Computed tomography demonstration of distal femoral (trochlear) articular groove: a normal variant.

In computed tomography of the skeleton, as in other radiologic modalities, recognition of normal skeletal variants is essential for defining the extent and type of injury or neoplasm. Computed tomography findings, because of the unique use of cross-sectional anatomy, must be carefully studied to avoid labeling a normal variant as an abnormal entity. We describe here an observation of a normal variant--distal femoral, anterior articular (trochlear) groove--found in a patient with an osteochondral fracture and loose intra-articular bony fragment.