Knee Anatomy

Knee Anatomy, Rockville, Maryland

The knee is the largest joint in the body consisting of four bones, multiple ligaments and muscles, which act as shock absorbers during movement. Several large fibrous bands of tissue, called ligaments, support the knee on both sides. They provide strength and stability to the joint. The four ligaments that connect the thighbone (femur) and shinbone (tibia) are the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL). The ACL and PCL limit tibial movement forward and backward and also limit flexion and extension of the knee. The MCL and LCL provide stability to the inside and outside of the knee.

Contact sports or high-impact activities that feature rapid, twisting movements can place extreme forces on the knee, which can lead to injury. 

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