Carpometacarpal bossing
{{Short description|Immovable mass of bone on the wrist}}
Carpometacarpal bossing (or metacarpal/carpal bossing) is a small, immovable mass of bone on the back of the wrist. The mass occurs in one of the joints between the carpus and metacarpus of the hand, called the carpometacarpal joints, where a small immovable protuberance{{cite journal|author=Conway, William F.|display-authors=etal|year=1984|title=The Carpal Boss: An Overview of Radiographic Evaluation|url=http://radiology.rsnajnls.org/cgi/reprint/156/1/29.pdf|journal=Radiology|volume=156|issue=1|pages=29–31|doi=10.1148/radiology.156.1.3923555|pmid=3923555|access-date=27 July 2020}}{{dead link|date=November 2016|bot=InternetArchiveBot|fix-attempted=yes}} occurs when this joint becomes swollen or bossed.
The joint between the index metacarpal and the capitate is a fibrous non-mobile joint. Some people have a gene that leads to this growth. It looks like arthritis (bone spurs on each side of the joint) on X-ray. It looks like a ganglion on the hand, but more towards the fingertips.
Clinical significance
The carpometacarpal joint is usually found at the base of the second and third metacarpal bones at the point where they meet the small bones of the wrist.{{cite web|last=Walker|first=Lorenzo G.|title=Carpometacarpal Boss|url=http://www.handoc.net/carpoletacarpal%20boss.htm|url-status=dead|archive-url=https://web.archive.org/web/20090608065731/http://www.handoc.net/carpoletacarpal%20boss.htm|archive-date=2009-06-08|access-date=27 July 2020|publisher=The Hand Center of Ventura County}}
Bosses are usually painless and will never cause more than a slight ache. They tend to be of manageable size, but on occasion the extensor tendons can slide over the bump, which can be annoying. Sometimes there is a ganglion cyst along with the boss.
Often, this condition will be mistaken for a ganglion cyst because of its location and external appearance.
Carpometacarpal boss is uncommon and there is not much scientific data. Its etiology has yet to be fully defined, but can be congenital in the form of an accessory ossicle (os styloideum) or may be acquired from trauma, repetitive use, or degenerative osteophytosis.{{cite web |url=https://pubs.rsna.org/doi/abs/10.1148/radiology.156.1.3923555 |title=The carpal boss: an overview of radiographic evaluation. |first=W.F. |last=Conway |publisher=Radiological Society of North American |access-date=April 13, 2020 }} The condition usually begins to show in the 3rd or 4th decade.{{citation needed|date=February 2010}}
Additional images
{{gallery
|height=120|width=120|File:Hand of embryo.jpg|Micro-radiography of 8 weeks human embryo hand
|Image:Gray230.png|Second metacarpal bone
|Image:Gray231.png|Third metacarpal bone
|Image:Carpal-boss-xray.jpg|Carpal boss in plain X-Ray.
|Image:Carpal-boss-ct-sag.jpg|Carpal boss in CT.
}}
References
{{reflist}}
External links
{{Commons category|Carpal boss}}
- {{cite web
| title = "Bossing" of the second and third Carpo-Meta-Carpal joint
| url = http://www.edoc.co.za/modules.php?name=News&file=article&sid=527
| publisher = Electronic Doctor
| first = Ulrich | last = Mennen
| date = May 2004 | access-date = 22 February 2010
}}
- [http://orthopedics.about.com/od/handwrist/g/bossing.htm About.com: Orthopedics - Bossing] {{Webarchive|url=https://web.archive.org/web/20071116144407/http://orthopedics.about.com/od/handwrist/g/bossing.htm |date=2007-11-16 }}
- [http://radiology.rsnajnls.org/cgi/reprint/156/1/29.pdf Carpal Boss: An Overview of Radiographic Evaluation]{{dead link|date=November 2016 |bot=InternetArchiveBot |fix-attempted=yes }}
- [http://www.edoc.co.za/modules.php?name=News&file=article&sid=527 Electronic Doctor]
- [http://www.emedicine.com/plastic/topic338.htm eMedicine from WebMD]