What Is De Quervain’s Tenosynovitis? AKA Mommy Thumb Or Texter’s Thumb

Thumb pain: Mothers and fathers get it from picking up their babies… Gamers from their controllers… Cell phone users from too much texting – And let’s not forget percussionists, golfers and anglers!

It’s not a SIMPLE case of Tendonitis. It’s a more complicated tendon syndrome known as a ‘Tenosynovitis’ in this case, one that involves two thumb tendons and the special wrappers called ‘Synovial Sheaths’ around them where they cross the wrist.

• TENO means tendon – (Tendons are the “ropes” which connect muscles to bones)
• SYNO refers to the Synovial Sheaths – (which are special protective tendon sleeves)
• ITIS had to do with irritation, inflammation and pain – (although inflammation is not the primary issue and is often wrongly and unfairly blamed – MORE on that later!)

Fritz De Quervain was a Swiss surgeon, who first described the condition about a century ago, and so it’s called ‘De Quervain’s Tenosynovitis.’ (Wiki)

The Common Symptoms

The pain is felt on the back side of the thumb at the wrist (not the palm side) and it ranges from a dull ache to fiery, burning, even stabbing, pain with certain thumb and wrist motions.

• Pain at the base of the dorsal thumb (back side of wrist on thumb side)
• Stabbing pain with gripping and twisting motions (forget opening jars!)
• Tenderness to the touch around the dorsal, radial wrist (back, thumb side)
• Swelling / stiffness on the thumb side of the back of the wrist / lower forearm
• A “snapping” or “catching” sensation in the wrist area with thumb movement
• And fluid-filled cysts sometimes appear in this area at the same time

It can be a shockingly painful and disruptive injury that can begin to affect all your basic, daily activities. (How many activities DON’T require your thumbs!?)

In this article, we’re going to cover WHO gets it, WHAT it is – and what it’s NOT, including similar injuries that can either mimic it or sometimes overlap with it…

Medical Term Variants

• De Quervain’s Stenosing Tenosynovitis
• De Quervain’s Tendonitis or Tendinosis
• De Quervain’s Tendinopathy
• Radial Styloid Tenosynovitis
• Wrist Tenosynovitis

Some of these medical diagnostic terms are basically synonymous but there are some important nuances and distinctions that we’ll explore as we get deeper.

Common Name Variants

This painful tendon disorder goes by many names and is suffered my many people engaged in a range of activities.

• Texter’s / Texting / Smartphone Thumb
• Mommy Thumb (or Daddy Thumb)
• New Mother’s Syndrome
• Mother’s Wrist
• Designer’s Thumb
• Gamer’s Thumb

And there are likely several, if not a dozen more, although these are general terms that are used casually by regular people and may refer to pain in other parts of the thumb or wrist.

‘Smartphone Thumb’ or ‘Texter’s Thumb,’for example, can also be Osteoarthritis of one or more of the thumb joints in more severe, chronic cases – and, according to the Daily Mail, is becoming a major problem in the US:

‘Smartphone Thumb’ Becoming a Big Issue in the US | https://t.co/hmK7pwtRMQ

— Tennis Elbow Tutor (@TennisElbowTutr) January 1, 2024

Generally, adult and middle-aged people (30-50 years old) suffer De Quervain’s the most – and Women are a lot much more likely to develop it – Especially when pregnant or postpartum. (Source)

The Common Causes Of De Quervain’s

The activities that lead to and cause this fairly common thumb tendon pain are countless – Basically, any thumb-intensive sport or activity:

• Picking up a baby / holding a baby while nursing
• Hammering / construction / using tools, in general
• Playing the piano or drums (and a few other instruments)
• Golf and racket sports
• Skiing (poles)
• Gardening
• Fly Fishing

New mothers are particularly prone to this injury from the repetitive lifting and awkward wrist positions needed to support the newborn baby’s head while cradling and nursing, hence the common name ‘Mommy Thumb.’

But expectant mothers are also prone to it due, in part, to hormonal changes and fluid retention.

“Fluid retention during the third trimester of pregnancy and repetitive picking up of the baby in particular positions that are needed for nursing and care of the child predispose the patient to De Quervain disease.”

PubMed | Arch Bone Jt Surg. 2021 May; 9(3): 345–349

Hormonal changes during pregnancy and after birth are related to Estrogen, which tends to increase fluid retention, and Relaxin, which increases laxity (flexibility / looseness) in ligaments and tendons. bodybeyondbirth.com

And whether it’s Mother’s Thumb or it’s related to another cause there’s often a common theme.

The wrist and thumb holding / gripping positions typically involve what’s called ‘Wrist Deviation’ which comes in two varieties:

1. Radial Deviation: A “Sideways” wrist motion toward thumb side of wrist
2. Ulnar Deviation: A “Sideways” wrist motion toward pinkie side of wrist

Sometimes the thumb is wrapped around the hammer, club, pole or racket and sometimes the thumb is straight rather than curled with the fingers – as with the most common golf club grip.

Sometimes your thumb even gets pressed back toward you, like when you pick up your child repeatedly, a common dynamic with Mother’s Wrist / Thumb.

But whatever the specific motion, it’s just as much a wrist problem as a thumb problem, especially considering that the pain is localized on the thumb side of the wrist.

It’s also important to understand that De Quervain’s is not an ‘Acute’ injury like a cut, bruise, sprain or fracture – but, rather a cumulative, and ‘Chronic’ injury; it happens slowly and builds to a crescendo.

These issues are usually known as Repetitive Strain Injuries / RSIs.

What Is Tenosynovitis?

As we covered briefly at the beginning, Synovial Sheaths are the Synovial Fluid filled wrappers or tubes surrounding certain tendons.

Their purpose is to cushion and protect certain longer tendons where they are subject to friction and vulnerable to injury. (Mostly in the hands and feet.)

The majority of muscles that articulate your thumb and fingers are found in your forearm and have long tendons, which, in some cases, reach nearly to your finger tips.

These tendons of your thumb and fingers (as well as the wrist) are particularly exposed and vulnerable as they approach and cross your wrist joints.

And they all have Synovial Fluid filled sheaths surrounding and protecting them in that area.

When all is well, your tendons glide back and forth beautifully, without friction, as you move your wrist, fingers and thumb.

Here’s an excellent illustration of the two thumb tendons involved in De Quervain’s Tennosynovitis.

The muscles (red) become tendons (white) and pass into their protective Synovial Sheaths (purple) and under the Extensor Retinaculum (white)

This area and just beyond it, toward the back of the thumb is where the syndrome gets painful, due to swelling, fibrosis and degenerative changes.

However, with Tenosynovitis, there is a process (driven by the repetitive motions involved) that leads to increasing friction, irritation, inflammation and swelling between your tendons and your sheaths.

This is the early phase – sometimes called the ‘Acute Stage’ and if it continues, it leads to a more advanced, ‘Chronic’ stage of the syndrome.

Which brings us to another key term and part of one of the common diagnostic names:

Stenosis or Stenosing “a part of a passage or opening in the body that has become abnormally narrow, or the act of this happening” [Dictionary Ref.]

And when we put that together we get:

Stenosing Tenosynovitis – The narrowing of a Synovial Sheath, due to fibrosis and thickening of the tendon and/or its sheath, which increases the pressure and friction between the tendon and the sheath.

This is the same dynamic involved in what’s called ‘Trigger Finger’ – In fact, another name for De Quervain’s Stenosing Tenosynovitis is ‘Trigger Thumb.’

‘Adhesions’ – Adhesions are areas where different layers of tissue are sticking and binding to each other. (Think Velcro!)

This is another key term to know. Its critical when it comes to understand the deeper causes of this painful syndrome.

Scar Tissue is very similar (perhaps synonymous) but it may be helpful to think of the adhesion formation process as a gradual, degenerative one, and to picture Scar Tissue as the rapid result of Acute, traumatic injury, like a tear.

But, it’s a bit of a semantic distinction, since the result is the same; stuff gets stuck.

And at the epicenter of the Tenosynovitis injury dynamic is the point where you have your tendons adhering – literally sticking to – your own sheaths.

AND your tendon sheaths adhering to the other, surrounding tissues that make up the ‘compartment’ that the two tendons and their sheaths pass through on their way to the wrist.

The Compartment

There are several compartments in which different tendons – or groups of tendons – pass through at your wrist. The one involved with De Quervain’s, contains two tendons:

1. The Abductor Pollicis Longus and
2. The Extensor Pollicis Brevis

(Pollicis is Latin for “of the thumb.”)

And as your tendons abnormally thicken, bind to their own sheaths and swell, this compartment becomes narrower and more restricted.

As this gets progressively worse, those two tendons can adhere to your compartment itself as it fills in with fibrotic adhesions / scar tissue.

NOW, we’re getting to the essence of the problem (especially, when it starts to progress into the chronic / persistent form of the injury) and here’s how and why this happens.

The Injury Dynamic / Vicious Cycle At Work

In the case of Tenosynovitis, as with all tendon disorders, there is a shortening of the muscles involved that increases the tension on your tendons and the friction between your tendons and their sheaths.

With increased friction comes irritation, inflammation and the formation and build up of adhesions / scar tissue progressively over time (over weeks or months.)

As the space in the compartment and within the Synovial Sheaths becomes narrower and more restricted you get even more friction, irritation, inflammation, fibrosis and swelling.

And swelling increases the pressure in the limited space, creating even more friction and feeding the vicious cycle – And increasing the pain, of course.

(Carpal Tunnel Syndrome, which occurs on the opposite side of the wrist, is an even more serious version of this dynamic, because the nerve that shares that compartment can also be damaged as the syndrome escalates.)

The Fall Guy / Patsy: Inflammation

There is a great deal of confusion, misunderstanding and outright disagreement that comes into play at this point, however.

Because the symptom all too often gets blamed for causing the problem – when, in fact, he’s just the “middle man” or “patsy.”

The symptom is inflammation, which causes two other symptoms: Swelling and pain.

If you’ve had De Quervain’s Tenosynovitis for some time and read medical explanations or received conventional medical treatment, you’re undoubtedly familiar with how inflammation gets blamed and targeted.

There are prescriptions for anti-inflammatory pills and gels, admonitions to ice your tendons and a Cortisone Shot or two if all of that doesn’t help.

All of which often fails for one simple reason:

Attacking and suppressing inflammation can’t help you heal.

Why not? Because inflammation IS a symptom of your healing process at work – In the first place.

Inflammation is just a “middle man” because it’s a reaction to injury or irritation – It’s not the cause (even though it DOES cause “downstream” symptomatic effects of its own: swelling and pain.)

And what’s worse, as the syndrome persists and moves from the early, acute phase to the chronic stage, inflammation becomes the least of your worries.

Tendinosis: The Tooth Decay Of Tendons

With most tendon disorders, there is often an early ‘Acute’ stage where your tendon is just starting to reach a point of overload and irritation, and your body is attempting to heal it.

Some inflammation may be present at this point, which is just your healing process at work as your body tries to heal and REgenerate your tendon.

However, what so often happens, as time passes and the excessive load on your tendon continues, your body fails to heal the tendon (and/or the tendon sheath) and it becomes a ‘Chronic’ injury.

And a chronic tendon injury is not just a persistent, longer-term condition – It’s a tendon condition that has slipped into a stagnant, degenerative state.

Tendinosis – A degenerative, failed-healing state marked by collagen breakdown and disorganization.

When you dig deeper into the medical research you begin to see the recognition of this:

“The exact pathophysiology of DQT is unknown, but it appears to be related to thickening of the tendon sheath and the overlying extensor retinaculum, as well as thinning and degeneration of the affected tendons.”

“Involvement of inflammation remains controversial but intrinsic degeneration due to overuse appears to be the most likely mechanism.”

Management of de Quervain Tenosynovitis | Challoumas, MD; et al
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2811119

Notice that the medical researchers admit that the role of inflammation is “controversial.”

Again, it’s inevitable that inflammation will appear whenever there is irritation and damage as the body attempts to repair that damage.

In this case, the synovial lining becomes irritated and inflamed and may swell in the early stages of the syndrome…

However, in the later stages, as that process fails and the tissues break down there isn’t much if any inflammation any to be found.

“While the exact cause of De Quervain Tenosynovitis is unclear, it has been attributed to myxoid degeneration with fibrous tissue deposits and increased vascularity rather than acute inflammation of the synovial lining.”

“This deposition results in the thickening of the tendon sheath, painfully entrapping the abductor pollicis longus and extensor pollicis brevis tendons.”

De Quervain Tenosynovitis | Satteson; Tannan
https://www.ncbi.nlm.nih.gov/books/NBK442005/

Note the references to “thinning” and “degeneration” of the tendons themselves and the “thickening” of their surrounding tendon’s sheaths.

What they’re describing here is primarily a degenerative process in which the tendon and/sheath breaks down and literally “rots.”

And how abnormal, “fibrotic” (Scar Tissue) starts filling in the synovial lining space, which entraps and binds the two thumb tendons causes pain and feeding the vicious cycle.

But, please don’t panic! This doesn’t happen overnight!

This doesn’t even happen in all cases – Only in moderate to severe chronic ones – and it usually takes many months.

And there are many degrees of severity of this, most of which are likely reversible without surgery (in my opinion.)

But once your tendons have reached this degenerative state, which has more in common with tooth decay than it has with inflammatory “Tendonitis” or Tenosynovitis…

Then it usually does significant energy and effort to stimulate a reversal and recover.

It’s not going to go away from some pills, some ice and a brace.

The BIG question is: Do the standard inflammation-fighting “treatments” actually WORSEN the injury?

But rather than get into treatment just yet, let’s stick with the “What is it?” and “What causes it?” discussion and look at other issues with similar pain patterns.

(My next article will be on the standard treatment protocol and why it’s a terrible strategy.)

Other Causes of Similar (Or Overlapping) Pain

Intersection Syndromes

These syndromes are a Kissing Cousins to De Quervain’s; essentially, it’s the same thing happening in a slightly different place just an inch or two away – AND quite possibly at the same time.

The term “intersection” is used because these overuse syndromes occur at the intersections of two major wrist tendons – and the thumb tendons involved in De Quervain’s (and one other thumb tendon) where the thumb tendons cross over the wrist tendons.

Proximal Intersection Syndrome – A Tenosynovitis occurring around the intersection of the first extensor compartment (which holds the Abductor Pollicis Longus and Extensor Pollicis Brevis tendons) and the second extensor compartment (which holds the Extensor Carpi Radialis Longus and Brevis tendons.)

https://radiopaedia.org/articles/proximal-intersection-syndrome-1

Distal Intersection Syndrome – Is a Tenosynovitis that happens between the second compartment (which holds the two Extensor Carpi Radialis Tendons) and the third dorsal compartments (which contains the Extensor Pollicis Longus tendon)

https://radiopaedia.org/articles/distal-intersection-syndrome

The proximal version is more closely related to De Quervain’s because it involves the same thumb tendons, so it’s not unheard of to develop one and then the other or even both at the same time.

Wartenberg’s Syndrome

Wartenberg’s Syndrome – Is a nerve disorder that occurs in the same area involving entrapment and compression of the superficial branch of the Radial Nerve.

Symptoms often include pain over the lower, thumb side of the forearm and wrist, as well as numbness and tingling over the back, thumb side of the hand.

https://www.physio-pedia.com/Wartenberg%27s_Syndrome

Thumb Joint Osteoarthritis

Carpometacarpal Joint Arthritis – The Carpometacarpal Joint is underneath the area where the symptoms are felt with De Quervain’s.

Arthritis in this joint, also known as the basal joint, can easily mimic (or overlap) with the De Quervain’s / Mommy Thumb pain pattern.

This joint is highly susceptible to Arthritis as people age. (Osteoarthritis is a common, degenerative joint condition that involves the cartilage inside the joint wearing out and breaking down.)

https://orthoinfo.aaos.org/en/diseases–conditions/arthritis-of-the-thumb/

Triscaphoid (STT) joint arthritis – which is also common, is another possibility – although the pain pattern is usually felt more on the palm side of the base of the thumb.

The ‘Triscaphoid’ or Scaphotrapeziotrapezoidal’ Joint of the wrist is just up from the CMC joint of the thumb and involves three Carpal bones; the Scaphoid, Trapezium and Trapezoid.