Base of Thumb Arthritis: What Are the Treatments

Arthritis at the base of the thumb is extremely common and can make surprisingly simple activities painful.

Opening a jar, turning a key, using scissors, gardening or even holding a coffee cup can become difficult. Patients often notice pain when pinching or gripping and may gradually lose strength in the hand.

The good news is that having arthritis at the base of the thumb does not automatically mean you need surgery.

There are several effective treatment options, ranging from simple activity modification and splinting through to surgery. If surgery is eventually required, modern options include both traditional procedures and CMC joint replacement.

The best treatment depends on the severity of your symptoms, your age and activity level, the appearance of the joint and what you need your hand to do.

What is base of thumb arthritis?

The main joint at the base of the thumb is called the carpometacarpal joint, or CMC joint.

It is formed between the first metacarpal bone of the thumb and a small wrist bone called the trapezium.

This joint gives the thumb an enormous amount of movement. It allows us to bring the thumb across the palm and, importantly, to pinch against the fingers.

The trade-off for this mobility is that considerable forces pass through a relatively small joint.

Over time, the cartilage covering the joint surfaces can wear away, producing CMC osteoarthritis.

What does CMC arthritis feel like?

The most common symptom is pain at the base of the thumb.

You may notice pain when:

• Opening jars or bottles
• Turning keys
• Pinching objects
• Using scissors
• Gardening
• Writing
• Using kitchen utensils
• Playing golf or racquet sports
• Performing manual work

As the arthritis progresses, the thumb can become stiff and weaker.

Some patients develop a visible prominence at the base of the thumb as the joint gradually changes shape.

In more advanced cases, the thumb can develop a characteristic deformity, with the base of the thumb moving inwards and the next joint compensating by bending backwards.

Does arthritis on an X-ray mean I need treatment?

No.

Base of thumb arthritis is very common on X-rays, particularly as we get older.

Some people have quite advanced arthritis on imaging but surprisingly few symptoms.

For this reason, we treat your symptoms rather than simply treating the X-ray.

If your thumb is functioning well and the discomfort is manageable, there is usually no reason to have an operation just because arthritis is visible on imaging.

What can I do without surgery?

Most patients should initially try non-operative treatment.

Activity modification

Sometimes relatively small changes can make a significant difference.

Using larger handles, avoiding sustained heavy pinching and modifying repetitive activities can reduce the load passing through the CMC joint.

This does not mean that you need to stop using your hand.

The aim is to identify the activities that particularly aggravate the joint and find ways of performing them more comfortably.

Splinting

A thumb brace can support the CMC joint and reduce painful movement.

Some people wear a splint during activities that aggravate their symptoms, while others find it useful during periods when the arthritis is particularly painful.

There are many different types of braces, ranging from soft supports to more rigid thermoplastic splints.

Hand therapy

A hand therapist can help with:

• Strengthening
• Maintaining thumb movement
• Improving hand mechanics
• Activity modification
• Providing an appropriate splint

Therapy cannot restore worn cartilage, but it can improve how efficiently the thumb functions.

Medication

Simple pain relief or anti-inflammatory medication may be useful, provided it is appropriate for your general health.

These medications do not reverse the arthritis but can help manage periods when symptoms are more troublesome.

What about a cortisone injection?

A corticosteroid injection into the CMC joint can provide useful pain relief.

For some patients, the improvement lasts several months or longer. For others, the benefit is relatively short-lived.

An injection does not restore the damaged cartilage and therefore does not cure the arthritis.

However, it can be a very reasonable option when symptoms are significant but you are not yet ready to consider surgery.

Repeated injections need to be considered carefully, particularly if the benefit from each injection is becoming progressively shorter.

When should I consider surgery?

There is no particular X-ray appearance or level of arthritis that automatically means surgery is required.

Surgery becomes reasonable when:

Pain from the base of the thumb is interfering with your quality of life and appropriate non-operative treatments are no longer providing acceptable relief.

You might notice that you are increasingly avoiding everyday activities, struggling at work or giving up hobbies because of your thumb.

At this point, it is reasonable to discuss surgical options.

What operations are available?

There is no single operation that is appropriate for every patient.

The main surgical options include:

• Trapeziectomy
• Trapeziectomy with additional soft-tissue procedures
• CMC joint replacement
• Joint fusion in selected patients

Each has advantages and disadvantages.

What is a trapeziectomy?

A trapeziectomy has traditionally been one of the most commonly performed operations for CMC arthritis.

The trapezium — the small arthritic bone at the base of the thumb — is removed.

Removing the painful arthritic joint prevents the two damaged joint surfaces from continuing to rub against each other.

The space left behind gradually fills with scar tissue.

Different techniques can also be used to support or stabilise the thumb following removal of the trapezium. These include ligament reconstruction, tendon procedures or various forms of suspension.

However, the central part of the operation remains the same:

The arthritic trapezium is removed.

What are the advantages of trapeziectomy?

Trapeziectomy has been performed for many years and has a long track record.

Its major advantages include:

• Reliable pain relief for many patients
• No artificial joint to wear out
• No implant that can dislocate
• Good long-term results
• Suitability for a wide range of patients

For these reasons, trapeziectomy remains an excellent operation.

What are the disadvantages of trapeziectomy?

The main disadvantage is recovery time.

After the trapezium has been removed, the tissues need time to heal and the thumb needs to adapt to its new mechanics.

Strength can take several months to recover.

Patients may notice weakness with pinch and grip during the recovery period, and the thumb can shorten slightly as the metacarpal settles into the space previously occupied by the trapezium.

Although most patients ultimately do very well, recovery is not instantaneous.

What is a CMC joint replacement?

CMC replacement takes a different approach.

Instead of removing the arthritic joint and allowing the thumb to function without the trapezium, the damaged joint surfaces are replaced with an artificial joint.

Modern CMC replacements generally use a small implant designed to recreate the ball-and-socket mechanics of the base of the thumb.

The aim is to:

• Relieve pain
• Preserve thumb length
• Maintain more normal joint mechanics
• Restore movement
• Allow earlier functional recovery

CMC replacement has become an increasingly attractive option for appropriately selected patients.

What are the potential advantages of CMC replacement?

One of the major potential advantages is faster functional recovery.

Because the thumb’s length and joint mechanics are preserved, patients may regain useful movement and function more quickly than following a traditional trapeziectomy.

Potential advantages include:

Earlier return of function

The thumb does not need to settle into the space created by removing the trapezium.

Preservation of thumb length

The metacarpal continues to articulate with the trapezium through the artificial joint.

Good pinch strength

Maintaining the biomechanics of the CMC joint may help preserve effective pinch and grip.

More normal thumb mechanics

The aim is to reproduce the natural movement of the CMC joint rather than remove it.

For the right patient, these can be important advantages.

What are the disadvantages of CMC replacement?

The main difference compared with trapeziectomy is that CMC replacement introduces an artificial implant.

As with any joint replacement, potential problems include:

• Dislocation
• Loosening
• Wear
• Fracture
• Infection
• Persistent pain
• Implant failure
• The need for further surgery

Careful positioning of the implant and appropriate patient selection are therefore important.

A replacement is not necessarily the best option for every arthritic thumb.

Who is a good candidate for CMC replacement?

CMC replacement may be particularly attractive for patients with painful, isolated CMC arthritis who want to maintain good thumb movement and strength.

The condition of the trapezium and surrounding joints is important.

Your surgeon will also consider:

• Your age
• Activity level
• Bone quality
• Pattern of arthritis
• Thumb stability
• Previous injuries or surgery
• Work requirements
• Sporting activities

Someone performing extremely heavy repetitive manual work may have different priorities from someone whose main concerns are everyday activities, office work or recreational sport.

Trapeziectomy or CMC replacement: which is better?

This is an increasingly common question.

There is not a single answer that applies to everyone.

Trapeziectomy has the advantage of a very long track record and avoids the potential problems associated with an artificial joint.

CMC replacement aims to preserve more normal anatomy and mechanics and may offer a quicker recovery of movement and function in appropriately selected patients.

The trade-off is that a replacement introduces implant-specific risks, including loosening and dislocation, and we have less very long-term follow-up compared with traditional trapeziectomy.

For many patients, either operation may be reasonable.

The decision therefore comes down to your anatomy, age, functional requirements and priorities.

What about fusion?

CMC fusion, or arthrodesis, permanently joins the two bones of the arthritic joint together.

This eliminates painful movement at the joint.

Fusion can provide a strong and stable thumb and may occasionally be considered in younger patients performing particularly heavy manual work.

However, the trade-off is loss of movement at the CMC joint.

There is also a risk that the bones do not successfully unite, known as non-union.

For these reasons, fusion is used selectively.

What does recovery from surgery look like?

Recovery depends on which procedure is performed.

Following a trapeziectomy, the thumb is usually protected initially and rehabilitation then progresses gradually.

Movement and function improve over several months, but recovery of strength can be slow.

CMC replacement can potentially allow an earlier return to movement and function, although the joint still needs to be protected while the tissues around the implant heal.

With either procedure, hand therapy is an important part of recovery.

Patients should think of recovery as a progressive process rather than an immediate return to normal hand function.

Can I still use my hand normally after surgery?

The goal of surgery is to return you to comfortable everyday use of the hand.

Most patients want to be able to grip, pinch, cook, garden, exercise and perform work activities without constantly thinking about their thumb.

Both trapeziectomy and CMC replacement can achieve excellent functional outcomes in appropriately selected patients.

However, no operation recreates a completely normal joint, and very heavy repetitive loading may remain uncomfortable or inappropriate depending on the procedure performed.

So which treatment should I choose?

The first decision is usually not:

“Trapeziectomy or replacement?”

It is:

“Do I need surgery at all?”

If your symptoms remain manageable with splinting, activity modification, hand therapy or an occasional injection, continuing non-operative treatment is entirely reasonable.

If pain is significantly affecting your quality of life despite these measures, surgery becomes an option.

We can then consider which procedure best suits your particular thumb.

For some patients, the long-established reliability of a trapeziectomy makes it the preferred option.

For others, CMC joint replacement offers an attractive alternative that preserves the joint’s anatomy, thumb length and mechanics while potentially allowing a faster return of function.

The bottom line

Base of thumb arthritis is common, and most patients do not need to rush into surgery.

Initial treatment usually involves activity modification, splinting, hand therapy, appropriate medication and sometimes a corticosteroid injection.

When these treatments no longer provide acceptable relief, surgery can be very effective.

Trapeziectomy remains a reliable and well-established operation with excellent long-term results.

Modern CMC joint replacement provides another option for appropriately selected patients, with the potential advantages of preserving thumb length and joint mechanics and allowing faster functional recovery.

The best operation is therefore not necessarily the same for every patient.

The aim is to choose the treatment that provides reliable pain relief while preserving the strength, movement and function you need from your thumb.

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