STT Arthritis: A Common Cause of Wrist Pain

Scaphotrapeziotrapezoidal (STT) joint arthritis affects the tiny joint at the base of the wrist, just below the thumb. It’s less common than other wrist conditions, but it can significantly affect hand and wrist function, particularly gripping and pinching. This article explains the presentation, investigation, and treatment options for STT joint arthritis.

What is the STT joint of the wrist?

The STT joint connects three bones on the thumb side of the wrist: the scaphoid, trapezoid, and trapezium. Arthritis typically begins between the scaphoid and trapezoid, then moves to involve the scaphoid and trapezium.

Symptoms of STT joint arthritis

People with STT joint arthritis often report localised pain on the thumb side of the wrist. Activities that involve pinching, gripping, or repetitive wrist motion worsen the pain. Some also notice swelling, reduced range of motion, or a grinding sensation in the wrist.

Your doctor examines your wrist for features of arthritis, including tenderness on the thumb side of the wrist and a grinding or popping sensation during wrist motion. It’s also essential to examine the other structures in the wrist to exclude other causes, such as:

Wrist pain sometimes has more than one cause. In one study, about 65% of X-rays showing thumb arthritis also showed STT arthritis.

How is STT arthritis diagnosed?

X-rays are the first-line test to confirm the diagnosis. They may reveal joint space narrowing, osteophytes (bone spurs), or subchondral sclerosis.

MRI gives a more detailed view of the soft tissues, and helps rule out other conditions that can mimic arthritis — such as ligament injuries, synovitis, De Quervain’s tenosynovitis, or a ganglion. Ultrasound can also detect STT arthritis by showing joint swelling, bone spurs, and increased synovitis.

Treatment of STT joint arthritis

Management depends on the severity of symptoms and your activity level, and ranges from simple measures to surgery. We always start with conservative treatment.

Activity modification. Reducing the activities that flare symptoms — heavy lifting or repetitive wrist motion — eases pain.

Bracing. A wrist splint or brace immobilises the joint and reduces pain during activity.

Physiotherapy. A tailored programme maintains joint mobility and strengthens the supporting muscles.

Medication. Topical and oral anti-inflammatories (NSAIDs) reduce pain and inflammation.

Injections for STT arthritis

Injections are a valuable adjunct to simple measures, reducing pain and improving function. We recommend injections under ultrasound guidance to improve accuracy and effectiveness. Options include:

Corticosteroid injections into the STT joint reduce inflammation and temporarily relieve pain — useful for moderate arthritis, or to delay surgery.

Hyaluronic acid injections are used less often but may lubricate the joint and ease early arthritis symptoms. Symptoms. They can give a longer-lasting effect than cortisone, without its harsher side effects.

Where more than one joint is involved — such as the thumb CMC joint or the radiocarpal joint — it can help to inject both joints at the same time.

Surgery for severe STT joint arthritis

Surgery is considered when conservative treatment fails to relieve symptoms, and the condition significantly affects daily life.

Resection arthroplasty removes part of the trapezium to relieve pain while preserving motion and is often combined with tendon interposition or soft-tissue reconstruction.

STT joint fusion (arthrodesis) fuses the bones of the STT joint to eliminate pain. It reduces joint mobility but preserves overall wrist stability and strength.

Joint replacement, though less common, is an option for patients seeking to keep motion while reducing pain.

Frequently asked questions about STT arthritis

What’s the difference between STT arthritis and thumb (CMC) arthritis?

They affect adjacent joints on the thumb side of the wrist and often coexist — in one study, about 65% of X-rays with thumb arthritis also showed STT arthritis. Both cause thumb-side wrist pain with gripping and pinching, making them hard to tell apart. An examination and X-ray usually distinguish them, and where both are involved, we sometimes inject both joints together.

Can STT arthritis be treated without surgery?

Yes — most cases are managed without surgery, using activity modification, a wrist splint, physiotherapy, anti-inflammatories, and injections. Surgery is reserved for severe arthritis that hasn’t responded and is significantly affecting daily life.

What activities make STT arthritis worse?

Pinching, gripping, and repetitive wrist movements are the main aggravators, so tasks like opening jars, wringing out cloths, and heavy lifting tend to flare it. A splint and activity modification help reduce the load on the joint.

Does a cortisone injection help STT arthritis?

It can. An ultrasound-guided cortisone injection into the STT joint reduces inflammation and pain, and can be a useful way to delay surgery. Hyaluronic acid is an alternative that may last longer without the side effects of cortisone.

Is STT arthritis serious?

It isn’t dangerous, but it can meaningfully affect grip and pinch, and therefore daily activities and quality of life. Early diagnosis and treatment help keep the wrist functioning and delay or avoid surgery.

Final word from Sport Doctor London about scaphotrapeziotrapezoidal joint arthritis

STT joint arthritis can significantly affect wrist function and quality of life. Early diagnosis, through clinical assessment and imaging, is key to effective management. It’s sometimes confused with other conditions, such as thumb arthritis or De Quervain’s tenosynovitis, so an accurate diagnosis matters.

If you suspect STT joint arthritis, Dr Masci can assess you in London, including an ultrasound in the clinic. Contact the team here or call +44 (0) 203 488 0350.