|Finkelstein's test for DeQuervain's tenosynovitis|
De Quervain syndrome ([də kɛʁvɛ̃]; also known as BlackBerry thumb, texting thumb, gamer's thumb, washerwoman's sprain, radial styloid tenosynovitis, de Quervain disease, de Quervain's tenosynovitis, de Quervain's stenosing tenosynovitis, mother's wrist, or mommy thumb), is a tenosynovitis of the sheath or tunnel that surrounds two tendons that control movement of the thumb.
Signs and symptoms
Symptoms are pain at the radial side of the wrist, spasms, tenderness, occasional burning sensation in the hand, and swelling over the thumb side of the wrist, and difficulty gripping with the affected side of the hand. The onset is often gradual. Pain is made worse by movement of the thumb and wrist, and may radiate to the thumb or the forearm.
The cause of de Quervain's disease is not established. Evidence regarding a possible relation with occupational risk factors is debated. A systematic review of potential risk factors discussed in the literature did not find any evidence of a causal relationship with occupational factors. However, researchers in France found personal and work-related factors were associated with de Quervain's disease in the working population; wrist bending and movements associated with the twisting or driving of screws were the most significant of the work-related factors. Proponents of the view that De Quervain syndrome is a repetitive strain injury consider postures where the thumb is held in abduction and extension to be predisposing factors. Workers who perform rapid repetitive activities involving pinching, grasping, pulling or pushing have been considered at increased risk. Specific activities that have been postulated as potential risk factors include intensive computer mouse use, trackball use, and typing, as well as some pastimes, including bowling, golf, fly-fishing, piano-playing, sewing, and knitting.
Women are affected more often than men. The syndrome commonly occurs during and after pregnancy. Contributory factors may include hormonal changes, fluid retention and—more debatably—lifting.
De Quervain syndrome involves noninflammatory thickening of the tendons and the synovial sheaths that the tendons run through. The two tendons concerned are those of the extensor pollicis brevis and abductor pollicis longus muscles. These two muscles run side by side and function to bring the thumb away from the hand; the extensor pollicis brevis brings the thumb outwards radially, and the abductor pollicis longus brings the thumb forward away from the palm. De Quervain tendinopathy affects the tendons of these muscles as they pass from the forearm into the hand via a fibro-osseous tunnel (the first dorsal compartment). Evaluation of histopathological specimens shows a thickening and myxoid degeneration consistent with a chronic degenerative process, as opposed to inflammation. The pathology is identical in de Quervain seen in new mothers.
De Quervain syndrome is diagnosed clinically, based on history and physical examination, though diagnostic imaging such as x-ray may be used to rule out fracture, arthritis, or other causes, based on the patient's history and presentation. Finkelstein's test is a physical exam maneuver used to diagnose de Quervain syndrome. To perform the test, the examiner grasps the thumb and sharply deviates the hand toward the ulnar side. If sharp pain occurs along the distal radius (top of forearm, about an inch below the wrist), de Quervain's syndrome is likely. While a positive Finkelstein's test is often considered pathognomonic for de Quervain syndrome, the maneuver can also cause pain in those with osteoarthritis at the base of the thumb.
Differential diagnoses include:
- Osteoarthritis of the first carpo-metacarpal joint
- Intersection syndrome—pain will be more towards the middle of the back of the forearm and about 2–3 inches below the wrist
- Wartenberg's syndrome
As with many musculoskeletal conditions, the management of de Quervain's disease is determined more by convention than scientific data. From the original description of the illness in 1895 until the first description of corticosteroid injection by Jarrod Ismond in 1955, it appears that the only treatment offered was surgery. Since approximately 1972, the prevailing opinion has been that of McKenzie (1972) who suggested that corticosteroid injection was the first line of treatment and surgery should be reserved for unsuccessful injections. A systematic review and meta-analysis published in 2013 found that corticosteroid injection seems to be an effective form of conservative management of de Quervain's syndrome in approximately 50% of patients, although more research is needed regarding the extent of any clinical benefits. Efficacy data are relatively sparse and it is not clear whether benefits affect the overall natural history of the illness.
Most tendinoses are self-limiting and the same is likely to be true of de Quervain's although further study is needed.
Palliative treatments include a splint that immobilized the wrist and the thumb to the interphalangeal joint and anti-inflammatory medication or acetaminophen. Systematic review and meta-analysis do not support the use of splinting over steroid injections.
Surgery (in which the sheath of the first dorsal compartment is opened longitudinally) is documented to provide relief in most patients. The most important risk is to the radial sensory nerve.
Some physical and occupational therapists suggest alternative lifting mechanics based on the debatable theory that the condition is due to repetitive use of the thumbs during lifting such as seen in new mothers picking up their child. Physical/Occupational therapy can suggest activities to avoid based on the theory that certain activities might exacerbate one's condition, as well as instruct on strengthening exercises based on the theory that this will contribute to better form and use of other muscle groups, which might limit irritation of the tendons. This approach may risk reinforcing catastrophic thinking (pain catastrophizing) and kinesiophobia.
Some physical and occupational therapists use other treatments based on the rationale that they reduce inflammation and pain and promote healing: UST, SWD, or other deep heat treatments, as well as TENS, acupuncture, or infrared light therapy, and cold laser treatments. However, the pathology of the condition is not inflammatory changes to the synovial sheath and inflammation is secondary to the condition from friction. Teaching patients to reduce their secondary inflammation does not treat the underlying condition but may reduce their pain.
Society and culture
BlackBerry thumb is a neologism that refers to a form of repetitive strain injury (RSI) caused by the frequent use of the thumbs to press buttons on PDAs, smartphones, or other mobile devices. The name of the condition comes from the BlackBerry, a brand of smartphone that debuted in 1999, although there are numerous other similar eponymous conditions that exist such as "Wiiitis", "Nintendinitis", "Playstation thumb", "texting thumb", "cellphone thumb", "smartphone thumb", "Android thumb", and "iPhone thumb". The medical name for the condition is De Quervain syndrome and is associated with the tendons connected to the thumb through the wrist. Causes for the condition extend beyond smartphones and gaming consoles to include activities like golf, racket sports, and lifting.
Symptoms of BlackBerry thumb include aching and throbbing pain in the thumb and wrist. In severe cases, it can lead to temporary disability of the affected hand, particularly the ability to grip objects.