JOINTS OF THE UPPER LIMB
I. TYPES OF JOINTS
A. Fibrous - immovable
1. Sutures - junction of 2 flat bones (skull)
2. Syndesmosis - joining of 2 opposed bones by intervening fibrous tissue
B. Cartilaginous - transitional stage on complete bony union
1. Synchondrosis - temporary
2. Symphysis - 2 bones united by fibrocartilage - some movement
a. intervertebral disks
b. pubic symphysis
C. Synovial - most movable
1. Characteristics
a. articular surfaces covered by hyaline cartilage
b. enclosed in fibrous capsule
c. capsule lined by synovial membrane - elaborates synovial fluid
d. reinforced by accessory ligaments
e. may contain articular disks
2. Types
a. Plane - gliding or sliding - surfaces are flat (joints of hand and foot)-AC joint
b. Hinge (ginglymus) - movement around single axis-flex and extend only
c. Pivot (trochoidal) - movement around single axis longitudinal to bone-
rotation
d. Condyloid - ellipsoidal surface (metacarpalphalangeal joints)-permits flex/ext/ab/ad
e. Saddle - biaxial -complex curvature (carpometacarpal – thumb joint)
f. Ball and socket- greatest freedom of movement - hip
3. Innervation
a. proprioception (joint position, direction of movement)
b. pain
c. Hilton's Law-nerves supplying the joint also supply the muscles
moving that joint or the skin covering that attachment
4. Blood supply - from collateral circulation around joint
II. JOINTS OF THE UPPER LIMB
A. Sternoclavicular - saddle type of synovial joint
1. Only connection between trunk and upper limb
2. Articular disc in joint capsule
3. Ligaments
a. Anterior sternoclavicular
b. Posterior sternoclavicular
c. Interclavicular-superiorly
d. Costoclavicular-inferior
4. Blood supply - branches of internal thoracic and suprascapular arteries
5. Innervation - branches of supraclavicular and nerve to subclavius
B. Acromioclavicular - plane type of synovial joint
1. contains articular disc-incomplete
2. Ligaments
a. acromioclavicular
b. coracoclavicular
i. conoid-vertical-attach to conoid tubercle to clavicle
ii. trapezoid-horizontal-to trapezoid line of clavicle
3. Blood supply - suprascapular and thoracoacromial
4. Innervation - supraclavicular, lateral pectoral, axillary nn.
C. Glenohumeral (shoulder joint) - ball and socket type of synovial joint
1. Glenoid labrum - fibrocartilaginous rim
2. Tendon of long head of biceps
3. Capsule-loose
a. Apertures
4. Ligaments
a. Glenohumeral-interior of capsule
i. anterior wall
ii. supraglenoid tubercle of scapula to lesser tubercle of humerus
iii. superior, middle and inferior ligaments
b. Coracohumeral
i. prevents superior displacement of head of humerus
c. Transverse Humeral Ligament
5. Stability of joint
a. shallowness leads to instability
b. strength due to rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis)
6. Bursae
a. Subscapular bursa
b. Subacromial bursa (subdeltoid)
7. Blood supply - anterior and posterior circumflex humeral aa.
8. Innervation - suprascapular, axillary, lateral pectoral nn.
D. Elbow joint - hinge type of synovial
1. 3 articulations
a. Humeroulnar - uniaxial - trochlea (humerus) and trochlear notch (ulna)
b. Humeroradial - capitulum (humerus) and head of radius
c. Proximal radioulnar - pivot - head of radius and radial notch (ulna)
2. Capsule
3. Collateral ligaments
a. radial collateral ligament - fan-shaped - radius to humerus
b. ulnar collateral ligament - 3 cords - humerus to ulna
4. Blood supply - collateral br. of brachial and recurrent br. of radial and ulnar aa.
5. Innervation - musculocutaneous and radial nn.
6. Bursa
a.Olecranon
b.Radioulnar
E. Proximal radioulnar - pivot type
1. Ligaments
a. annular ligament
b. quadrate ligament
c. oblique cord
F. Distal radioulnar - pivot type
1. Articular disc-"Triangular Ligament"
2. Allows pronation and supination
3. Blood supply - anterior and posterior interosseus aa.
4. Innervation - anterior and posterior interosseus nn.
G. Wrist joint - condyloid type
1. radiocarpal joint
2. Ligaments
a. Dorsal radiocarpal
b. Palmar radiocarpal
c. Radial collateral ligament
d. Ulnar collateral ligament