Knee joint plan Flashcards
Classify the knee joint
Modified synovial hinge joint
What are the bones / articulation of the knee joint?
Patella, femoral condyles and tibial plateau
Tibiofemoral and femoropatellar
What type of cartilage is at the knee &what is its function?
Hyaline cartilage on articular surfaces
Reduce friction and shock absorption
Describe the meniscus at the knee
Semilunar cartilages
- Make the knee joint more congruent and absorb shock
Name the bursae at the knee joint
- Suprapatellar bursa
- Prepatellar bursa
- Infrapatellar bursa
- Pes anserine bursa
- Semimembranosus bursa
Where is the Suprapatellar bursa located?
Suprapatellar bursa - extension of synovial cavity of the knee that’s located between the quadriceps and the femur
Where is the Prepatellar bursa located?
Between the apex of the patella & the skin
Where is the Infrapatellar bursa located?
Deep - between patella tendon and tibia
Superficial - between patella tendon and skin
Where is the Pes Anserine bursa located?
Pes anserinus is the area on the medial aspect of the knee where the tendons for gracilis, sartorius and semitendinosus muscles attach. The bursa is under the tendons separating them from the tibia
Where is the Semimembranosus bursa located?
Posteriorly in the knee between semimbranosus and the medial head of gastrocnemius
Describe the capsule of the knee joint
- Contains the whole joint
- Attached to articular margins
- Contains the patella anteriorly
Describe the synovial membrane of the knee joint
It lines the capsule
- Secretes synovial fluid - which lubricates, removes waste and provides nutrients for cartilage
- The synovium bathes the area of the femoral condyles
- ACL and PCL are intracapsular but extrasynovial
What are the ligaments at the knee joint?
- ACL
- PCL
- MCL
- LCL
What are the permitted movements at the knee joint?
- Flexion / Extension
2. Some medial / lateral rotation when knee is flexed
How many degrees of freedom is at the knee?
1 degree (2 degrees as rotation into closed-packed position)
What arteries supply the knee?
Branches from femoral, tibial and popliteal artery
What nerves supply the knee?
Branches of obturator, femoral and sciatic nerves
What muscles flex the knee?
- Semimembranosus
- Semitendinosus
- Biceps femoris
- Gastrocnemius
What muscles extend the knee?
- Rectus femoris
- Vastus medialis
- Vastus lateralis
- Vastus intermedius
What muscles laterally rotate the knee?
Biceps femoris
What muscles medially rotate the knee?
- Semimembranosus
- Semitendinosus
- Gracilis
- Sartorius
- Popliteus
Gracilis
- Origin
- Insertion
- Action
- Innervation
- Inferior border of pubic body near symphsis
- Proximal medial surafce of tibia (part of pes anserinus)
- Adducts thigh at hip
- Obturator nerve (L3,L4)
Semitendinosus
- Origin
- Insertion
- Action
- Innervation
- Ischial tuberosity of os coxa
- Proximal tibia, medial to tibial tuberosity (part of pes anserinus)
- Extends thigh at hip
Flexes leg at knee
Medially rotates knee when knee is flexed - Tibial portion of sciatic nerve (L5, S1, S2)
Semimembranosus
- Origin
- Insertion
- Action
- Innervation
- Ischial tuberosity of os coxa
- Posterior medial condyle of tibia
- Extends thigh at hip
Flexes leg at knee
Medially rotates knee when knee is flexed - Tibial portion of sciatic nerve (L5, S1, S2)
Biceps femoris
- Origin
- Insertion
- Action
- Innervation
- Long head - Ischial tuberosity of os coxa
Short head - distal linea aspera & lateral supracondylar ridge of femur - Long & short head - head of fibular and lateral condyle of tibia
- Extends thigh at hip
Flexes leg at knee
Laterally rotates leg at knee when knee is flexed - Long head - Tibial portion of sciatic nerve (S1-S3)
Short head -common peroneal nerve (L5, S1,S2)
Rectus femoris
- Origin
- Insertion
- Action
- Innervation
- Anterior inferior iliac spine and ilium above the acetabulum
- Quadriceps tendon to base of patella and onto tibial tuberosity via the patellar ligament
- Flexes thigh at hip
Extend the knee - Femoral nerve (L2-L4)
Vastus medialis
- Origin
- Insertion
- Action
- Innervation
- Intertrochanteric line. It also attaches to the medial lip of linea aspera of femur
- Quadriceps tendon to base of patella and onto tibial tuberosity via the patellar ligament
- Flexes thigh at hip
Extend the knee - Femoral nerve (L2-L4)
Vastus lateralis
- Origin
- Insertion
- Action
- Innervation
- Greater trochanter. It also attaches to the lateral lip of linea aspera of femur
- Quadriceps tendon to base of patella and onto tibial tuberosity via the patellar ligament
- Flexes thigh at hip
Extend the knee - Femoral nerve (L2-L4)
Vastus intermedius
- Origin
- Insertion
- Action
- Innervation
- Anterior and lateral surafces of shaft of femur
- Quadriceps tendon to base of patella and onto tibial tuberosity via the patellar ligament
- Flexes thigh at hip
Extend the knee - Femoral nerve (L2-L4)
Sartorius
- Origin
- Insertion
- Action
- Innervation
- Anterior superior iliac spine
- Proximal tibia, medial to tibial tuberosity (part of pes anserinus)
- Flexes thigh at hip
Medially rotates knee - Femoral nerve (L2-L3)
Popliteus
- Origin
- Insertion
- Action
- Innervation
- Lateral surface of lateral condyle of femur
- Proximal posterior surface of tibia, just above the soleal (popliteal line)
- Medially rotates knee
- Tibial nerve (L4, L5, S1)
