UE Osteology Flashcards
The upper extremity consists of the shoulder, axillary region, _______ (arm), ___________ (forearm), and ______ (hand)
- brachium (arm)
- antebrachium (forearm)
- manus (hand)
- bone that articulates w/ the manubrium of the sternum and acromion of the scapula
- has a sternal end, body, and acromial end
clavicle
- part of the clavicle
- possesses articular surface for manubrium
- possesses sternal facet which articulates w/ the manubrium at the clavicular notch
- possesses the impression for the costoclavicular L. which is a small depression on inferior surface of clavicle and provides attachment for costoclavicular L. to the 1st rib
sternal end
- part of the clavicle
- possesses the subclavian groove which is on the inferior surface and is an attachment point for subclavius M.
body (shaft)
- part of the clavicle
- possesses the acromial facet which articulates w/ an articular facet on the acromion of the scapula
- possesses the conoid tubercle on the inferior surface, which provides attachment for the conoid L.
- possesses the trapezoid line on the inferior surface which provides attachment for the trapezoid L.
acromial end
Why is the clavicle one of the most fractured bones?
What is an incomplete clavicle fracture called in children?
- clavicle is often fractured due to direct and indirect injuries received by falling
- incomplete clavicle fractures in younger children are referred to as a Greenstick fracture (partial break in the clavicle usually of the superior aspect, gives the appearance of a partially broken stick)
- triangular, flat bone that rests on the posterior thoracic wall
- capable of a good deal of movement at the physiological scapulothoracic joint
- borders: lateral, medial, and superior
- angels: superior, inferior, and lateral
- posterior surface is convex and costal (anterior) surface is concave)
scapula
What are the borders of the scapula and points of importance?
- lateral (axillary) border
- medial (vertebral) border
- superior border: suprascapular notch (transmits suprascapular A. and N.) and coracoid process (anteriorly bent process, provides attachment for numerous muscles and ligaments)
What are the angles of the scapula and points of importance?
- superior (between superior and medial borders)
- inferior (between medial and lateral borders)
- lateral (between superior and lateral borders):
scapular head: glenoid cavity (articular surface for humoral head), supraglenoid tubercle (superior to glenoid cavity, attachment for long head of biceps brachii M.), infraglenoid tubercle (triangular bump, inferior to glenoid cavity, attachment for long head of triceps brachii M.)
scapular neck: slight constriction between scapular head and lateral border
What are the important points of the posterior and costal (anterior) surfaces of the scapula?
Posterior surface:
- scapular spine (bony ridge, stretches transversely across the posterior surface from the medial border to the lateral angle ending in the acromion): acromion (the point of the shoulder, possesses an articular surface for the clavicle) and deltoid tubercle (attachment point for the deltoid M.)
- greater scapular notch: short passage between the lateral border and the lateral attachment point of scapular spine to the posterior surface
- supraspinous fossa: location of supraspinatus M.
- infraspinous fossa: location of infraspinatus M.
Costal (Anterior) surface:
- subscapular fossa: location of subscapularis M.
- bone in the upper extremity
- articulates proximally w/ the glenoid cavity of the scapula and distally w/ the ulna and radius bones
humerus
What are the important points on the proximal end of the humerus?
- humeral head: rounded, smooth surface, articulates w/ glenoid cavity of scapula
- humeral neck: anatomical neck (exists between humeral head and humeral tubercles, analogous to femoral neck) and surgical neck (between proximal end of humerus and shaft, common fracture site)
- greater humeral tubercle: lateral border of the humerus, attachment point for the supraspinatus, infraspinatus, and teres minor M.
- lesser humeral tubercle: projects anteriorly, attachment point for the subscapularis M.
- intertubercular groove: between humeral tubercles, transmits the long head of the biceps brachii T., also provides attachment points for pectoralis major, teres major, and latissimus dorsi M.
Where is the humerus most commonly fractured?
What is the greater tubercle of the humerus also susceptible to in terms of injury?
- most common fracture site of humerus: surgical neck
- greater tubercle also susceptible to avulsion by supraspinatus, infraspinatus, and teres minor Ms. that insert there
What are the important points on the body (shaft) of the humerus?
- deltoid tuberosity: insertion point for the deltoid M.
- groove for the radial N.: transmits the radial N. and deep brachial A. (according to Olinger this is not easily visible on most bones)
What are the important points on the distal end of the humerus?
- medial and lateral supracondylar ridges: transition point between body and the widened distal end
- lateral humeral epicondyle: common origin for several antebrachial extensors
- medial humeral epicondyle: common origin for several antebrachial flexors; also possesses groove for ulnar N.
- humeral condyle: arrangement of articular surfaces and depressions for the articulation w/ the ulna and radius Bs.; articular surfaces (trochlea and capitulum), anterior depressions (radial fossa and coronoid fossa), and posterior depression (olecranon fossa)
What are the important points of the humeral condyle of the humerus?
- articular surfaces: trochlea (articulates w/ the trochlear notch of the proximal ulna) and capitulum (smooth, rounded process, articulates w/ concave radial head)
- anterior depressions: radial fossa (accommodates the radial head when the antebrachium is flexed) and coronoid fossa (coronoid process of the ulna when the antebrachium is flexed)
- posterior depression: olecranon fossa (accommodates the olecranon of the ulna when the antebrachium is extended)
What is the origin of the expression “funny bone” when hitting the medial portion of the humeral epicondyle on a hard object?
- the origin of this expression is related to the presence of the ulnar N. in the groove for the ulnar N. on the humerus (humerous = funny)
- when the ulnar N. is compressed within the groove, it becomes painful
Severe abduction of the extended elbow, an abnormal movement at this joint, can result in avulsion of the:
medial humeral epicondyle
- bone in forearm
- medial of the two antebrachial bones, articulates w/ the humerus and radius proximally and radius distally
ulna
What are the important points of the proximal end of the ulna?
(larger than the distal end)
- olecranon: provides level for extension of the antebrachium, point of the elbow
- coronoid process (projects anteriorly): radial notch (lateral, smooth notch, articulates w/ the radial head)
- trochlear notch: formed by the olecranon and coronoid processes, grips the humeral trochlea
- ulnar tuberosity: anterior, distal to the coronoid process, attachment point for the brachialis M.
- supinator crest: lateral aspect, distal to the radial notch, attachment point for the supinator M.
- often referred to as “fractured elbow”
- common in cases of falling
- because of the forceful nature of the triceps brachii M., this is considered an avulsion fracture and is difficult to repair
olecranon fracture
- part of the ulna
- relatively smaller than the proximal end
- possesses articular surface for articular disc and the ulnar styloid process
- does not reach the carpus
ulnar head (distal end)
- bone in the forearm
- lateral of the two antebrachial bones
- always on the thumb side
- articulates w/ the humerus and ulna proximally and the ulna and proximal row of carpal bones distally
radius
What are the important points of the proximal end of the radius?
(smaller than the distal end)
- radial head (proximal, disc shaped, concave superior proximal surface): posseses the fovea of the radial head (smooth pit, articulates w/ capitulum of the humeral condyle)
- radial neck (slight constriction distal to the radial head): possesses the radial tuberosity (separates proximal end from body, attachment point for the biceps brachii T.)
What are the important points of the distal end of the radius?
(larger than the proximal end)
- styloid process of radius: distal most point of the radius, lateral constraint to the radiocarpal joint
- ulnar notch: articulates w/ the ulnar head
- radial articular surface for carpal bones: smooth depression: articulates w/ the lunate and scaphoid bones
- dorsal tubercle: acts as a pulley for the extensor pollicis longus M.
- fractures of the distal end of the radius
- usually occurs from breaking falls w/ outstretched arm
- styloid process is often avused in this situation
- sometimes called “fork deformity” due to the shape of the wrist and hand after sustaining injury
Colle’s fracture
What does the mnemonic “Some Lovers Try Positions That They Can’t Handle” stand for?
(memorizing carpal bones from the posterior aspect, going from proximal 4 bones in a lateral to medial direction, then the distal 4 bones in a lateral to medial direction)
- Scaphoid
- Lunate
- Triquetrum
- Pisiform
- Trapezium
- Trapezoid
- Capitate
- Hamate
What are the 4 carpal bones in the proximal row?
- scaphoid: articulates w/ the radius proximally and trapezium and trapezoid distally, most commonly fractured carpal B., largest bone in the proximal row, exists in the floor of the anatomical snuffbox (also possesses scaphoid tubercle, a ligamentous attachment point)
- lunate: articulates w/ the radius proximally, scaphoid and triquetrum on either side and the capitate and hamate distally
- triquetrum: three cornered, articulates w/ the articular disc of the radiocarpal joint proximally, lunate laterally, pisiform anteriorly, and hamate distally
- pisiform: articulates w/ the triquetrum anteriorly
What is the most commonly fractured carpal bone?
What is commonly the cause of this fracture?
- scaphoid fracture is the most commonly fractured carpal bone
- usually the result of trying to break a fall with an outstretched hand
- fracture is often not visible on a radiograph and therefore misdiagnosed as a severe sprain
- distal fragment of bone is susceptible to avascular necrosis since it is usually separated from its blood supply
What structures are passed through the carpal tunnel?
What happens if swelling of tendons occur in this area?
- carpal tunnel transmits tendons of flexor digitorum profundus and superficialis Ms., as well as flexor carpi radialis T. and median N.
- if swelling of tendons occurs, the median N. can be compressed resulting in carpal tunnel syndrome (causes paresthesia, anesthesia, and pain)
What are the 4 carpal bones in the distal row?
- trapezium: articulates w/ the scaphoid proximally, trapezoid medially, and 1st and 2nd metacarpal bones distally (also possesses the tubercle of the trapezium)
- trapezoid: articulates w/ the scaphoid proximally, trapezium and capitate on either side, and the 2nd metacarpal bone distally
- capitate: largest carpal bone, articulates w/ the scaphoid and lunate proximally, trapezoid and hamate on either side, and 3rd and 4th metacarpal bone distally
- hamate: articulates w/ the triquetrum proximally, capitate laterally, and the 4th and 5th metacarpal bones distally (also possesses the hamulus (hook) of hamate which extends anteriorly)
The depression between the pisiform and hamulus of the hamate is known as the ulnar canal (______ ______) and the _______ ___ passes through this canal and is susceptible to compression, which manifests as loss of sensation and muscular weakness
- Guyon canal
- ulnar N.
What are the 5 metacarpal bones?
(base articulates with carpal bones while head articulates w/ proximal phalanges)
- 1st: articulates w/ the trapezium
- 2nd: articulates w/ the trapezium and trapezoid
- 3rd: articulates w/ the capitate (possesses a styloid process on the lateral side)
- 4th: articulates w/ the capitate and hamate
- 5th: articulates w/ the hamate
- head of the 5th metacarpal is susceptible to fracture when an individual punches something with a closed fist
Boxer’s fracture
What is the only inconsistency between the proximal, middle, and distal phalanges?
there are 5 proximal and distal phalanges, while only 4 middle phalanges (because pollux does not have a middle phalange)
What is the common cause of distal phalanges fractures?
- often the result of fingers being closed in a door
- because of the intricate relationship between phalanges and flexor tendons, bone fragments must be realigned carefully to maintain function
- joint between the manubrium of the sternum and the clavicle
- contains a fibrocartilaginous disc in the joint space
sternoclavicular joint
- joint between the distal end of the clavicle and the acromion
- contains a fibrocartilaginous disc in the joint space
acromioclavicular joint
- joint between the glenoid cavity of the scapula and the humeral head
- contains the glenoid labum which is a fibrocartilaginous ring that surrounds and deepens the glenoid cavity
glenohumeral joint
- joint between the radius and carpal bones
- contains articular disc of the distal radioulnar joint: a triangular shaped fibrocartilaginous disc between distal ulna and proximal row of carpal bones
radiocarpal joint
The ______ _______ commonly tears in individuals repeatedly throwing a ball, usually in response to a sudden contraction of the biceps brachii M., and occurs in the anterosuperior part of the labrum
glenoid labrum
