(Part B)mc3cb.com/pdf_ap_lecture_s6/C9_2_joints_extra_info_S2014.pdf · ligament˜ Lateral condyle...

© 2013 Pearson Education, Inc.

Joints(Part B)

--------------------Shape of Joints

Knee Joint

Shoulder Joint

Elbow Joint

Hip Joint

Temporal-mandibular Joint

Common Joint Injuries


Types of Synovial Joints

• Six types, based on shape of articular surfaces:

– Plane– Hinge– Pivot– Condylar– Saddle– Ball-and-socket


The shapes of the joint surfaces define the types of movements that can occur at a synovial joint; they also determine the classification of synovial joints into six structural types.

Flatarticularsurfaces

Gliding

Plane joint Nonaxial movement

Examples: Intercarpal joints, intertarsal joints, joints between vertebral articular surfaces

Carpals

Metacarpals



Hinge joint Uniaxial movement

Examples: Elbow joints, interphalangeal joints

Flexion and extension

CylinderTrough

Medial/lateralaxis

Humerus

Ulna



Pivot joint Uniaxial movement

Rotation

Sleeve(bone andligament)

Radius

Examples: Proximal radioulnar joints, atlantoaxial joint

Axle (roundedbone)

Vertical axis

Ulna



Phalanges

Metacarpals

Condylar joint Biaxial movement

Ovalarticularsurfaces

Examples: Metacarpophalangeal (knuckle) joints, wrist joints

Medial/lateralaxis

Flexion andextension

Adduction andabduction

Anterior/posterioraxis



Flexion andextension

Adduction andabduction

Articularsurfacesare bothconcaveand convex

Medial/lateralaxis


Trapezium

Metacarpal Ι

Example: Carpometacarpal joints of the thumbs

Saddle joint Biaxial movement


The shapes of the joint surfaces define the types of movements that can occur at a synovial joint; they also determine the classification of synovialjoints into six structural types.

Sphericalhead(ball)

Examples: Shoulder joints and hip joints

Flexion and extension Adduction andabduction Rotation

Humerus

Scapula

Cup(socket)

Medial/lateralaxis


Vertical axis

Ball-and-socket joint Multiaxial movement


• Largest, most complex joint of body• Three joints surrounded by a single

joint cavity– Femoropatellar joint

• Plane joint• Allows gliding motion during knee flexion

– Lateral and medial tibiofemoral joints• Femoral condyles with lateral and medial

menisci of tibia• Allow flexion, extension, and some rotation

when knee partly flexed

Knee Joint


Patellar ligament

Sagittal section through the right knee joint

Anteriorcruciateligament

Posteriorcruciateligament

Tibia

Femur

Lateralmeniscus

Articularcapsule

Lateral meniscusSynovial cavity

Infrapatellarfat pad

Subcutaneousprepatellar bursa

Patella

Suprapatellarbursa

Tendon ofquadricepsfemoris

Deep infrapatellerbursa


Articularcartilage on lateral tibialcondyle

Posteriorcruciateligament

Lateralmeniscus

Superior view of the right tibia in the knee joint, showingthe menisci and cruciate ligaments


Medialmeniscus

Articularcartilageon medialtibial condyle

Anterior


Knee Joint

• At least 12 associated bursae

• Capsule is reinforced by muscle tendons– E.g., quadriceps and semimembranosus tendons

• Joint capsule is thin and absent anteriorly

• Anteriorly, quadriceps tendon gives rise to three broad ligaments– Medial and lateral patellar retinacula– Patellar ligament

© 2013 Pearson Education, Inc.Anterior view of right knee

Quadricepsfemorismuscle

Lateralpatellarretinaculum

Tibialcollateralligament

Fibula

Fibularcollateralligament

Patella

Tendon ofquadricepsfemorismuscle

Patellarligament

Medialpatellarretinaculum

Tibia


Ligaments Stabilizing Knee Joint

• Capsular and extracapsularligaments– Help prevent hyperextension of knee– Fibular and tibial collateral ligaments– Oblique popliteal ligament– Arcuate popliteal ligament


Tibia

Arcuatepoplitealligament

Obliquepoplitealligament

Bursa

Popliteusmuscle(cut)

Lateralhead ofgastrocnemiusmuscle

ArticularcapsuleMedial head of

gastrocnemiusmuscle

Fibularcollateralligament

Tibialcollateralligament

Tendon ofsemimembranosusmuscle

Posterior view of the joint capsule, including ligaments

FemurTendon ofadductormagnus


Ligaments Stabilizing Knee Joint

• Intracapsular ligaments – Prevent anterior-posterior displacement– Reside outside synovial cavity– Anterior cruciate ligament

• Attaches to anterior tibia– Posterior cruciate ligament

• Attaches to posterior tibia


Fibularcollateralligament�

Lateralcondyleof femurLateralmeniscus

Tibia

Fibula

Anterior view of flexed knee, showingthe cruciate ligaments (articularcapsule removed, and quadricepstendon cut and reflected distally)

PosteriorcruciateligamentMedialcondyleTibialcollateralligament

Medialmeniscus

PatellarligamentPatella


Quadricepstendon


Medial femoralcondyle

Anterior cruciateligament

Medial meniscuson medial tibialcondyle

Patella

Photograph of an opened knee joint;view similar to (e)


Knee Joint Injuries

• Absorbs great vertical force

• Vulnerable to horizontal blows, especially laterally blows to extended knee

– Three C's• Collateral ligaments• Cruciate ligaments• Cartilages


A common knee injury.

Lateral

Patella(outline)

Medial

Tibialcollateralligament(torn)

Medialmeniscus(torn)

Hockey puck

Anteriorcruciateligament(torn)


Shoulder (Glenohumeral) Joint

• Ball-and-socket joint– Head of humerus with glenoid

cavity of scapula• Most freely moving joint in

body– Stability sacrificed


The shoulder joint.

Acromionof scapulaCoracoacromialligamentSubacromialbursa

Fibrous layer ofarticular capsule

Tendonsheath

Tendon oflong headof bicepsbrachii muscle

Synovial membraneFibrous layer ofarticular capsule

Humerus

Articularcartilage

Synovial cavityof the glenoidcavity containingsynovial fluid

Frontal section through right shoulder joint


Fibrous layer ofarticular capsule

Humerus

Articularcartilage

Synovial cavityof the glenoidcavity containingsynovial fluid

Cadaver photo corresponding to (a)

The shoulder joint.


Shoulder Joint

• Reinforcing ligaments– Primarily on anterior aspect– Coracohumeral ligament

• Helps support weight of upper limb– Three glenohumeral ligaments

• Weak and sometimes absent


• Reinforcing muscle tendons– Tendon of long head of biceps brachii

• Travels through the intertubercularsulcus

• Secures humerus to glenoid cavity– Four rotator cuff tendons encircle the

shoulder joint• Subscapularis• Supraspinatus• Infraspinatus• Teres minor

Shoulder Joint


AcromionCoracoacromialligamentSubacromialbursaCoracohumeralligamentGreatertubercleof humerusTransversehumeralligamentTendon sheath

Tendon oflong headof bicepsbrachiimuscle

Articularcapsulereinforced byglenohumeralligaments

SubscapularbursaTendon of thesubscapularismuscleScapula

Coracoidprocess

Anterior view of right shoulder joint capsule


Lateral view of socket of right shoulderjoint, humerus removed

CoracoidprocessArticularcapsuleGlenoid cavity

Glenoid labrum

Tendon of longhead of bicepsbrachii muscleGlenohumeralligamentsTendon of thesubscapularismuscleScapula

Posterior Anterior

Acromion


The shoulder joint.

Head ofhumerus

Muscle ofrotatorcuff (cut)

Anterior view of an opened shoulder joint

Capsule ofshoulderjoint(opened)

Glenoidcavity ofscapula

Acromion(cut)


• Articulation of radius and ulna with humerus

• Hinge joint– Primarily trochlear notch of ulna

with trochlea of humerus– Flexion and extension only

Elbow Joint


Humerus

Fat pad

Tendon oftricepsmuscleBursa

Articular cartilageof the trochlearnotch

Trochlea

Articularcapsule

Synovialmembrane

Synovial cavity

Ulna

Median sagittal section through right elbow (lateral view)

Articular cartilage

Coronoid process

Tendon ofbrachialis muscle


Elbow Joint

• Anular ligament– Surrounds head of radius

• Two capsular ligaments restrict side-to-side movement– Ulnar collateral ligament– Radial collateral ligament


Humerus

Lateralepicondyle

ArticularcapsuleRadialcollateralligament

Olecranon

Anularligament

Radius

Ulna

Lateral view of right elbow joint


ArticularcapsuleAnularligamentCoronoidprocess

Radius

Humerus

MedialepicondyleUlnarcollateralligament

Ulna

Medial view of right elbow

© 2013 Pearson Education, Inc.Cadaver photo of medial view of right elbow

Anularligament

Radius

Articularcapsule

Coronoidprocess

Humerus

Medialepicondyle

Ulnarcollateralligament

Ulna


• Ball-and-socket joint• Head of the femur

articulates with acetabulum• Good range of motion, but

limited by the deep socket – Rim of fibrocartilage -

Acetabular labrum• Enhances depth of socket so

hip dislocations rare

Hip (Coxal) Joint


Ligament of thehead of the femur(ligamentum teres)

Coxal (hip) boneArticular cartilage

Acetabular labrum

Femur

Frontal section through the right hip joint

Synovial cavity

Articular capsule


The hip joint.

Acetabularlabrum

Ligament of the headof the femur(ligamentumteres)

Synovialmembrane

Headof femur

Articularcapsule (cut)

Photo of the interior of the hip joint, lateral view


Hip Joint

• Reinforcing ligaments– Iliofemoral ligament– Pubofemoral ligament– Ischiofemoral ligament– Ligamentum teres


IliofemoralligamentIschiofemoralligament

Greatertrochanterof femur

Posterior view of right hip joint, capsule in place

Ischium


Iliofemoralligament

Pubofemoralligament

Greatertrochanter

Anterior inferioriliac spine

Anterior view of right hip joint, capsule in place


Temporomandibular Joint (TMJ)

• Mandibular condyle articulates with temporal bone

• Two types of movement– Hinge—depression and

elevation of mandible– Gliding—e.g., side-to-side

(lateral excursion) grinding of teeth

• Most easily dislocated joint in the body


Ramus of mandible

Articularcapsule

Externalacousticmeatus

Mandibular fossaArticular tubercleZygomatic processInfratemporal fossa

Location of the joint in the skull

Lateral ligament


Inferior jointcavity

Superiorjointcavity

Articulartubercle

Articular disc

Mandibularfossa

Articularcapsule

Synovialmembranes

Condylarprocess ofmandible

Ramus of mandible

Enlargement of a sagittal section through

the joint


Superior viewOutline of themandibularfossa

Lateral excursion: lateral (side-to-side) movements of the mandible



• Cartilage tears– Due to compression and shear stress– Fragments may cause joint to lock or

bind– Cartilage rarely repairs itself– Repaired with arthroscopic surgery

• Ligaments repaired, cartilage fragments removed with minimal tissue damage or scarring

– Partial menisci removal renders joint less stable but still mobile; complete removal leads to osteoarthritis

– Meniscal transplant in younger patients– Perhaps meniscus grown from own

stem cells in future


Arthroscopic photograph of a torn medial meniscus.

Femur

Meniscus

Tear inmeniscus

Tibia



• Sprains– Reinforcing ligaments stretched or torn– Partial tears slowly repair heal

• Poor vascularization– Three options if torn completely

• Ends sewn together• Replaced with grafts• Time and immobilization



• Dislocations (luxations)– Bones forced out of alignment– Accompanied by sprains,

inflammation, and difficulty moving joint

– Caused by serious falls or contact sports

– Must be reduced to treat• Subluxation—partial

dislocation of a joint


Inflammatory and Degenerative Conditions

• Bursitis– Inflammation of bursa, usually

caused by blow or friction– Treated with rest and ice and, if

severe, anti-inflammatory drugs• Tendonitis

– Inflammation of tendon sheaths typically caused by overuse

– Symptoms and treatment similar to bursitis


Arthritis

• >100 different types of inflammatory or degenerative diseases that damage joints

• Most widespread crippling disease in the U.S.

• Symptoms: pain, stiffness, and swelling of joint

• Acute forms: caused by bacteria, treated with antibiotics

• Chronic forms: osteoarthritis, rheumatoid arthritis, and gouty arthritis


Osteoarthritis (OA)

• Common, irreversible, degenerative (''wear-and-tear'') arthritis

• May reflect excessive release of enzymes that break down articular cartilage

• By age 85 half of Americans develop OA, more women than men

• Probably related to normal aging process


Osteoarthritis (OA)

• More cartilage is destroyed than replaced in badly aligned or overworked joints

• Exposed bone ends thicken, enlarge, form bone spurs, and restrict movement

• Treatment: moderate activity, mild pain relievers, capsaicin creams– Glucosamine, chondroitin sulfate, and

nutritional supplements not effective


Rheumatoid Arthritis (RA)

• Chronic, inflammatory, autoimmune disease of unknown cause– Immune system attacks own cells

• Usually arises between ages 40 and 50, but may occur at any age; affects 3 times as many women as men

• Signs and symptoms include joint pain and swelling (usually bilateral), anemia, osteoporosis, muscle weakness, and cardiovascular problems


Rheumatoid Arthritis

• RA begins with synovitis of the affected joint

– Inflammatory blood cells migrate to joint, release inflammatory chemicals that destroy tissues

– Synovial fluid accumulates joint swelling and inflamed synovial membrane which thickens pannus that clings to articularcartilage

– Pannus erodes cartilage, scar tissue forms and connects articulating bone ends (ankylosis)


Rheumatoid Arthritis: Treatment

• Disrupt destruction of joints by immune system

• Steroidal and nonsteroidal anti-inflammatory drugs decrease pain and inflammation

• Immune suppressants slow autoimmune reaction

• Some agents target tumor necrosis factor to block action of inflammatory chemicals

• Can replace joint with prosthesis


A hand deformed by rheumatoid arthritis.


Gouty Arthritis

• Deposition of uric acid crystals in joints and soft tissues, followed by inflammation

• High fructose leads to metabolic pathway with elevates uric acid crystals! (high fructose corn syrup)

• More common in men

• Typically affects joint at base of great toe

• In untreated gouty arthritis, bone ends fuse and immobilize joint

• Treatment: drugs, plenty of water, avoidance of alcohol


Lyme Disease

• Caused by bacteria transmitted by tick bites

• Symptoms: skin rash, flu-like symptoms, and foggy thinking

• May lead to joint pain and arthritis• Treatment

– Long course of antibiotics


Developmental Aspects of Joints

• By embryonic week 8, synovial joints resemble adult joints

• Joint's size, shape, and flexibility modified by use

• Advancing years take toll on joints– Ligaments and tendons shorten and weaken– Intervertebral discs more likely to herniate– Most people in 70s have some degree of OA

• Full-range-of-motion exercise key to postponing joint problems

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