The knee Flashcards
what are the two main joints
- tibiofemoral (between femur and tibia)
- patellofemoral (between patella and femur)
what are the functions of the knee joint
- support body weight
- transmit forces between femur and tibia
- provide movement for locomotion and activities of daily living
where is the tibiofemoral joint located
between the femoral condyles and the tibial articular surfaces
what are femoral condyles
- femoral condyles at distal end of femur
- lateral condyles articular profile is longer
- convex, cartilage covered
what are tibia condyles
- prominences at proximal end
- tibial articular surfaces is where the femoral condyles join
what is the difference between the medial articular surface and the lateral articular surface
the medial articular surface is larger and more oval compared to the lateral articular surface which is smaller and circular
what are menisci
- semi lunar fibrocartilage discs
what is the function of menisci
- congruence between articular surfaces
- assist weight bearing across joint
- shock absorbers
- facilitate accessory movements
what are the major ligaments across the tibiofemoral joint
- medial collateral ligament
- lateral collateral ligament
- anterior cruciate ligament
- posterior cruciate ligament
what is the medial collateral ligament (MCL)
- broad flat band, 10cm long
- extra capsular (outside joint capsule)
- prevents valgus displacement (abduction of a joint which shouldn’t abduct)
what is the lateral collateral ligament (LCL)
- extra capsular (outside joint capsule)
- a strong cord
- prevents varus displacement (adduction of a joint which shouldn’t adduct)
what is the anterior cruciate ligament (ACL)
- intra-capsular (inside joint capsule)
- from anterior intercondylar area of tibia to lateral femoral condyle
- prevents anterior tibial displacement
what is the posterior cruciate ligament (PCL)
- intra-capsular (inside joint capsule)
- posterior intercondylar area of tibia to medial femoral condyle
- prevents posterior tibial displacement
what is the patellofemoral joint
- a synovial saddle joint
- positioned between the articular surface of the patella and the patella surface of femur
what is the patella
- largest sesamoid bone in the body
- embedded in tendon of quadriceps
what is the function of the patella
- an anatomic pulley
- reduces friction between quadriceps tendon and femoral condyles
what is the positioning and shape of the articular surfaces on the patella
- oval shaped, cartilage covered
- vertical ridge separates medial and lateral areas
- lateral area = larger
- medial area = smaller
what are the movements of the patella
- moves distally in flexion
- moves proximally in extension
what is a bursae (bursa singular)
- fluid filled sacs
- reduced friction
what movements are possible at the knee joint
- flexion/extension
- medial and lateral rotation
what are the knee flexors
- lateral head of gastrocnemius
- medial head of gastrocnemius
- long head of biceps femoris
- short head of biceps femoris
- semitendinosus
- semimembranosus
- sartorius
- gracilis
where does the lateral head of the gastrocnemius originate and insert
- it originates in the lateral condyle and lateral supracondylar line of femur
- it inserts in the posterior surface of calcaneus via calcaneal tendon
where does the medial head of the gastrocnemius originate and insert
- it originates in the medial condyle and popliteal surface of femur
- it inserts at the posterior surface of calcaneus via calcaneal tendon
where does the long head of the biceps femoris originate and insert
- it originates in the ischial tuberosity
- it inserts at the head of the fibula
where does the short head of the biceps femoris originate and insert
- it originates in the linea aspera and lateral supracondylar line
- it inserts at the head of the fibula
where does the semitendinosus originate and isnert
- it originates in the ischial tuberosity
- it inserts at the medial aspect of proximal part of tibia
where does the semimembranosus originate and inert
- it originates at the ischial tuberosity
- it inserts at the medial condyle of tibia
where does the sartorius originate and insert
- it originates at the anterior superior iliac spine
- it inserts at the medial aspect of proximal part of tibia
where does the gracilis originate and insert
- it originates at the body of pubis and inferior pubic ramus
- it inserts at the medial aspect of proximal part of tibia
what are the knee extensors
- rectus femoris
- vastus medialis
- vastus intermedius
- vastus lateralis
- tensor fasciae latae
where does the rectus femoris originate and insert
- it originates in the anterior inferior iliac spine and supracetabular groove of ilium
- it inserts at the tibial tuberosity via tendon of quadriceps femoris muscle and patella ligament
where does the vastus medialis originate and insert
- it originates in the medial part of the intertrochanteric line and medial to the spiral line and linea aspera of the femur, extending inferiorly to the medial supracondylar line
- it inserts at the tibial tuberosity via tendon of quadriceps femoris muscle and patellar ligament and medial border of patella
where does the vastus intermedius originate and insert
- it originates in the anterior and lateral surfaces of body of femur
- it inserts at the tibial tuberosity via tendon of quadriceps femoris muscle and patella ligament
where does the vastus lateralis originate and insert
- it originates in the intertrochanteric line, greater trochanter, gluteal tuberosity and lateral lip of linea aspera of femur
- it inserts at the tibial tuberosity via tendon of quadriceps femoris muscle and patella ligament; lateral border of patella
where does the tensor fasciae latae originate and insert
- it originates at the anterior superior iliac spine and anterior one third of outer lip of iliac crest
- it inserts at the tubercle of iliotibial tract on the tibia, via iliotibial tract
what are the medial rotators of the knee
- popliteus
- semitendinosus
- semimembranosus
- gracilis
- sartorius
where does the popliteus originate and insert
- it originates in the groove for popliteus muscle
- it inserts at the posterior surface of tibia, superior to soleal line
where does the semitendinosus originate and insert
- it originates at the ischial tuberosity
- it inserts at the medial aspect of proximal part of tibia
where does the semimembranosus originate and insert
- it originates in the ischial tuberosity
- it inserts at the medial condyle of tibia
where does the gracilis originate and insert
- it originates at the body of pubis and inferior pubic ramus
- it inserts at the medial aspect of proximal part of tibia
where does the sartorius originate and insert
- it originates at the anterior superior iliac spine
- it inserts at the medial aspect of proximal part of tibia
what are the lateral rotators of the knee
- long head of biceps femoris
- short head of biceps femoris
where does the long head of the biceps femoris originate and insert
- it originates at the ischial tuberosity
- it inserts at the head of fibula
where does the short head of the biceps femoris originate and insert
- it originates at the linea aspera and lateral supracondylar line
- it inserts at the head of fibula
