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Duke Orthopaedics
presents
Wheeless' Textbook of Orthopaedics

Anatomy of Patella


- Discussion:
    - sesamoid bone w/ in quadriceps tendon;
    - cartilaginous posterior surface is divided by a rounded vertical ridge into a larger, lateral portion for articulation w/ lateral condyle of femur and smaller
           medial portion for articulation w/ medial condyle of femur;
    - w/ increasing knee flexion, contact pressure moves proximally on patella up to superior pole and onto quadriceps tendon;
    - articular surface of patella, varying in thickness from approximately 2 to 5.5 mm, is divided into 7 fascets;
           - medial and lateral facets are divided into = 1/3 sections;
           - superiorly and inferiorly, with the 7th facet being the most medial portion called the odd facet;
    - Wiberg: 3 shapes based on position of vertical ridge;
           - type I:  there are roughly = medial and lateral facets
           - type II  most common: medial facet is only 1/2 size of lat. facet;
           - type III medial facet is so far medial that the central ridge is barely noticable;

- Blood Supply:
    - blood supply to patella originates from as many as 12 nutrient arteries at the inferior pole,
           which run upward on the anterior surface of the bone in a series of furrows;
    - may arise from mid patellar vessels penetrating middle 1/3 of anterior surface & inferior pole vessels that anastomose at inferior pole of patella;
    - geniculate system feeds these primary vessels;
           - anterior tibial recurrent vessels
           - inferior medial genicular
           - inferior lateral genicular
    - ref: Quantitative and Qualitative Assessment of Bone Perfusion and Arterial Contributions in a Patellar Fracture Model Using Gadolinium-Enhanced Magnetic Resonance Imaging: A Cadaveric Study.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Monday, October 14, 2013 9:17 am