Introduction:
The term carpus is derived from the Greek word Karpos, which means wrist. The wrist is surrounded by a band of fibrous tissue that usually functions to support the wrist joint. There is a tight space between the fibrous band and the wrist bone called the carpal tunnel. The carpal tunnel is a narrow passage found on the anterior portion of the wrist. It is the pathway for several tendons and the median nerve (nerve of the upper limb). The median nerve receives sensations from the thumb, index, and middle fingers of the hand.
What Is Carpal Tunnel Syndrome?
Carpal tunnel syndrome is known as median nerve compression in the carpal tunnel region. They are a collection of signs and symptoms due to the pinched median nerve. The median nerve is vital for the purpose of sense and movement to the parts of the hand. As the median nerve is squeezed or irritated, its implications are felt over the palm and fingers.
What Are the Symptoms of Carpal Tunnel Syndrome?
Carpal tunnel syndrome is characterized by:
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Pain, numbness, and tingling sensation of the hand.
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They may also lead to muscle damage and weakness of the fingers.
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Pain will extend up to the elbow and is mostly present in both hands.
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Coordination and fine movements of the fingers are affected, thus making it difficult for the hand to grip or carry the objects.
If the pressure on the median nerve continues without intervention, it can lead to nerve damage and worsening symptoms.
What Are the Causes of Carpal Tunnel Syndrome?
The cause of carpal tunnel syndrome is usually unknown; also, there is no underlying disease contributing to pressure on the nerve. Some other reasons for the pinched nerve are:
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Hereditary: Naturally, some people have smaller carpal tunnel or the other anatomic features that make the tunnel narrow. Such traits run in families.
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Infection: Swelling of the tendons during infection, associated with the median nerve in the carpal tunnel, places pressure on the median nerve.
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Injury: Any trauma to the wrist can lead to joint dislocations and fractures compressing the median nerve.
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Wrist Position: Keeping the wrist bend (as with typing on the computer keyboard) for a long time can irritate the muscles and the median nerve.
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Repetitive Wrist Movements: Repeating the same hand or wrist strokes, such as in writing and drawing, for a prolonged period can apply stress on the median nerve.
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Pregnancy: Fluid retention and swelling caused by hormonal changes during pregnancy exert pressure on the median nerve.
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Health Conditions: Hypothyroidism, rheumatoid arthritis, and diabetes mellitus are other health issues associated with carpal tunnel syndrome.
When to Consider Carpal Tunnel Release Surgery?
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The treatment for carpal tunnel syndrome includes medicines to relieve symptoms, bracing, steroid shots, physical therapy, gliding exercises, and surgery.
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Non-surgical therapies are tried before proceeding to surgery. When the symptoms do not alleviate after six to seven weeks of conservative treatment, surgery is considered.
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Early surgery is preferred when there is a complete loss of nerve transmission, as in case of injury or trauma, muscle weakness, or when there is constant pain and numbness.
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Individual preference of the patient can lead to direct surgery as well.
How Is Carpal Tunnel Release Surgery Performed?
Carpal tunnel release surgery aims to divide the fibrous tissue band (transverse carpal ligament) present over the carpal bones to release the median nerve from compression. The two major surgical techniques followed are open carpal tunnel release and endoscopic carpal tunnel release.
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Open Carpal Tunnel Release: Open surgery is considered a gold standard treatment for carpal tunnel syndrome. Under local anesthesia, a longitudinal incision (Kaplan’s incision) is done at the base of the palm. The site is identified as in line with the ring finger. The incision extends through the skin, fascia, and muscles over the ligament. Once the ligament is visible, a neat and deep surgical cut is placed in the ligament, exposing the median nerve. The ligament is completely divided to release the entire pressure from the median nerve.
After surgery, the ligament grows back with more space in the carpal tunnel, thus avoiding compression of the median nerve.
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Endoscopic Carpal Tunnel Release: Endoscopic carpal tunnel release is a minimally invasive approach where one or two small incisions are made. Fine instruments and an endoscope (a fiberoptic instrument to visualize internal parts through a camera) are inserted to visualize and access the procedure.
Thus, the skin, fascia, and muscles are saved to a great extent from long incisions. Only the ligament is divided to serve the purpose of decompressing the median nerve. Limited visual field and mechanical delicacy make this procedure technique sensitive.
Apart from these two significant techniques, some other choices with minor modifications were developed. They are:
- Limited Open Carpal Tunnel Release - This procedure involves a small incision in the palm and release of only the far end of the ligament under an open approach.
- Carpal Tunnel Release Through a Mini-Transverse Approach (CTRMTA) - A small incision of about 1.5 cm is made in the transverse (horizontal) direction along the wrist crease. It is also called Sayed Issa's approach.
- Thread Carpal Tunnel Release - This is a unique incision-less technique where a piece of thread is used under the skin to dissect the ligament. The procedure is monitored with the help of an ultrasound.
How Long Does It Take To Recover From Carpal Tunnel Release Surgery?
The recommendation is to move the wrist and fingers immediately after surgery to minimize swelling and stiffness. Mild pain and soreness may persist for a few weeks. Recovery depends on the severity of the symptoms and the technique used in surgery. In severe cases, the wrist and fingers may take a longer time (up to 12 months) to regain their strength and work as usual. Some patients can still experience symptoms, but surgery is essential to halt the worsening of the condition.
Minimally invasive procedures have less discomfort post-surgery, and the recovery is faster than the traditional open approach because of minor surgical trauma. But research suggests no significant difference in the treatment outcome between the open and endoscopic techniques in the longer run. Rehabilitation involves:
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Gentle massage.
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Applying heat and ice packs.
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Strengthening exercises for muscles and joints.
Risks and complications of carpal tunnel release surgery include persisting pain, swelling, stiffness of the wrist joint, infection, bleeding, presence of blood clots, and injury to the median nerve and tendons. Complete recovery may not be possible for patients with other health issues.
Conclusion:
The symptoms of carpal tunnel syndrome worsen over time. If untreated, there may be permanent function loss in the wrist and fingers. Muscle weakness and loss of sensation hinder daily and work-related activities. Therefore, it is crucial to diagnose and treat carpal tunnel syndrome at the earliest. Recurrence of carpal tunnel syndrome after treatment is rare.