bones of the lower limb Flashcards
Bones of the Lower Limb
What are the different segments of the lower limb?
What are the bones within each segment?
What increases distally?
How are lower limb bones different from upper limb bones?
Pelvic Girdle
- Hip bone, sacrum, coccyx
Thigh
- Femur
- Patella
Leg
- Tibia (medially)
- Fibula (laterally)
Foot
- Tarsal bones(x7)
Talus, calcaneus, navicular, cuboid, medial, intermediate and lateral cuneiforms
- Metatarsal bones (x5)
- Phalanges (x14)
- the number of bones increases distally
- leg bones are much more robust, thicker and stronger than upper limb bones
Pelvic girdle
What is the pelvic girdle (pelvis) formed by?
what it the pelvic girdle well suited for?
what is its physical anatomical function? (attaches – to —)
what are the 5 functions of the pelvic girdle?
- The pelvic girdle is formed by the hip bones, sacrum and coccyx
- it is well suited for stability during standing, walking and running
- It attaches the lower limb to the axial skeleton
5 functions:
- transfers body weight (upper body weight) to the lower limbs
- provides an almost rigid, complete ring for weight bearing and child birth
- supports the pelvic organs
- provides muscle attachment for limb movement
- provides “gateways” for neurovascular structures to pass to and from the limbs
Hip bone
What 3 bones fuse to form the Hip bone?
What is between the 3 parts of the hip bone?
Where do the hip bones articulate with each other?
- Ilium, Ischium and Pubic bones are fused to form the Hip bone
- Tri-radiate cartilage between the 3 parts of the hip bone. The cartilage is visible radiologically, but ossifies by late teens
- The hip bones articulate with each other at the pubic symphysis
Pelvic Girdle
On a coronal plane, what 3 structures of the pelvic girdle are in line together?
what is the highest point of the iliac crest?
the anterior superior iliac spine is on the same coronal plane as the pubic tubercle and pubic crest
the highest point of the iliac crest is at the level of L4
Pelvic joints
What are the two pelvic joints?
What type of joint are they?
what ligaments are they each supported by?
what is the function of each?
Pubic symphysis
- Is a secondary cartilaginous (or fibrocartilage) joint
- Supported by superior and arcuate ligaments
- Disc between articular surfaces
Sacro-iliac joint
- Synovial anteriorly, fibrous posteriorly
- Supported by the Anterior and Posterior sacro-iliac and Interosseous ligaments
- Extremely limited movement
Pelvic joints
what does body weight want to rotate?
what ligaments prevent the sacrum from tilting forward?
what do these same ligaments also do?
- Body weight wants to rotate S1 downwards and S4 upwards
- The Sacrospinous and Sacrotuberous ligaments prevent the sacrum tilting forwards (support the sacro-iliac joint)
- Sacrospinous and Sacrotuberous ligaments also convert the sciatic notches into Greater and Lesser sciatic foramina for the passage of nerves and vessels
What are the 4 gateways for the Pelvic Girdle?
- Sciatic Nerve and Gluteal Neurovascular Bundle
- Internal Pudendal Neurovascular Bundle
- Obturator Neurovascular Bundle
- Femoral Neurovascular Bundle
Hip Joint
what type of joint is the Hip joint?
what is its characteristic?
Ball and socket type synovial joint
STABLE but LIMITED MOBILITY
Hip Joint
what are the features of the Acetabulum: hip joint at the hip bone?
what are the features of the Head of femur: hip joint at the femur?
- The acetabular rim is raised by the acetabular labrum (a special type of cartilage which is more effective for stability)
- the labrum bridges across the acetabular notch as the Transverse acetabular ligament
- Lunate surface covered with cartilage
- Acetabular fossa (2)
- Acetabular notch (1)
- all of below covered by hyaline cartilage except fovea
- Head of femur (3)
- Fovea of head of femur (1)
- Neck of femur (6)
- Greater trochanter (2)
- Lesser trochanter (5)
- Intertrochanteric crest (Quadrate tubercle) (8)
- Intertrochanteric line (4)
(insert image)
Hip Joint: joint capsule
what 4 structures is the joint capsule attached to?
what does the synovial membrane cover?
what do the synovial layers of the capsule do?
- Attached to the acetabular rim, transverse acetabular ligament, intertrochanteric line and neck of the femur
- Synovial membrane covers everything except the articular cartilage and forms a sleeve around the ligament of the head of femur.
- The synovial layers of the capsule sends retinacular fibres medially along the femoral neck towards the head.
Hip joint: ligaments
what do intrinsic/capsular ligaments do around the joint?
for what 4 reasons does it do this?
what do some deep fibres of the fibrous capsule do and what do they form?
- All (intrinsic) capsular ligaments of the hip joint spiral around the joint and attach to femur
- they are taut in extension.
- Prevent hyper-extension
- Stabilize the joint
- Save energy during standing
- Some deep fibres of the fibrous capsule wind circularly around the neck and form Zona orbicularis
Hip joint: capsular (intrinsic) ligaments
what are the 3 capsular ligaments and what do they prevent?
Iliofemoral - strongest
- Prevents hyper-extension of hip joint during standing
Pubofemoral
- Prevents hyper-abduction of hip joint; tightens during abduction and extension of hip
Ischiofemoral – weakest
Demonstrate the following movements:
- flexion
- extension
- abduction
- adduction
- medial rotation
- lateral rotation
Hip Joint: X-ray
What is the purpose of Shenton’s line on the X-ray of the hip joint
If Shenton’s line is disturbed when there is a fracture of dislocation (not a smooth continuous line)
Knee joint:
How big is the knee joint compared to other joints?
what features allow it to be weight bearing?
what are the 3 common characteristics of all hinge joints that the knee joint shows?
- Knee is largest and one of the most complex joints
- free movement in one plane only+ joint stability = weight-bearing
Shows the common characteristics of all hinge joints.
- The articular surfaces are reciprocally shaped
- They have strong collateral ligaments
- The muscles are grouped at the sides of the joint where they do not interfere with movement
Knee joint: distal femur + patella
what are the key features of the distal femur?
what are the key features of the patella?
Medial condyle (8) and epicondyle (9)
Lateral condyle (5) and epicondyle (6)
Patellar surface (11)
Popliteal surface (12)
Intercondylar fossa (4)
Base of patella
Lateral articular surface (3)
Apex of patella (1)
Knee joint: Proximal tibia and Fibula
what are the key features of proximal tibia?
Lateral condyle (6)
Medial condyle (9)
Intercondylar tubercles (eminence) (13)
Tibial tuberosity (14)
Anterior intercondylar region (2)
Posterior intercondylar region (11)
Medial (9) and lateral (6) tibial plateaus
Intercondylar eminence (14)
(insert image)
Knee joint: joint capsule
where is the fibrous capsule attached to?
what is the fibrous capsule lined by?
since the fibrous capsule is not present anteriorly, what replaces it?
what reinforces this?
The fibrous capsule is incomplete and not present anteriorly so attaches to the articular margins
it is lined by synovial membrane
Anteriorly, the fibrous capsule is replaced by the quadriceps tendon (patellar ligament), the patella and fat pads on either side of patellar ligament + it is reinforced by the iliotibial tract and patellar retinacula from quadriceps
Knee joint: joint capsule
posteriorly, how is the fibrous capsule reinforced?
Posteriorly, the fibrous capsule is reinforced by the
- oblique popliteal ligament
which is an expansion of the semimembranosus muscle
- arcuate popliteal ligament
There is an opening in the capsule for the tendon of popliteus
Knee joint: bursae
why are there numerous bursae around the knee joint?
name 3 bursae which communicate with the articular cavity of the knee joint
- There are numerous bursae around the knee joint because most tendons run parallel to the bones and pull lengthwise across the joint during knee movements
- Some of these bursae communicate with the articular cavity of the knee joint:
Suprapatellar bursa*
popliteal bursa*
anserine bursa (pes bursa)
gastrocnemius bursa
Knee joints: collateral ligaments
what are the two collateral ligaments of the knee?
what do theses ligaments each start from and end?
what does they each prevent?
Lateral (Fibular)
- strong cord from Lateral femoral epicondyle to Head of fibula with the Tendon of popliteus is between this ligament &capsule
- this ligament prevents adduction of leg
Medial (Tibial)
- broad, flat band from Medial femoral epicondyle to Tibial condyle which is fused to joint capsule and medial meniscus
- this ligament prevents abduction of leg
- ^these medial collateral ligaments and the bones surrounding it are considered a unit since they are fused together meaning they all get injured together
Knee joint: menisci
what are the meniscus?
what are the two meniscus?
what are the 6 funtcions of them?
where are the horns of the menisci found?
what are the menisci interconnected by anteriorly?
during flexion/extension of the knee, how do the menisci move?
describe the thirds of the menisci?
- Two crescent-shaped fibrocartilage (fibrocartilage is resistance to wear and tear)
-Medial meniscus + Lateral meniscus
6 functions:
- Increase the congruence of articular surfaces
- Dissipate the forces/stress on articular cartilage
- Absorb shock
- Decrease friction
- Participate in locking of knees
- Proprioception
The horns of the menisci are attached to the intercondylar areas of the tibial plateau
The menisci are interconnected anteriorly by the transverse ligament of the knee
They move antero-posteriorly during flexion/extension of knee
Inner 2/3 is avascular, outer 1/3 partially vascular
(Inner 2/3 will not heal if there is a tear and surgery must be performed (due to lack of vascular supply), the Outer 2rd will heal, but slowly)
knee joint: menisci + meniscofemoral ligaments
how is the medial meniscus attached?
how is the lateral meniscus attached?
how are the meniscofemoral ligaments placed?
The medial meniscus
- is attached round its margin to the joint capsule AND to the medial collateral ligament
The lateral meniscus
- is attached to the joint capsule but NOT to the lateral collateral ligament
- tendon of the popliteus muscle attach to lateral meniscus
Meniscofemoral ligaments extend from the posterior horn of lateral meniscus to medial condyle of femur
Knee joint: cruciate ligaments
how are cruciate ligaments named?
what does the anterior cruciate ligament prevent?
what does the posterior cruciate ligament prevent?
what other action do they also do?
- Named according to their tibial attachment
Anterior cruciate ligament - Prevents anterior movement of tibia and hyperextension
- if unstable, anterior drawer sign
Posterior cruciate ligament - Prevents posterior movement of tibia (as in walking downhill)
- if unstable, posterior drawer sign
- They also act as a pivot for rotatory movements between the bones
what is the collodiaphysial andle?
- when is it wider?
what is the Q-angle?
Collodiaphysial angle: The angle between the long axes of the neck and shaft of the femur
- Wider in children
Q-angle: The angle between the anatomical axis of the femur and that of the tibia
ankle joint: distal tibia + fibula
what are the features of the distal tibia?
what are the features of the distal fibula?
Fibular notch (2)
Medial malleolus (6)
Inferior articular facet
Groove for flexor hallucis longus (3)
Groove for tibialis posterior (4)
Lateral malleolus (9)
Malleolar fossa (10)
Articular surface (6)
ankle joint: talus
what is the stability like in the talus bone?
label the diagram
Broad anteriorly: More stable in dorsiflexion
Narrow posteriorly: Less stable in plantar flexion
insert photo
ankle joint: capsule and collateral ligaments
what is the capsule like of the ankle joint?
where do the ligaments of the ankle originate and fan out to?
what does the medial (deltoid) ligament resist?
what does the lateral ligament resist?
Loose fibrous capsule with synovial folds within capsule
(collateral) Ligaments of ankle all originate at malleoli and fan out to tarsal bones:
Medial (deltoid) ligament: Resists dislocation during eversion of the foot
Lateral ligament: Resists over-inversion
Ankle joint (tarocrural): movements
what type of joint is the tarocrural?
what movements is it involved in?
(Hinge joint) Weight bearing!
- Extension (dorsiflexion)
- [Plantar] Flexion (more unstable because of narrow trochlea)
Ankle joint (tarocrural): movements
what type of joint is the tarocrural?
what movements is it involved in?
(Hinge joint) Weight bearing!
- Extension (dorsiflexion)
- [Plantar] Flexion (more unstable because of narrow trochlea)
Bones of the foot
- what are the three types of bones in the foot?
- what two bones are within the proximal row?
- what three bones are within the distal row?
- what two bones are between these rows?
what is important about the talus?
Tarsal bones, metatarsals and phalanges
Proximal row: Talus, Calcaneus
Distal row (M to L) medial (1) cuneiform, intermediate (2) cuneiform, lateral (3) Cuneiform
cuboid and Navicular (clog)
Talus is the only bone to link leg with foot
joints and movements of the foot
what type of joint is the distal tibiofibular? + what movements?
what type of joint is the ankle joint? + what movements?
what type of joint is the intertarsal joint? + what movements?
what type of joint is the intermetatarsal + tarsometatarsal joints? + what movements?
what type of joint is the metatarsophalangeal joints? + what movements?
what type of joint is the interphalangeal joints? + what movements?
Distal Tibiofibular: Syndesmose
No movement, helps to stabilise ankle and foot
Ankle: hinge joint
Plantar flexion and dorsiflexion
Intertarsal: Plane joints
- Subtalar (Talocalcaneal)
- Talo-navicular
- Calcaneo-cuboid
Intermetatarsal & Tarsometatarsal: Plane joints
Gliding movements
Metatarsophalangeal: Condyloid joints
Flexion, extension, Abduction, adduction
Interphalangeal: Hinge joints
Flexion and extension
