Knee Joint Anatomy

Knee Joint is one of the most complex and strongest parts of the entire human body. It plays a very significant role in leg movements as well as in carrying the weight of the entire body. The usage of the legs is enhanced only because they can be bent, and the knee joint makes this possible.  The movement of the lower legs relative to the thighs above is also made possible because of the efficient and effective functioning of the knee joint.

What is a Knee Joint?

A Joint or articulation is the location or point where two or more bones in the body meet. The joints are constructed in such a way as to allow for variations in movement in terms of type and degrees. The joint which connects the thigh and the lower leg is known as the knee joint. The medical description for the knee joint is hinge type synovial joint.

What are components of the Knee Joint?

The Knee Joint is a modified hinge joint and it is made up of the following three bones –

  • Femur – The thigh bone.
  • Patella – The patella is also known as the “knee cap”.
  • Tibia – The main bone of the lower leg.

 

What are the additional structures that properly describe the Knee Joint Anatomy?

  • Hyaline Cartilage:
  • Meniscus
  • Joint Capsule
  • Ligaments
  • Bursae
  • Adipose Tissue

 

What is the Hyaline Cartilage?

The thin layer which covers the joint forming surfaces of each of the above motioned bones is referred to as the hyaline cartilage. It protects the bone from damage and gives it a very smooth surface.

What is the function of the Meniscus?

Meniscus is a figure-8 shaped fibro-cartilage which is rubbery and tough. It is located between the femur and the tibia. Its main function is to act as shock absorber when the legs are involved in strenuous activities such as running or jumping.

What is the need for a Joint Capsule in the knee?

Knee joints are synovial joints and they surrounded the bones to provide lubrication and strength. The synovial membrane that lines the joint capsule produces the necessary synovial fluid which is oily and helps in lowering the wear and tear of the knee.

What are the two ligaments that help in the alignment of the knee?

Ligaments and tissue are necessary to keep the joints in place. There are many strong ligaments that surround the joint capsule of the knee which help in various movements. The two cruciate ligaments i.e. Anterior and Posterior or ACL and PCL play an important role in marinating the proper alignment of the knee. The anterior cruciate ligament also prevents the knee from hyperextension.

What are the Bursae?

Bursae or the small pockets of synovial fluid which surround the knee. They help in –

  • Reducing friction due to tendon movements across the joint surfaces.
  • Reduce friction between the patella and femur.
  • Providing cushion to protect the knee joint from friction and external forces.

 

Note:

Synovial denotes a type of joint which has a surrounding sac-like membrane that is thick, flexible, and stores viscous fluid for lubrication.