Content deleted Content added
WhatamIdoing (talk | contribs) →Fracture: Red link to a missing article |
capitalized #article-section-source-editor Tags: Mobile edit Mobile app edit iOS app edit |
||
(42 intermediate revisions by 37 users not shown) | |||
Line 1:
{{Short description|Bone of the carpus}}
{{Anatomy terms}}
{{Infobox bone
| Name =
| Pronunciation = {{IPAc-en|ˈ|s|k|æ|f|ɔɪ|d}}
| Latin =
| Image = Scaphoid bone (left hand) 01 palmar view.png
| Caption = Left hand anterior view (palmar view). Scaphoid bone shown in red.
Line 10 ⟶ 11:
| Origins =
| Insertions =
| Articulations =
}}
The '''scaphoid bone''' {{IPAc-en|'|s|k|ae|f|oi|d}} (from the Greek word ''scaphoides'', boat-shaped) is one of the [[carpus|carpal]] [[bone]]s 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 [[radius (bone)|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 bone'''
==Structure==▼
The scaphoid is situated between the [[Anatomical terms of location#Proximal and distal|proximal and distal]] rows of [[carpal bone]]s. It is located on the radial side of the wrist, and articulates with the [[radius (bone)|radius]], [[lunate bone|lunate]], [[trapezoid bone|trapezoid]], [[trapezium (bone)|trapezium]] and [[capitate]].<ref name=BEASLEY2003>{{cite book|title=Beasley's Surgery of the Hand|year=2003|publisher=Thieme New York|isbn=9781282950023}}</ref> {{rp|176}} Over 80% of the bone is covered in articular [[cartilage]].<ref name=EATHORNE2005 />▼
▲== Structure ==
▲The scaphoid is situated between the [[Anatomical terms of location#Proximal and distal|proximal and distal]] rows of [[carpal bone]]s. It is located on the radial side of the wrist,<ref
===Bone===
The palmar surface of the scaphoid is concave, and forming a distal [[tubercle]], giving attachment to the [[Flexor retinaculum of the hand|transverse carpal ligament]]. The proximal surface is triangular, smooth and convex
The dorsal surface of the bone is narrow, with a groove running the length of the bone and allowing
===Blood supply===
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 portions of the bone, but
===Variation===
The dorsal blood supply, particularly of the proximal portion, is highly variable.<ref name=BEASLEY2003 />
===In animals===
In reptiles, birds, and amphibians,
== Function ==
The carpal bones function as a unit to provide a bony superstructure for the
==Clinical significance==
Line 45 ⟶ 40:
===Fracture===
{{main|Scaphoid fracture}}
{{multiple image
| align = right
| image1 = Scaphoidfraktur 1 pfeil.jpg
| width1 = 180
| alt1 =
| caption1 =
| image2 = Scaphoidfraktur 2 postoperativ.jpg
| width2 = 150
| alt2 =
| caption2 =
| footer = [[Scaphoid fracture]] before and after operation
}}
[[Scaphoid fracture|Fractures of the scaphoid]] are the most common of the carpal bone injuries, because of its connections with the two rows of carpal bones.<ref name=BEASLEY2003 />
The scaphoid can be slow to heal because of the limited circulation to the [[bone]]. Fractures of the scaphoid must be recognized and treated quickly, as prompt treatment by immobilization or surgical fixation increases the likelihood of the bone healing in anatomic alignment, thus avoiding mal-union or non-union.<ref name=":0">{{cite journal | vauthors = Wijetunga AR, Tsang VH, Giuffre B | title = The utility of cross-sectional imaging in the management of suspected scaphoid fractures | journal = Journal of Medical Radiation Sciences | volume = 66 | issue = 1 | pages = 30–37 | date = March 2019 | pmid = 30160062 | pmc = 6399186 | doi = 10.1002/jmrs.302 }}</ref> Delays may compromise healing. Failure of the fracture to heal ("non-union") will lead to post-traumatic
Healing of the fracture with a non-anatomic deformity (frequently, a volar flexed "humpback") can also lead to [[post-traumatic arthritis]]. Non-unions can result in loss of blood supply to the proximal pole, which can result in [[avascular necrosis]] of the proximal segment.
Scaphoid fractures may be difficult to diagnose via plain x-ray. A repeat x-ray may be required at a later date, as might cross-sectional imaging via MRI or CT scan.<ref name=":0" />
===Other diseases===
A condition called [[scapholunate instability]] can occur when the [[scapholunate ligament]] (connecting the scaphoid to the [[lunate bone]]) and other surrounding ligaments are disrupted. In this state, the distance between the scaphoid and [[lunate]] bones is increased.<ref name=BEASLEY2003 />
===Palpation===
Line 63 ⟶ 71:
Clicking of the scaphoid or no anterior translation can indicate scapholunate instability.
==
The
==Additional images==
Line 78 ⟶ 82:
File:Gray220 - Scaphoid bone.png|Scaphoid shown in yellow. Left hand. Dorsal surface.
File:Ospoignet - Scaphoid bone.png|Cross section of wrist (thumb on left). Scaphoid (labelled as "Navicular") shown in red.
File:
File:Slide1dsds - Scaphoid bone.png|Scaphoid forms the radial (thumb-side) border of the [[carpal tunnel]]. Wrist joint. Deep dissection. Anterior (palmar) view.
</gallery>
==
{{Commons}}
{{
{{Bones of upper extremity}}
{{Authority control}}
[[Category:Skeletal system]]
[[Category:Wrist]]
[[Category:Bones of the hand]]
[[Category:
|