Joints of the Lower Limb

Question 1

How are joints classified?

Answer 1

by the type of tissue between the bones

-fibrous, cartilaginous, synovial

Question 2

What are fibrous joints?

Answer 2

united by fibrous connective tissue, degree of mobility varies (ex. superior tibial fibular joint)

Question 3

What is a cartilaginous joint?

Answer 3

a joint united by hyaline cartilage (1st sternocostal joint) or fibrocartilage (pubic symphysis)

degree of mobility is limited

Question 4

What is a synovial joint?

Answer 4

joint is united by a complex joint capsule, most common type of joint in human body, highly mobile

Question 5

Name the components of all synovial joints

Answer 5

synovial cartilage

joint capsule

joint cavity

Question 6

What is synovial cartilage?

Answer 6

a thin layer of hyaline cartilage covering each bone in the joint, coats each articulating surface (no bone to bone contact, reduces friction

Question 7

What is a joint capsule?

Answer 7

surrounds articulating bones and consists of 2 layers
-fibrous later: SF layer, tough/fibrous, protects joint contents

-synovium: inner layer facing joint cavity; secretes synovial fluid, articular nutrition

Question 8

What is a joint cavity?

Answer 8

the potential space defined by a joint capsule, filled with small amount of synovial fluid for lubrication and nutrition

avascular

Question 9

Name the variable structures of a synovial joint

Answer 9

bursae

tendon sheaths

fibrocartilage structures

ligaments

Question 10

Bursae

Answer 10

may communicate with a joint capsule

facilitates movement of structures that cross a joint

Question 11

tendon sheaths

Answer 11

specialized bursa that wrap around tendons crossing the wrists and ankles to facilitate tendon movement

Question 12

Articular disc? What are its functions?

Answer 12

fibrocartilage pad between bones in a joint

Functions: shock absorption, increase contact area between bones, distributing synovial fluid

Question 13

Meniscus

Answer 13

C shaped disks between bones in a joint, similar to articular discs.

Question 14

Labrum

Answer 14

fibrocartilage rim, increases contact between articulating bones, maintains flexibility ex. acetabular labrum

Question 15

What is a ligament? How are they classified?

Answer 15

bands of connective tissue crossing a joint

based on their relationship to the joint capsule

Question 16

extracapsular ligament

Answer 16

ligament outside the joint capsule

Question 17

capsular ligament

Answer 17

thickening of the joint capsule

Question 18

intracapsular ligament

Answer 18

ligament inside the joint capsule

Question 19

What kind of joint is the sacroiliac joint (SI joint)?

Answer 19

compound joint; partly fibrous, partly synovial, becomes more fibrous with age

strengthen by ligaments
-intrinsic: anterior sacroiliac ligament, posterior sacroiliac ligament

-extrinsic: sacrotuberous ligament, sacrospinous ligament

Question 20

What kind of joint is the hip joint?

Answer 20

ball and socket synovial joint, strengthen by a cuff of capsular ligaments

Question 21

What are the ligaments of the hip joint? What do they do?

Answer 21

iliofemoral and ischiofemoral become tight in extension to prevent hyperextension

pubofemoral ligament: becomes tight in abduction to prevent hyper abduction

Question 22

What is the fovea capitis?

Answer 22

small depression on the ball shaped surface of the femur, point of attachment for the round ligament

Question 23

Round ligament

Answer 23

attached to the fovea capitis of the femur, weakly holds the femoral head against the acetabulum

Question 24

What arteries supply blood to the hip?

Answer 24

lateral circumflex femoral a.

medial circumflex femoral a. (primary supply to femoral head and neck)

acetabular branch of the obturator a.

Question 25

What can result due to a "hip fracture"

Answer 25

fracture of the femoral neck can disrupt the blood supply to the femoral head/neck (medial circumflex branches) if acetabular branch is insufficient can result in avascular necrosis of the head and neck

Question 26

What kind of joint is the knee joint?

Answer 26

Patellofemoral joint hinge synovial joint, located between patella and femur, patella slides back in forth in patellar groove

Question 27

What movements can occur at the knee joint?

Answer 27

flexion, extension

Question 28

What movements can occur at the hip joint?

Answer 28

flexion/extension abduction/adduction lateral/medial rotation

Question 29

What do the medial and lateral menisci of the knee do?

Answer 29

improve the contact between femur and tibia, making the joint more stable, shock absorption

Question 30

What are the ligaments of the knee? What are there functions?

Answer 30

Lateral collateral ligament (LCL) : extracapsular ligament, prevents lateral bowing of knee medial collateral ligament (MCL): capsular ligament, attached to the medial meniscus, prevents medial bowing of knee Anterior cruciate ligament (ACL): origin on anterior tibia, inserts posteriorly on femur, prevents hyperextension Posterior cruciate ligament (PCL): origin on posterior tibia, inserts on anterior femur, prevents hyperflexion

Question 31

Describe the "unhappy triad" injury

Answer 31

lateral force applied to knee with foot planted and knee extended- can produce hyperextension and medial bowing tearing the ACL, MCL and medial meniscus

Question 32

What is the main stabilizer of the knee when flexed and weight bearing?

Answer 32

the posterior cruciate ligament

Question 33

What are the 2 tibiofibular joints?

Answer 33

superior tibiofibular joint (proximal): synovial inferior tibiofibular joint (distal): fibrous allow for little movement as possible

Question 34

What kind of joint is the talocrural joint? Where is it located?

Answer 34

hinge synovial joint located between distal tibia and lateral malleolus of distal fibula proximally and the talus

Question 35

What kind of movement occurs at the talocrural joint?

Answer 35

dorsiflexion and plantar flexion

Question 36

What kind of joint is the subtalar joint? Where is it located?

Answer 36

synovial joint located between the talus and the calcaneus

Question 37

What kind of movement occurs at the subtalar joint?

Answer 37

inversion and eversion

Question 38

What are the ligaments associated with the talocrural and subtalar joints?

Answer 38

medial collateral (deltoid) ligament lateral collateral ligament

Question 39

What makes up the medial collateral (deltoid ligament)? What does it do?

Answer 39

tibionavicular ligament, tibiocalcaneal ligament, anterior tibiotalar, posterior tibiotalar prevents hypereversion

Question 40

What makes up the lateral collateral ligament of the ankle? What does it do?

Answer 40

anterior talofibular, posterior talofibular, calcaneofibular prevents hyperinversion

Question 41

Arches of the foot

Answer 41

located between weight bearing points act as shock absorbers and assist in propelling the body forward

Question 42

What makes up the medial longitudinal arch?

Answer 42

the calcaneus, talus, navicular, 3 cuneiforms, and 1-3 MTs talus forms keystone of arch

Question 43

What makes up the lateral longitudinal arch?

Answer 43

calcaneus, cuboid, and 4-5 MTs rests on the ground while standing

Question 44

What makes up the transverse arch?

Answer 44

the 3 cuneiform, cuboid and bases of all MTs

Question 45

What maintains the arches of the foot?

Answer 45

configuration of the bones, plantar aponeurosis, muscles/tendons (tibialis posterior, fibularis longus, flexor hallucis longus, flexor digitorium longus, intrinsic muscles of foot) ligaments

Question 46

What are the ligaments that help maintain the arches of the foot?

Answer 46

long plantar ligament short plantar ligament spring ligament

Question 47

Where is the long plantar ligament located?

Answer 47

attaches to calcaneus, cuboid and bases of metatarsals

Question 48

Where is the short plantar ligament located?

Answer 48

attaches to calcaneus and cuboid

Question 49

Where is the spring ligament located?

Answer 49

attaches to calcaneus and navicular, supports the talus

Question 50

What kind of joints are the MTP joints? What kind of movement occurs at these joints?

Answer 50

synovial joints flexion/extension, adduction/abduction

Question 51

What ligaments strengthen the MTP joints?

Answer 51

collateral ligaments, plantar ligaments, deep transverse metatarsal ligaments (between adjacent metatarsals)