Upper Limb Joints Flashcards
Sternoclavicular joint (SC)
. Only articulation btw upper extremity and axial skeleton
. Saddle-shaped synovial joint btw med. clavicle, manubrium, and 1st. Costal cartilage
. Has fibrocartilaginous articular disc
Where does articular disc attach in SC joint and function?
. Inf. To 1st costal cartilage
. Sup. To med. clavicle
. Ant. And post. Edges attach to fibrous joint capsule
. Resists sup. And med. dislocation of clavicle and provides additional mobility
Ligaments in SC joint and functions
. Ant. And post. Sternoclavicular ligaments: resist sup. And lat. dislocation
. Costoclavicular ligament: goes from inferomedial clavicle to 1st costalcartilage/rib, strongest ligament, resists sup. Dislocation of clavicle
. Interclavicular ligament: spans sup. Manubrium, resists lat. dislocation
Motions of sternoclavicular joint
. Anteroposterior axis: elevation/depression of pectoral girdle
. Vertical axis: protraction/retraction of pectoral girdle
. Circumduction: rotary motion combining above movement
T/F clavicle will fracture before sternoclavicular ligaments rupture
T
Acromioclavicular joint (AC) structure
. Plane-type btw lat. clavicle and acromion process
. Incomplete wedge-shaped articular disc
AC joint ligaments
. Acromioclavicular ligament (intrinsic)
. Coracoclavicular ligament (extrinsic)
Acromioclavicular ligament structure and function
. Thickening of sup. Joint capsule
. Resists sup. Dislocation
Coracoclavicular ligament span, portions, and functions
. Main supper of AC joint
. Resists sup. Dislocation of clavicle, suspends clavicle and supports weight of upper extremity
. Runs from inferolateral clavicle to coracoid process
. Conoid ligament: med. vertically oriented portion extending from root of coracoid
. Trapezoid ligament: lat, horizontally oriented portion extending from body of coracoid
Motion of AC joint
Gliding movements enabling rotation of scapula
Shoulder separation
. Dislocation of AC joint
. Common athletic injury
. Rupture of acromioclavicular and coracoclavicular ligaments and inferomedial dislocation of acromion
. Graded
Glenohumeral (shoulder) joint structure
. Ball and socket synovial joint btw glenoid fossa and humerus head
. Glenoid labrum
. Fibrous joint capsule attaches to margins of glenoid fossa and anatomical neck of humerus
. Thin ad loose except at extreme ROM
. Pierced by tendons of Bicep long head
Glenoid labrum
.Fibrocartilaginous ring encircling glenoid fossa
. Improves congruence by deepening (slightly) the fossa
Excess friction w/in intertubercular groove can ____
Fray biceps brachii long head tendon causing it to rupture
Shoulder joint ligaments and functions
. Glenohumeral ligaments (sup., middle., inf.): intrinsic, reinforce ant. Capsule
. Coracohumeral ligament (intrinsic): reinforces sup. Capsule and resists inf. Dislocation
. Coracoacromial ligament (extrinsic): prevents sup. Dislocation of humerus
. Transverse humeral ligament: bridges intertubercular groove creating canal for long head bicep tendon
Coracohumeral ligament structure
. Goes from base of coracoid process to greater tubercle of humerus
. Ligament is free at ant. Margin but fuses w/ capsule posteriorly
Coracoacromial ligament structure
. Bridges coracoid process and acromion to form coracoacromial arch
Shoulder joint bursae
. Subscapular bursa
. Subacromial (subdeltoid) bursa
Subscapular bursa
. Btw tendon of subscapularis m. And neck of scapula
. Communicates w/ synovial cavity of glenohumeral joint
Subacromial (subdeltoid) bursa
. Sup. To supraspinatus tendon
. Doesn’t normally communicate w/ joint cavity
. Reduces friction from overlying coracoacromial arch and deltoid m.
Adhesive capsulitis
. Inflammation of rotator cuff tendons causing thickening of glenohumeral joint capsule
. Reduces ROM
Calcific tendonitis
. Ca deposits in rotator cuff tendons
. common cause of shoulder pain
What limits range of abduction in gelenohumeral joint?
Greater tubercle of humerus
What limited range of extension in glenohumeral joint?
. Muscular and ligamentous tension
How rotator cuff tendons contribute to glenohumeral joint integrity
. Tendons fuse w/ and reinforce fibrous joint capsule
. Tonic muscle contraction maintains contact btw humeral head and glenoid fossa to stabilize joint
Where is glenohumeral joint weakest?
Inferiorly
Subluxation
Partial displacement of bone in joint
Common subluxation/dislocations in glenohumeral joint
. Inferior in older adults
. Ant. Dislocations w/ excessive force to abducted, extended arm rupturing ant. Joint capsule
Elbow joint articulations and functions
. Hinge-type synovial joint w/ 2 articulations
. Humeroulnar aritculation btw trochlea of humerus and trochlear notch of ulna, permits flexion/extension and minor ab/adduction
. Humeroradial articulation btw capitulum of humerus and head of radius, allow flexion/extension and rotation
Elbow joint capsule
. Lose and thin ant. And post.
. Strengthened med. and lat. by intrinsic ligaments
Elbow joint ligaments paths
. Ulnar (med) collateral ligament: strong intrinsic, extends from med. epicondyle of humerus to coronoid and olecranon processes of ulna
. Radial (lat.) collateral ligament: fan-shaped intrinsic, from lat. epicondyle of humerus to blend distally w/ annular ligament of prox. Radioulnar joint
Second most common joint dislocation and what typically causes it?
. Post. Dislocation of elbow
. Caused by hyperextension or fall onto flexed forearm and can be accompanied by rupture of ant. Capsule
Wrist (radiocarpal) joint structure
. Condyloid synovial joint btw distal radius and triangular ligament and scaphoid, lunate, and triquetrum
. Fibrous joint capsule goes from distal radius and ulna to prox. Row of carpal bones
Triangular ligament and function
. Extrinsic ligament of radiocarpal joint
. Prevents ulnar head from articulating w/ prox. Carpals
. When wrist fully adducted force can be transmitted from triquetrum to ulna
Intrinsic ligaments of wrist joint paths and functions
. Palmar and dorsal radiocarpal ligaments: thickenings of ant. And post. Capsule, limits fl/extension of wrist
. Radial collateral ligament: radial styloid process to scaphoid, limits adduction
. Ulnar collateral ligament: ulnar styloid process to triquetrum and pisiform, limits abduction
Radiocarpal joint motion
. Limited rotation and translation possible, but mostly biaxial
. Transverse axis: fl/extension, greater flexion, extension limited from muscular tension and structure of distal radius
. Anteroposterior axis: ab/adduction, greater adduction, abduction limited by radial styloid process
. Circumduction: rotary motion combining overeats
Proximal radioulnar joint and ligament
. Pivot-type synovial joint btw head of radius and radial notch of ulna
. Synovial cavity continuous w/ elbow joint
. Annular ligament: holds radial head in contact w/ radial notch of ulna, forms osseotendinous ring where radial head rotates
Nursemaid’s elbow
. Inf. Displacement of radial head
. Occurs in small children from lifting/pulling child by pronated forearm
. Fixed by firm supination of flexed forearm
Middle intermediate) radioulnar joint
. Mobile radioulnar syndesmosis
. Formed by interosseous membrane uniting radial and ulnar shafts
Distal radioulnar joint
. Pivot-type synovial joint btw ulnar head and ulnar notch of distal radius
. Articular disc (triangular ligament/fibrocartilage)
Articular disc of distal radioulnar joint properties
. Triangular fibrocartilaginous disc from styloid process of ulna to med. edge of ulnar notch of radius
. Separates synovial cavity of distal radioulnar joint from radiocarpal joint
. Forms pivot for distal radius during pro/supination
Triangular fibrocartilage complex (TFCC)
. Articular disc of distal radioulnar joint and its ligaments (radioulnar, ulnotriqetral, and ulnolunate)
. Degenerative/traumatic TFCC tears common cause of med. wrist pain
Radioulnar joint functions
. 3 radioulnar joints coordinate pro/supination
. Motion occurs around oblique axis extending from center of radial head through distal radioulnar articulation
. Pronation: distal end of radius rotates ant. And med. around stationary ulnar head
. In fully prone state: distal radius lies anteromedial to ulnar head so radial shaft crosses ulnar shaft ant.
Collies fracture
. Scaphoid fractures at bone’s narrow waist
. Accompanies by extension fracture of distal radius
Scaphoid fractures caused by ___
FOOSH
Transverse carpal (midcarpal) joint structure
. Composite joint from many articulations btw prox. And distal carpal rows
. Functions as condyloid joint, head of capitatte and hamate articulate w/ socket formed by scaphoid, lunate, and triquetral bones
. S-shaped synovial cavity reinforced by many intercarpal ligaments
Movements of transverse carpal joints
. Limited gliding movement in all cardinal planes from individual articulations
. Contributed significantly to all wrist movements
Carpometacarpal and intermetacarpal joints in digits II-V
. Plane-type synovial joints btw distal carpals and metacarpal bases
. Share common joint space and fibrous capsule reinforced by carpometacarpal and intermetacarpal ligaments
Carpometacarpal joints in II-V movements
. Limits fl/extension
. 5th carpometacarpal joint permits limited rotations during opposition
1st carpometacarpal joint
. Saddle-shaped synovial joint btw trapezium and metacarpal I
. Highly mobile w/ separate joint capsule
. Contributes significantly to all movements of thumb
Metacarpophalangeal (MP) joint structure
. Condyloid synovial joints btw heads of metacarpals and prox. Phalanges
. Fibrous capsules deficient post. And are replaced by extensor tendon assemblies
MP joint ligaments paths
. Palmar plate (extrinsic): fibrocartilage plate attaches metacarpal head to phalangeal base
. Med. and lat. collateral ligaments (intrinsic): unite metacarpal head w/ prox. Phalangeal base and palmar plate
. Deep transverse metacarpal ligaments (extrinsic): connect adjacent palmar plates (II-V only)
Palmar plate function
. Reinforces ant. Capsule and creates socket for metacarpal head
Med. and lat. collateral ligament of MP joint functions
. Reinforce med. and lat. aspects of fibrous capsule
. Tighten w/ flexion limiting abd/adduction of flexed joint
MP joint motions
. Allows fl/extension and abd/adduction
Skier/gamekeeper thumb
. FOOSH w/ thumb in abduction causing dislocation fo 1st MP joint
. Rupture of med. (ulnar) collateral ligament
T/F dislocation of MP joints II-V are common in adults
F, uncommon
Interphalangeal (IP) joints
. Thumb only has 1
. Formed btw heads (distal) and bases (prox) of adjacent phalanges
. Similar to MP joints: palmar plates attach adjacent phalanges, joint capsules w/ med. and lat. collateral ligaments
. Hinge joints: uniaxial fl/extension only
. Anteroposterior compression of articular surfaces and tension of collateral ligaments prevent abd/adduction
Dislocations of IP joints occur most frequently at ___ and how does it happen?
DIP
. Hyperextension in combo w/ axial compression (jammed finger) causes dorsal dislocation of distal phalanx and may rupture palmar plate
Hilton’s law
Joints receive sensory innervation via articular branches of named nerves innervation muscles that act across them
How superficial joints are innervated
. Not directly crossed by muscle
. Supplied by articular branches of cutaneous nerves that supply adjacent skin
Joint blood supply
. Major joints supplied by articular branches from assoc. arterial anastomotic networks and vessels that form them
. Minor joints supplied by articular branches of adjacent arteries
