The presentation describes the anatomy of shoulder joint-articular surfaces, ligaments,relations,movements,muscles producing movements,bursae in relation to it and applied anatomy of the joint
2. LEARNING OBJECTIVES
1. To enumerate the shoulder joint complex or components of
Gleno-humeral articulations
2. To learn the type/variety of shoulder joint and its constituent
bones
3. To know about the ligamentous support of the joint
4. To describe bursae in relation to the joint
5. To learn about relations of the joint
6. Movements & muscles producing movements at the joint
7. Factors providing stability to the joint
8. To discuss the clinical conditions affecting the joint.
4. 2. TYPE & ARTICULAR SURFACES
DEFINITION: It is a joint between the head of humerus &
glenoid cavity of scapula.
It is an incongruent joint (least stable) but most movable joint.
TYPE: MULTIAXIAL ,BALL AND SOCKET variety of
SYNOVIAL JOINT
ARTICULAR SURFACES:
large round head of humerus & Shallow glenoid cavity of
scapula
The cavity is deepened by Glenoid labrum , a fibro-
cartilaginous ring attached to its margin. Superiorly the
labrum is continuous with the tendon of long head of biceps
brachii
8. 3. (i)FIBROUS CAPSULE
Surrounds the glenohumeral
joint
Medially attached to the
margin of glenoid cavity
beyond the attachment of
glenoid labrum (enclosing the
origin of long head of biceps
brachii)
Laterally attached to the
anatomical neck of the
humerus, except inferiorly
here it extends 1.5 cm
downwards on the surgical neck
of the humerus.
9.
10. The synovial membrane lines the inner surface of the
fibrous capsule.
It reflects from glenoid labrum to humerus as far as the
articular margin of head.
It forms a tubular sheath over the long head of biceps
brachii, in the bicipital groove.
It communicates with subscapular and infraspinatus bursae
around the joint.
Three deficiencies in synovial membrane:
1. Inferiorly at inter-tubercular aperture for passage of long
head of biceps brachii
2. Another opening inferior to coracoid process to allow
communication with the subscapular bursa
3. Deficiency posteriorly to communicate with infraspinatus
bursa
14. 3. (iii) CORACOHUMERAL LIGAMENT
From base
of
Coracoid
process to
the
anterior
part of
greater
tubercle
15. 3.(iv)TRANSVERSE HUMERAL LIGAMENT
3.(v) CORACO-ACROMIAL LIGAMENT
Transverse band of fibres bridging the gap between
greater & lesser tubercle
Fibres running between acromion process and coracoid
process.
Protects & supports the superior part of fibrous capsule
16. 4. BURSAE AROUND THE JOINT
1. Subscapular bursa
2. Subacromial bursa
3. Infraspinatus bursa
Subacromial or subdeltoid bursa
22. 6.b)MUSCLES PRODUCING MOVEMENTS
MOVEMENT MUSCLE PRODUCING
FLEXION P.MAJOR, DELTOID,
BICEPS,
CORACOBRACHIALIS
EXTENSION DELTOID, LD,T.MAJOR,LONG
HEAD TRICEPS
ADDUCTION P.MAJOR,LD,T. MAJOR
ABDUCTION DELTOID,
SUPRASPINATUS,SA,TRAPEZI
US
MEDIAL ROTATION SUBSCAPULARIS,P.MAJOR
LATERAL ROTATION DELTOID,INFRASPINATUS,
T.MINOR
23. MECHANISM OF ABDUCTION
Total range= 180 degree
0-90 degree occurs at shoulder joint
90-120 degree occurs only if head of humerus is
rotated laterally
More than 120 degree occurs with rotation of
scapula.
24. 7. FACTORS PRODUCING STABILITY
1. ROTATOR CUFF
2. CORACOACROMIAL ARCH
3. LONG HEAD OF BICEPS TENDON
4. GLENOID LABRUM
26. also called as musculotendinous cuff
Composed of SITS muscle
supraspinatus fuses superiorly
Infraspinatus & teres minor fuses posteriorly
Subscapularis fuses anteriorly
It stabilizes the joint
Its function is to grasp the head of the humerus
& hold it against the shallow glenoid cavity
27. CLINICAL ANATOMY
1. The joint is most the most commonly dislocated joint in
the body-
due to incongruent articular surface & laxity of joint
capsule.
2. It is commonly dislocated inferiorly- stability of joint is
dependent on surrounding muscles. Since it is least
supported inferiorly, rest all surfaces are taken care by the
SITS muscle ( musculotendinous cuff). The head of
humerus on dislocation can be felt beneath the anterior
axillary fold.
3. Damage to axillary nerve (surgical neck) usually
accompanies the inferior dislocation.
28.
29. 4.Frozen shoulder- presents as pain and uniform
limitation of movements at the joint. Occurs due to
shrinkage of capsule ; adhesive capsulitis.
5.Painful arc syndrome- it is a condition
characterize by pain in shoulder region and Arm
during abduction in mid range (60-120 degrees).
There is no pain in initial and last phases of
abduction.
Occurs due to sub acromial bursitis and /or
calcification of tendon of supraspinatus.
6. Recurrent dislocation –anterior dislocation