Anatomy of the Knee Joint

1. ANATOMY OF THE
KNEE JOINT
DR. M. TAQI EHSANI PGY1 OF ORTHOPEDICS, FMIC

2. KNEE JOINT
• Largest synovial joint in the body, consist of:
• Articulation between the femur and tibia (weigh-
bearing)
• Articulation between patella and the femur
• Two fibrocartilaginous menisci, one on each side
• Basically a hinge joint that allows mainly flexion and
extension

3. ARTICULAR SURFACES
• Covered by hyaline cartilage
1. Medial condylar joint
2. Lateral condylar joint
3. Patellofemoral joint
• The patellofemoral joint is V-Shaped trench
• surfaces of the femoral condyle that articulate with the tibia:
• in flexion of the knee = curved or round
• Full extension = Flat

4. MENISCI
• two menisci, fibrocartilaginous C-shaped cartilages,
medial and lateral meniscus
• Attached to the each end to facets in the intercondylar
region of the tibial plateau
• Lateral meniscus is more mobile
• Interconnected anteriorly by a transverse ligament
• Improve congruency between the femoral and tibial
condyles

5. SYNOVIAL MEMBRANE
• Attaches to the margins of the
articular surfaces and to the superior
and inferior outer margins of the
menisci
• Forms pouches in two locations
• The Smallest, Subpopliteal recess
• Large bursa, Suprapatellar bursa
• Other bursae associated with the
knee but not normally
communicating with the articular
cavity include:
• Subcutaneous prepatellar bursae and
numerous others associated with
tendons and ligaments around the

6. FIBROUS MEMBRANE
• Partly formed and reinforced by
extensions from tendons of the
surrounding muscles
• Encloses the articular cavity and the
intercondyle region
• Medially, attached
• Laterally, not attached
• Anteriorly, attached to margins of
patella

7. LIGAMENTS
• Patellar ligament
• Tibial (medial) Collateral Ligament
• Fibular (lateral) Collateral Ligament
• Anterior Cruciate Ligament
• Posterior Cruciate Ligament

8. LOCKING MECHANISMS
1. When standing, the knee joint is locked into
position, thereby reducing the amount of
muscle work needed to maintain the
standing position
2. Medial rotation of femur on the tibia during
extension, tighten all the associated
ligaments
3. The body’s center of gravity is positioned
along the vertical line that passes anterior to
the knee joint, keeps knee extended
4. The popliteus muscle unlocks the knee by
initiating lateral rotation of the femur on
the tibia

9. MUSCLES PRODUCING MOVEMENT
• Extension
• Quadriceps femoris
• Flexion
• Biceps femoris
• Semitendinosus
• semimembranosus
• Medial rotation
• Popliteus
• Semimembranosus
• semitendinosus
• Lateral rotation
• Biceps femoris

10. VASCULAR SUPPLY
• five major constant arteries, namely, the superior medial
and lateral, the middle (posterior), and the inferior
medial and lateral genicular arteries
• Descending and genicular branches from:
• Femoral artery
• Popliteal artery
• Lateral circumflex femoral artery
• Circumflex fibular artery
• Recurrent branches of anterior tibial artery in leg
These vessels form an anastomotic network around the
joint

11. INNERVATION
• Innervated by branches from:
• Obturator
• Femoral
• Tibial
• Common fibular nerves

12. TIBIOFIBULAR JOINT
• The small proximal tibiofibular joint is synovial,
little movement
• Joint surfaces, lateral condyle of tibia and
superomedial surface of head of the fibula, flat and
circular
• The capsule is reinforced by anterior and posterior
ligaments

13. POPLITEAL FOSSA
• Important area of transition between the thigh
and leg, diamond shape behind the knee joint
formed between muscles in the posterior
compartment of the thigh and leg
• Boundaries
• Nerves and vessels
• Superficial structures

14. Thank you for your
attention