Joints
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Definition of a joint - a place where two or more bones come together.
Articulation - a joint
Kinesiology - the study of the mechanics of motion, biomechanics, study of the movement of
joints
Classification of Joints
According to the type of material that holds the bones together and the method used to unite the
boney components.
Synarthrosis
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Fibrous joints - joined by fibrous connective tissue
– suture - found only in the skull
• serrate suture - sawlike interlocking articulations
• squamous - edges overlap
• plane - edges are smooth and do not overlap
– syndesmosis - joined by a ligament
• interosseous ligament - FCT sheet between two bones
– tympanostapedial
– between the radius and ulna
– interspinous ligament
– between tibia and fibula
– gomphoses
Cartilaginous Joint
Primary Cartilaginous Joint - synchondrosis
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synostosis
• epiphyseal plates
costochondral articulations
Secondary Cartilaginous Joint - symphysis
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symphysis pubis
intervertebral joint
Diarthrosis
Synovial Joints
Range of Motion
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Anatomic shape of the articular surfaces
Joint capsule
Presence of adjacent structures
Types of Movement
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Uniaxial - one plane
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two types - hinge and pivot
Biaxial - two planes
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two types - condyloid and saddle
Multiaxial - three planes
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two types - ball and socket and plane
Associated Structures
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Ligaments
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Intrinsic
Extrinsic
Bursae
Tendon sheath
Kinds of Synovial Joints
p. 198 - 200
Uniaxial Joints
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Hinge - ginglymus
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Humeroulnar - cubital joint
Interphalangeal joint
Knee joint
Pivot - trochoid
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Proximal radioulnar joint
Atlantoaxial joint
Biaxial Joints
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Condyloid - ellipsoidal joint
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Metacarpophalangeal joint
Saddle - sellar joint
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Radiocarpal joint
carpometacarpal joint of the thumb
• trapezium and first metacarpal bone
articulation between the malleus and the incus
Multiaxial Joints
Gliding Joints - plane
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Zygapophyseal joints
Intercarpal and intertarsal joints
Sternoclavicular joint
Sternocostal joints - planar
Sacroiliac joint - planar
Ball and socket joints - spheroid
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hip - coxofemoral joint
knee - stifle joint
Specific Joints of the Body
p. 208 - 218
Atlanto-occipital Joint
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Synovial, diarthrodial
Ginglymus and condyloid - the condyles of the occiput rest on the superior articular facets of
the atlas (condyloid portion); the condyles converge anteriorally and allow motion in only one
plane (flexion and extension - hinge portion)
Anterior atlanto-occipital membrane - anterior arch of atlas to anterior margin of foramen
magnum, direct continuation of the anterior longitudinal ligament
Atlanto-occipital Joint
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Posterior atlanto-occipital membrane - posterior arch of atlas to posterior margin of foramen
magnum
Lateral Atlanto-occipital membrane - (Anterior Oblique Ligament), these two ligaments connect
TP of atlas to jugular process of occiput
Articular Capsule (capsular ligament) - these ligaments enclose the articular surfaces and are
lined with a synovial membrane
Occipito-Axial Complex
the axis is NOT in direct articulation with the occiput so it is called a complex NOT a joint
Ligaments attach the axis to the occiput
Membrana-tectoria - occipito-axial ligament, tectorial membrane - continuation of the posterior
longitudinal ligament; attaches on the occipital bone medial to the hypoglossal canal; closely
adherent to the cranial dura once inside the cranial vault
Alar Ligament - check ligament, odontoid ligament; one on each side, apex of dens to medial
surface of occipital condyles, serve to limit or check the degree of rotation of the axis
Occipito-Axial Complex
Apical ligament (suspensory ligament) - single ligament, tip of dens to anterior margin of
foramen magnum; may be remains of embryonic notochord as there is no disc here
Cruciate ligament - 3 components
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caudal crus - attaches central portion of the transverse ligament to posterior body of axis
Atlantoaxial Joints
Ligaments associated with the Atlanto-axial joint
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cranial crus - attaches central portion of the transverse ligament to ant. margin of FM
2 joints here: both are Synovial, diarthrodial
1) bilateral joints between the inferior articular facets of the atlas and the superior articular
facets of the axis; these zygapophyseal joints are plane, gliding joints
2) articulation between dens and anterior arch of the atlas and the dens and the transverse
ligament of the atlas - trochoid, pivot joint
Atlantoaxial Joints
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transverse ligament of the atlas - lateral mass over posterior aspect of dens to lateral mass
Anterior atlanto-axial ligament - anterior surface of body of axis to anterior arch of atlas
Posterior atlanto-axial ligament - from the laminae of the axis to the posterior arch of the
atlas
Accessory Ligaments - runs from the medial surface of the lateral masses of atlas down to
the posterior surface of the body at the base of dens
Transverse Ligament of the Atlas - runs from lateral mass across the neural ring over the
posterior aspect of the dens to hold the dens firmly against the fovea dentalis of the atlas,
does not attach to the dens, small synovial pocket between the two
Joint of Luschka
Uncovertebral joint
Diarthrosis, synovial
Between the uncinate processes and a small indentation found on the inferior surface of the
vertebra it articulates with
typically undergo degeneration with resulting bony outgrowth which may encroach on
neighboring structures such as the vertebral artery and the exciting spinal nerves
Intervertebral Joints
Secondary cartilaginous, symphysis, amphiarthrotic
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Intervertebral Disc
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23 total
25% of the height of the vertebral column
lordotic curve areas - disks are thicker anterior
Components
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Annulus fibrosus - peripheral portion, fibrocartilage
Nucleus pulposus - 88% H2O at birth, 70% at age 70
Zygapophyseal Joints
Synovial
Diarthrodial
Plane
Gliding
Multiaxial
Spinous Process Articulation
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Syndesmosis of the spine
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Interspinous ligament - between spinous processes
Supraspinous ligament - connects tips of spinous processes from C7 - S1 (first sacral
tubercle)
Ligamentum nuchae - direct continuation of the supraspinous ligament, from EOP and
median nuchal crest to C7
what about the ligamentum flavum, Anterior longitudinal ligament and the Posterior
longitudinal ligament of the spine?
Temporomandibular Joint
Synovial, diarthrodial, hinge, gliding, multiaxial
Components - articular disc fibrocartilage
Articular surfaces lined with fibrocartilage
Movement – depression and elevation - hinge
– protraction and retraction - gliding
– lateral rotation
Ligaments – lateral ligament - prevents posterior displacement
– stylomandibular - styloid process to ramus of mandible
– sphenomandibular ligament - sphenoid bone to lingula
Sternoclavicular Joint
Synovial, diarthrodial, gliding, multiaxial
There is an articular disc made of fibrocartilage
Ligaments
– Anterior sternoclavicular ligament - covers anterior aspect of the joint
– Posterior sternoclavicular ligament - covers posterior aspect of the joint
– Interclavicular ligament - attaches the two sternal ends
– Costoclavicular ligament - costal cartilage of the first rib to the costal tubercle
Glenohumeral Joint
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Synovial, diarthrodial, ball and socket, spheroid, multiaxial
Components
– head of the humerus and the glenoid fossa of the scapula, most freely moveable joint in
the body
Ligaments
– coracohumeral ligament - coracoid process to greater tubercle of humerus
– glenohumeral ligament - thickenings of joint capsule
– transverse humeral retinaculum - from greater tubercle to lesser tubercle of humerus,
holds bicipital tendon in place
Glenohumeral joint, cont.
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Protected from trauma from above by:
– acromion, coracoid process, lateral aspect of the clavicle
Bursae
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subdeltoid bursa - between deltoid m and joint capsule
subacromial bursa - between acromion and joint capsule
Rotator cuff muscles - musculotendinous cuff
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Supraspinatus m. - support from above
Infraspinatus m. - support from posterior
Teres minor m. - support from posterior
Subscapularis m. - support from anterior
The Elbow Joint
Humeroulnar and humeroradial joint
Cubital joint - trochlea of humerus and trochlear notch of ulna and the capitulum of the
humerus and the head of the radius
Synovial, diarthrodial, hinge, uniaxial
Ligaments
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Radial (lateral) collateral ligament
Ulnar (medial) collateral ligament
Annular ligament - encircles the head of the radius
Olecranon bursa - on posterior side of elbow
Proximal Radioulnar Joint
Formed by the head of the radius and the radial notch of the ulna
Synovial
Diarthrodial
Trochoid
Uniaxial
Annular Ligament
Metacarpophalangeal Joints
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Synovial, diarthrodial, biaxial
Condyloid
Interphalangeal Joints
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Synovial, diarthrodial, uniaxial
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Hinge
The Coxal (Hip) Joint
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Formed by the head of the femur and the acetabulum of the os coxae
Bears weight of the body
Synovial, diarthrodial, spheroid, multiaxial
Acetabular labrum - fibrocartilage
The Coxal (Hip) Joint
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Ligaments of the hip
– Iliofemoral ligament - “Y” ligament of Bigelow
• AIIS to intertrochanteric line, prevents hyperextension
– Pubofemoral ligament
• pubis to intertrochanteric line, limits hyperextension and abduction
– Ischiofemoral ligament
• ischium to greater trochanter, limits hyperextension
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Round ligament - ligamentum teres - intrinsic ligament, fovea capitis of femur to transverse
acetabular ligament
Transverse acetabular ligament - crosses the acetabular notch, connects joint capsule to
ligamentum capitis femoris
Tibiofemoral - Stifle Joint
Largest and most complex joint of body,
Synovial, diarthrodial, “modified hinge”, biaxial
Classified as a double condyloid joint, capable of flexion, extension and medial and lateral
rotation
Hyperextension of knee - foot on ground, medial rotation of femur
Ligaments
– Function
• control excessive knee extension
• control abduction and adduction stresses
• control anterior and posterior displacement of tibia on femur
• control medial and lateral rotation of tibia beneath femur
• give rotatory stabilization
Ligaments of the knee, cont.
Lateral and medial patellar retinacula - tendinous insertion of quadriceps femoris m. Gives
anterior stability. Attaches to patella and tibial tuberosity
Oblique popliteal ligament - posterior aspect of joint capsule, provides posterior stability and
limits hyperextension.
Arcuate popliteal ligament - Head of fibula over tendon of popliteus m. to intercondylar area
of tibia and lateral epicondyle of femur. Limits hyperextension of knee.
Collateral Ligaments - provide medial and lateral stability
– Medial (tibial) collateral ligament
– Lateral (fibular) collateral ligament
Cruciate ligaments
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Anterior cruciate ligament
• Anterior tibia to posterior medial aspect of the lateral condyle of the femur
• Prevents anterior displacement of the tibia on the femur
• During extension of the knee the ACL is pulled taut
• Torn ACL = Anterior drawer sign
Posterior cruciate ligament
• Posterior tibia to lateral aspect of medial condyle of femur, prevents posterior
displacement of the tibia.
• Shorter and less oblique than ACL
• During flexion of the knee the PCL is pulled taut
• Torn PCL = Posterior drawer sign
Bursa
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Popliteal bursa - between tendon of popliteus m. and lateral condyle of femur
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Prepatellar bursa - between patella and skin
Suprapatellar bursa - between quadriceps tendon and anterior femur
Menisci
Medial meniscus - semicircular, attached to medial collateral lig. And to semimembranosus m.
Lateral meniscus - 4/5’s of a circle, attached to posterior cruciate lig. And popliteus muscle via
coronary lig. And posterior joint capsule.
Talocrural (ankle) Joint
Synovial, diarthrodial, hinge, uniaxial
Ligaments
– Deltoid
• posterior tibiotalar ligament
• tibiocalcaneal ligament
• tibionavicular ligament
• anterior tibiotalar ligament
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Lateral collateral ligaments
• anterior and posterior talofibular ligament
• calcenofibular ligament
Terms Related to Joint Pathology
Strain - stretched or pulled tendon or ligament
Sprain - hyperextension, with tearing of tendons or lig. Luxation - derangement of the
articulating bones that compose a joint
Subluxation - partial dislocation of a joint
Bursitis - inflammation of a bursa
Tendonitis - inflammation of a tendon
Osteoarthritis - degenerative joint disease
Rheumatoid arthritis - autoimmune disease
Gouty arthritis - abnormal accumulation of uric acid