True about patella is

PATELLA:- Largest sesamoid bone developed in tendon of quadriceps femoris.Triangular shape.Apex, 3 borders( sup, lateral and medial), 2 surfaces( anterior and posterior ). Attachments:-1. Superior border/ base- rectus femoris ,vastus intermedius . Vastus intermedialis attached proximal to rectus femoris.2. Medial border- vastus medialis.3. Lateral border- vastus lateralis.4. Posterior surface- ligamentum patellae. Ossification:- several centers which appear during 3-6 years of age. Fusion complete at pubey.One or two centers at the superolateral angle may form separate pieces of bone, forming bipaite/ tripaite patella. Patella supplied by genicular anastomosis. <img src=" /> {Reference: BDC 6E pg no. 20,21}