Carpal bone cysts: a clinical and radiographic study.

In order to analyse and correlate the clinical and radiographic features of intracarpal bone cysts a review of 80 cysts in 77 patients is presented. Some cysts were found to develop very slowly from an area of trabecular fading to a well-defined cavity, bordered by a zone of radiopacity. Pain was constantly correlated to cysts with marginal sclerosis and at operation these cysts were found to be made up of fibrous tissue with mucoid changes. Most cysts were located in the scaphoid and lunate which are known to have vulnerable vascular supplies. These bones are also exposed to heavy load during power grip. It is, therefore, plausible that these cysts are caused by intramedullary vascular disturbances, followed by bone resorption and fibroblastic proliferation, and that pain is elicited by increasing pressure inside the cyst.