The carpal tunnel is a structure formed by two layers - a deep carpal arch and a superficial flexor retinaculum. The deep carpal arch forms a concave surface which is converted into a tunnel by the overlying flexor retinaculum (transverse carpal ligament).
The carpal tunnel contains a total of nine tendons, surrounded by synovial sheaths, and the median nerve. Compression of the median nerve within the carpal tunnel can cause carpal tunnel syndrome (CTS). Its aetiology is, however, most often idiopathic.
The carpal arch is concave on the palmar side, forming the base and sides of the carpal tunnel. It is formed laterally by the scaphoid and trapezium tubercles, and medially by the hook of the hamate and the pisiform.
The flexor retinaculum is a thick connective tissue that forms the roof of the carpal tunnel. It turns the carpal arch into the carpal tunnel by bridging the space between the medial and lateral parts of the arch, spanning between the hook of hamate and pisiform (medially) to the scaphoid and trapezium (laterally).
The carpal tunnel contains a total of nine tendons, surrounded by synovial sheaths, and the median nerve.
The eight tendons of the flexor digitorum profundus and flexor digitorum superficialis are surrounded by a single synovial sheath. The tendon of flexor pollicis longus is surrounded by its own synovial sheath. These sheaths allow for free movement of the tendons.
Once it passes through the carpal tunnel, the median nerve divides into two branches - the recurrent branch and palmar digital nerves. The palmar digital nerves give sensory innervation to the palmar skin and dorsal nail beds of the lateral three and a half digits. They also provide motor innervation to the lateral two lumbricals. The recurrent branch supplies the thenar muscle group.
Compression of the median nerve within the carpal tunnel can cause carpal tunnel syndrome (CTS). It is the most common mononeuropathy and can be caused by thickened ligaments and tendon sheaths. Its aetiology is, however, most often idiopathic. If left untreated, CTS can cause weakness and atrophy of the thenar muscles.
Clinical features include numbness, tingling and pain in the distribution of the median nerve. The pain will usually radiate to the forearm. Symptoms are often associated with waking the patient from their sleep and being worse in the mornings.
Tests for CTS can be performed during physical examination. Tapping the nerve in the carpal tunnel to elicit pain in median nerve distribution (Tinel’s Sign) and holding the wrist in flexion for 60 seconds to elicit numbness/pain in median nerve distribution (Phalen’s manoeuvre).
Treatment of carpal tunnel syndrome involves the use of a splint, holding the wrist in dorsiflexion overnight to relieve symptoms. If this is unsuccessful, corticosteroid injections into the carpal tunnel can be used. In severe cases, surgical decompression of the carpal tunnel may be required.
The carpal tunnel is a narrow, rigid passageway located at the base of the hand and is made up of bones and ligaments from the carpal arch. The tunnel is enclosed by a tough fibrous sheath, also known as the flexor retinaculum, and contains eight flexor tendons which allow the fingers to bend. It's also the path for the median nerve, that when compressed or irritated can cause various symptoms such as tingling, burning, numbness, and pain in the hand and wrist, which is often worse during nights.
Diagnosing carpal tunnel syndrome can be done with a series of clinical tests, such as Tinel's sign and Phalen's manoeuvre. Treatment for the condition will depend on the severity of the symptoms and can range from the use of splints, corticosteroid injections, or even surgery in some cases. A possible consequence of prolonged carpal tunnel syndrome can be the wasting or weakening of the thenar muscles, which are located in the thumb.
Carpal tunnel syndrome has a wide array of symptoms which depend on the severity and duration of the condition. Most common of these is a tingling, burning, or numb feeling in the hand and wrist, which can sometimes extend to the arm. Pain is also a symptom of carpal tunnel syndrome and it usually worsens over time. It can also be worse at night, with some people experiencing discomfort that can wake them up. In severe cases, the pain and other symptoms can be felt during the day as well. In addition to the previously mentioned symptoms, carpal tunnel syndrome can also cause a sensation of swelling in the fingers and a feeling of weakness in the hand. Some people can also experience an increased sensitivity to touch.
Carpal tunnel syndrome is typically diagnosed by a combination of physical and neurological examinations, as well as the patient's medical history. Common tests for determining the presence of carpal tunnel syndrome include Tinel's sign and Phalen's manoeuvre, both of which involve tapping the wrist or bending the hand in certain positions. Other tests, such as electrophysiological tests, ultrasounds and MRIs can also be used to properly diagnose the condition.
Treatment for carpal tunnel syndrome will vary depending on the severity and duration of the condition. In mild cases, the use of splints and physical therapy can be effective in reducing symptoms. For more severe cases, corticosteroid injections may be indicated. Surgery is sometimes required in cases of recurring or persistent symptoms.
Carpal tunnel syndrome can lead to various complications, depending on the severity and duration of the condition. One of the most frequent complications is the wasting or weakening of the thenar muscles, which are located in the thumb. In more extreme cases, carpal tunnel syndrome can also lead to sensory loss and complete paralysis of the hand. In addition, people with existing conditions such as arthritis can experience an exacerbation of the condition if carpal tunnel syndrome is left untreated.
Avoiding activities that put an excessive strain on the hands and wrists can help reduce the risk of developing carpal tunnel syndrome. This includes tasks such as excessive keyboard use, using vibrating tools, and repetitive motion in general. It can also be beneficial to take frequent breaks and use ergonomically designed tools. Additionally, people should also wear wrist splints while doing any tasks that can potentially lead to carpal tunnel syndrome.
Carpal tunnel syndrome is a common condition that can lead to a range of unpleasant symptoms. Proper diagnosis and treatment can help reduce the risk of complications, such as thenar muscle wasting and sensory loss. To help reduce the risk of developing carpal tunnel syndrome, it is important to practice prevention methods such as taking frequent breaks, wearing wrist splints, and using ergonomically designed tools. Awareness of the condition and its symptoms can help people take necessary steps to prevent the condition and reduce the risk of complications.
