When cartilage is compressed water is squeezed out of the ex

When cartilage is compressed, water is squeezed out of the extracellular matrix; when pressure is removed, water flows back in. Why do you think cartilage at weight-bearing joints (like the knees) can degenerate when they\'re used often? Why are you least likely to damage your lateral (fibular) collateral ligament from a contact knee injury compared to your ACL, PCL or MCL? Only if you feel comfortable, share your war stories regarding any bone breaks or ligament tears you (or a friend) have experience. Include the injury, how it happened, and what the treatment was on the whiteboard.

Solution

1.The cartilage at the weight bearing joints degenerate because there occurs loss of molecules known as proteoglycans in the extracellular matrix as a result of which the extracellualr matrix is disrupted.This increases the permeability of water and the water content becomes more then 90%.There occurs decreased modulus of elasticity ultimately resulting in reduction in load bearing capability of cartilage.

2.We are least likely to damage our lateral collateral ligament (LCL) from a contact knee injury compared to ACL.PCL or MCL because lateral collateral ligament is present at the inner and outer side of the knee joint.Contact injury cannot damage LCL.Lateral collateral ligament of the knee can be damaged only by varus stress or repeated stress that causes the LCL to lose its elasticity.

3.I once experienced a sprain in my ankle as I stepped onto a brick at night in the dark while walking.This was a mild sprain and there was just a little bit of stretching and damage to the fibres of the ligament followed by swelling.The treatment included putting ice on the injured part so as to reduce the swelling .This was followed by use of an elastic bandage to compress the swelling in case it occurs.Taking rest for some days and avoiding pressure on the joint was followed.