Lower limb Flashcards
What are the movements of the hip joint?
1) Flexion/Extension
2) Abduction/Adduction
3) Medial/lateral rotation
Owing to the ________________________________ during development, the original dorsal/extensor surface of the lower limbs becomes _____________, while the ventral/flexor surface becomes ______________.
Medial rotation of lower limb through 180° →
i) dorsal/extensor → anterior
ii) ventral/flexor → posterior
How is the body weight transferred to the lower limbs?
From vertebral column → sacroiliac joints → pelvic girdle
→ hip joints → femurs
→ knee joint → tibia
→ ankle joint → talus → tarsals + metatarsals
What are the 3 bones that form each hip bone?
1) Ilium → socket/articulation with femoral head
2) Ischium → posteroinferior part of the acetabulum
3) Pubis → anterior part of acetabulum & anteromedial part of hip bone
Which of the constituent hip bones contributes the cup-like cavity/socket on the superolateral aspects of the hip bone for articulation with the head of the femur?
Ilium
What are 4 components/features of the proximal end of the femur?
1) Head
2) Neck
3) Greater and lesser trochanters
4) Articular cartilage covering head except fovea for ligament of head
How do the cause of pathological lateral rotation and medial of a lower limb differ?
Lateral rotation (foot pointing lateral) → Femoral/Hip fracture
Medial rotation (foot pointing medial) → posterior dislocation of the hip
Which is more common, anterior/posterior dislocation of the hip?
Posterior
The _____________ surface of the neck of the femur is completely intracapsular whereas the only the __________ of the _________ surface is intracapsular.
The anterior surface of the neck of the femur is completely intracapsular whereas the only the medial half of the surface posterior is intracapsular.
Most of the femoral shaft is smoothly rounded, except for ___________________________ which diverges inferiorly.
a prominent double-edge ridge on its posterior aspect: the linea aspera
The distal end of the femur ends in _____________________.
two spirally curved femoral condyles (medial and lateral)
On the femur, the _____________ may be felt at the superior part of the medial femoral condyle.
adductor tubercle, a small prominence of bone
What are the bone components to form the knee joint?
The femoral condyles articulate with the tibial condyles to form the knee joint
What is the function of the angle of inclination of the femur?
Allows greater mobility of the femur at the hip joint because it places the head and neck more perpendicular to the acetabulum.
This is advantageous for bipedal walking; however, it imposes considerable strain on the neck of the femur.
What type of joint is the hip joint?
a strong and stable multiaxial ball and socket joint
The cup-shaped acetabulum is deepened by the ________________ which is made of ______________.
Deepened by acetabular labrum (made up of fibrocartilage)
How would a pes anserine bursitis of the knee be differentiated from OA?
Palpable joint line
→ if tender → intra-articular → OA
→ if not tender → extra-articular → bursitis
What are the 3 points of attachment of the hip joint capsule?
1) Acetabular lumen (medial)
2) Intertrochanteric line
3) Posterior aspect of the neck of the femur (lateral)
What are the 2 layers of the hip joint capsule?
1) Outer longitudinal (retinacular)
2) Inner circular fibres
What are 4 ligaments of the hip and their functions?
1) Ligamentum teres → carrier for the foveal artery
2) Iliofemoral → prevent hyper extension (strongest)
3) Pubofemoral → prevent overabduction of hip joint
4) Ischiofemoral → prevent hyperextension + limit medial rotation
What are 4 factors that contribute to the stability of the hip joint?
1) Depth of acetabulum
2) Three ligaments (iliofemoral, pubofemoral, ischiofemoral)
3) Strength of the surrounding muscles
4) Length and obliquity of the neck of femur
What is the cure for a flat foot?
Strengthening of posterior tibialis
Which muscles are involved in hip flexion?
1) Psoas major
2) Iliacus
3) Sartorius
4) Rectus femoris
5) Pectineus
Which muscles are involved in hip extension?
1) Gluteus maximus
2) Hamstrings
Which muscles are involved in hip abduction?
1) Gluteus medius
2) Gluteus minimus
3) Tensor fascia latae
4) Sartorius
Which muscles are involved in hip adduction?
1) Adductor longus
2) Adductor brevis
3) Adductor magnus
4) Pectineus
5) Gracilis
Which muscles are involved in hip medial rotation?
1) Anterior fibres of gluteus minus
2) Anterior fibres of gluteus medius
3) Tensor fascia lata
Which muscles are involved in hip lateral rotation?
1) Piriformis
2) Obturator internus
3) Obturator externus
4) Superior gemelli
5) Inferior gemelli
6) Quadratus femoris
Describe the innervation for the movements of the hip?
L2/3:
i) Flexion
ii) Adduction
iii) Medial rotation
L4/5:
i) Extension
ii) Abduction
iii) Lateral rotation
What are 5 arteries that supply the hip joint?
1) Obturatory artery (artery → head)
2-3) Superior and inferior gluteal arteries (trochanteric & cruciate anastomosis)
Branches from profunda femoris:
4-5) Medial and lateral circumflex femoral artery (head + neck)
What are 3 types of femoral neck fractures?
1) Intracapsular
Extracapsular:
2) Trochanteric
3) Sub-trochanteric
What is a common cause of aseptic vascular necrosis of the hip joint?
Fracture of femoral neck
→ impingement/disruption of medial circumflex femoral artery
→ retinacular arteries torn
→ inadequate perfusion of femoral head
→ aseptic vascular necrosis
The most common demographic for femoral neck fractures?
Women > 60y
- osteoporosis
What is a common cause and complication of posterior hip dislocation?
Car accident → femoral head forced out of acetabulum posteriorly
→ compression/stretching of sciatic nerve
→ paralysis of hamstrings and muscles distal to knee joint
Where does the ligamentum patella attach to?
Tibial tuberosity
Where does the deltoid ligament attach to?
Medial malleolus
The medial malleolus is (higher/lower) than the lateral malleolus.
The medial malleolus is higher than the lateral malleolus.
What muscles of the leg are attached to the fibula?
All of the leg except Tibialis anterior, Gastrocnemius, and Plantaris
True or False: With the Tibia, the fibula transmits half the body’s weight to the foot.
False.
Fibula does not take part is transmission of body weight.
The patella is the largest ______ bone found in the tendon of ____________.
Sesamoid bone in quadriceps femoris
The apex of the patella faces (upwards/downwards) while the base faces (upwards/downwards).
Patella:
Apex downwards
base upwards
What are the 2 articular surfaces of the posterior aspect of the patella and which articulates with the lateral femoral condyle?
Medial and lateral
Large lateral surface articulates with lateral femoral condyle
Which direction does the patella dislocate in most commonly?
Laterally
- due to upwards and lateral pull by Quadriceps
What are 3 factors that prevent patellar lateral dislocation?
1) Most forward projection of lateral femoral condyle
2) More prolonged insertion of Vastus medialis to medial border than of Vastus lateralis to lateral border of Patella
3) medial pull exerted by medial patellar retinaculum
What type of joint is the knee joint?
Modified hinge joint
1) Condylar
- articulation of lateral and medial femorotibial condyles
2) Saddle
- Femoropatellar articulation
What nerves innervate the knee joint?
1) Femoral
2) Tibial
3) Common peroneal
4) Obturator
What are the factors maintaining the stability of the knee joint?
1) Strength and actions of the surrounding muscles and tendons
2) Medial and lateral collateral ligaments maintain side to side stability
3) Cruciate ligaments maintain anteroposterior stability
4) Iliotibial tract helps in stabilising a partially flexed knee
What are 4 factors that make the knee joint structurally weak?
1) Incongruence of its articular surfaces
2) Tibial condyles are small and shallow to hold the large convex femoral condyles
3) Shallow articular surfaces of femur and patella
4) Outward angulation between the long axes of femur and tibia
What are the 3 bursae formed by the outpocketing of the synovial membrane of the knee joint?
1) Suprapatellar
2) Semimembranous
3) Popliteal
What are the extracapsular ligaments of the knee?
1) Ligamentum patellae
2) Lateral/Fibular collateral ligament
3) Medial/Tibial collateral ligament
4) Oblique popliteal ligament
What are the intra-articular ligaments of the knee joint?
1) Anterior cruciate ligament
2) Posterior cruciate ligament
3) Meniscus
True or false: Only in a fully extended position, both cruciate ligaments of the knee are relaxed.
False.
Because of their oblique orientation, in every position one cruciate ligament, or parts of one or both ligaments, is tense
Which of the 2 cruciate ligaments of the knee is weaker?
ACL
What is the function of the ACL?
1) Prevent posterior displacement of femur on tibia
2) Prevent hyperextension of knee joint
The ACL, which has a relatively poor blood supply, arises from _______________ and extends to _________________.
Anterior intercondylar area of tibia (posterior to medial meniscus attachment)
→
posterior part of medial surface of medial condyle of femur
What is the main stabilising factor of the femur when the knee is flexed and weight-bearing (eg. walking downhill)?
PCL
What is the function of the PCL?
1) Prevents anterior displacement of the femur on the tibia (with tibia on ground)/ posterior displacement of tibia on femur (within tibia off ground)
2) Prevent hyperflexion of the knee joint
The PCL arises from _____________ to the _________________.
Posterior intercondylar area of tibia
→
Anterior part of lateral surface of the medial condyle of the femur
What are the menisci of the knee joint and how are they orientated?
Lateral and menisci are crescenteric plates of fibrocartilage on articulating surfaces of the tibia
- thicker at external margins (attached to fibrous capsule of knee joint), thinner unattached edges interiorly
How are the movements of the 2 menisci coupled in knee movement?
Transverse ligament joins anterior edges of menisci, allowing them to move together during knee movements
What are the functions of the menisci of the knee joint?
1) Deepen articular surface of tibia
2) Shock absorption
How are the medial and lateral menisci of the knee differentiated?
Medial:
- C-shaped
- broader posteriorly than anteriorly
Lateral:
- nearly circular
- smaller
- more freely movable
In the knee, what separates the lateral meniscus from the fibular/lateral collateral ligament?
Tendon of popliteus
What are the 3 attachments of the medial meniscus of the knee joint?
Anterior/horn:
- anterior intercondylar area of tibia (anterior to ACL attachment)
Posterior:
- posterior intercondylar area (anterior to PCL attachment)
Medial:
- Deep surface of tibial collateral ligament
Which of the menisci of the knee are more prone to injury and why?
Medial > later
because of its firm fixity to the tibial collateral ligament,and greater excursion during the rotatory movements. (eg. Twisting strain as in kicking a football with a slightly flexed knee)
How does the popliteus muscle protect the lateral meniscus?
medial fibres of popliteal pull the posterior horn of meniscus backward so that it is not crushed between the articular surfaces
Which of the cruciate ligaments of the knee is taut during flexion?
ACL
What is the sign associated with an ACL injury?
Anterior drawer sign
- ACL rupture → free tibia can slide anteriorly under femur
What is the most common cause of a PCL injury?
Landing on tibial tuberosity when knee is flexed
What sign is associated with a PCL injury?
Posterior drawer sign
- PCL rupture → free tibia slides posteriorly under fixed femur
Which other ligaments usually rupture in conjunction with the PCL?
1) Tibial ligament
2) Fibular ligament
Describe how the knee “locks” and “unlocks”.
Fully extended leg w foot on ground → medial rotation of femur on tibia → “locking”
Popliteus contract → lateral rotation of femur on tibia plateau → “unlock” → allow flexion
What is the benefit of “locking” the knee?
1) Makes lower limb a solid column → more adapted for weight bearing
2) Thigh and leg muscles can relax briefly without making knee joint too unstable
Which muscles allow knee flexion?
Hamstrings
Which muscles allow knee extension?
Quadriceps femoris
Which muscles allow knee medial rotation?
1) Semitendinous
2) Semimembranosus
3) Popliteus
Which muscles allow knee lateral rotation?
Biceps femoris
What are the 3 points of articulation between the tibia and fibula?
1) Superior:
- plane synovial joint
- btwn head of fibula and lateral condyle of tibia
2) Middle
- fibrous joint
- interosseus membrane + ligament
3) Inferior
- syndesmosis fibrous joint
- strongest of all 3 joints
What are the movements at the ankle joint?
Dorsi/plantarflexion
What are the type and articulations of the ankle joint?
Hinge joint
Above: Lower end of the tibia and 2 malleoli
Below: Body of tallus
What nerves supply the ankle joint?
1) Deep peroneal
2) Tibial
Which of the muscles allow dorsiflexion at the ankle?
Mainly Tibialis anterior
Which of the muscles allow plantarflexion at the ankle?
Mainly
1) Gastrocnemius
2) Soleus
In which movement is the ankle joint more stable, dorsiflexion or plantarflexion?
Dorsiflexion