Lower Limb Anatomy (Bones and Joints) Flashcards
Hip bones articulate with one another at the ____ ____.
Each hip bone is firmly fixed to ____ part of ____ at ____ joint.
Rigid bony pelvis transmits body weight through ____ to the lower limbs.
Hip bones articulate with one another at the PUBIC SYMPHYSIS.
Each hip bone is firmly fixed to LATERAL part of SACRUM at SACROILIAC joint.
Rigid bony pelvis transmits body weight through ACETABULUM to the lower limbs.
State the distribution of body weight starting from vertebral column down to the foot.
State the bone that does not bear any body weight.
vertebral column -> sacroiliac joints -> pelvic girdle -> femur -> knee joint -> tibia -> talus
fibula does not bear any weight as it does not articulate with femur
Female femurs are more ____ than males –> ____ pelvis
Female femurs are more OBLIQUE than males –> WIDER pelvis
Identify structures of hip bone
Identify structures of femur (anterior aspect)
Identify structures of femur (posterior aspect)
Head of femur is covered with ____ cartilage, except for ____ (medially placed depression) which is for ____ of the head of femur ( ____ ____ )
State the arteries located in the ligamentum teres. State its significance.
Head of femur is covered with ARTICULAR cartilage, except for FOVEA (medially placed depression) which is for LIGAMENT of the head of femur (LIGAMENTUM TERES)
Artery located in ligamentum teres = artery to the head of femur (branch of obturator A)
- Neck of femur fracture –> avascular necrosis
Which surface of the neck of femur is intracapsular?
anterior surface of neck of femur is completely intracapsular + medial half of posterior surface is intracapsular
HIP JOINT
- Function
- Type of Joint
- Articulation
- Capsule
- Ligaments involved
HIP JOINT
- Function = forms connection between LL and pelvic girdle –> stability over a wide range of motion
- Type of Joint = ball and socket synovial joint
- Articulation = hemispheral head of femur + acetabulum of hip bone (deepened by acetabular labrum formed by fibrocartilage)
- Capsule = outer longitudinal, inner circular (encloses joint and is attached to acetabular labrum, intertrochanteric line and neck of femur)
- Ligaments involved = iliofemoral, pubofemoral, ischiofemoral
State the functions and location of each ligament involved in stability of hip joint
(1) ILIOFEMORAL LIGAMENT
- strongest ligament
- function = prevents hyperextension of hip joint
- AIIS –> intertrochanteric line
(2) PUBOFEMORAL LIGAMENT
- function = prevents overabduction of hip
- lies inferiorly
(3) ISCHIOFEMORAL LIGAMENT
- function = prevents hyperextension of hip joint and limits medial rotation of hip
- lies posteriorly
State the 4 ways that the stability of hip joint is maintained.
- depth of acetabulum (increased by presence of fibrocartilage labrum)
- 3 ligaments - iliofemoral, pubofemoral, ischiofemoral
- strength of surrounding muscles
- length and obliquity of neck of femur
SUMMARISE!
(State muscles and nerve roots)
Hip flexion
Hip extension
Hip abduction
Hip adduction
Hip medial rotation
Hip lateral rotation
Hip flexion - psoas major, iliacus, sartorius, rectus femoris, pectineus - L2-L3
Hip extension - gluteus maximus, hamstrings - L4-L5
Hip abduction - gluteus medius, gluteus minimus, tensor fascia latae, sartorius - L4-L5
Hip adduction - adductor brevis, adductor longus, adductor magnus, pectineus, gracilis - L2-L3
Hip medial rotation - anterior fibres of gluteus medius and minimus, tensor fascia latae - L2-L3
Hip lateral rotation - piriformis, obturator internus, obturator externus, gemellus superior, gemellus inferior, quadratus femoris - L4-L5
The trochanteric anastomosis in the neck of femur involves 4 arteries. Name the arteries.
Which artery supplies the femoral head.
- medial circumflex femoral A
- lateral circumflex femoral A
- superior gluteal A
- inferior gluteal A
Femoral head blood supply:
Adults - medial circumflex femoral A
Children - obturator A
State the arteries involved in the blood supply to (1) Head and (2) Neck of femur.
HEAD
- Obturator A
- Profunda femoris A (femoral A) –> Medial and Lateral Circumflex A
NECK
- Profunda femoris A (femoral A) –> Medial and Lateral Circumflex A
Others - superior and inferior gluteal A (trochanteric and cruciate anastomosis)
State everything you know about neck of femur fractures.
Fracture of neck of femur leads to AVASCULAR NECROSIS of HEAD of femur
- Medial circumflex A supplies most of the blood to head and neck of femur –> retinacular arteries (branch of MCA) are torn during fracture
- Blood supply to head of femur only occurs through obturator A –> inadequate –> avascular necrosis
- Common in elderly >60 year olds + post-menopausal women (femoral necks weak due to osteoporosis exacerbated by decreased oestrogen)
Summarise the difference between neck of femur fracture and trochanteric fracture
State everything you know about dislocation of head of femur from acetabulum
Dislocation of head of femur
- Femoral head is likely to be forced out of the acetabulum (posterior dislocation of hip joint)
- Sciatic nerve injured (compressed or stretched) –> paralysis of hamstrings and muscles distal to knee joint
Identify structures of tibia (anterior aspect)
Identify structures of tibia (posterior aspect)
State everything you know about the patella bone
- largest sessamoid bone in tendon of the quadriceps femoris
- flat, triangular bone with apex facing down and base facing upwards
- anterior aspect = convex and rough
- posterior aspect = medial and lateral articular surfaces –> lateral articular surface articulates with femoral lateral condyle
KNEE JOINT
- Function
- Type of Joint
- Articulation
- Capsule
- Ligaments involved
KNEE JOINT
- Function = flexion and extension of knee
- Type of Joint = modified hinge synovial joint
- Articulation = lateral and medial femorotibial condyles + femoropatellar articulation
- Capsule = attached to margins of articular surfaces at the sides and posterior of knee joint (front of joint is capsule deficient)
- Ligaments involved =
(1) Extracapsular ligaments - ligamentum patellae, oblique popliteal ligament, medial collateral ligament, lateral collateral ligament
(2) Intra-articular ligaments - cruciate ligaments (ACL,PCL), menisci
State the 3 bursa formed from the ____ of the ____ membrane.
The 3 bursa formed from the OUTPOCKETING of the SYNOVIAL membrane.
1. Semimembranous bursa
2. Popliteal bursa
3. Suprapatellar bursa - outpouching of synovial membrane beneath the quadriceps tendon since front of knee joint is capsule deficient
State the conditions where medial and lateral collateral ligaments are injured. State the test for integrity of each ligament.
MCL (medial collateral ligament) injury –> due to blow to the lateral site of the knee
- Test = excessive gapping on medial side of joint when one attempts to adduct tibia on the femur
LCL (lateral collateral ligament) injury –> due to blow to the medial side of the knee
- Test = excesive gapping on lateral side of joint hwen one attempts to adduct tibia on femur
State the 3 intra-articular ligaments within the knee joint
- Cruciate ligaments - ACL, PCL
- Menisci - medial and lateral menisci
- Popliteal tendon
ANTERIOR CRUCIATE LIGAMENT (ACL)
- ____ of the two ligaments
- has relatively ____ blood supply
- o = anterior ____ area of tibia
- extends ____ + ____ + ____ to attach to posterior part of ____ surface of ____ condyle of femur
- FUNCTIONS:
(1)
(2)
(3)
(4)
ANTERIOR CRUCIATE LIGAMENT (ACL)
- WEAKER of the two ligaments
- has relatively POOR blood supply
- o = anterior INTERCONDYLAR area of tibia
- extends SUPERIOR + POSTERIOR + LATERALLY to attach to posterior part of MEDIAL surface of LATERAL condyle of femur
- FUNCTIONS:
(1) Prevents posterior displacement of the femur on tibia
(2) Prevents hyperextension of knee
(3) Prevents anterior displacement of tibia when knee flexed
(4) Serves as pivot for rotatory movements of the knee –> ACL is taut during flexion
State everything you know about ACL Injury
ACL INJURY
- More common than PCL injury as PCL is thicker and hence stronger –> has higher tensile strength
- Most common knee injuries in skiing accidents –> causes free tibia to slide anteriorly under femur –> anterior drawer sign
- Occurs when there is hyperextension or severe force directed anteriorly
POSTERIOR CRUCIATE LIGAMENT (PCL)
- ____ of the 2 ligaments
- o = ____ intercondylar area of tibia
- extends ____ + ____ + ____ to attach to anterior surface of the ____ condyle of femur
- FUNCTIONS:
(1)
(2)
(3)
(4)
POSTERIOR CRUCIATE LIGAMENT (PCL)
- STRONGER of the 2 ligaments
- o = POSTERIOR intercondylar area of tibia
- extends SUPERIOR + ANTERIOR + MEDIALLY to attach to anterior surface of the MEDIAL condyle of femur
- FUNCTIONS:
(1) Prevents anterior displacement of femur on tibia (when tibia on ground)
(2) Prevents hyperflexion of knee
(3) Prevents posterior displacement of tibia on femur (when tibia off ground)
(4) Main stabilising factor of femur in weight-bearing knee
State everything you know about PCL Injury
PCL INJURY
- Although PCL is strong, PCL rupture can occur when a person lands on the tibial tuberosity when knee is flexed
- PCL rupture usually occurs in conjunction with tibial or fibular ligament tears
- Posterior drawer sign present –> free tibia slides posteriorly under fixed femur
MENISCI
- ____-shaped sheets of ____
- ____ articular surface
- has role in ____ ____
- ____ at external margin, ____ & ____ in interior of joint
- firmly attached to their ends of ____ area of tibia
- ____ margin attached to ____ layer of capsule of knee joint
MENISCI
- C-shaped sheets of FIBROCARTILAGE
- DEEPENS articular surface
- has role in SHOCK ABSORPTION
- THICKER at external margin, THIN & UNATTACHED in interior of joint
- firmly attached to their ends of INTERCONDYLAR area of tibia
- EXTERNAL margin attached to FIBROUS layer of capsule of knee joint
MEDIAL MENISCUS
- C-shaped and broader ____ than ____
- Attachment = ____ end attached to ____ intercondylar area of tibia (anterior to ACL attachment site)
- Attachment = ____ end attached to ____ intercondylar area (anterior to PCL attachment site)
- Firmly laterally adhered to ____ surface of tibial collateral ligament
MEDIAL MENISCUS
- C-shaped and broader POSTERIORLY than ANTERIORLY
- Attachment = ANTERIOR end attached to ANTERIOR intercondylar area of tibia (anterior to ACL attachment site)
- Attachment = POSTERIOR end attached to POSTERIOR intercondylar area (anterior to PCL attachment site)
- Firmly laterally adhered to DEEP surface of tibial collateral ligament
LATERAL MENSICUS
- Nearly ____ and is ____ and more freely movable than medial meniscus
- Attachment = ____ tendon (separates lateral meniscus from ____ collateral ligament)
LATERAL MENSICUS
- Nearly CIRCULAR and is SMALLER and more freely movable than medial meniscus
- Attachment = POPLITEUS tendon (separates lateral meniscus from FIBULAR(LATERAL) collateral ligament)
ANKLE JOINT
- Articulation
- Type
- Capsule
- Innervation
- Movements
ANKLE JOINT
- Articulation = lower end of tibia and malleoli + body of talus
- Type = synovial hinge joint
- Capsule = enclosed by capsule which is attached to articular margins, lined by synovial membrane
- Innervation = deep peroneal N + tibial N
- Movements = plantarflexion and dorsiflexion
State the 4 factors that maintain the stability of the ankle joint
- Close interlocking of articular surfaces
- Capsule, medial and lateral collateral ligaments
- Inferior transverse tibiofibular ligaments (Syndesmosis) –> strongest interosseous ligament
- Tendons crossing in front and behind ankle joint
Identify structures in foot
ARCHES
(1) Medial Arch:
- ____ than lateral arch
- More ____ due to presence of ____ and ____ joints
- More involved in ____
(2) Transverse Arch:
- Formed by ____, ____ and base of ____
- Formed by ____ part of ____ and ____ joints
- ____ and ____ arches serve as pillars for transverse arch
ARCHES
(1) Medial Arch:
- HIGHER than lateral arch
- More PLIANT due to presence of TALOCALCANEONAVICULAR and SUBTALAR joints
- More involved in PROPULSION
(2) Transverse Arch:
- Formed by CUBOID, 3 CUNEIFORMS and base of METATARSALS
- Formed by TALONAVICULAR part of TALOCALCANEONAVICULAR and CALCANEOCUBOID joints
- MEDIAL and LATERAL LONGITUDINAL arches serve as pillars for transverse arch
