collapses into a zigzag, with the base pulled inward and the next joint hyperextended
Pain slightly higher, over the bony bump of the wrist, sharp with lifting rather than pinching, is De Quervain's tenosynovitis, which often coexists. Numbness in the thumb and fingers points to carpal tunnel syndrome, and catching of the thumb as it bends is a trigger thumb.
Causes & Risk Factors
The cause is wear of a joint that carries high loads on a small surface, accelerated by laxity of the ligament that holds the metacarpal in its saddle. Women over 50 are affected far more often than men, and hormonal changes at menopause are thought to contribute. A previous fracture at the base of the thumb, joint hypermobility, and decades of forceful pinching in trades such as dentistry, carpentry and hairdressing all raise the risk. Younger patients usually have a specific injury in their history, such as a ski-pole fall; in older patients it develops without any single event and often affects both hands.
How It Is Diagnosed
Dr. O'Donnell localizes tenderness to the CMC joint, then performs the grind test, pressing the thumb metacarpal into the trapezium and rotating it, which reproduces the pain and often a palpable crunch. He measures pinch strength and checks whether the middle thumb joint hyperextends to compensate, because that changes what is done at surgery. Finkelstein's test and a check for median-nerve symptoms identify coexisting tendinitis and carpal tunnel.
X-rays of the thumb, including a view taken with the hand pronated to profile the CMC joint, confirm the diagnosis and show joint-space narrowing, bone spurs, subluxation, and whether the adjacent joint between the trapezium and scaphoid is involved, which guides the choice of operation. MRI and CT are rarely required. Ultrasound guides injections into a joint that is small and often partly covered by a spur. Out-of-town patients can upload X-rays through mymedicalimages.com for a telemedicine review.
Treatment Options
Non-operative care
Most patients are managed for years without an operation. A hand-based thumb spica orthosis that supports the CMC joint while leaving the wrist and fingers free is worn for heavy tasks and during flares. A hand therapist teaches joint protection, wider-grip tools, and exercises for the muscle that pulls the metacarpal back into its saddle. When these are not enough, an ultrasound-guided corticosteroid injection into the joint usually gives several months of relief, most effectively in earlier stages, and is repeated at most two or three times a year. Dr. O'Donnell recommends surgery when pain limits daily tasks despite three to six months of this, not because the X-ray has reached a certain stage.
Trapeziectomy with ligament reconstruction (LRTI)
The standard operation for advanced CMC arthritis removes the worn trapezium so bone no longer grinds on bone, then stabilizes the thumb by weaving a strip of a nearby wrist tendon through the metacarpal to reconstruct the ligament and fill the space. Pain relief is reliable and durable, motion is preserved, and pinch strength returns over months. A suture-button suspension between the thumb and index metacarpals allows earlier motion; for a young, heavy-demand worker, fusion gives strength at the cost of motion. All are outpatient procedures at Bayside Surgery Center.
Recovery & What to Expect
There is no fixed protocol for thumb arthritis because the operation varies, and progression is individualized. The timeline below is a general guide for trapeziectomy with ligament reconstruction; a suspension procedure moves faster and a fusion is protected until the bone unites.
| Phase | Timing | What happens |
|---|---|---|
| Protection | Weeks 0–4 | Thumb spica splint or cast; fingers, elbow and shoulder move from day one; sutures out at two weeks. |
| Motion | Weeks 4–8 | Removable orthosis; hand therapy begins gentle thumb and wrist motion, scar management, light functional use. |
| Strengthening | Weeks 8–12 | Progressive pinch and grip strengthening; orthosis weaned for daily tasks. |
| Full function | Months 3–12 | Heavier gripping and sport from about three months; pinch strength keeps improving for six to twelve months. |
Desk work in a splint is possible within a week; driving once the cast is exchanged for a removable orthosis, around four to six weeks; and golf and tennis at about three months. Non-operative patients continue normal activities, with the brace on for tasks that provoke pain.
Frequently Asked Questions
Does thumb arthritis get worse without surgery?
The X-ray changes progress slowly over years, but pain does not correlate with the X-ray. Many patients stay comfortable for a long time with a brace and an occasional injection, and delaying surgery does not make the eventual operation harder. Surgery is recommended when the thumb can no longer do what you need it to do.
What is the best brace for thumb arthritis?
A hand-based thumb spica orthosis that supports the base of the thumb but leaves the wrist and thumb tip free, stabilizing the CMC joint during pinching without stiffening the whole hand. A custom orthosis from a hand therapist fits best; a soft neoprene support is reasonable for lighter tasks and at night.
How long does a cortisone injection last for thumb arthritis?
Typically a few months, longer in earlier stages and shorter once bone is rubbing on bone. Dr. O'Donnell performs these under ultrasound so the steroid reaches the joint, and limits them to two or three a year. Injections that wear off in weeks rather than months are a sign that reconstruction is worth discussing.
What is LRTI surgery for the thumb?
Ligament reconstruction and tendon interposition. The worn trapezium is removed so bone no longer grinds on bone, and a strip of forearm tendon is woven through the base of the thumb metacarpal to hold it in place and fill the gap. It reliably relieves pain and preserves motion; pinch strength recovers over months.
How long is recovery after thumb arthritis surgery?
Roughly four weeks in a splint or cast, motion in therapy from weeks four to eight, strengthening from week eight, and heavier use from about three months. Pinch strength keeps improving for six to twelve months. A suspension procedure allows earlier motion.
This page is for general education and is not a substitute for a medical evaluation. Treatment recommendations depend on your individual diagnosis and goals. Kevin O'Donnell, MD sees patients from Coral Gables, Miami, Brickell, Pinecrest and Coconut Grove at 475 Biltmore Way, and out-of-town patients by telemedicine.