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chapter 1: normal anatomy

Osseous Structure

A transverse section of the patella (Fig. 1.8) through the middle of the articulating surface gives a view similar to what one can see using computerized tomography or magnetic resonance imaging (Fig. 1.9). Magnetic resonance imaging (Fig. 1.9) differentiates osseous, cartilaginous, and retinacular structures. Subchondral bone outlines the medial and lateral facets. The lateral line is generally thicker, suggesting greater loading. Subchondral bone density is maximal at the proximal lateral facet (15). The medial line rarely reaches the medial margin of the patella, often dwindling near the junction of the medial and odd facets. Between these two layers of compact bone, the trabeculae of cancellous bone are aligned more or less parallel to each other and perpendicular to the coronal plane of the patella, therefore slightly oblique vis a vis the articular facets. The trabeculae of the femur are aligned perpendicular to the articular facets of the femoral trochlea.

        

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