Carpal tunnel syndrome

What is carpal tunnel syndrome?

In carpal tunnel syndrome, the median nerve is narrowed at the level of the wrist. The so-called carpal tunnel is a natural passage made up of carpal bones and a strong ligamentous roof. If it becomes too narrow in this tunnel, the nerve reacts sensitively: initially with abnormal sensations, later with loss of sensitivity and muscle weakness.

• Affected fingers: thumb, index and middle fingers as well as the thumb-side half of the ring finger
• Frequency: especially in people who work a lot with their hands, during pregnancy or with metabolic diseases
• Course: gradual; Treated early and usually easily controllable

Anatomy: The carpal tunnel at a glance

The carpal tunnel is located on the inside of the wrist. It is bordered bony by the carpal bones and closed above by the tight flexor retinaculum (carpal roof).

• Contents: median nerve and nine flexor tendons of the fingers
• Tight conditions: Even small increases in volume (e.g. tendon sheath irritation, tissue swelling) can increase the pressure in the tunnel
• Vulnerability of the nerve: The median nerve supplies sensitive skin areas and the ball of the thumb muscles

Symptoms: How do I recognize carpal tunnel syndrome?

The symptoms often begin gradually. Nighttime discomfort in the thumb, index and middle fingers is typical. Hands are often shaken to relieve the tingling sensation.

• Tingling, pins and needles, numbness in the mentioned fingers
• Night pain and morning stiffness, relieved by shaking
• Pain that can radiate to the forearm
• Dropping objects, grasping unsteadily (e.g. when opening bottles)
• Decrease in fine motor skills (buttoning, typing)
• Later: weakness and regression of the ball of the thumb (thenar atrophy)

Important: The little finger is not affected by carpal tunnel syndrome. Numbness or tingling there suggests an ulnar nerve problem.

Causes and risk factors

Carpal tunnel syndrome occurs due to increased pressure in the tunnel - either because the contents swell or because the tunnel volume decreases relatively.

• Overload and repetitive wrist movements (work, sport, hobby)
• Fluid retention, e.g. B. during pregnancy
• Metabolic and hormonal disorders: diabetes, hypothyroidism, rheumatoid arthritis
• Tendonitis, ganglia, after fractures or scars
• Anatomical narrowness and genetic predisposition
• Rare: masses (cysts, tumors) in the carpal tunnel

A clear cause is not always found. This makes a careful anamnesis and examination all the more important.

Diagnostics: How is carpal tunnel syndrome diagnosed?

The diagnosis is based on conversation, clinical examination and, if necessary, technical tests. The aim is to determine the extent of the nerve impairment and rule out other causes.

• Clinical tests: Phalen's test (flexion of the wrist), Durkan's test (pressure on the carpal tunnel), Tinel's sign (tenderness to knock).
• Sensitivity and strength: Testing the sensation of touch and the strength of the thumb apart (M. abductor pollicis brevis).
• Nerve conduction velocity (ENG) and, if necessary, EMG: objectify the nerve impairment and the severity.
• Ultrasound: Depiction of the median (cross-sectional enlargement) and structural causes (ganglion, tendon sheaths).
• X-ray: only if bony changes or previous fractures are suspected.
• Differential diagnoses: ulnar nerve constrictions, radial nerve congestion, cervical spine problems, polyneuropathy.

Conservative therapy: Treat gently first

Many patients initially benefit from non-surgical measures. These aim to reduce pressure in the carpal tunnel, reduce inflammation and protect the nerve.

• Night splint in neutral position: Stabilizes the wrist, prevents bending during sleep and reduces nighttime discomfort.
• Activity adjustment: Short-term relief, ergonomic adjustments at work and hobbies, micro-breaks.
• Physiotherapy: Nerve gliding exercises (median nerve), gentle mobilization, strengthening and stretching in low-pain areas.
• Anti-inflammatory: Cooling in acute phases, if necessary short-term anti-inflammatory medication (in consultation, alternatives in case of intolerance).
• Injection therapy: A targeted cortisone injection can provide temporary relief; ideally supported by ultrasound and placed outside the course of the nerve. Multiple injections should be considered critically.
• Treatment of the cause: control of underlying diseases (e.g. diabetes), reduction of swelling, weight management.
• Pregnancy: Often spontaneous improvement after delivery; Until then, conservative approach (rail, protection).

How long should I treat conservatively? Usually over 6-12 weeks with follow-up checks. If symptoms persist, measurable nerve conduction disorders or muscle weakness begin, the surgical option should be discussed.

Regenerative and complementary processes: What is proven?

Procedures such as PRP, hyaluronic or so-called hydrodissections are sometimes discussed. To date, evidence for carpal tunnel syndrome is limited and inconsistent. They are not part of the standard and are only considered - if at all - in selected cases after careful information.

• The standard remains the combination of splint, activity adjustment, physio and, if necessary, cortisone injection.
• New procedures should be assessed individually with regard to benefits, risks and costs.

Operation: Carpal roof splitting if there is a clear indication

If symptoms persist despite consistent conservative therapy, if nerve conduction velocity is significantly restricted or if there are motor deficits/thenar atrophy, surgery may make sense. The aim is to relieve pressure on the median nerve by splitting the flexor retinaculum.

• Procedure: open (small skin incision in the palm of the hand) or endoscopic (keyhole technique). Both procedures aim to completely split the band roof.
• Anesthesia: usually under local anesthesia, on an outpatient basis.
• Advantages: high success rate for nighttime pain and tingling; Motor deficits often require longer recovery.
• Risks: Impaired wound healing, bruising, nerve or vascular injury (rare), temporary pillar pain, scar tenderness, incomplete relief.
• Aftercare: Early functional mobilization of the fingers, elevation, scar care; Stitches removed after 10-14 days.

Ability to work and play sports depends on the activity and course: office work often after 1-2 weeks, strenuous manual work after 4-6 weeks, heavy loads possibly later. An individual procedure is determined during the inspection.

Aftercare and rehabilitation

Structured aftercare supports the recovery of the nerve and prevents scars and column problems.

• Pain and edema control: elevation, cooling, adapted pain therapy.
• Movement: Early finger movement, later targeted mobilization of the wrist.
• Scar management: Gentle massage after wound closure, silicone plaster if necessary.
• Nerve gliding: median nerve gliding exercises in coordination with the therapy.
• Building up the load: Gradually, based on pain and strength.
• Warning signs: increasing numbness, severe pain, fever, severe redness - please seek medical advice.

Prevention: ergonomics and everyday strategies

Not all causes can be influenced. Nevertheless, the risk can be reduced through good ergonomics and break management.

• Neutral position of the wrist when typing and handling tools.
• Soft wrist rest and ergonomic mouse/keyboard.
• Micro-breaks every 30-45 minutes, stretching and loosening exercises.
• Changing activities, avoiding prolonged bending or stretching positions.
• Compensatory training for forearm and shoulder muscles.

Differential diagnoses: If it is not the median

Several illnesses can cause similar symptoms. An exact assignment is important because the treatment varies.

• Ulnar nerve constriction at the elbow (cubital tunnel syndrome) or wrist (Guyon-Loge): often affects the ring and little fingers.
• Radial nerve constrictions (e.g. Cheiralgia paresthetica): Pain and abnormal sensations on the back of the thumb.
• Radiculopathy of the cervical spine (e.g. C6), thoracic outlet, proximal median nerve compression (pronator teres syndrome).
• Polyneuropathies: often symmetrical complaints in both hands and feet.
• Complex regional pain syndrome (CRPS): persistent pain, vegetative changes after injury/surgery.

Special situations: pregnancy, diabetes, work

• Pregnancy: Frequent tendency to swelling. Preferably treat conservatively (splint, rest). Often regression after delivery.
• Diabetes/Hypothyroidism: Increased risk of nerve compression; Close monitoring and good control of the underlying disease make sense.
• Workplace: Ergonomic adjustments and micro-breaks; If necessary, temporary rail provision even during the day when there is load.

Our approach in Hamburg

As a conservatively oriented orthopedic specialist practice in Hamburg-Winterhude, we value structured diagnostics, understandable information and a step-by-step approach. Many carpal tunnel problems can be significantly improved with splints, targeted physiotherapy, ergonomic adjustments and – in selected cases – an injection. We only recommend surgical relief if there is a clear indication. We offer flexible appointments online via Doctolib or by email.

When should I see a doctor?

• Frequent nighttime numbness and pain in the thumb and middle finger for several weeks
• Increasing numbness or persistent loss of sensitivity during the day
• Loss of strength, uncertainty in the tweezer grip, visible loss of the ball of the thumb
• Severe pain, redness, swelling after injury
• Bilateral complaints with additional symptoms (e.g. foot involvement, general symptoms)