Joints of the upper limb Flashcards
Shoulder girdle
Shoulder girdle = incomplete bony ring - made up the scapulae and clavicles. Attach anteriorly to manubrium of sternum
True Articulations
sternoclavicular joint
acromioclavicular joint
glenohumeral joint
Scapulothoracic articulation
Sternoclavicular joint (SC joint)
synovial, saddle joint
Includes: sternal end of clavicle, manubrium of sternum, 1st costal cartilage
Only articulation between upper limb and axial skeleton
Articular disc: divides the joint space into 2 compartments, serves as a shock absorber
Clavicle fracture
Common fracture site
Typically fractures in middle 1/3
Usually caused from a fall on an outstretched arm
Acromioclavicular joint (AC joint)
Synovial, plane (gliding) joint
Includes: acromion of the scapula, lateral end of the clavicle
Loose fibrous joint capsule: allows for rotation of the acromion process on the end of the clavicle, no muscles move joint directly
Acromioclavicular ligament: strengthens AC joint superiorly
AC joint ligaments
Main stabilizer of AC joint: prevents superior translation of the clavicle
Coracoclavicular ligaments: accessory ligament, anchors clavicle to coracoi dprocess. Cornoid ligament - located medial and slightly more posterior. Trapezoid ligament - located lateral and slightly more anterior
Shoulder separation
AC joint dislocation
Glenohumeral joint (GH joint)
Synovial, ball and socket joint - very mobile, but unstable
Articulation: large humeral head, shallow glenoid cavity (fossa). Deepened by glenoid labrum
Loose fibrous joint capsule strengthened by muscolo-tendinous rotator cuff
GH joint ligaments
Strengthens anterior aspect of capsule
Intrinsic ligaments
Superior/middle/inferior GH ligament
Coracohumeral ligament: from coracoid process to anterior aspect of greater tubercle, part of fibrous capsule, strengthens capsule superiorly
Transverse humeral ligament: greater to lesser tubercle, holds the long head of the biceps brachii in place
Coracoacromial ligament: spans between coracoid process and acromion process. STRONG superior support
GH joint dislocation
Anterior - more common
Posterior - rare
Name indicates where the humeral head is positioned
Median, radial, and axillary nerves are at risk
Elbow joint
Synovial, hing joint
3 joints: humeroulnar, humeroradial, proximal radioulnar
Fibrous joint capsule: weak anteriorly and posteriorly. covers all 3 articulations
Olecranon (elbow) bursitis
Elbow joint ligaments
Radial collateral ligament: lateral aspect, lateral epicondyle to annular ligament, prevents against a varus force
Ulnar collateral ligament: medial aspect - three bands. Medial epicondyle to olecranon. Prevents against a valgus force
Ulnar collateral ligament tear
Proximal radioulnar joint
Annular ligament: encircles and holds head of the radius in the radial notch of the ulna
Permits pronation and supination of forearm
Subluxation and dislocation of radial head
Distal radioulnar joint
Synovial, pivot joint
head of ulna to ulnar notch of radius
Articular disc binds ulna and radius - triangular ligament
radius moves around ulna
Wrist (radiocarpal) joint
Synovial, condyloid joint
Radiocarpal joint between: radius, scaphoid, lunate, triquetrum, articular disc. NOT the ulna
Scaphoid fracture
most commonly fractured carpal bone
blood supplied by radial a. but there is poor blood supply to the prox. pole waist of bone
Clinical features: pain over anatomical snuffbox, often confused with wrist sprain
Erb Duchenne Palsy
Brachial plexus injury
Damage superior trunk (C5-C6) causes waiter’s tip appearance
Typically occurs at birth
Result of increased angle between head and shoulder
Damage ot ulnar nerve
Ulnar nerve palsy
Causes claw hand
ulnar nerve entrapment
loss of innervation to intrinsic hand mm.
Damage ot median nerve
sign of benediction
median n. damage at elbow or in forearm
loss of innervation to 5 intrinsic hand mm.
Damage to radial nerve
Wrist drop
damage to radial nerve by humerus break
unopposed flexion of digits
Damage to C8-T1
Klumpke paralysis
stretch or tear of C8-T1
injury to lower brachial plexus (ex: ABduction of arm at birth)
complete claw hand
