Trochlear calcification: a common entity.

Purpose: This study aims to quantify the prevalence of trochlear calcification.

Methods: A retrospective case review was performed on orbital CT scans ordered at Wills Eye Emergency room and Jefferson Hospital for Neuroscience for patients from June 2009 through September of 2009.

Results: In our series, we examined 132 scans, 61% (81/132) men, 39% (51/132) women, ranging in age from 10-83. We found a 13% (17/132) prevalence of calcification of the trochlea, 53% (9/17) unilateral and 47% (8/17) bilateral. Forty-one percent (7/17) were female, 59% male (10/17). Age (19-83) was not a factor in the presence of trochlear calcification. The calcification either came straight off of the bone or was free-floating in the trochlea.

Conclusions: Our study establishes that calcification of the trochlea is common in the general population with a prevalence of 13%. Calcification of the trochlea should be considered in the differential diagnosis of hyperintense densities in the superomedial orbit, especially in cases of trauma where it can be confused with a foreign body.