Flexor retinaculum of the hand

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Flexor retinaculum of the hand
Gray423.png
The mucous sheaths of the tendons on the front of the wrist and digits. (Transverse carpal ligament labeled at center.)
Details
Identifiers
Latin retinaculum musculorum flexorum manus (obsolete: ligamentum transversum carpi) [1]
TA98 A04.6.03.013
TA2 2550
FMA 39988
Anatomical terminology

The flexor retinaculum (transverse carpal ligament or anterior annular ligament) is a fibrous band on the palmar side of the hand near the wrist. It arches over the carpal bones of the hands, covering them and forming the carpal tunnel.

Contents

Structure

The flexor retinaculum is a strong, fibrous band that covers the carpal bones on the palmar side of the hand near the wrist. It attaches to the bones near the radius and ulna. On the ulnar side, the flexor retinaculum attaches to the pisiform bone and the hook of the hamate bone. On the radial side, it attaches to the tubercle of the scaphoid bone, and to the medial part of the palmar surface and the ridge of the trapezium bone.

The flexor retinaculum is continuous with the palmar carpal ligament, and deeper with the palmar aponeurosis. The ulnar artery and ulnar nerve, and the cutaneous branches of the median and ulnar nerves, pass on top of the flexor retinaculum. On the radial side of the retinaculum is the tendon of the flexor carpi radialis, which lies in the groove on the greater multangular between the attachments of the ligament to the bone.

The tendons of the palmaris longus and flexor carpi ulnaris are partly attached to the surface of the retinaculum; below, the short muscles of the thumb and little finger originate from the flexor retinaculum.

Function

The flexor retinaculum is the roof of the carpal tunnel, through which the median nerve and tendons of muscles which flex the hand pass.

Clinical significance

Indication of the site of the problem in carpal tunnel syndrome Carpal Tunnel Syndrome.png
Indication of the site of the problem in carpal tunnel syndrome

In carpal tunnel syndrome, one of the tendons or tissues in the carpal tunnel is inflamed, swollen, or fibrotic and puts pressure on the other structures in the tunnel, including the median nerve. Carpal tunnel syndrome is the most commonly reported nerve entrapment syndrome. [2] It is often associated with repetitive motions of the wrist and fingers. It is because of this that pianists, meat cutters, and people with jobs involving extensive typing are at particularly high risk. The tough flexor retinaculum along with the rest of the carpal tunnel cannot expand, putting pressure on the median nerve running through the carpal tunnel with the flexor tendons of the wrist. This results in the symptoms of carpal tunnel syndrome. [3]

Symptoms of carpal tunnel syndrome include tingling sensations and muscle weakness in the palm and lateral side of the hand and palm. It is possible that the syndrome may extend and radiate up the nerve causing pain to the arm and shoulder. [4]

Carpal tunnel syndrome may be treated surgically. This is usually done after all non-surgical methods of treatment have been exhausted. Non-surgical treatment methods include anti-inflammatory drugs. The wrist may be immobilized in order to prevent further use and inflammation. When surgery is needed, the flexor retinaculum is either completely severed or lengthened. [5] Surgery to divide the flexor retinaculum is the most common procedure.[ citation needed ] The scar tissue will eventually fill the gap left by surgery. The intent is that this will lengthen the flexor retinaculum enough to accommodate inflamed or damaged tendons and reduce the effects of compression on the median nerve. In a 2004 double blind-study, researchers concluded that there was no perceivable benefit gained from lengthening the flexor retinaculum during surgery and so division of the ligament remains the preferred method of surgery. [6]

See also

Related Research Articles

<span class="mw-page-title-main">Carpal bones</span> Eight small bones that make up the wrist (or carpus) that connects the hand to the forearm

The carpal bones are the eight small bones that make up the wrist (carpus) that connects the hand to the forearm. The term "carpus" and "carpal" is derived from the Latin carpus and the Greek καρπός (karpós), meaning "wrist". In human anatomy, the main role of the carpal bones is to articulate with the radial and ulnar heads to form a highly mobile condyloid joint, to provide attachments for thenar and hypothenar muscles, and to form part of the rigid carpal tunnel which allows the median nerve and tendons of the anterior forearm muscles to be transmitted to the hand and fingers.

<span class="mw-page-title-main">Median nerve</span> Nerve of the upper limb

The median nerve is a nerve in humans and other animals in the upper limb. It is one of the five main nerves originating from the brachial plexus.

<span class="mw-page-title-main">Wrist</span> Part of the arm between the lower arm and the hand

In human anatomy, the wrist is variously defined as (1) the carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; (2) the wrist joint or radiocarpal joint, the joint between the radius and the carpus and; (3) the anatomical region surrounding the carpus including the distal parts of the bones of the forearm and the proximal parts of the metacarpus or five metacarpal bones and the series of joints between these bones, thus referred to as wrist joints. This region also includes the carpal tunnel, the anatomical snuff box, bracelet lines, the flexor retinaculum, and the extensor retinaculum.

The flexor digitorum profundus is a muscle in the forearm of humans that flexes the fingers. It is considered an extrinsic hand muscle because it acts on the hand while its muscle belly is located in the forearm.

<span class="mw-page-title-main">Ulnar nerve</span> Nerve which runs near the ulna bone

In human anatomy, the ulnar nerve is a nerve that runs near the ulna bone. The ulnar collateral ligament of elbow joint is in relation with the ulnar nerve. The nerve is the largest in the human body unprotected by muscle or bone, so injury is common. This nerve is directly connected to the little finger, and the adjacent half of the ring finger, innervating the palmar aspect of these fingers, including both front and back of the tips, perhaps as far back as the fingernail beds.

<span class="mw-page-title-main">Metacarpal bones</span> Bones of hand

In human anatomy, the metacarpal bones or metacarpus, also known as the "palm bones", are the appendicular bones that form the intermediate part of the hand between the phalanges (fingers) and the carpal bones, which articulate with the forearm. The metacarpal bones are homologous to the metatarsal bones in the foot.

<span class="mw-page-title-main">Hamate bone</span> Carpal bone in the wrist

The hamate bone, or unciform bone, Latin os hamatum and occasionally abbreviated as just hamatum, is a bone in the human wrist readily distinguishable by its wedge shape and a hook-like process ("hamulus") projecting from its palmar surface.

<span class="mw-page-title-main">Pisiform bone</span> Bone in the wrist

The pisiform bone, also spelled pisiforme, is a small knobbly, sesamoid bone that is found in the wrist. It forms the ulnar border of the carpal tunnel.

<span class="mw-page-title-main">Ulnar artery</span> Artery of the forearm

The ulnar artery is the main blood vessel, with oxygenated blood, of the medial aspects of the forearm. It arises from the brachial artery and terminates in the superficial palmar arch, which joins with the superficial branch of the radial artery. It is palpable on the anterior and medial aspect of the wrist.

<span class="mw-page-title-main">Flexor pollicis brevis muscle</span> Muscle in the thenar compartment

The flexor pollicis brevis is a muscle in the hand that flexes the thumb. It is one of three thenar muscles. It has both a superficial part and a deep part.

The pronator teres is a muscle that, along with the pronator quadratus, serves to pronate the forearm. It has two origins, at the medial humeral supracondylar ridge and the ulnar tuberosity, and inserts near the middle of the radius.

<span class="mw-page-title-main">Palmaris longus muscle</span> Muscle of the upper limb

The palmaris longus is a muscle visible as a small tendon located between the flexor carpi radialis and the flexor carpi ulnaris, although it is not always present. It is absent in about 14 percent of the population; this number can vary in African, Asian, and Native American populations, however. Absence of the palmaris longus does not have an effect on grip strength. The lack of palmaris longus muscle does result in decreased pinch strength in fourth and fifth fingers. The absence of palmaris longus muscle is more prevalent in females than males.

<span class="mw-page-title-main">Abductor digiti minimi muscle of hand</span> Muscle in the hypothenar compartment

In human anatomy, the abductor digiti minimi is a skeletal muscle situated on the ulnar border of the palm of the hand. It forms the ulnar border of the palm and its spindle-like shape defines the hypothenar eminence of the palm together with the skin, connective tissue, and fat surrounding it. Its main function is to pull the little finger away from the other fingers.

The palmar carpal ligament is a thickened portion of antebrachial fascia on anterior/palmar side of the wrist which - together with the flexor retinaculum of the hand - retains the tendons of most of the flexor muscles of the hand.

<span class="mw-page-title-main">Ulnar canal</span>

The ulnar canal or ulnar tunnel (also known as Guyon's canal or tunnel) is a semi-rigid longitudinal canal in the wrist that allows passage of the ulnar artery and ulnar nerve into the hand. The roof of the canal is made up of the superficial palmar carpal ligament, while the deeper flexor retinaculum and hypothenar muscles comprise the floor. The space is medially bounded by the pisiform and pisohamate ligament more proximally, and laterally bounded by the hook of the hamate more distally. It is approximately 4 cm long, beginning proximally at the transverse carpal ligament and ending at the aponeurotic arch of the hypothenar muscles.

<span class="mw-page-title-main">Carpal tunnel</span> Structure of human wrist

In the human body, the carpal tunnel or carpal canal is a flattened body cavity on the flexor (palmar/volar) side of the wrist, bounded by the carpal bones and flexor retinaculum. It forms the passageway that transmits the median nerve and the tendons of the extrinsic flexor muscles of the hand from the forearm to the hand. There are described cases of the anatomical variant median artery occurrence.

<span class="mw-page-title-main">Hand</span> Extremity at the end of an arm or forelimb

A hand is a prehensile, multi-fingered appendage located at the end of the forearm or forelimb of primates such as humans, chimpanzees, monkeys, and lemurs. A few other vertebrates such as the koala are often described as having "hands" instead of paws on their front limbs. The raccoon is usually described as having "hands" though opposable thumbs are lacking.

<span class="mw-page-title-main">Wrist pain</span>

Wrist pain or open wrist is a syndrome inhibiting use of a hand due to pain in anatomical structures of the wrist. It most commonly results from an injury to a ligament. The pain may be sharp from a traumatic injury or from chronic repetitive wrist activities.

<span class="mw-page-title-main">Median nerve palsy</span> Medical condition

Injuries to the arm, forearm or wrist area can lead to various nerve disorders. One such disorder is median nerve palsy. The median nerve controls the majority of the muscles in the forearm. It controls abduction of the thumb, flexion of hand at wrist, flexion of digital phalanx of the fingers, is the sensory nerve for the first three fingers, etc. Because of this major role of the median nerve, it is also called the eye of the hand. If the median nerve is damaged, the ability to abduct and oppose the thumb may be lost due to paralysis of the thenar muscles. Various other symptoms can occur which may be repaired through surgery and tendon transfers. Tendon transfers have been very successful in restoring motor function and improving functional outcomes in patients with median nerve palsy.

<span class="mw-page-title-main">Muscles of the thumb</span>

The muscles of the thumb are nine skeletal muscles located in the hand and forearm. The muscles allow for flexion, extension, adduction, abduction and opposition of the thumb. The muscles acting on the thumb can be divided into two groups: The extrinsic hand muscles, with their muscle bellies located in the forearm, and the intrinsic hand muscles, with their muscles bellies located in the hand proper.

References

PD-icon.svgThis article incorporates text in the public domain from page 456 of the 20th edition of Gray's Anatomy (1918)

  1. Kachlika, David; Bozdechovac, Ivana; Cechd, Pavel; Musile, Vladimir; Bacaa, Vaclav (2009). "Mistakes in the usage of anatomical terminology in clinical practice". Biomedical Papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia. 153 (2): 157–61. doi: 10.5507/bp.2009.027 . PMID   19771143.
  2. Silverstein, Barbara A.; Fine, Lawrence J.; Armstrong, Thomas J. (1987). "Occupational factors and carpal tunnel syndrome". American Journal of Industrial Medicine. 11 (3): 343–358. doi:10.1002/ajim.4700110310. PMID   3578290.
  3. Saladin, Kenneth S. Anatomy & Physiology The Unity of Form and Function. 6th. New York: McGraw-Hill, 2012.[ page needed ]
  4. Saladin, Kenneth S. Anatomy & Physiology The Unity of Form and Function. 7th. New York: McGraw-Hill, 2015.[ page needed ]
  5. Saladin, Kenneth S. Anatomy & Physiology The Unity of Form and Function. 7th. New York: McGraw-Hill, 2015.[ page needed ]
  6. Dias, J.J.; Bhowal, B.; Wildin, C.J.; Thompson, J.R. (10 January 2017). "Carpal Tunnel Decompression. Is Lengthening of the Flexor Retinaculum Better than Simple Division?". Journal of Hand Surgery. 29 (3): 269–274. doi:10.1016/j.jhsb.2004.01.011. PMID   15142699. S2CID   25503344.