Knee (Tibiofemoral) Joint
Bones of the Knee Joint
•Femur
-Longest and strongest bone in the body
• Lateral and medial epicondyles
-The widest points of the femur at the knee
-Round prominences above lateral and medial condyles
-Will be attachments for thigh and leg muscles and knee ligaments
• Medial and Lateral Condyles
-distal end of the femur
-smooth round surfaces inferior to medial and lateral epicondyles
• Intercondylar Fossa
-Groove separating the medial and lateral condyles
Bones of the Knee Joint
Bones of the Knee Joint
•Tibia
-Larger bone of the lower leg
-Only weight bearing bone of crural region
-If tibial fracture occurs, what may a patient not be able to do?
• Medial and Lateral Condyles
-Articulate with medial and lateral condyles of the femur
-Insertion points for leg muscles
• Intercondylar Eminence
-ridge separating medial and lateral condyles of tibia
Bones of the Knee Joint
• Tibial Tuberosity
-can be palpated just below the patella
-An attachment for the powerful leg muscles that extend the knee
*****Important for muscle insertions (Quads)
Bones of the Knee Joint
•Fibula
-Slender lateral bone of lower leg
-Stabilizes the ankle, but does not bear any of the bodies weight
• Head
-Proximal end of fibula
-This Portion is thicker and broader than the distal end
• Patella
-roughly triangular sesamoid bone embedded in the tendon of the knee
Knee Ligaments
• Fibular or lateral collateral ligament
• Extends from the lateral epicondyle of femur to the lateral surface of the head of
fibula
• Tibial or medial collateral ligament
• Extends from medial epicondyle of femur to medial condyle and superior, medial
part of tibia
• Oblique popliteal ligament
• Expansion of tendon of semimembranosus
• Strengthens joint capsule posteriorly
• Arcuate popliteal ligament
• Arises from posterior aspect of the fibular head
• Passes over the popliteus tendon and covers posterior surface of knee joint
Knee Ligaments and cartilage
• Anterior cruciate ligament (ACL)
• Posterior cruciate ligament (PCL)
• ACL is the weaker of the two
• Cross like an X
• Medial Meniscus
• Adheres to tibial collateral ligament
• Lateral Meniscus
• Popliteus tendon separates it from the
Lateral collateral ligament
• Transverse Ligament
• Attaches the lateral portion of the menisci
Patellar Ligament and Quadriceps Femoris
Tendon
• Patellar ligament is an extension of the quadriceps femoris tendon
Knee Bursae
• Prepatellar bursa
• Suprapatellar bursa
• Deep infrapatellar bursa
• Subcutaneous infrapatellar bursa
Clinical Concerns
• Torn ACL
• Can be partial or complete
• Common sports injury for soccer, basketball and football players
• Can result from changing direction rapidly, stopping quickly, direct contact,
and landing a jump incorrectly
• Disrupts stability of knee, requires surgery
ACL Reconstruction
The muscles of the patellar joint:
• Rectus Femoris:
•
•
•
•
•
Origin: Anterior inferior iliac spine
Insertion: Tibial tuberosity
Action: Hip flexion, knee extension
Nerve: Femoral nerve
Roots: L2-L4
Vascular supply for the Rectus femoris:
• Lateral circumflex femoral artery
Nerve innervation Rectus femoris:
• Femoral nerve
• L2-L4
Vastus intermedialis, lateralis, and medialis:
• Origin: anterior femur( VI) and Linea aspera (VL
And VM)
• Insertion: Tibial tuberosity via patellar tendon
• Action: Knee extension
• Nerve: Femoral nerve
• Roots: L2-L4
• Vascular supply: Lateral circumflex
Biceps femoris
• Origin:
• Long head: Ischial tuberosity
• Short head: Lateral lip of linea aspera
• Insertion: Fibular head
• Action:
• Long head: Extends hip and flex knee
• Short head: Flex knee
Vascular Supply:
• Inferior gluteal artery
Nerve Innervation
• Long head: Tibial division of sciatic nerve
• Short head: Common peroneal nerve
• Roots: L5, S1, and S2
Semimembranosus:
• Origin: Ischial tuberosity
• Insertion: Posterior surface of medial condyle of tibia
• Action: Extend hip and flex knee
• Nerve: Sciatic nerve
• Roots: L5, S1, and S2
• Vascular supply: Inferior gluteal artery
Popliteus:
• Origin: Lateral condyle of femur
• Insertion: Posteriorly on medial condyle of tibia
• Action: Initiates knee flexion
• Nerve: tibial nerve
• Roots: L4-5, S1
Vascular supply to popliteus:
• Popliteal artery
• Popliteal vein
Semitendinosus:
• Origin: Ischial tuberosity
• Insertion: Anteromedial surface of proximal tibia
• Action: Extend hip and flex knee
• Nerve: Sciatic nerve
• Roots: L5, S1, and S2
Vascular supply to semitendinosus:
• Deep femoral artery
Gastrocnemius:
• Origin: Medial and lateral condyles of femur
• Insertion: Posterior calcaneus
• Action: Knee flexion, ankle plantar flexion
• Nerve: Tibial nerve
• Roots: S1-2
• Vascular supple: popliteal artery
Other nerves to know:
•
Deep fibular
•
Superficial fibular
Other arteries we need to know:
Other veins to know:
Surface Anatomy: Posterior
• Popliteal fossa
• Medial and lateral head of gastrocnemius
• Semitendinous tendon
• Semimembranosus
Tendon
• Soleus
• Biceps fermoris tendon
Surface Anatomy: Anterior
• Patella
• Vastus medialis
• Vastus lateralis