Carpal boss

Case contributed by Dr Dalia Ibrahim

Presentation

Hard bump on the dorsal of the hand.

Patient Data

Age: 25 years
Gender: Male
CT

Hypertrophied bony protuberance of the base of the 3rd metacarpal bone and the trapezoid bone with osteoarthritic changes manifesting by narrowing of the dorsal aspect of their joint space and subcortical pseudocystic changes.

Case Discussion

Carpal boss may occur secondary to:

  • os styloideum (an accessory ossicle of the wrist)
  • hypertrophied bony protuberance on the dorsal surfaces of the base of the second or third metacarpals, near the capitate and trapezium, as in this case, there's elongation of the 3rd metacarpal base and the trapezoid bone with secondary pseudoarthrosis.

Degenerative changes at the site of the pseudoarthrosis are also common, as in this case.

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Case information

rID: 83196
Published: 15th Oct 2020
Last edited: 15th Oct 2020
Inclusion in quiz mode: Included