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 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.
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 due to its location and external appearance.
Carpometacarpal boss is uncommon and there is not much scientific data. It is likely genetic as often present on both hands. There is no evidence that it is related to hand use. Typically, this condition will begin to show itself in the 3rd or 4th decade.
- Conway, William F. et al. (1984). "The Carpal Boss: An Overview of Radiographic Evaluation" (PDF). Radiology 156 (1): 29–31. doi:10.1148/radiology.156.1.3923555. PMID 3923555. Retrieved February 2010.
- Walker, Lorenzo G. "Carpometacarpal Boss". The Hand Center of Ventura County. Retrieved February 2010.
|Wikimedia Commons has media related to Carpal boss.|
- Mennen, Ulrich (May 2004). ""Bossing" of the second and third Carpo-Meta-Carpal joint". Electronic Doctor. Retrieved February 2010.
- About.com: Orthopedics - Bossing
- Carpal Boss: An Overview of Radiographic Evaluation
- The Internet Journal of Orthopedic Surgery
- Electronic Doctor
- eMedicine from WebMD