Download Knee joint

8
Articulations
PowerPoint® Lecture Presentations prepared by
Alexander G. Cheroske
Mesa Community College at Red Mountain
© 2011 Pearson Education, Inc.
Section 1: Joint Design and Movement
• Learning Outcomes
• 8.1 Describe the basic structure of a synovial
joint, and describe common accessory
structures and their functions.
• 8.2 Explain the relationship between structure
and function for each type of synovial joint.
• 8.3 Describe flexion/extension,
abduction/adduction, and circumduction
movements of the skeleton.
• 8.4 Describe rotational and special movements
of the skeleton.
© 2011 Pearson Education, Inc.
Section 1: Joint Design and Movement
• Articulations (joints)
• Where two bones interconnect
• Bones are relatively inflexible so necessary to
allow movement
• Reflect compromise between need for strength
versus need for mobility
• Anatomical structure of each joint determines
type and amount of movement possible
• Categories from range of motion and
subgroups from anatomical structure
© 2011 Pearson Education, Inc.
Section 1: Joint Design and Movement
• Three functional categories
1. Synarthrosis (no movement)
2. Amphiarthrosis (little movement)
3. Diarthrosis (free movement)
•
•
Synarthrotic and amphiarthrotic joints
•
Relatively simple structure
•
Direct connections between bones
Diarthrotic joints
•
Complex in structure
•
Permit greatest range of motion
© 2011 Pearson Education, Inc.
Module 8.1: Synovial joints
• Components of synovial joints
• Articular cartilages
• Resemble hyaline cartilages
• Matrix contains more water comparatively
• Have no perichondrium
• Slick and smooth, so reduce friction
• Are separated by thin film of synovial fluid
© 2011 Pearson Education, Inc.
Module 8.1: Synovial joints
• Components of synovial joints (continued)
• Synovial fluid
• Similar in composition to ground substance in
loose connective tissues
• Produced at the synovial membrane
• Circulates from areolar tissue to joint cavity
• Percolates through articular cartilages
• Total quantity is less than 3 mL
© 2011 Pearson Education, Inc.
Module 8.1: Synovial joints
• Components of synovial joints (continued)
• Joint capsule
• Dense and fibrous
• May be reinforced with accessory structures
(tendons and ligaments)
• Continuous with periosteum of each bone
© 2011 Pearson Education, Inc.
The structure of synovial joints
Medullary cavity
Components of Synovial Joints
Periosteum
Articular cartilage
Joint capsule
Synovial fluid
Synovial membrane
Spongy bone of epiphysis
Compact bone
Figure 8.1
© 2011 Pearson Education, Inc.
1
Module 8.1: Synovial joints
• Functions of synovial fluid
• Lubrication
• With articular cartilage compression, synovial fluid is
squeezed out and reduces friction between moving
surfaces
• Nutrient distribution
• Provide nutrients and oxygen, as well as waste disposal
for the chondrocytes of articular cartilages
• Compression and reexpansion of articular cartilages pump
synovial fluid in and out of cartilage matrix
• Shock absorption
• Distributes compression forces across articular surfaces
and outward to joint capsule
© 2011 Pearson Education, Inc.
Module 8.1: Synovial joints
• Accessory structures
• Provide support and additional stability
• Not all are included in every joint
• Most are seen in the knee
© 2011 Pearson Education, Inc.
Module 8.1: Synovial joints
• Accessory structures in knee
• Tendons of quadriceps
• Pass across joint
• Limit movement
• Provide mechanical support
• Bursa (a pouch)
• Small pocket filled with synovial fluid
• Often form in areas where tendon or ligament
rubs against other tissues
• Reduce friction and act as shock absorbers
© 2011 Pearson Education, Inc.
Module 8.1: Synovial joints
• Accessory structures in knee (continued)
• Fat pads
• Adipose tissue covered by synovial membrane
• Protect articular cartilages
• Act as packing material for joint
• Meniscus (a crescent)
• Pad of fibrous cartilage between bones of
synovial joint
• May subdivide joint cavity and affect fluid flow or
allow variations in shapes of articular surfaces
© 2011 Pearson Education, Inc.
Module 8.1: Synovial joints
• Accessory structures in knee (continued)
• Accessory ligaments
• Support, strengthen, and reinforce joint
• Intrinsic ligaments
• Localized thickening of joint capsule
• Example: cruciate liagments of knee
• Extrinsic ligaments
• Separate from joint capsule
• May pass inside (intracapsular) or outside
(extracapsular) the joint capsule
• Intracapsular example: cruciate ligaments
• Extracapsular example: patellar ligament
© 2011 Pearson Education, Inc.
Accessory structures of complex synovial joints,
as seen in a diagrammatic view of a
sagittal section of the knee
Tendon of the quadriceps muscles
Patella
Synovial
membrane
Accessory Structures
Femur
Joint
capsule
Bursa
Fat pad
Joint cavity
Articular
cartilage
Meniscus
Tibia
Extracapsular ligament
Intracapsular ligament
Figure 8.1
© 2011 Pearson Education, Inc.
3
Module 8.1: Synovial joints
• Mobility vs. strength in joints
• Greater range of motion = weaker joint
• Examples:
• Synarthrosis (strongest type of joint, no movement)
• Diarthrosis (far weaker but broad range of motion)
• Dislocation (luxation)
• Movement beyond normal range of motion
• Articulating surfaces forced out of position
• Can damage joint structures
• No pain from inside joint but from nerves or
surrounding structures
© 2011 Pearson Education, Inc.
Module 8.1 Review
a. Define a joint dislocation (luxation).
b. Describe the components of a synovial joint,
and identify the functions of each.
c. Why would improper circulation of synovial
fluid lead to the degeneration of articular
cartilages in the affected joint?
© 2011 Pearson Education, Inc.
Module 8.2: Types of motion and structural
types of synovial joints
•
Types of motion permitted at synovial joints
•
Gliding
•
•
Movement along two axes in one plane
Angular motion
•
Movement along two axes in one plane with
additional change in angle
© 2011 Pearson Education, Inc.
Module 8.2: Types of motion and structural
types of synovial joints
•
Types of motion permitted at synovial joints
(continued)
•
Circumduction
•
•
•
Special complex angular movement
Proximal end of bone remains fixed while distal end can
move in a circle (“trace circumference”)
Rotation
•
Bone ends remain fixed and shaft rotates
Animation: Synovial Joints: Movement
© 2011 Pearson Education, Inc.
The general types of movement at synovial joints
Starting position
Gliding
Angular motion
Circumduction
Rotation
Figure 8.2
© 2011 Pearson Education, Inc.
1
– 5
The anatomical types of synovial joints, with joint models and examples
Types of Synovial Joints
Models of Joint Motion
Gliding joint
Examples
• Acromioclavicular and
claviculosternal joints
• Intercarpal and
intertarsal joints
• Vertebrocostal joints
• Sacro-iliac joints
Manubrium
Hinge joint
Humerus
• Elbow joints
• Knee joints
• Ankle joints
• Interphalangeal joints
Ulna
Pivot joint
Atlas
• Atlas/axis
• Proximal radio-ulnar
joints
Axis
Ellipsoid joint
Scaphoid bone
• Radiocarpal joints
• Metacarpophalangeal
joints 2–5
• Metatarsophalangeal
joints
Ulna
Radius
Saddle joint
• First carpometacarpal
joints
Metacarpal bone
of thumb
Trapezium
Ball-and-socket joint
Scapula
• Shoulder joints
• Hip joints
Humerus
Figure 8.2
© 2011 Pearson Education, Inc.
6
Module 8.2 Review
a. Identify the types of synovial joints based on
the shapes of the articulating surfaces.
b. What type of synovial joint permits the widest
range of motion?
c. Indicate the type of synovial joint for each of
the following: shoulder, elbow, ankle, and
thumb.
© 2011 Pearson Education, Inc.
Module 8.3: Specific angular movements
•
Flexion and extension
•
Usually applied to movements of long bones of
limbs but also axial skeleton
•
Flexion
•
Anterior/posterior movement that reduces angle
between articulating elements
•
Lateral flexion
•
•
Dorsiflexion
•
•
Vertebral column bending to the side
Flexion at ankle joint and elevation of sole
Plantar flexion (planta, sole)
•
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Extension at ankle joint and elevation of heel
Module 8.3: Specific angular movements
•
Flexion and extension (continued)
•
Extension
•
Anterior/posterior movement that increases
angle between articulating elements
•
Hyperextension
•
Extension past anatomical position
Animation: Foot Dorsiflexion: Plantar Flexion
Animation: Elbow Flexion/Extension
Animation: Wrist Flexion/Extension
© 2011 Pearson Education, Inc.
Flexion and extension
Extension
Flexion
Hyperextension
Lateral flexion
Dorsiflexion
(ankle flexion)
Flexion
Extension
Plantar flexion
(ankle extension)
Flexion
Hyperextension
Figure 8.3
© 2011 Pearson Education, Inc.
1
Module 8.3: Specific angular movements
•
Abduction and Adduction
•
Always refers to movements of appendicular skeleton, not
axial
•
Movements are usually toward or away from body midline
•
•
For fingers or toes, movements are spreading digits apart or
bringing them together
Abduction (ab, from)
•
•
Movement away from body longitudinal axis in frontal plane
Adduction (ad, to)
•
Movement toward body longitudinal axis in frontal plane
Animation: Humerus Abduction/Adduction
© 2011 Pearson Education, Inc.
Abduction and adduction
Adduction
Abduction
Abduction
Adduction
Abduction
Adduction
Abduction
Adduction
Abduction
Adduction
Figure 8.3
© 2011 Pearson Education, Inc.
2
Module 8.3: Specific angular movements
•
Circumduction
•
Moving arm or thigh as if to draw a big circle at
distal end of limb
Animation: Wrist Circumduction
Animation: Humerus Circumduction
Animation: Synovial Joints: Angular Movement
© 2011 Pearson Education, Inc.
Module 8.3 Review
a. When doing jumping jacks, which lower limb
movements are necessary?
b. Which movements are associated with hinge
joints?
c. Compare dorsiflexion to plantar flexion.
© 2011 Pearson Education, Inc.
Module 8.4: Rotation and special movements
•
Rotation
•
When applied to the trunk, described as left
and right rotation
•
When applied to limbs
•
Medial rotation (internal or inward rotation)
•
•
Anterior surface of limb toward trunk long axis
Lateral rotation (external or outward rotation)
•
Anterior surface of limb away from trunk long axis
Animation: Humerus Rotation
© 2011 Pearson Education, Inc.
Rotational movements
Left
rotation
Right
rotation
Lateral
(external)
rotation
Medial
(internal)
rotation
Figure 8.4
© 2011 Pearson Education, Inc.
1
Module 8.4: Rotation and special movements
•
Rotation (continued)
•
Other special terms for rotation of forearm
•
•
Pronation
•
Proximal end of radius rotates near ulna
•
Distal end rolls across anterior ulnar surface
•
Turns the wrist and hand from palm facing front to
palm facing back
Supination
•
Opposing movement
•
Palm is turned anteriorly
Animation: Elbow Pronation/Supination
© 2011 Pearson Education, Inc.
Rotational movements
Supination
Pronation
Figure 8.4
© 2011 Pearson Education, Inc.
1
Module 8.4: Rotation and special movements
•
Special movements
•
Opposition
•
•
Movement of thumb toward palm surface or other fingers
Protraction
•
•
Movement forward in anterior plane
Retraction
•
•
Reverse of protraction
Inversion (in, into + vertere, to turn)
•
•
Twisting foot motion to turn sole inward
Eversion (e, out)
•
Opposing movement to inversion
© 2011 Pearson Education, Inc.
Module 8.4: Rotation and special movements
•
Special movements (continued)
•
Depression
•
•
Movement inferiorly
Elevation
•
Movement superiorly
Animation: Foot Inversion/Eversion
Animation: Hand Opposition
© 2011 Pearson Education, Inc.
Special movements
Opposition
Eversion
Retraction
Protraction
Inversion
Depression
Elevation
Figure 8.4
© 2011 Pearson Education, Inc.
2
Module 8.4 Review
a. Snapping your fingers involves what
movement with the thumb and third
metacarpophalangeal joint?
b. What movements are made possible by the
rotation of the radius head?
c. What hand movements occur when wriggling
into tight-fitting gloves?
© 2011 Pearson Education, Inc.
Section 2: Articulations
• Learning Outcomes
• 8.5 Describe the articulations between the
vertebrae of the vertebral column.
• 8.6 Describe the structure and function of the
shoulder and hip joints.
• 8.7 Describe the structure and function of the
elbow and knee joints.
• 8.8 CLINICAL MODULE Explain arthritis, and
describe its effects on joint structure and
function.
© 2011 Pearson Education, Inc.
Section 2: Articulations
• Axial skeleton articulations
• Typically are strong but very little movement
• Appendicular skeleton articulations
• Typically have extensive range of motion
• Often weaker than axial articulations
© 2011 Pearson Education, Inc.
Joints of the
Axial Skeleton
Sutures of the skull
Temporomandibular joint
(temporal bone and
mandible)
Atlanto-occipital joint
(occipital bone and atlas)
and the atlanto-axial joint
(C1–C2)
Joints of the thoracic cage
Intervertebral joints
The lumbosacral joint,
which attaches the last
lumbar vertebra to the
sacrum
The sacrococcygeal and
intercoccygeal joints,
which structurally
resemble simplified
intervertebral joints
Figure 8 Section 2
© 2011 Pearson Education, Inc.
1
Joints of the
Appendicular Skeleton
The sternoclavicular joint,
the only articulation between
the axial skeleton and the
pectoral girdle and upper
limb
Shoulder joint
The sacro-iliac joint, which
firmly attaches the sacrum
of the axial skeleton to the
pelvic girdle of the
appendicular skeleton
Elbow joint
Superior and inferior
radio-ulnar joints
Pubic symphysis
Wrist joint
Joints of the hand
and fingers
Hip joint
Knee joint
Ankle joint
Joints of the foot and toes
Figure 8 Section 2
© 2011 Pearson Education, Inc.
2
Module 8.5: Vertebral articulations
• Vertebral articulations
• Between superior and inferior articular
processes of adjacent vertebrae
• Gliding diarthrotic joints
• Permit flexion and rotation
• Adjacent vertebral bodies form symphyseal
joints with intervertebral discs
• Numerous ligaments attach bodies and
processes of vertebrae to stabilize column
© 2011 Pearson Education, Inc.
Module 8.5: Vertebral articulations
• Intervertebral discs
• Composition
• Anulus fibrosis
• Tough outer layer of fibrous cartilage
• Collagen fibers attach to adjacent vertebrae
• Nucleus pulposus
• Soft, elastic, gelatinous core
• Provides resiliency and shock absorption
• Account for ¼ length of vertebral column
• Water loss from discs causes shortening of vertebral
column with age and increases risk of disc injury
© 2011 Pearson Education, Inc.
An intervertebral disc
Anulus fibrosus
Nucleus pulposus
Superior view
Figure 8.5
© 2011 Pearson Education, Inc.
1
Module 8.5: Vertebral articulations
• Primary vertebral ligaments
• Ligamentum flavum
• Connects adjacent vertebral laminae
• Posterior longitudinal ligament
• Connects posterior surfaces of adjacent vertebral bodies
• Interspinous ligament
• Connects spinous processes of adjacent vertebrae
• Supraspinous ligament
• Connects spinous processes from sacrum to C7
• Ligamentum nuchae from C7 to base of skull
• Anterior longitudinal ligament
• Connects anterior surfaces of adjacent vertebral bodies
© 2011 Pearson Education, Inc.
The ligaments attached to the bodies and processes of all vertebrae
Primary Vertebral Ligaments
Ligamentum flavum
Intervertebral disc
Anulus fibrosus
Posterior longitudinal ligament
Nucleus pulposus
Spinal cord
Interspinous ligament
Spinal nerve
Supraspinous ligament
Posterior
longitudinal
ligament
Anterior longitudinal ligament
Lateral view
Sectional view
Figure 8.5
© 2011 Pearson Education, Inc.
2
Module 8.5: Vertebral articulations
• Disorders of vertebral column
• Slipped disc
• Posterior longitudinal ligaments weaken causing
more pressure on discs
• Nucleus pulposus compresses, distorts anulus
fibrosus
• Disc bulges into vertebral canal (doesn’t actually slip)
• Herniated disc
• Nucleus pulposus breaks through anulus fibrosus
• Spinal nerves are often affected
© 2011 Pearson Education, Inc.
A slipped disc, as seen in a lateral view
T12
Normal
intervertabral
disc
L1
Slipped
disc
L2
Figure 8.5
© 2011 Pearson Education, Inc.
3
A herniated disc, as seen in a superior view
Compressed area
of spinal nerve
Nucleus pulposus
of herniated disc
Spinal nerve
Spinal cord
Anulus
fibrosis
Figure 8.5
© 2011 Pearson Education, Inc.
4
Module 8.5: Vertebral articulations
• Disorders of vertebral column (continued)
• Osteopenia (penia, lacking)
• Inadequate ossification leading to loss of bone
mass
• Often occurs with age beginning between ages
30 and 40
• More severe in women than men
• Osteoporosis (porosus, porous)
• Bone loss sufficient to affect normal function
© 2011 Pearson Education, Inc.
The effects of osteoporosis on spongy bone
Clinical scan of a compression
fracture in a lumbar vertebra
Figure 8.5
© 2011 Pearson Education, Inc.
5
The effects of osteoporosis on spongy bone
Normal spongy bone
SEM x 25
Spongy bone with
osteoporosis
SEM x 21
Figure 8.5
© 2011 Pearson Education, Inc.
5
Module 8.5 Review
a. Identify the primary vertebral ligaments.
b. Describe the nucleus pulposus and anulus
fibrosus of an intervertebral disc.
c. Compare a slipped disc with a herniated disc.
© 2011 Pearson Education, Inc.
Module 8.6: Shoulder and hip joints
•
Shoulder joint (glenohumeral joint)
•
Greatest range of motion of any joint
•
Most frequently dislocated joint
•
Demonstrates stability sacrificed for mobility
•
Most stability provided by surrounding skeletal muscles,
associated tendons, and various ligaments
•
Ball-and-socket diarthrosis
•
Formed by head of humerus and glenoid cavity of
scapula
•
Socket of glenoid cavity increased by fibrous-cartilaginous
glenoid labrum (labrum, lip or edge)
Animation: Scapula Clavicle Humerus
© 2011 Pearson Education, Inc.
Module 8.6: Shoulder and hip joints
•
Shoulder joint (continued)
•
Ligaments stabilizing the shoulder
•
Coracoclavicular ligaments
•
Acromioclavicular ligament
•
Coraco-acromial ligament
•
Coracohumeral ligament
•
Glenohumeral ligaments
© 2011 Pearson Education, Inc.
The shoulder joint (glenohumeral joint)
Coracoid process
Clavicle
Acromion
Ligaments Stabilizing
the Shoulder
Bursae
Coracoclavicular ligaments
Articular
capsule
Tendon of the biceps
brachii muscle
Acromioclavicular ligament
Scapula
Coraco-acromial ligament
Coracohumeral ligament
Glenohumeral ligaments
Humerus
Figure 8.6
© 2011 Pearson Education, Inc.
1
The structures within and surrounding the shoulder joint
A frontal section of the shoulder joint
A lateral view of the shoulder joint
Subdeltoid Articular Coraco-acromial Coracoclavicular
ligament
ligaments
bursa
capsule
Acromioclavicular
ligament
Clavicle
Clavicle
Tendon of
supraspinatus muscle
Tendon of
infraspinatus muscle
Tendon of biceps
brachii muscle
Articular
cartilages
Humerus
Articular
capsule
Coracohumeral
ligament (cut)
Glenoid
cavity
Glenohumeral
ligaments
Scapula
Subscapularis muscle
Glenoid
labrum
Synovial
membrane
Frontal section
Glenoid
labrum
Teres minor muscle
Scapula
Lateral view
Figure 8.6
© 2011 Pearson Education, Inc.
2
– 3
Module 8.6: Shoulder and hip joints
•
Hip joint
•
Sturdy ball-and-socket joint
•
Although not directly aligned with weight distribution along
femur shaft, which can produce fractures of femoral neck or
intertrochanteric region
•
Permits flexion, extension, adduction, abduction,
circumduction, and rotation
•
Formed by head of femur and acetabulum of hip bone
•
Socket of acetabulum increased by projecting rim of fibrous
cartilage (acetabular labrum)
•
Articular capsule extends from lateral/inferior surfaces of pelvic
girdle to intertrochanteric line and crest of femur
© 2011 Pearson Education, Inc.
The hip joint in lateral view
Iliofemoral ligament
Fibrous cartilage pad
Acetabular labrum
Acetabulum
Fat pad
Ligamentum teres
(ligament of the
femoral head)
Transverse acetabular ligament
Figure 8.6
© 2011 Pearson Education, Inc.
4
Module 8.6: Shoulder and hip joints
•
Hip joint (continued)
•
Reinforcing ligaments
1.
Transverse acetabular ligament
•
2.
Crosses acetabular notch, filling gap in inferior border
Ligamentum teres (teres, long and round)
•
Originates along transverse acetabular ligament and
attached to fovea capitis
3.
Pubofemoral ligament
4.
Iliofemoral ligament
5.
Ischiofemoral ligament
Animation: Pelvic Girdle: Hip Femur
© 2011 Pearson Education, Inc.
The ligaments of the hip joint
Reinforcing Ligaments
Pubofemoral ligament
Iliofemoral ligament
Ischiofemoral ligament
Greater
trochanter
Ischial
tuberosity
Posterior view
Intertrochanteric
line
Lesser trochanter
The ligaments of the hip joint in posterior view
Anterior view
The ligaments of the hip joint in anterior view
Figure 8.6
© 2011 Pearson Education, Inc.
5
Module 8.6 Review
a. Which tissues or structures provide most of
the stability for the shoulder joint?
b. At what site are the iliofemoral ligament,
pubofemoral ligament, and ischiofemoral
ligament located?
c. A football player received a hard tackle to the
upper surface of his shoulder, causing a
shoulder separation. What bones and
ligaments would be affected?
© 2011 Pearson Education, Inc.
Module 8.7: Elbow and knee joints
•
Elbow joint
•
Complex hinge joint involving humerus, radius, and
ulna
•
Extremely strong and stable due to:
1.
Bony surfaces of humerus and ulna interlock
2.
Single, thick articular capsule surrounds both humeroulnar and proximal radio-ulnar joints
3.
Articular capsule reinforced by strong ligaments
•
Severe stresses can still produce dislocations or other
injuries
•
•
Example: nursemaid’s elbow
Muscles flexing elbow attach on anterior while those
extending attach on the posterior
© 2011 Pearson Education, Inc.
Module 8.7: Elbow and knee joints
•
Elbow joint (continued)
•
Specific joints of the elbow
•
Humeroradial joint
•
•
•
Capitulum of humerus articulating with head of radius
Humero-ulnar joint
•
Largest and strongest articulation
•
Trochlea of humerus articulates with trochlear notch of ulna
•
Shape of ulnar notch determines plane of movement
•
Shapes of olecranon fossa and olecranon limit degree of
extension
Proximal radio-ulnar joint is not part of elbow joint
© 2011 Pearson Education, Inc.
The elbow joint
Humeroradial joint
Anterior
view
Humerus
Humeroulnar joint
Radius
Ulna
Proximal radio-ulnar joint
(not part of the elbow joint)
Figure 8.7
© 2011 Pearson Education, Inc.
1
Module 8.7: Elbow and knee joints
•
Elbow joint (continued)
•
Reinforcing ligaments
•
Radial collateral ligament
•
•
Ulnar collateral ligament
•
•
Stabilizes lateral surface of joint
Stabilizes medial surface of joint
Annular ligament
•
Binds head of radius to ulna
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The elbow joint
Humerus
Posterior
view
Olecranon
fossa
Humeroulnar joint
Ulna
Olecranon
Figure 8.7
© 2011 Pearson Education, Inc.
1
Module 8.7: Elbow and knee joints
•
Knee joint
•
Contains three separate articulations
1. Medial condyle of tibia to medial condyle of femur
2. Lateral condyle of tibia to lateral condyle of femur
3. Patella and patellar surface of femur
•
Permits flexion, extension, and very limited
rotation
Animation: Patella Tibia Fibula
© 2011 Pearson Education, Inc.
Module 8.7: Elbow and knee joints
•
Knee joint (continued)
•
External support
•
Quadriceps tendon to patella
•
•
Fibular collateral ligament
•
•
Medial support
Popliteal ligaments
•
•
Lateral support
Tibial collateral ligament
•
•
Continues as patellar ligament to anterior tibia
Posterior support extending between femur and heads of tibia
and fibula
Tendons of several muscles that attach to femur and tibia
© 2011 Pearson Education, Inc.
The knee joint
Superficial
anterior view
Femur
Quadriceps
tendon
Joint capsule
Fibular
collateral
ligament
Bursa
Patella
Fibular
collateral
ligament
Superficial
posterior view
Tibial collateral
ligament
Cut tendon
of biceps
femoris
muscle
Patellar
ligament
Popliteal ligaments
Tibia
Fibula
Fibula
Tibia
Figure 8.7
© 2011 Pearson Education, Inc.
3
– 4
Module 8.7: Elbow and knee joints
•
Knee joint (continued)
•
Internal support
•
Cruciate ligaments limit anterior/posterior
movement of femur and maintain alignment of
condyles
•
•
Anterior cruciate ligament (ACL)
•
At full extension, knee becomes “locked”
(slight lateral rotation tightens ACL, and lateral
meniscus forced between tibia and femur)
•
Opposite motion to “unlock”
Posterior cruciate ligament (PCL)
© 2011 Pearson Education, Inc.
Module 8.7: Elbow and knee joints
•
Knee joint (continued)
•
Internal support (continued)
•
Medial and lateral menisci
•
Fibrous cartilage pads between tibial and femoral
condyles
•
Act as cushions and provide lateral stability to joint
© 2011 Pearson Education, Inc.
The knee joint
Deep anterior
view, flexed
Fibular
collateral
ligament
Patellar
surface
of femur
Lateral
condyle
PCL
ACL
ACL
PCL
Medial
condyle
Tibial collateral ligament
Tibia
Deep posterior
view, extended
Femur
Lateral
condyle
Medial
condyle
Fibular
collateral
ligament
Medial and lateral menisci
Tibia
Fibula
Fibula
Figure 8.7
© 2011 Pearson Education, Inc.
3
– 4
Module 8.7 Review
a. Between the elbow and knee joints, which
have menisci?
b. What signs and symptoms would you expect
in an individual who has damaged the menisci
of the knee joint?
© 2011 Pearson Education, Inc.
CLINICAL MODULE 8.8: Disruption to normal
joint function
•
Arthritis
•
Damage to articular cartilages but specific cause varies
•
Exposed surfaces change from slick, smooth-gliding to rough
feltwork of collagen fibers increasing friction
•
Rheumatism (pain and stiffness affecting the skeletal and/or
muscular systems) is often a symptom
•
Osteoarthritis
•
Also known as degenerative arthritis or degenerative joint
disease
•
Generally affects individuals age 60 and older
•
•
25% of women, 15% of men
Can result from cumulative wear and tear of joints or genetic
factors affecting collagen formation
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Comparisons of normal articular cartilage with articular cartilage damaged by osteoarthritis
Arthritic Joint
Normal Joint
Fibrous
remains
of the
articular
cartilage
Articular
cartilage
Degenerating
articular
cartilage
LM x 180
Arthroscopic view of normal cartilage
LM x 180
Arthroscopic view of damaged cartilage
Figure 8.8
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1
– 2
CLINICAL MODULE 8.8: Disruption to normal
joint function
•
Visualizing problematic joints
•
Arthroscopic surgery
•
Optical fibers (arthroscope) inserted into joint
through small incision without major surgery to
visualize joint interior
•
If necessary, other instruments can be inserted
through other incisions to permit surgery within
view of arthroscope
•
Magnetic resonance imaging
•
Cost-effective and noninvasive viewing technique
that allows examination of soft tissues around joint
as well
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An arthroscopic view of the interior of the left knee,
showing injuries to the anterior and
posterior cruciate ligaments.
PCL
Femoral
condyle
ACL
Meniscus
Figure 8.8
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3
Figure 8.8
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4
CLINICAL MODULE 8.8: Disruption to normal
joint function
•
Artificial joints
•
May be last resort if other solutions (exercise,
physical therapy, drugs) for joint problems fail
•
Not as strong as natural joints, so most suitable for
elderly
•
Typically have service life of about 10 years
© 2011 Pearson Education, Inc.
Figure 8.8
© 2011 Pearson Education, Inc.
5
CLINICAL MODULE 8.8 Review
a. Compare rheumatism to osteoarthritis.
b. Explain the use of an arthroscope.
c. What can a person do to slow the progression
of arthritis?
© 2011 Pearson Education, Inc.