Posttraumatic cystlike defects of the scaphoid: late sign of occult microfracture and useful indicator of delayed union.

OBJECTIVE: To investigate the association between radiolucencies in the scaphoid and trauma, we studied the unenhanced radiographs and CT images of 1087 adult patients.
CONCLUSION: Three (0.3%) of the 1087 patients had scaphoid radiolucencies that developed after trauma. We hypothesize that in these patients a microfracture of the scaphoid or subtle fractures are the cause of persisting clinical symptoms. Persistent loading of the scaphoid due to wrist movement can lead to unrestricted compressive forces and ischemia and to the development of a bone cyst-like pathologic change, apparent on the radiograph as a radiolucency and often misreported as a cyst. An alternate term, "cystlike defect" or "pseudocyst" of the scaphoid, is suggested. Such radiolucencies are indicators of previous microfractures or an untreated episode of trauma to the scaphoid.