Download - Anatomy of shoulder joint - vamshi kiran
ANATOMY OF SHOULDER JOINT
PRESENTOR :DR.B.VAMSHIKIRAN
INTRODUCTION• Shoulder girdle is formed by scapula and clavicle
and humerus upper end.• The only skeletal connection of upper limb to trunk
is clavicle[scapula is connected only through muscular attachments].
• Shoulder area include- -gleno humeral -acromio clavicular -scapulo thoracic -sterno clavicular
• Surface anatomy land marks• Joint structures.• Ligaments and tendons.• Relations ,muscles and nerves.• Blood supply.• Bursae around shoulder joint• Range of movements.• Applied anatomy.
SURFACE ANATOMY• Anteriorly -Clavicle -Tip of coracoid process of scapula -Greater tubercle of humerus. -Deltoid contour -axilla and its folds -medial epicondyle shows head of humerus direction -lateral epicondyle show greater tuberosity direction• Posteriorly –Scapula-acromian,crest of spine[T3] medial and lateral borders,inferior angle
Surface anatomyAnterior aspect Posterior aspect
BONES• Clavicle-Lateral end• Scapula• Upper end of humerus• Superior shoulder suspensory complex-it is a group of bony and ligamentous attachments
includes coracoid,acromian,glenoid,distal clavicle,coracoclavicular ligament[main bond
b/w scapula and clavicle].• Superior strut by middle 1/3rd clavicle a• Inferior strut by lateral scapular body and spine
OSSIFICATION CENTRES• PROXIMAL HUMERUS-3 ossification centre.• Humeral head-ossifies at 6mths• Greater tuberosity-ossifies at 1 to 3yrs• Lesser tuberosity-ossifies at 4 to 5yrs.• Tuberosities coalesce at 6to 7yrs and then fuses to humeral head 7 to13yrs.• Physis close at 14-17yrs girls and 16-18yrs boys.• Proximal physis is extra-articular except at medial
aspect
OSSIFICATION CENTRES• CLAVICLE-It’s the 1st bone to ossify .• It has no medullary cavity.• It occurs by intramembranous ossification.• Secondary ossification centres via endochondral.• Medial epiphysis ossifies at 12-19yrs and fuses at 22
to 25yrs.• Lateral epiphysis ossifies and fuses at 19yrs.• It is most commonly #long bone in body.
SCAPULA OSSIFICATION CENTRES
OSSIFICATION CENTRES• SCAPULA-body,spine,coracoid,acromian,glenoid -Body and spine[posterior] ossify at birth -Coracoid process[anterior]-atavastic epiphysis. - centre at1yr,base at 10yrs,tip at variable - all 3 fuse by 15-16yrs. -Acromian[lateral projection]-fuses by 22yrs via 2- 5centres form at puberty -Glenoid-upper1/4th ossify at 10yrs -lower3/4th appear at puberty ,fuse by22
ACROMIOCLAVICULAR JOINT• Its a plane synovial joint formed by articular facets
of lateral end of clavicle and medial acromial margin
• Cavity of joint is subdivided ay ARTICULAR DISC which may be perforated• Blood supply- suprascapular thoracoacromial [br. of axillary artery]
• Nerve supply-lateral supraclavicular nerve
SHOULDER JOINT• It’s multiaxial synovial ball and socket[dish]joint.• In anatomical position -
-Glenoid articular surface has 7*posterior version -Proximal end of humerus is 45*tilted upwards
vertical angle with long axis of humerus and 20* RETROVERTED with reference to transverse distal intercondylar line. -Scapula is 30*anterior to body’s transverse plane• The humeral retroversion is 27* right and 21*left• Anatomical neck and surgical neck
• Glenoid cavity diameters- -transversely-24+/-3mm -superioinferiorly-35+/-4mm -radius curvature 36+/-7mm
-articular surface is PEAR shaped due to anterior incisura acetabuli and relatively small and flat.
-only 1/4th of humeral head is in contact with glenoid cavity hence greater mobility is seen.
JOINT STABILITYPassive mechanisms like• Joint confirmity• Vacum effect of limited
joint volume• glenoid labrum [static stabiliser]• joint capsule• glenohumeral ligaments• coracoacromial
arch[osseo-ligamentous arch]
• Scapular inclination
Active mechanisms like• Musculo-tendinious
rotator cuff[dynamic stabiliser]
• Muscles attaching limb to thorax like pectoralis major
• Long head of BICEPS and TRICEPS
LIGAMENTS AROUND SHOULDER JOINT
• GLENOID LABRUM• CAPSULAR LIGAMENT• GLENOHUMERAL LIGAMENT• CORACOHUMERAL LIGAMENT• TRANSVERSE HUMERAL LIGAMENT• CORACOACROMIAL LIGAMENT• CORACOCLAVICULAR LIGAMENT
GLENOID LABRUM• It’s a fibrocartilagenous rim attached to margin of
glenoid cavity and inc concavity by 50% and suface area of humeral attachment by 75%.
• It further strengthens by long head of biceps origin and sup glenohumeral ligament
• It is a STATIC stabiliser of joint and prevents excessive rollback of humerus
JOINT CAPSULE• It is lax and attaches along epiphyseal lines of
glenoid and humeral head and extends onto surgical neck medially.
• Capsule is surrounded by synovial membrane which prolongs along tendon of biceps as tubular sheath• Inf part weakest-resulting in dislocations• APPLIED ANATOMY-OSTEOMYELITIS of humerus
upper end spreads directly to joint due to capsule extension to medial side of neck
RELATIONS OF ARTICULAR CAPSULE• MEDIALLY-beyond supraglenoid tubercle
andlabrum• LATERALLY-attaches to anatomical neck of humerus• INFERIORLY-attachment extends to surgical neck• SUPERIORLY-deficient for biceps long head passage • ANTERIORLY-reinforced by GLENOHUMERAL LIGAMENTS[sup,middle,inf]
GLENOHUMERAL LIGAMENTS• SUPERIOR-It is the most superior capsular
thickening from labrum anterior to long head of biceps at level of coracoid base
• It passes under supraspinatus and inserts on ANATOMICAL NECK medial to anterosuperior base of lesser tuberosity.
• MIDDLE GLENOHUMERAL-most variable in size• Arises just inferior to superior GHL and inserts along
middle area of ANATOMICAL NECK opposite to lesser tuberosity
• INFERIOR GLENOHUMERAL-It’s the THICKEST part• It is very broad arising from lower half of
labrum[anterior,inferior,posterior]• Thick superior margin is called SUPERIOR BAND, rest of it is called AXILLARY POUCH.• Superior band and anterior pouch insert on
ANATOMICAL NECK while the posterior pouch on SURGICAL NECK
APPLIED ASPECTS OF GLENOHUMERAL LIGAMENTS
• They restrain the selective arcs of abduction and external rotation.
• In arm dependent position all are slack.• The SUPERIOR GHL is primary resistrant to
inferior translation of adducted shoulder• The MIDDLE GHL limits external rotation at 45*
of abduction• The INFERIOR GHL limits external rotation at 45
to 90* of abduction[mainly superior band of it].
• CORACOHUMERAL LIGAMENT-arises from lateral base of coracoid process and extends onto both tuberosities.
• It forms roof of bicipitaltendon sheath and strengtens capsule anteriorlyImportance-resists inferior and posterior translation.• TRANSVERSE HUMERAL LIGAMENT-bridges upper
part of bicipital groove through which long head of biceps passes down.
CORACOACROMIAL LIGAMENT• It’s a trapezoidal ligament from base of acromian to
apophysis of coracoid• It along with coracoid and acromian forms CORACOACROMIAL ARCH which is a SECONDARY SOCKET to humerus head.• It plays role in resisting upward displacement of
humerus
CORACOCLAVICULAR LIGAMENT• Very strong ligament from outer and inferior
clavicular surface to coracoid base• 2components-CONOID and TRAPEZOID• IMP FUNCTION-It is prime suspensory ligament of
upper extremity that couples”glenohumeral abduction and flexion”to”scapular rotation on thorax”.
• Conoid portion is primary restraint to anterior and superior rotation and anterior and superior displacement of clavicle
• Trapezoid has relatively less role than conoid part
BURSAE RELATED TO SHOULDER JOINT• SUBACROMIAL BURSA-protect suprspinatus• SUBSCAPULARIS BURSA• INFRASPINATUS BURSA
RELATIONS OF SHOULDER JOINT• SUPERIORLY- coracoacromial arch, subacromial bursa, supraspinatus,deltoid• INFERIORLY- long head of triceps• ANTERIORLY-subscapularis,coracobrachialis biceps short head,deltoid[ant fibres]• POSTERIORLY-infraspinatus,teres minor,deltoid• WITHIN JOINT-Long head of biceps
BLOOD SUPPLY• Anterior circumflex humeral
artery[axillaryartery]• Posterior circumflex humeral artry[axillaryartery]• Suprascapular[thyrocervical br.] and subscapular
artery[largest br. of axillary artery]
NERVE SUPPLY
• Axillary nerve-passes close to surgical neck of humerus abt 5cm below acromian
• Musculocutaneous nerve• Suprascapular nerve-Just passes over clavicle
PRINCIPAL MUSCLES AROUND SHOULDER• Primary role -a.movements of arm b.dynamic stabilisation of glenohumeral joint.• There are 14 muscles which are divided into 4
functional groups.they are1.Three heads DELTOID[anterior,middle,posterior]2.Four rotator cuff muscles and BICEPS muscle3.Two axiohumeral muscles[PECTORALIS MAJOR and
LATTISMUS DORSI] and TERES MAJOR.4.Scapular muscle group –SERRATUS
ANTERIOR,TRAPEZIUS,RHOMBOID MAJOR and MINOR and LEVATOR SCAPULAE
Pectoralis majorDeltoid-
Long head of triceps
Coracobrachialis ,short head of biceps
subscapularissupraspinatus
infraspinatus
Teres minor
• SCAPULA POSTERIOR ANTERIOR
MUSCLE ORIGIN INSERTION NERVE SUPPL ACTION
DELTOID-4septa originAnt border lat 1/3rd clavicleAcromian lateral borderLower lip crest of spine of scapula
Deltoid tuberosity on humerus
Axillary nerve[c5,6]
Acromial fibres-abductors From90*Anterior fibres-flexors and medial rotatorsPosterior fibres-extensors and lateral rotators
SUPRASPINATUS-medial2/3Of supraspinatus fossa
Greater tubercle upperimpresi
Suprascapular nerve[c5,6]
Initiator of abduction0*15* steadies humeralhead
INFRASPINATUS-medial2/3 of infraspinatus fossa
Greater tubercle
Suprascapular nerve[c5,6]
Lateral rotator of arm
TERES MINOR-Upper2/3 of dorsal surface of scapula
Greater tubercle
Axillary nerve[c5,6]
Lateral rotator of arm
SUBSCAPULARIS-medial 2/3 of subscapular fossa
Lesser tubercle
Upper ,lower subscapular N
Medial rotator and adductor of arm
BICEPS-Short head-tip of coracoidLong head-supraglenoid
Radial tuberosity of posteriorly
Musculocutaneous nerve[c5,6]
Strong supinator when forearm flexedFlexor of elbowShort head-arm flexorLong head-prevents upward displacement
• Table of page 143 chaurasia
MUSCLE ORIGIN INSERTION NERVE SUPPLY ACTION
PECTORALIS MAJORAnt surface of claviclAnt manubrium[ant lamina]2nd-6th coastal cartilageExternal oblique abdominus aponeurosis[post lamin]
Bilaminar tendon on lateral lip.two lamina are continous Fibres from sternum and aponeurosis are twisted and inserted
Medial and lateral pectoral nerve
Adduction and medial rotation of shoulderClavicular-arm flexorSternoclavicular part-extension of flexed arm against resistance
LATTISMUS DORSI-Outer lip of iliac crest post 1/3rd
Posterior layer of lumbar fasciaT7-12 spinous processLower 4ribsInf angle scapula
Winds round lower border of teres major and forms posterior axillary foldTendon is twisted upside down insert into intertubercular sulcus of humerus
Thoracodorsal nerve[c6,7,8]
Adduction,extension,medial rotation of shoulderHelps in voilent expiratory effortClimbing muscleHolds inferior angle of scapula in place
TERES MAJOR-Lower 1/3rd of dorsal surface of lateral and inferior angle scapula
Medial lip of bicipital groove
Lower subscapular nerve[c5,6]
Medial rotator and adductor arm
MUSCLE INSERTIONS ON HUMERUS
scapula
Serratus anterior insertion
Dorsal aspect of scapula
MUSCLE ORIGIN INSERTION NERVE SUPPLY ACTION
SERRATUS ANTERIOR-8digitations of upper 8ribs
Coastal surface of scapula medial border1st digitation sup angle to root of spineNext two-medial borderLower 5-inferior angle
Nerve to serratus anterior c5,6,7
Pulls scapula forward around chest wall to protract limbInf fibres-pull it forward and rotate Steadies scapulaForced inspiration
TRAPEZIUS-Medial 1/3 of superior nuchal lineExternal occipital protuberanceLigamentum nuchaeC7 spineT1-12 spines
Upper fibres-posterior border of clavicle lat 1/3Middle fibres-medial margin acromian and upper lip crest of spine of scapula
Spinal part of accesory nerve-motorC3,4-proprioceptive
Upper fibres[+LS]-elevate scapulaMiddle fibres[+R]-retract scapulaLower fibres[+SA]-rotate scapula forwards ;arm abductio beyond 90*Steadies scapula
RHOMBOIDES MINOR-Ligamentum nuchaeSpines c7-T1
Base of triangular area at root of spine of scapul
Dorsal scapular nerve[c5]
Retraction of scapula
RHOMBOIDES MAJOR Medial border of scapula below of root of spine
Dorsal scapular nerve[c5]
Retraction of scapula
LEVATOR SCAPULA
MUSCLE ORIGIN INSERTION NERVE ACTION
LEVATOR SCAPULA-Transverse process of c1,2Posterior tubercles of transverse process of c3,4
Superior angle and upper part of medial border of scapula
Branch of dorsal scapular nerve[c5]
Elevation of scapulaSteadies scapula during arm movements
MOVEMENTS AROUND SHOULDER• Shoulder movements occur by coordinated
motions of –1. Clavicular and sternoclavicular2. Acromioclavicular motion3. Scapulothoracic motion4. Glenohumeral motion
CLAVICULAR AND STERNOCLAVICULAR MOTION• At sternoclavicular joint,clavicle rises slow and
steadiely 30* with 90* of arm elevation• Clavicular protraction ,retraction also occurs• the clavicle rotates 45* on its long axis during
elevation of arm to full overhaed position180*. ACROMIOCLAVICULAR MOTION• It provides only two small arcs of motion about
15* during first and last 40* of arm elevation.• Clavicular rotation is essential for terminal arc
mobility of acromioclavicular joint
SCAPULOTHORACIC MOTION• Its not a true joint but scapula glides freely on the
loose aereolar tissue between two surfaces• Direction of movement described by acromian
motion and sternoclavicular joint integrity
• Rotation of scapula is facilitated by sternoclavicular and acromioclavicular joints
SCAPULA MOVEMENTS• Elevation - moving the superior border of the scapula and the
acromion in an upward direction.• Depression - moving the superior border of the scapula and
the acromion in an downward direction.• Upward Rotation - Moving the scapula so that the glenoid
cavity faces upward.• Increases the ranges of motion during abduction and/or
flexion of the shoulder.• Downward Rotation - moving the scapula so that the glenoid
cavity faces inferiorly.• Increases range of motion during extension and / or
adduction of the shoulder.• Protraction ( Abduction)- moving the scapula away from
midline• Retraction (Adduction) - moving the scapula toward midline
SCAPULOTHORACIC MOTIONMOVEMENT MUSCLE
VERTICAL PLANEELEVATION
Upper fibres of trapeziusLevator scapulae
Infero lateral compartment
DEPRESSION Lower fibres of serratus anterior and p.minor
Infero lateral compartment
HORIZONTAL PLANEPROTRACTION-moving away from vertical spine
Serratus anterior and pectoralis minor
Superomedial compart.Seen in pushing or punching actions
RETRACTION-moving towards vertical spine
Rhomboides and middle trapezoid fibres
Superomedial compart.seen in squarring of shoulders
FORWARD ROTATION-occurs in arm over head abduction
Trapezius upper fibresSerratus ant lower fibres
Inferolateral compartment
BACKWARD ROTATION Rhomboides and levator scapula
Inferolateral compartment
GLENOHUMERAL MOTION• Arm elevation is classified by its plane of action• Flexion ,extension in SAGITTAL PLANE• Abduction adduction in CORONAL/FRONTAL PLANE• Medial and lateral rotations with a midflexed elbow• CIRCUMDUCTION-combination of different
movements by which arm moves in circle
MOVEMENTS OF THE GLENOHUMERAL JOINT – Movements of the shoulder joint (glenohumeral
joint) usually involve moving the humerus on the scapula.
– All movements are to be studied starting from the ANATOMICAL POSITION
– Axis of motion• Flexion - Extension
– Coronal axis through head of humerus
• Abduction /Adduction– Sagittal axis through humeral head
• Rotation– Longitudinal axis through shaft of humerus
SHOULDER MOVEMENTS
FLEXION
FLEXIONEXTENSION
ADDUCTIONABDUCTION
• MEDIAL ROTATION LATERAL ROTATION
• Flexion moving the humerus forward and upward in the sagittal plane.• Extension - bringing the arm down to the side in the sagittal plane.• Abduction - moving the arm in the coronal plane away from the midline
– Stage-initiate -supraspinatus 15*-90*- deltoid 90*-180* - deltoid with upward rotation of scapula
• Adduction - moving the arm in the coronal plane towards the midline.• Inward Rotation - rotating the arm in a transverse plane so that the
anterior surface of the bone turns inward.• Outward Rotation - rotating the arm in a transverse plane so that the
anterior surface of the bone turns outward.
MOVEMENTS MAIN MUSCLE ACCESSORY MUSCLE
FLEXION0-135*
PECTORALISMAJOR(clavicular part)DELTOID ant fibres
CoracobrachialisBiceps short head
EXTENSION45-60*
DELTOID post fibresLATISSMUS DORSI
Teres majorTriceps long headP major[sternocoastal head]
ADDUCTION PECTORALIS MAJORLATISSMUS DORSIBICEPS long headTRICEPS short head
Teres majorcoracobrachialis
ABDUCTION SUPRASPINATUS[0-15*]DELTOID[15*-90*]SERRATUS ANTERIOR[90*-180*]TRAPEZOIDupper,lower fibres[90-180]
MEDIAL ROTATION[INTERNAL]90*
PECTORALIS MAJORDELTOID ant fibresLATISSMUS DORSITERES MAJOR
subscapularis
LATERAL ROTATION[EXTERNAL]70*-90*
DELTOID posterior fibresINFRASPINATUSTERES MINOR
PRINCIPLE MUSCLES ACTING ON SHOULDER
• Scapulohumeral Rhythm-Coordinated movements of the scapula and the humerus increasing the range of motion at the glenohumeral joint– Most noticeable during complete flexion and
abduction of the shoulder– 2 * of humeral abduction is associated with 1* of
scapula rotation
• Humerus and scapula move in 2:1 ratio during abduction
• For every 15* of elevation 10* occur at shoulder joint and 5* by scapular movements
• ABDUCTION-• Humeral head permits only upto 90*• By scapula rotaion making glenoid cavity facing
ouwards the abduction range increased to 180• This is brought about serratus anterior and trapezius
REFERENCES• Text book of upperlimb-chaurasia• Operative orthopaedics-campbell• Hand book of fractures-zuckerman• Manual of clinical surgery-Das