The body looks at this as toxic and if it gets absorbed, the liver deals with it mostly as a toxin rather than a nutrient. Eating the chalk will put a large quantity of this material in your body and is not a good idea at all.
This operation can be done either through the same incision as the medial patellofemoral ligament reconstruction or through a larger incision around the knee. It allows the patella to sit more centrally within its groove and not tilt as the patella engages in the trochlear groove.
A medial patellofemoral ligament reconstruction involves making a new ligament to compensate for the damaged one. One of your hamstring tendons (gracilis or semitendinosus tendon) are removed through a small incision at the front inner part of the tibia bone.