|"Advanced atrophy of the ball of the thumb"|
under the theme
Clinical Pictures in
Carpal Tunnel Syndrome
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:
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
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:
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.
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
back to top
|Home | About Dr. Lowka | Advanced Education/Publications | The Hand
Hand Surgery Diagnosis and Operations | Clinical Pictures in Hand Surgery | Areas of Emphasis in Hand Surgery
Post-operative Treatment | Center for Diagnosis and Out-patient Surgery
Contact Us | Legal Information