Anatomy of the Knee Joint: Tibial Femoral Joint

Introduction

• Focus on the Tibial Femoral Joint, not the Patellofemoral joint.
• Tibial Femoral Joint: Articulation between tibia and femur.
• Separate lecture for the Patellofemoral Joint.

Common Knee Injuries

• High incidence of non-contact injuries, e.g., during pivoting or cutting.
• Most Common Knee Injuries in High School Sports:
  • 1st: MCL (Medial Collateral Ligament)
  • 2nd: Patella Tendon/Tendonitis
  • 3rd: ACL injuries

Gender Differences in Injuries

• Females are more prone to ACL injuries due to factors like:
  • Weaker hamstrings
  • Landing in genu valgus
  • Increased laxity during menstruation

Mechanism of Injury

• Genu Verus: LCL injury example

Anatomy and Key Structures

Femur

• Important landmarks:
  • Lateral & Medial Epicondyles
  • Adductor Tubercle
  • Lateral & Medial Condyles
• Covering in hyaline cartilage to protect the bone.

Tibia

• Tibial Tuberosity
• Medial & Lateral Tibial Plateaus
• Gerdy's Tubercle: Distal attachment of the IT Band

Fibula

• Not directly part of the tibial femoral joint.

Muscles

Anterior Thigh Muscles

• Quadriceps: Vastus Lateralis, Rectus Femoris, Vastus Medialis
• Sartorius

Posterior Thigh Muscles

• Hamstrings: Biceps Femoris, Semitendinosus, Semimembranosus

Pes Anserinus (Sergeant Muscles)

• Sartorius, Gracilis, Semitendinosus

The Screw Home Mechanism

• Close Packed Position: Medial and lateral condyles are locked in full extension.
• Involved in both locking and unlocking of the knee.

Role of Popliteus

• Unlocks the knee in open kinetic chain.

Ligamentous Support

Joint Capsule

• Envelops the knee joint, providing stability and housing synovial fluid.

Key Ligaments

• Medial Collateral Ligament (MCL):

  • Superficial and deep layers
  • Prevents valgus stress

• Lateral Collateral Ligament (LCL):

  • Prevents varus stress

• Anterior Cruciate Ligament (ACL):

  • Prevents anterior translation of tibia
  • Controls internal/external tibial rotation
  • Prevents hyperextension

• Posterior Cruciate Ligament (PCL):

  • Prevents posterior displacement of tibia

Menisci

• Roles:
  • Shock absorption
  • Deepen articulation
  • Lubricate articulating surfaces
  • Improve joint stability
  • Serve as proprioceptive organs

Important Ligaments

• Ligament of Risberg & Humphries:

  • Stabilize lateral meniscus
  • Attach it to medial femoral condyle

• Transverse Ligament:

  • Connects medial and lateral menisci

Posterior Lateral Corner

• Composed of various structures including IT Band, LCL, and Popliteus.

Arcuate Ligament

• Assists cruciate ligaments in controlling instability.

Conclusion

• Understanding the anatomy and mechanics of the tibial femoral joint is crucial for diagnosing and treating knee injuries effectively.
• Please reach out with any questions.