Trochlear calcification: a common entity

This study aims to quantify the prevalence of trochlear calcification.

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.

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.

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.