Thumb CMC arthritis usually produces pain directly at the base of the thumb and is often aggravated by pinch, grip and joint compression. De Quervain tenosynovitis involves the APL and EPB tendons near the radial styloid and is more strongly provoked by thumb and wrist tendon loading. Because the two regions are close together, diagnosis should be based on symptom reproduction and anatomy rather than location alone.
The two conditions are common, they can occur in the same hand, and they are treated differently, so it is worth getting the distinction right.
Why the x-ray is only part of the answer
Studies reviewed
10
on radiographic progression of thumb CMC arthritis, with 32 to 289 subjects each
Progression estimates
20%–70%
depending on follow-up length and scoring system
PMID 35415524
Radiographs describe joint structure. They do not by themselves show which structure is producing the pain.
Two structures a few centimeters apart
The thumb CMC joint, also called the first carpometacarpal or trapeziometacarpal joint, sits at the base of the thumb where the first metacarpal meets the trapezium, a small carpal bone. It is a saddle joint that allows the thumb to oppose the fingers, pinch and grasp. The thumb CMC joint trades stability for mobility, which leaves a small joint carrying substantial forces during pinch and grip.
De Quervain tenosynovitis affects two tendons, the abductor pollicis longus (APL) and extensor pollicis brevis (EPB), as they pass through the first dorsal compartment, a tunnel over the radial styloid at the end of the radius. The radial styloid sits closer to the wrist than the CMC joint and slightly toward the back of the hand.
So one condition is a joint problem at the thumb base, and the other is a tendon and sheath problem just above it. The overlap in location is why both are often called "thumb pain" or "wrist pain" by patients.
What thumb CMC arthritis feels like
- Aching pain at the base of the thumb, sometimes described as deep in the joint
- Pain with pinching: turning keys, opening jars, fastening buttons, pulling up zippers
- Pain with gripping and twisting, such as wringing a towel or using tools
- Weakness of pinch and grip, and dropping objects
- Stiffness after rest or heavy use
- In more advanced disease, a prominent bump at the thumb base and a thumb that sits more tucked in
Thumb CMC symptoms often become most obvious during pinch because substantial joint forces are generated during everyday gripping and opposition tasks.
What De Quervain's feels like
- Pain over the radial styloid, sometimes spreading up the forearm or toward the thumb
- Pain with thumb extension and abduction, lifting with the thumb spread, and moving the wrist toward the little-finger side
- Pain with repetitive hand use such as lifting a baby, texting or using a mouse
- Sometimes visible swelling or thickening over the first compartment
- Pinch can be uncomfortable too, but the most painful tasks usually load the tendons rather than compress the joint
Why location alone is not enough
The CMC joint and the first dorsal compartment are close enough that pain from either can be felt across the same small area. Pain also spreads: CMC arthritis can ache toward the wrist, and De Quervain's can ache toward the thumb. Patients often point with a whole finger rather than a fingertip.
That is why the examination looks for which structure reproduces the familiar pain under specific loads, not just where the pain is felt at rest.
Telling them apart
| Feature | Thumb CMC arthritis | De Quervain tenosynovitis |
|---|---|---|
| Structure | First CMC joint (first metacarpal and trapezium) | APL and EPB tendons in the first dorsal compartment |
| Main location | Base of the thumb, just beyond the wrist crease | Radial styloid, closer to the wrist |
| Typical aggravators | Pinch, grip, twisting, joint compression | Thumb extension and abduction, wrist ulnar deviation, lifting |
| Useful exam findings | Pain with CMC compression and rotation, joint tenderness, sometimes prominence or instability | Tenderness and swelling over the first compartment, pain with resisted thumb extension and abduction |
| Helpful imaging | Radiographs | Ultrasound |
| Common in | Middle-aged and older adults | New parents and people with repetitive hand use, among others |
These patterns overlap, and both conditions can be present in the same thumb.
The exam tests and their limits
CMC compression and grind maneuvers. The examiner compresses the thumb metacarpal into the trapezium and rotates it. Joint compression can support CMC involvement when it reproduces the patient's familiar pain, but no single provocative maneuver should be treated as a stand-alone diagnosis. A positive test does not prove CMC arthritis on its own, and a negative test does not rule it out.
Finkelstein, Eichhoff and WHAT tests. These stretch or load the APL and EPB tendons. They are useful for De Quervain's, but stretching the thumb also moves and loads the CMC joint, so a painful Finkelstein test can occur with CMC arthritis too. Where the pain appears during the test matters as much as whether it hurts. The tendon tests are discussed in more detail in De Quervain's vs intersection syndrome.
Resisted tendon loading. Resisted thumb extension and abduction load the first compartment tendons without compressing the CMC joint as much. Pain with resisted loading and tenderness over the radial styloid points toward De Quervain's.
Pinch and grip. Key pinch, tip pinch and grip are tested for pain and strength. These are functional measures that matter for daily life, and they help track progress over time.
Questions the exam tries to answer
- Is the pain at the thumb base, over the radial styloid or somewhere in between?
- Does pinch or CMC compression reproduce it, or does resisted tendon loading?
- Is there swelling over the first dorsal compartment, or prominence and instability at the CMC joint?
- Are there nerve symptoms, or a history of a fall?
- Which daily tasks are limited, and how much?
The answers usually point clearly toward one structure. When they do not, imaging helps.
Imaging
Radiographs show CMC arthritis: joint space narrowing, bone spurs, subluxation of the metacarpal and changes in the trapezium. They do not show tendon sheath inflammation. Ultrasound can show De Quervain's directly: a thickened first compartment, fluid in the sheath and sometimes a septum dividing the compartment.
Imaging severity and symptom severity are not interchangeable. A systematic review of radiographic progression in thumb CMC arthritis found 10 studies, ranging from 32 to 289 subjects. Progression estimates varied from 20% to 70%, depending on follow-up length and scoring system, and there was no uniformly accepted imaging method or scoring system (Shapiro, 2020).
Older adults often have some radiographic CMC change. If the exam points to the first dorsal compartment instead, an x-ray showing arthritis does not settle the question.
When both are present
CMC arthritis and De Quervain's can coexist, and both are common in middle-aged and older adults. When both are present, the exam tries to identify which is driving the main complaint, and the plan may address both.
Other causes of radial thumb and wrist pain
- STT joint arthritis: pain slightly closer to the wrist, between the scaphoid, trapezium and trapezoid. It may occur on its own or with CMC arthritis (Alder, 2023). See thumb-base pain: CMC vs STT vs FCR.
- Flexor carpi radialis tendon: pain on the palm side of the wrist near the thumb, provoked by resisted wrist flexion.
- Intersection syndrome: pain and sometimes crepitus a few centimeters up the back of the forearm.
- Superficial radial nerve: burning, tingling or sensitivity on the back of the thumb is nerve pain, not arthritis or tenosynovitis.
- Thumb MCP joint: pain or instability at the middle knuckle of the thumb is a separate joint problem.
- Scaphoid fracture: radial wrist pain after a fall onto an outstretched hand, with snuffbox tenderness, needs imaging.
Treatment differs
For symptomatic thumb CMC arthritis, current high-level evidence supports hand exercise, multimodal care and splinting. A network meta-analysis of 22 studies found clinically important short-term pain improvement with multimodal treatment and hand exercise, while a rigid CMC-MCP splint showed medium-term benefit for pain and function (Thakker, 2025). A separate network meta-analysis of 11 trials and 619 patients supported thumb orthoses for pain (Marotta, 2021). Focused shockwave therapy has small direct randomized evidence, reviewed in shockwave therapy for thumb CMC osteoarthritis.
For De Quervain's, corticosteroid injection with immobilization is the established first-line treatment, with loading and a thumb spica splint as part of care. Shockwave evidence for De Quervain's is a separate body of research and should not be mixed with the CMC trials.
Splints differ too. A CMC or CMC-MCP splint for arthritis aims to support the basal joint during pinch and grip, while a thumb spica splint for De Quervain's immobilizes the thumb and wrist to rest the first-compartment tendons. Bracing that suits one condition is not automatically right for the other.
Rehabilitation should restore useful pinch and grip capacity rather than simply protecting the thumb indefinitely, but the exercises and progressions are chosen for the diagnosis.
When to seek prompt assessment
A fall onto an outstretched hand with bone tenderness, a sudden thumb injury with instability, marked swelling or deformity, a hot, red, swollen joint, or progressive numbness should be assessed promptly rather than managed as arthritis or tendon pain.
How Novo approaches thumb-base pain
We localize the pain to the CMC joint, the radial styloid or elsewhere, test pinch, grip, joint compression and tendon loading, screen for nerve and bone causes, and use radiographs or ultrasound when they change the plan. See how we approach thumb CMC arthritis and thumb-base pain, and for tendon-related wrist pain, wrist and forearm tendon pain.
References
- Shapiro LM, McQuillan TJ, Kerkhof FD, Ladd A. Radiographic progression of thumb CMC osteoarthritis: a systematic review. Journal of Hand Surgery Global Online. 2020;2(6):343-348. PMID 35415524. (link)
- Thakker A, Ramchandani JP, Divall P, Sutton A, Johnson N, Dias J. What are the most clinically effective nonoperative interventions for thumb carpometacarpal osteoarthritis? An up-to-date systematic review and network meta-analysis. Clinical Orthopaedics and Related Research. 2025;483(4):719-736. PMID 39560669. (link)
- Marotta N, Demeco A, Marinaro C, et al. Comparative effectiveness of orthoses for thumb osteoarthritis: a systematic review and network meta-analysis. Archives of Physical Medicine and Rehabilitation. 2021;102(3):502-509. PMID 32668206. (link)
- Alder KD, Feroe AG, Karim KE. Management of scaphotrapeziotrapezoid osteoarthritis: a critical analysis review. JBJS Reviews. 2023;11(10):e23.00093. PMID 38096476. (link)
- Patrick NC, Hammert WC. Hand and wrist tendinopathies. Clinics in Sports Medicine. 2020;39(2):247-258. PMID 32115083. (link)
