2. The Knee

3. From the Sports Medicine Perspective

4. Bony Anatomy Femur Patella Tibia Fibula

5. Bony Anatomy Femur: Longest Bone in Body Tibia: WB bone of lower extremity Fibula: Site of Muscle Attachment Patella: Sesamoid Bone A bone that develops within a tendon

6. Knee Skeletal Lateral Condyle Head of Fibula Femoral Groove Gerdy’s Tubercle Tibial Tuberosity Pes Anserine

7. Sagittal MRI View

8. Knee Connective Tissue

9. Knee Menisci

10. Menisci

11. Medial Meniscus Lateral Meniscus PCL ACL

12. Knee Ligaments

13. Medial Collateral Ligament MCL

14. MCL Thick Band of Tissue Tibia  Femur Resists Valgus Force

15. Valgus Outside to Inside Force MCL resists this force Occurs in FRONTAL PLANE

16. Lateral Collateral Ligament LCL

17. LCL Narrow cord like band of tissue Fibula  Femur Resists Varus Forces

18. Varus Inside to Outside Force LCL resists this force FRONTAL PLANE

19. Increased Valgus

20. Collateral Ligament Ruptures

21. Ligament Structures

22. Anterior Knee

23. Anterior Cruciate Ligament ACL Composed of 3 bands Prevents anterior translation of tibia Stabilizes against excessive rotation Stabilizing Ligament

24. Healthy ACL

25. Torn ACL

26. Knee Posterior

27. Posterior Cruciate Ligament PCL Stabilizes the posterior aspect of knee Prevents hyperextension

28. Cadaver Knee

29. Quadriceps Anterior Thigh Musculature Four Muscles: Rectus Femoris Vastus Lateralis Vastus Medialis Vastus Intermedius Extend the Knee

30. Quadriceps

31. Rectus Femoris 2 Joint Muscle Crosses hip and knee Flexes Hip Extend the knee Converges with rest of quadriceps muscles at tibial tubercle

32. Hamstrings Three Muscles Semimembranosus Semitendinosus Biceps Femoris Common Origin the ischial tuberosity Flex the Knee

33. Hamstrings

34. Popliteus

36. MCL Sprains Valgus Force Tensile Mechanism  MCL  Flexed knee more vulnerable (open pack position = less stable)

37. MCL Injuries Direct trauma in frontal plane injures MCL Combination of rotation can result in ACL and meniscus tears

38. MCL/LCL Injuries GRADE I: No instability Mild Effusion ROM full Mild tenderness w/ palpation

39. MCL/LCL Injuries GRADE II: Laxity w/ valgus or varus stress (more with 30 degrees of flexion) Decrease in ROM Increase medial (MCL) or lateral (LCL) pain GRADE III: Complete ligament rupture Complete loss of stability Immediate pain that transitions into dull ache

40. Treatment Based on severity of injury RICE Modify activity Crutches Exercises in sagittal plane Progress to functional exercise