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Clinical Pictures in Hand Surgery - Carpal Tunnel Syndrome
"Advanced atrophy of the ball of the thumb"

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Clinical Pictures in
Hand Surgery

Dupuytren's Contracture
Ganglion Cysts

Carpal Tunnel Syndrome
Trigger Finger
de Quervain's Tendinitis

"Massive, hourglass-shaped narrowing of the median nerve"
Definition of Carpal Tunnel Syndrome:

The "carpal tunnel" begins anatomically at the transition from the wrist to the carpal. In the area of the carpal, eight bones form a U-shaped bow that acts as the floor and sides of the tunnel. The strong, transverse carpal ligament (transverse flexor retinaculum) covers the tunnel on the flexor side. (Illustration 1).

Illustration 1: Cross section through the carpal tunnel

Nine flexor tendons for the fingers and thumb and the median nerve pass through the carpal tunnel.
The median nerve is composed of thousands of nerve fibers that control the feeling in the flexor side and part of the extensor side for the thumb, pointer, middle and half of the ring finger. (Illustration 2). Therefore, the median nerve also has a motorical component which supplies an important part of the musculature of the thumb.
The median nerve lies between the transverse carpal ligament and the flexor tendons and can therefore be constricted by the stretching and bending of the wrist or fingers.

Illustration 2: Sensory Regions of the Hand

Carpal tunnel syndrome arises from an increasing stress in the carpal tunnel which results in the compression of the median nerve. When the soft structure of the nerve is pushed against the transverse carpal ligament of the wrist, this causes decreased blood circulation to the compromised part of the nerve, which leads to the typical symptoms (see below).

Causes of Carpal Tunnel Syndrome

Various causes can lead to the development of carpal tunnel syndrome:
  • Inflammation of the tendon sheath
  • Water retention
  • Fractures with displacement or false positioning of healed fractures in the area of the wrist
  • Crush injury with heavy swelling
  • Rheumatic und degenerative arthritis
  • Diabetes mellitus
  • Swelling of the nerve
  • Tumors or tumor-like growths (almost always benign)
  • Pregnancy
The constant repetition of strain/injury with respect to stressful tasks seldom cause carpal tunnel syndrome per se. However, these activities can often worsen an already present case of carpal tunnel syndrome or provoke a case of latent carpal tunnel syndrome where no symptoms were evident. Occupational as well as recreational and every-day activities can all evoke symptoms of the syndrome (for example, mowing lawn, bike riding, knitting, wood work).
Avoidance of these activities, taking breaks or the use of ergonometric tools can improve the circumstances. It is difficult to determine whether the syndrome should be ascribed to work or recreational activities.

Signs and Symptoms of Carpal Tunnel Syndrome

The most common symptoms are feelings of numbness, burning and tingling of one or more fingers, though as a rule with the exception of the little finger. These symptoms can appear at any time but typically occur at night or in the early morning when the patient awakes.
Improvement of symptoms is achieved by shaking, massage and holding up the affected hand as well as placing it in cold water.
The pain can spread through the forearm and elbow and even up into the shoulder and neck. In such cases, the physician must be able to diagnostically distinguish between carpal tunnel syndrome and other medical conditions such as those relating to the cervical spine.
The presence of carpal tunnel syndrome can cause numbness or tingling when carrying out daily activities that require wrist bending or gripping, such as talking on the telephone or driving.
The impairment of sensation in the hand can manifest itself as clumsiness or weakness in the affected hand. Patients tend to drop things or can no longer carry out specific fine motor tasks or can not firmly grasp with the tips of the fingers.

Illustration 3: Path of the median nerve, musculature of the ball of the thumb

The ball of the thumb (thenar eminence) consists of the thenar musculature, which, as described above, is partially controlled by the median nerve. In advanced carpal tunnel syndrome, a thenar atrophy develops, which means a degradation of the thenar musculature. As a result, the maneuverability and the strength of the thumb are limited.

Diagnosis of Carpal Tunnel Syndrome

As a rule, the typical case history (anamnesis) and a clinical examination with the determination of the described symptoms leads to a reliable diagnosis. In order for a final diagnosis to be made, a neurological examination and an x-ray of the wrist are required (the latter to rule out bone-related causes of the symptoms).

Treatment of Carpal Tunnel Syndrome

  1. Non-surgical:
    • Avoidance of certain activities
    • Taking breaks during specific activities
    • A splint that lightly stretches the wrist, usually worn at night but also during the day depending on the ailments
    • Vitamin B Therapy (not scientifically proven)

  2. Surgical:
    Surgical treatment is necessary when non-surgical therapy is unsuccessful, the ailments of the patient are too severe or the syndrome is diagnosed as being very advanced.

There are various possibilities for ensuring that the patient is free of pain during the surgery. These possibilities will be explained to you by the anesthesiologist.

Technical Aspects of the Surgery:

Surgery for carpal tunnel syndrome is usually out-patient, that is, the patient can go home once the operation is completed.

1. General surgical preparation:

  • Exsanguination:
    In order to provide optimal viewing conditions and to reduce the risk of damage to healthy, neighboring structures (nerves, vasculature, tendons) during hand surgery, so-called exsanguination is necessary. The entire arm is wrapped in a rubber bandage which pushes the blood out of the arm. A cuff is then placed on the arm to prevent blood from reentering the arm during the course of the surgery.
  • Skin disinfection and sterile conditions:
    In order to decrease the risk of infection, the skin is disinfected and the surgical field is covered with sterile cloth.
  • Magnifying glasses:
    The surgeon utilizes magnifying glasses in order to see and manipulate the hand structures as well as possible.
Traditional (open) Surgical Methods:

  • Incision (Illustration 4)
  • Transection of the transverse carpal ligament (Illustration 5)
  • Exposure of the median nerve and the motorical thenar branches
  • Splitting of the outer nerve sheath (epineurium) of the median nerve
  • If necessary, the removal of the flexor tendon sheath (synovialektomy) in cases of inflammation-induced tissue changes
  • The transverse carpal ligament is not sutured, functional disadvantages are not expected
  • Suture
  • Compression bandage
  • Immobilization with a splint of the forearm on the extensor-side
Illustration 4: Incision with "open method"

Illustration 5: Incision with "Endoscopic Method"

3. "Endoscopic" Method:

This method was primarily developed in the U.S.A. and over the past few years has also been increasingly implemented in Europe:
Two small incisions (Illustration 5) are made. The scope is inserted into one in order to provide the surgeon with a view of the transverse carpal ligament. A small scalpel is inserted into the other incision in order to split the ligament.

  • Less discomfort from scar
  • Smaller scars
  • Shorter duration of inability to work (not proven)
  • The nerve cannot be inspected during the surgery
  • The potential of an existing flexor tendon sheath inflammation can not be assessed and treated
  • The chance of damaging important functional structures such as the nerve branches to the fingers, the motorical thenar branches leading to the ball of the thumb or the palmar arterial arch is relatively high.
Illustration 6: Split flexor retinaculum of the hand

Post-operative treatment:

  • The patient is allowed to return home after the surgery. The joints not in a cast should be moved but not heavily used.
  • One day after surgery: Cast and soft tissue control, and when appropriate the removal of redon drainage (although sometimes not until 2-3 days after surgery).
  • Five to seven days after the surgery: Removal of cast splint and bandage change (can also be performed by family physician), initiation of exercises to relieve strain in wrist.
  • Fourteen days after surgery: Bandage change and removal of stitches (can also be performed by family physician).
  • The bandage is no longer necessary the day after the stitches are removed.
    Begin of regular (3-4 times daily) exercises in cold water (with addition of ice cubes). Cold reduces swelling and pain. Patients that cannot tolerate cold should use lukewarm water.
  • The scar treatment can begin five days after the removal of stitches. The scar should be massaged with a fatty cream or salve 4-5 times daily so that the scar becomes softer, less painful, and more resistant to stress ("toughening" of the scar).
    Also beneficial is the tapping of the scar, for example with a soft brush.
  • Physical and/or occupational therapy are rarely necessary although would be prescribed in cases of limited maneuverability.
  • The duration of the patient's incapacity to work is usually around 4-6 weeks.
  • A neurological examination and hand surgery control examination will be performed three months after the surgery.
Healing progression after the surgery:

As a rule, the ailments caused by carpal tunnel syndrome diminish the first night after the surgery.
Scar discomfort largely disappears after the first 6-8 weeks. After 3-6 months patients no longer complain of pain. However, the scars final state is not reached until approximately 12 months after surgery.

© Dr. Klaus Lowka

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