An Anatomic Study on Whether the Patella is Centered in an Ideal Anteroposterior Radiograph of the Knee.

Background: Currently, an anteroposterior radiograph of the knee is judged based on a centered position of the patella between the femoral condyles. We are not aware of any anatomic literature supporting this recommendation.

Questions/purposes: Orthogonal images are required for accurate assessment of knee deformity.

Periosteum, bone's "smart" bounding membrane, exhibits direction-dependent permeability.

The periosteum serves as bone's bounding membrane, exhibits hallmarks of semipermeable epithelial barrier membranes, and contains mechanically sensitive progenitor cells capable of generating bone. The current paucity of data regarding the periosteum's permeability and bidirectional transport properties provided the impetus for the current study. In ovine femur and tibia samples, the periosteum's hydraulic permeability coefficient, k, was calculated using Darcy's Law and a custom-designed permeability tester to apply controlled, volumetric flow of phosphate-buffered saline through periosteum samples.