KNEE JOINTBy: Emily Drake & Baylie Wilson

Classification

Functional: Diarthroses (freely moving)

Structural: Synovial joint (filled with synovial fluid)

The knee joint is a hinge type synovial joint

Allows for flexion and extension  

formed by articulations between the patella, femur and tibia

The shape of the knee joint makes it weak so it relies on muscles and ligaments for stability

Meniscus

Medial and lateral menisci are fibrocartilage structures in the knee that serve two functions:

1. increase stability of the joint.2. To act as shock absorbers.

They are C shaped on both the lateral and the medial condyles

The Menisci keep your knee steady by balancing your weight across the knee

The lateral meniscus is smaller making it fairly mobile

Meniscus Tear A tear in the fibrocartilage

Usually caused by twisting or turning quickly, often with the foot planted and the knee is bent

Minor tear Slight pain and swelling

Usually goes away on its own in 2-3 weeks with rest and ice

Moderate tear Pain at the side or center of your knee

Swelling gets worse over 2 or 3 days

Can heal itself in 1 or 2 weeks with rest and ice

Severe tear Pieces of the meniscus move around in joint

May not be able to straighten it

Swell and become stiff

Surgery may or may not fix the tear

ACL & PCL

Anterior Cruciate Ligament and Posterior Cruciate Ligament cross each other to connect the femur and the tibia

ACL Attached at the anterior region of the tibia and the posterior region of

the femur in the intercondylar fossa It prevents anterior dislocation of the tibia onto the femur.

PCL Attached at the posterior region of the tibia, and anterior of the femur

in the intercondylar fossa It prevents posterior dislocation of the tibia onto the femur.

ACL & PLC Tears A partial or complete tear in the ligament ACL tear

Caused by Twisting your knee with the foot planted Getting hit on the knee Extending the knee too far Jumping and landing on a flexed knee Stopping suddenly when running

Treatment Surgery with ligament graft from the hamstring or Achilles to replace the ACL

PCL tear Caused by

Hitting the knee Falling on the knee while it's bent

Treatment Physical therapy Graft surgery

Collateral Ligaments

Two strap-like ligaments They act to stabilize the hinge motion of the knee,

preventing any medial or lateral movement Tibial (medial) collateral ligament

A wide and flat ligament, found on the medial side of the joint. Proximally, it attaches to the medial epicondyle of the femur, distally it attaches to the medal surface of the tibia.

Fibular (lateral) collateral ligament

Thinner and rounder than the tibial collateral, this attaches proximally to the lateral epicondyle of the femur, distally it attaches to a depression on the lateral surface of the fibular head.

Patellar Ligament

A continuation of the quadriceps femoris tendon distal to the patella. It attaches to the tibial tuberosity.

It holds the knee cap in place

Dislocated Knee Cap

Patellar Subluxation The kneecap slides abnormally or dislocates along the

thigh bone during activity Knee pain around the patella and shifted patella

Causes Sudden change in direction

Direct hit to the patella

Treatment Place knee straight and pop it back in place Surgery is rare Ice and elevate

Sources

Knee Joint. (n.d.). Retrieved March 24, 2015, from http://

www.innerbody.com/image/skel16.htm l

Knee joint. (n.d.). Retrieved March 24, 2015, from http://www.medicinenet.com/script/main/art.asp?articlekey=8845

(n.d.). Retrieved March 24, 2015, from http://www.webmd.com/pain-management/knee.../picture-of-the-knee