1. Anatomy of the Knee
Not a true hinge joint

2. The knee is NOT a true hinge joint!
Non-weight bearing
Full extension the tibia rotates laterally
In flexion the tibia rotates medially
Weight bearing the femur rotates medially on tibia

3. Lateral Collateral Ligament (LCL)
Connects the lateral condyle of femur to the fibular head
Shaped like a pencil-1”-1.5” long
Function: prevents adduction of the tibia

4. Medial Collateral Ligament(MCL)
Connects medial condyle of femur to the abductor tubercle of tibia
Flat, long, thick ligament - 6”-6.5”long
Attaches to medial meniscus
Prevents abduction of tibia

5. Anterior Cruciate Ligament (ACL)
Located anteriorly on tibia and twists as it attaches posteriorly on femur (medial-lateral)

6. Function of ACL Prevents anterior displacement of tibia
Prevents hyperextension
Prevents medial/lateral rotation of tibia
Prevents posterior displacement of femur

7. Rotation of ACL Prevents medial/lateral rotation
ACL is stretched and torn during rotation

8. Which knee?
Notice medial insertion on tibia and lateral insertion of femur

9. Posterior Cruciate Ligament (PCL)
Runs lateral from tibia to medial attachment of femur
MAJOR STABILZER OF THE KNEE
Hyperextension damages PCL; during lateral rotation PCL tightens

10. Posterior Cruciate Ligament (PCL)
Function:
1. Prevents anterior displacement of femur
2. Prevents posterior displacement of tibia

11. Meniscus Medial – C shaped Lateral – O shaped
Function: deepens the articulation of joint and adds stability
Complaint – “giving out”

12. Bursae Sacs of Knee
Fat pads around the knee that provide cushioning

13. Synovial capsule
Encapsulated watertight membrane that secretes a fluid that lubricates and nourishes the joint
When irritated a cyst forms at the weakest part of the capsule – back of the knee – popliteal space

14. Retinaculum
Thick fascia that holds tendons in place around the knee

15. Patella and patellar tendon
Patella - sesamoid bone that increases the torque
Quadriceps tendon attaches rectus femoris to superior aspect of patella
Patella tendon attaches the quadriceps to the tibial tuberosity

16. Quadriceps Rectus femoris – 2 joints Vastus lateralis
Vastus intermedius
Vastus medialis

17. Hamstrings Biceps femoris – lateral Semitendinosus – medial 2nd
Semimembranosus – medial 1st

18. Gastrocnemius/Soleus
Gastrocnemius is a two jointed muscle:
Plantar flexion of the ankle and flexion of the knee.