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<div class="editorbox">'''Original Editor'''- [[User: Nina Myburg| Nina Myburg]]
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== Description  ==
== Description  ==
The navicular bone is the largest bone of the proximal row, and has received its name from its fancied resemblance to a boat. It is situated at the radial side of the carpus, its long axis being from above downward, lateralward, and forward. The '''superior surface''' is convex, smooth, of triangular shape, and articulateswith the lower end of the radius. The '''inferior surface,''' directed downward, lateralward, and backward, is also smooth, convex, and triangular, and is divided by a slight ridge into two parts, the lateral articulating with the greater multangular, the medial with the lesser multangular. On the '''dorsal surface''' is a narrow, rough groove, which runs the entire length of the bone, and serves for the attachment of ligaments. The '''volar surface''' is concave above, and elevated at its lower and lateral part into a rounded projection, the '''tubercle,''' which is directed forward and gives attachment to the transverse carpal ligament and sometimes origin to a few fibers of the Abductor pollicis brevis. The '''lateral surface''' is rough and narrow, and gives attachment to the radial collateral ligament of the wrist. The '''medial surface''' presents two articular facets; of these, the superior or smaller is flattened of semilunar form, and articulates with the lunate bone; the inferior or larger is concave, forming with the lunate a concavity for the head of the capitate bone.
The scaphoid is the largest bone of the proximal row of carpal bones.<ref name=":1">Moore KL, Dalley AF. ''Clinically Oriented Anatomy.'' Fifth edition. Philadelphia: Lippincot Williams & Wilkins; 2006</ref> The word scaphoid is derived from the Greek word ''skaphos'' which means "a boat". The name refers to the boat-like shape of the bone. Previously it was called the navicular bone (derived from the Latin word ''navis'' which means "boat") of the hand. However, there is a tarsal bone in the foot that is also called navicular due to its boat-like shape. The scaphoid is situated at the radial side of the wrist.<ref name=":0">Gray H. ''[https://www.bartleby.com/107/54.html Anatomy of the Human Body].'' Twentieth edition. Philadelphia: Lea & Febiger; 1918 Available from: https://www.bartleby.com/107/54.html [Accessed 19 June 2019]</ref>
 
The navicular articulates with ''five'' bones: the radius proximally, greater and lesser multangulars distally, and capitate and lunate medially.<ref name=":0" />
 
The '''scaphoid bone''' is one of the carpal bones of the wrist. It is situated between the hand and forearm on the thumb side of the wrist (also called the lateral or radial side). It forms the radial border of the carpal tunnel. The scaphoid bone is the largest bone of the proximal row of wrist bones, its long axis being from above downward, lateralward, and forward. It is approximately the size and shape of a medium cashew.
 
The scaphoid is situated between the proximal and distal rows of carpal bones. It is located on the radial side of the wrist, and articulates with the radius, lunate, trapezoid, trapezium and capitate.<sup>[1]:176</sup> Over 80% of the bone is covered in articular cartilage.<sup>[2]</sup>
 
=== Bone[edit] ===
The palmar surface of the scaphoid is concave, and forming a tubercle, giving attachment to the transverse carpal ligament. The proximal surface is triangular, smooth and convex, and articulates with the radius and adjacent carpal bones, namely the lunate, capitate, trapezium and trapezoid.<sup>[2]</sup> The lateral surface is narrow and gives attachment to the radial collateral ligament. The medial surface has two facets, a flattened semi-lunar facet articulating with the lunate bone, and an inferior concave facet, articulating alongside the lunate with the head of the capitate bone.<sup>[3]</sup>
 
The dorsal surface of the bone is narrow, with a groove running the length of the bone and allowing ligaments to attach, and the surface facing the fingers (anatomically inferior) is smooth and convex, also triangular, and divided into two parts by a slight ridge.<sup>[3]</sup>
 
=== Blood supply[edit] ===
It receives its blood supply primarily from lateral and distal branches of the radial artery, via palmar and dorsal branches. These provide an "abundant" supply to middle and distal bone, but neglects the proximal portion, which relies on retrograde flow.<sup>[1]:189</sup> The dorsal branch supplies the majority of the middle and distal portions, with the palmar branch supplying only the distal third of the bone.<sup>[2]</sup>
 
=== Variation[edit] ===
The dorsal blood supply, particularly of the proximal portion, is highly variable.<sup>[1]:189</sup> Sometimes the fibers of the abductor pollicis brevis emerge from the tubercle.<sup>[3]</sup>
 
=== In animals[edit] ===
In reptiles, birds, and amphibians, this bone is instead commonly referred to as the '''''radiale''''' because of its articulation with the radius.
 
== Function[edit] ==
The carpal bones function as a unit to provide a bony superstructure for the hand.<sup>[4]:708</sup> The scaphoid is also involved in movement of the wrist.<sup>[1]:6</sup> It, along with the lunate, articulates with the radius and ulna to form the major bones involved in movement of the wrist.<sup>[4]</sup>The scaphoid serves as a link between the two rows of carpal bones. With wrist movement, the scaphoid may flex from its position in the same plane as the forearm to perpendicular.<sup>[1]:176–177</sup>


The scaphoid can be palpated at the base of the anatomical snuff box. It can also be palpated in the volar (palmar) hand/wrist. Its position is the intersections of the long axes of the four fingers while in a fist, or the base of the thenar eminence. When palpated in this position, the bone will be felt to slide forward during radial deviation (wrist abduction) and flexion.
[[File:Scaphoid bone (left hand) - animation.gif|center|thumb|Scaphoid bone (animation) - Left hand]]


Clicking of the scaphoid or no anterior translation can indicate scapholunate instability
=== Structure ===
The scaphoid is situated below the [[radius]] at the radial (lateral) side of the [[Wrist and Hand|wrist]]. It has a boat-like shape with many articulation surfaces. Over 80% of the bone is covered in cartilage. On the palmar surface of the bone, there is a tubercle that can be palpated at the base and medial aspect of the thenar eminence when the hand is extended. <ref name=":1" /> It can also be palpated at the base of the anatomical snuffbox.
[[File:Scaphoid bone (picture of only the bone) - animation1.gif|center|thumb|Scaphoid bone]]


The etymology of the scaphoid bone (Greek: σκαφοειδές) is derived from the Greek ''skaphos,'' which means "a boat," and the Greek ''eidos,'' which means "kind".<sup>[5]</sup> The name refers to the shape of the bone, supposedly reminiscent of a boat. In older literature about human anatomy,<sup>[3]</sup> the scaphoid is referred to as the navicular bone of the hand (this time from the latin word “navis” = boat), since there is also a bone in a similar position in the foot which is called the navicular.
== Function ==
The scaphoid, together with other carpal bones, provide bony structure to the hand and wrist. It is involved in the movement of the wrist together with the [[lunate]] and distal surfaces of the [[radius]] and [[ulna]]. It forms the radial border of the carpal tunnel and serves as attachment site.  


== Clinical significance ==
== Articulations ==
<ref name=":0">Gray H. ''[https://www.bartleby.com/107/54.html Anatomy of the Human Body].'' Twentieth edition. Philadelphia: Lea & Febiger; 1918 Available from: https://www.bartleby.com/107/54.html [Accessed 19 June 2019]</ref><ref>Moore KL, Dalley AF. ''Clinically Oriented Anatomy.'' Fifth edition. Philadelphia: Lippincot Williams & Wilkins; 2006</ref>
The scaphoid articulates with five bones:<ref name=":0" />
* [[Radius]] (proximally)
* [[Trapezoid]] and [[trapezium]] (distally)
* [[Capitate]] and [[Lunate]] (medially)


== Structure ==
== Soft tissue attachments ==
* The transverse carpal ligament attaches to the tubercle of the [[scaphoid]]
* Sometimes a few fibres of [[Abductor Pollicis Brevis|abductor pollicis brevis]] attaches to the tubercle of the [[scaphoid]]
* The radial collateral ligament attaches to the lateral surface


== Function  ==
== Clinical relevance ==
Clicking of the scaphoid or no anterior translation can indicate scapholunate instability.


== Articulations  ==
== See also ==
[[Scaphoid Fracture]]


== Muscle attachments  ==
[[Scapholunate Dissociation]]


== Clinical relevance  ==
[[Scaphoid shift test]]


== See also  ==
== References ==
 
= References  =


<references />  
<references />  


[[Category:Anatomy]]  
[[Category:Anatomy]]  
[[Category:Anatomy Project]]
[[Category:Wrist - Anatomy]]
[[Category:Wrist - Anatomy]]
[[Category:Bones]]
[[Category:Bones]]
[[Category:Wrist - Bones]]
[[Category:Wrist]]
[[Category:Wrist]]
[[Category:Wrist Bones]]
[[Category:Anatomy Project]]
[[Category:Hand and Wrist Anatomy]]

Latest revision as of 20:05, 21 July 2022

Original Editor- Nina Myburg Top Contributors - Nina Myburg, Kim Jackson, Chrysolite Jyothi Kommu, Nikhil Benhur Abburi and Vidya Acharya

Description[edit | edit source]

The scaphoid is the largest bone of the proximal row of carpal bones.[1] The word scaphoid is derived from the Greek word skaphos which means "a boat". The name refers to the boat-like shape of the bone. Previously it was called the navicular bone (derived from the Latin word navis which means "boat") of the hand. However, there is a tarsal bone in the foot that is also called navicular due to its boat-like shape. The scaphoid is situated at the radial side of the wrist.[2]

Scaphoid bone (animation) - Left hand

Structure[edit | edit source]

The scaphoid is situated below the radius at the radial (lateral) side of the wrist. It has a boat-like shape with many articulation surfaces. Over 80% of the bone is covered in cartilage. On the palmar surface of the bone, there is a tubercle that can be palpated at the base and medial aspect of the thenar eminence when the hand is extended. [1] It can also be palpated at the base of the anatomical snuffbox.

Scaphoid bone

Function[edit | edit source]

The scaphoid, together with other carpal bones, provide bony structure to the hand and wrist. It is involved in the movement of the wrist together with the lunate and distal surfaces of the radius and ulna. It forms the radial border of the carpal tunnel and serves as attachment site.

Articulations[edit | edit source]

The scaphoid articulates with five bones:[2]

Soft tissue attachments[edit | edit source]

  • The transverse carpal ligament attaches to the tubercle of the scaphoid
  • Sometimes a few fibres of abductor pollicis brevis attaches to the tubercle of the scaphoid
  • The radial collateral ligament attaches to the lateral surface

Clinical relevance[edit | edit source]

Clicking of the scaphoid or no anterior translation can indicate scapholunate instability.

See also[edit | edit source]

Scaphoid Fracture

Scapholunate Dissociation

Scaphoid shift test

References[edit | edit source]

  1. ↑ 1.0 1.1 Moore KL, Dalley AF. Clinically Oriented Anatomy. Fifth edition. Philadelphia: Lippincot Williams & Wilkins; 2006
  2. ↑ 2.0 2.1 Gray H. Anatomy of the Human Body. Twentieth edition. Philadelphia: Lea & Febiger; 1918 Available from: https://www.bartleby.com/107/54.html [Accessed 19 June 2019]
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