What happens in the first carpal tunnel?
The tendons pass through osteofibrous canals lined with a gliding sheath. The first carpal tunnel contains two tendons: the abductor pollicis longus and the extensor pollicis brevis. With repeated repeated movements, the shell and wall of the canal thicken, the lumen narrows, and the tendon glide is disrupted. There is pain, sometimes a clicking or squeaking sound when moving. Over time, the canal tissue becomes denser, so early treatment is more effective.
- Narrowing of the first carpal tunnel
- Thickening of the canal wall and tendon sheath
- Thumb tendon slip disorder
- Sometimes - an additional partition inside the canal
Causes and risk factors
Most often, the disease is associated with repetitive stress: thumb abduction combined with wrist tilt. The classic scenario is a mother who lifts her child dozens of times a day, picking him up under her arms. Other common situations include working with tools, sewing, playing musical instruments, typing for long periods of time, and holding the phone for long periods of time. Hormonal changes during pregnancy and breastfeeding contribute to tissue swelling. The risk is higher with diabetes, rheumatoid arthritis and thyroid disease.
- Frequently picking up a child
- Monotonous brush work: printing, sewing, tools
- Pregnancy and lactation period
- Direct trauma to the wrist area
- Rheumatoid arthritis
- Diabetes mellitus and thyroid diseases
- Age 30–50 years, female
Symptoms
The pain is located on the side of the wrist, where the base of the thumb meets the forearm. It intensifies when gripping, turning a key, opening a can, squeezing out laundry, and when moving the hand toward the little finger. A slight swelling is often noticeable, and sometimes a dense lump can be felt. Some people report squeaking or clicking noises when they move their thumb. The pain may radiate up the forearm or down into the finger, and as it progresses, it also appears at rest.
- Pain at the base of the thumb on the side of the radius
- Increased pain when gripping and turning the hand
- Swelling and compaction above the canal
- Creaking or clicking noise when you move your finger
- Weak grip, objects slip out
- Pain radiating to the forearm
Diagnostics
The key technique is the Finkelstein test: the thumb is clenched into a fist and the hand is moved towards the little finger; sharp pain over the canal confirms the diagnosis. The doctor also checks sensation in the fingers to rule out carpal tunnel syndrome and evaluates the joint at the base of the big toe. Ultrasound shows thickening of the tendon sheath, fluid in the canal, and the presence of a septum, which is important when planning an injection or surgery. X-rays are prescribed to exclude arthrosis of the carpometacarpal joint and the consequences of a fracture; MRI is rarely prescribed, if the picture is unclear.
- Finkelstein test
- Inspection and palpation of the first carpal tunnel
- Ultrasound of the wrist joint and tendons
- X-ray of the wrist joint
- MRI for doubtful diagnosis
- Testing finger sensitivity
Treatment and prevention
The first step is to reduce the load: change the way you lift the child, take breaks from work, temporarily abandon movements that cause pain. The orthosis, which fixes the wrist and thumb, is worn for several weeks, especially during the day when there is a load. The doctor may prescribe short-course anti-inflammatory drugs, ultrasound therapy, phonophoresis, and magnetic therapy. In case of severe pain, a glucocorticoid injection into the canal is used - it is performed by a doctor, preferably under ultrasound control. If the pain persists for several months, a minor operation is suggested: dissection of the canal wall, after which the tendons slide freely. Breastfeeding does not interfere with treatment, but the choice of medications during this period is discussed with your doctor.
- Wrist and thumb brace
- Changing the technique of lifting the child and working movements
- Breaks and unloading of the hand
- Ultrasound therapy and phonophoresis
- Anti-inflammatory drugs as prescribed by a doctor
- Ultrasound-guided glucocorticoid injection
- Surgery if conservative treatment is ineffective
- Gradual strengthening of the hand muscles after the pain subsides