The anatomy of the patellar tendon.

The morphology of the attachment of the patellar tendon, its bundle orientation, the differential fascicles length and the position of the apex of the patella were assessed in 22 cadaveric human knees. The patellar apex was 39+/-6% of the width of the tendon from its medial edge. The bulk of tendon was attached to the distal two-thirds of the anterior aspect of the patella. In six cases tendon fibres originated from the posterior surface of the apex of the patella, forming a ridge on the back of tendon. This may represent an anatomical variant accounting for the increased tendon thickness noted on MRI, both incidentally and during assessment for patellar tendonitis. Fascicles were parallel in the sagittal plane but converged in the frontal plane toward their tibial attachment. When bone-patellar tendon-bone (B-PT-B) grafts were harvested, as for anterior cruciate ligament reconstruction, the grafts narrowed distally. When harvesting B-PT-B, the oblique orientation of the fibres in the coronal plane must be borne in mind.