This document discusses the radiological anatomy of the upper limb joints, including the shoulder, elbow, and wrist. It provides detailed descriptions of the bones, joints, ligaments, and other structural aspects of the anatomy of these regions based on plain radiography, ultrasound, CT, MRI, and other imaging modalities. The shoulder is described as having 3 bones (humerus, scapula, clavicle), 3 joints (glenohumeral, acromioclavicular, sternoclavicular) and discussions of related structures. Details are also provided on the elbow and wrist joints, articulations, ligaments, compartments and osseous anatomy.

1. Radiological anatomy of the upper limb joints.
Dr/ ABD ALLAH NAZEER. MD.

2. Radiological imaging of the upper limb joints:
1- Plain X-Ray.
2- Ultrasonography.
3- Computerized tomography
(CT Scan).
4- Magnetic resonance imaging
(MRI) study.

3. Anatomy of the Shoulder.
The shoulder comprises bones, ligaments, tendons, and muscles that connect the
arm to the torso. The three bones that make up the shoulder joint include the
clavicle (collarbone), scapula (shoulder blade), and humerus (long bone of the
arm). The shoulder has two joints that work together to allow arm movement.
The acromioclavicular (AC) joint is a gliding joint formed between the clavicle and
the acromion. The acromion is the projection of the scapula that forms the point
of the shoulder. The AC joint gives us the ability to raise the arm above the head.
The glenohumeral joint, or shoulder joint, is a ball-and-socket type joint. The
"ball" is the top, rounded part of the humerus, and the "socket" is the bowl-
shaped part of the scapula, called the glenoid, into which the ball fits. This joint
allows the arm to move in a circular rotation as well as towards and away from
the body.
The labrum is a piece of cartilage that cushions the humerus head and the
glenoid. This cartilage also helps to stabilize the joint. The rotator cuff is a group
of four muscles that pull the humerus into the scapula. The rotator cuff muscles
stabilize the glenohumeral joint and help with rotation of the arm.
Two sac-like structures called bursae are also located in the shoulder. The bursae
secrete a lubricating fluid, which helps reduce friction between the moving parts
of the joint. Together, all of these structures create one of the most flexible joints
in the body.

4. The glenohumeral joint is the main joint of the shoulder and the generic
term "shoulder joint" usually refers to it. It is a ball and socket joint that
allows the arm to rotate in a circular fashion or to hinge out and up away
from the body. It is formed by the articulation between the head of the
humerus and the lateral scapula (specifically-the glenoid fossa of the
scapula). The "ball" of the joint is the rounded, medial anterior surface of
the humerus and the "socket" is formed by the glenoid fossa, the dish-
shaped portion of the lateral scapula. The shallowness of the fossa and
relatively loose connections between the shoulder and the rest of the body
allows the arm to have tremendous mobility, at the expense of being much
easier to dislocate than most other joints in the body. Approximately its 4
to 1 disproportion between the large head of the humerus and the shallow
glenoid cavity. The capsule is a soft tissue envelope that encircles the
glenohumeral joint and attaches to the scapula, humerus, and head
of the biceps. It is lined by a thin, smooth synovial membrane.
Joints:
There are three joints of the shoulder: The glenohumeral, acromioclavicular, and
the sternoclavicular joints.

5. This capsule is strengthened by the coracohumeral ligament which attaches the
coracoid process of the scapula to the greater tubercle of the humerus. There are
also three other ligaments attaching the lesser tubercle of the humerus to lateral
scapula and are collectively called the glenohumeral ligaments.
There is also a ligament called semicirculare humeri which is a transversal band
between the posterior sides of the tuberculum minus and majus of the humerus.
This band is one of the most important strengthening ligaments of the joint
capsule.
Sternoclavicular joint:
The sternoclavicular occurs at the medial end of the clavicle with the manubrium
or top most portion of the sternum. The clavicle is triangular and rounded and the
manubrium is convex; the two bones articulate. The joint consists of a tight
capsule and complete intra-articular disc which ensures stability of the joint. The
costoclavicular ligament is the main limitation to movement, therefore, the main
stabilizer of the joint. A fibrocartilaginous disc present at the joint increases the
range of movement. Sternoclavicular dislocation is rare, but may result from
direct trauma to the clavicle or indirect forces applied to the shoulder. Posterior
dislocations deserve special attention, as they have the potential to be life-
threatening because of the risk of damage to vital structures in the mediastinum.

6. Anatomy.
• 3 Bones
– Humerus.
– Scapula.
– Clavicle.
• 3 Joints
– Glenohumeral.
– Acromio-clavicular.
– Sternoclavicular.
• 1 “Articulation”
– Scapulothoracic.

7. • Humerus
– Head.
– Anatomic neck.
– Surgical neck.
– Greater tubercle.
– Lesser tubercle.
– Intertubercular
groove.
– Deltoid tuberosity.
– Shaft.

8. • Scapula
– Body
• Ventral (Costal) surface
• Dorsal surface
– Borders
• Superior
• Lateral (Axillary)
• Medial (Vertebral)
– Angles
• Superior
• Inferior
• Lateral (Head)

9. • Scapula
– Glenoid
– Acromion
– Coracoid
– Subscapular fossa
– Scapular spine
– Supraspinatus fossa
– Infraspinatus fossa
– Great scapular notch
– Suprascapular notch

10. • Scapular “Y” (Lateral).

11. AP View of the Shoulder.
• “Routine” AP View
– Clavicle
– Scapula
• Acromion & scapular
spine
• Coracoid
• Borders & angles
– AC & SC joints
– Glenoid
• Both ant & post lips
• May obscure HH
– Humerus
• Head & necks
• Gr & Lsr tuberosities

12. AP View of the Shoulder.
• “Glenohumeral,”
“Grashey,” or
“Scapular” AP View
– Same structures
– AC joint not visualized
as well
– Better visualize the
glenoid & humeral head
(especially with ER view)

13. AP View of the Shoulder
• AP View in External
Rotation
– Greater tuberosity &
soft tissues profiled and
better visualized
– Best w/ Scapular AP
• AP View in Internal
Rotation
– May demonstrate Hill-
Sachs lesions
• GH instability
– Best w/ Routine AP

14. Axillary Lateral View of the Shoulder.
• Good view of
anterior-posterior
relationship of GH
joint
• Coracoid
• Acromion
• Humerus
• Glenoid
• GH joint

15. Scapular “Y” Lateral View of the Shoulder.
• Relationship b/w
humeral head and
glenoid.
• Acromion.
• Coracoid.
• Scapular body.
• Scapular spine.

16. Ultrasonography.

48. Glenohumeral Joint
1- Anterior labrum
2- Subscapularis
3- Infraspinatus
4- Posterior labrum
5- Humerus
6- Glenoid cavity

55. CT and MR Arthrography of the Normal shoulder.
Normal biceps tendon in CT and transverse MR arthrogram.

56. Normal superior glenohumeral ligament. Sagittal fat-saturated T1- weighted MR
arthrogram shows the biceps tendon (t), subscapularis tendon (S), middle glenohumeral
ligament (open arrows), and superior glenohumeral ligament (solid arrow).

57. Normal middle glenohumeral ligament in transverse fat-saturated MR and CT arthrogram

58. Normal inferior glenohumeral ligament. Sagittal fat-saturated T1- weighted MR & CT arthrogram

59. Elbow Joint:
The elbow is a complex synovial joint formed by the articulations of the humerus , the
radius and the ulna .
Gross Anatomy
Articulations. The elbow joint is made up of three articulations:
radiohumeral: capitellum of the humerus with the radial head
ulnohumeral: trochlea of the humerus with the trochlear notch (with separate olecranon
and coronoid process articular facets) of the ulna
radioulnar: radial head with the radial notch of the ulna (proximal radioulnar joint )
In full flexion, the coronoid process is received by the coronoid fossa and the radial head is
received by the radial fossa on the anterior surface of the humerus and in full extension the
olecranon process is received by the olecranon fossa on the posterior aspect of the
humerus
Ligaments
medial (ulnar) collateral ligament complex
lateral (radial) collateral ligament complex
oblique cord
inconstant thickening of supinator muscle fascia and functionally insignificant
runs from tuberosity of the ulna to just distal to radial tuberosity
quadrate ligament (of Denuce)
thickening of the inferior aspect of the joint capsule
runs from just inferior to the radial notch of the ulna to insert to the medial surface of
the radial neck

60. Joint capsule
The joint capsule has two layers, deep and superficial, and attaches proximally to the
radial, coronoid and olecranon fossae. Distally, it attaches to the annular ligament of
the radius and coronoid process of the ulna . The volume of the joint capsule is 24-
30mL.
Fat pads
There are three fat pads of the elbow, which sit between the two layers of the joint
capsule, making them extra-synovial:
coronoid fossa fat pad (anterior)
radial fossa fat pad (anterior)
olecranon fossa fat pad (posterior)
Bursae
superficial olecranon bursa: lies between the olecranon and the subcutaneous tissue
subtendinous olecranon bursa: lies between olecranon and triceps brachii tendon
intratendinous olecranon bursa: variably lies in the triceps brachii tendon
bicipitoradial bursa
Relations
anteriorly: biceps brachii tendon; brachialis muscle , median nerve , brachial artery
posteriorly: olecranon bursae, triceps brachii tendon
laterally: common extensor tendon ; supinator muscle
medially: ulna nerve.

61. Adult Elbow - AP View

62. Adult Elbow - Oblique View.

63. Adult Elbow - Lateral View.

64. Adult Elbow - Lateral Radial Head View, in 10 years old.

65. Normal elbow X-ray in 10 years old.

66. Normal elbow X-ray – AP & Lateral Views in 10 years old.

67. Elbow Ultrasound.
For examination of the anterior elbow, the patient is seated facing
the examiner with the elbow in an extension position over the table.
The patient is asked to extend the elbow and supinate the forearm.
A slight bending of the patient’s body toward the examined side
makes full supination and assessment of the anterior compartment
easier. Full elbow extension can be obtained by placing a pillow
under the joint. Transverse US images are first obtained by sweeping
the probe from approximately 5cm above to 5cm below the
trochlea-ulna joint, perpendicular to the humeral shaft. Cranial US
images of the supracondylar region reveal the superficial biceps and
the deep brachialis muscles.
Along side and medial to these muscles, follow the brachial artery
and the median nerve:
the nerve lies medially to the artery.

68. a, brachial artery; arrow, median nerve; arrowheads, distal biceps tendon; asterisks,
articular cartilage of the humeral trochlea; Br, brachialis muscle; Pr, pronator muscle.

69. arrows, distal biceps tendon; asterisk, coronoid fossa and anterior fat pad; Br,
brachialis muscle; HC, humeral capitellum; RH, radial head; s, supinator muscle

70. arrow, brachialis tendon; arrowheads, anterior coronoid recess; asterisks,
articular cartilage of distal humeral epiphysis; Br, brachialis muscle; curved
arrow, anterior fat pad; HC, humeral capitellum; HTr, humeral trochlea.

71. arrow, posterior interosseous nerve; arrowhead, cutaneous sensory branch of the
radial nerve; Br, brachialis muscle; Br Rad, brachioradialis muscle; curved arrow,
main trunk of the radial nerve; RH, radial head; RN, radial neck; s1, superficial
head of the supinator muscle; s2, deep head of the supinator muscle.

74. arrow, ulnar nerve; asterisk, triceps tendon; ME, medial epicondyle; O, olecranon
process; void arrowhead, ulnar head of the flexor carpi ulnaris muscle; white
arrowhead, humeral head of the flexor carpi ulnaris muscle; 1, cubital tunnel
retinaculum (Osborne ligament); 2, arcuate ligament; 3, flexor carpi ulnaris muscle

80. Magnetic resonance imaging (MRI)
provides excellent delineation of the bones of the elbow and the
surrounding soft tissue structures. The components of the elbow can be
divided into osseous structures, the joint capsule and ligaments,
muscles and tendons, and nerves. In this article, the authors review the
normal anatomy and the appearance of these structures on MRI as
well as the anatomic variants that should be recognized and
distinguished from pathologic entities.
The elbow is a joint consisting of three separate articulations with
various structures providing stability in which the anterior bundle of
the ulnar collateral ligament on the medial side and lateral ulnar
collateral ligament on the lateral side play important roles. With its
superior evaluation of soft tissues, MRI provides excellent evaluation of
the osseous and neuromuscular structures. Precise understanding of
the imaging anatomy of the elbow and its normal variants is important
in the diagnosis and management of diseases of the elbow joint.

129. Radiological anatomy of the wrist.
Osseous Anatomy
The osseous structures of the wrist are the distal portions of the radius and ulna, the
proximal and distal rows of carpal bones, and the bases of the metacarpals. The
proximal row of carpal bones consists of the scaphoid, lunate, triquetrum, and the
pisiform. The distal row of carpal bones contains the trapezium, trapezoid, capitate,
and hamate bones. The distal row of bones articulates with the metacarpal bases. The
bases of the metacarpals articulate with the distal row of carpal bones and with each
other. The proximal carpal row is termed an intercalated segment because forces
acting on its proximal and distal articulations determine its position. This aspect of the
osseous anatomy becomes important when considering the pattern of collapse that
occurs in the different types of wrist instability.
Articular Compartmental Anatomy The wrist joint is separated into a number of
compartments by the many ligaments that attach to the carpal bones. These
compartments are of considerable significance for the interpretation of standard or
MR arthrogram and for identifying various patterns of arthritic involvement.
The compartments are as follows:
1. Radiocarpal compartment, 2. Midcarpal compartment, 3. Pisiform-triquetral
compartment, 4. Common carpometacarpal compartment, 5. First carpometacarpal
compartment, 6. Intermetacarpal compartments, 7. Inferior (distal) radioulnar
compartment.

130. Ligamentous Anatomy.
The ligaments of the wrist have been classified into intrinsic ligaments
because they arise and insert on carpal bones and extrinsic ligaments because
they connect the distal portion of the radius and the carpal bones. Two
intrinsic ligaments join the bones of the proximal carpal row, the
scapholunate interosseous ligament (joining the proximal surfaces of the
scaphoid and lunate) and the lunotriquetral interosseous ligament (joining
the proximal surfaces of the lunate and triquetrum). These ligaments connect
the bones from their palmer to dorsal surfaces. The intrinsic scapholunate
ligament complex and the lunotriquetral complex each consist of dorsal,
palmar, and proximal (membranous) components. When intact, they separate
the radiocarpal and midcarpal compartments of the wrist.
The ulnar ligamentous complex (ulnocarpal ligaments) is largely synonymous
with the triangular fibrocartilage complex (TFCC), comprising the triangular
fibrocartilage (TFC) proper (the articular disk) and the dorsal radioulnar
ligament, volar radioulnar ligament, ulnolunate ligament, ulnotriquetral
ligament, ulnar collateral ligament, and the meniscus homologue.4 The
literature includes the sheath of the extensor carpi ulnaris tendon in the
description of the TFCC.

151. Computerized Tomography (CT).
As with plain radiography and arthrography, CT employs ionizing radiation. It allows
three-dimensional visualization of the carpal bones and provides soft tissue detail.
Helical CT, also known as spiral CT, is a form of three-dimensional imaging that also
uses ionizing radiation. Its major advantage over conventional CT is the rapidity with
which it can image large areas. However, relative to conventional CT, spiral CT
produces an image which is less sharp. Because the wrist and hand have relatively
small anatomic areas and because a high degree of detail is required for accurate
assessment, conventional CT is often more practical than spiral CT for evaluation of
wrist/hand trauma. As in other anatomic regions, transaxial CT imaging of one or
both wrists may be performed. Images are obtained while the patient is prone and
with arm(s) stretched above the head. Because of the size and flexibility of the wrist,
it is possible to obtain direct scans of the wrist in the coronal and sagittal planes. (CT
scans acquired directly are sharper than reconstructed images and therefore easier to
interpret.) With the patient prone, the elbow in 90[infinity] of flexion above the
patient's head, and the palm face down on the CT table, direct sagittal scans may be
acquired through the symptomatic wrist. If the patient's palm is rotated 90[infinity] to
face the patient's head, direct coronal scans of the symptomatic wrist may be
acquired. Last, in the trauma setting, CT images may be acquired in one additional
plane, specially designed to assess the scaphoid. Images obtained in the sagittal
oblique plane are taken along the long axis of the scaphoid. The scan is performed
with the ulnarly-deviated wrist prone against the table.

171. Magnetic resonance (MR) imaging
is the optimal modality for characterizing the ligaments, tendons,
muscles, and neurovascular structures of the wrist joint.
Continued refinement in pulse sequence
and coil design permits high-resolution examination of the many
small structures and complex anatomy of this region. Frequent
anatomic variants and common false positives such as normal
areas of high signal intensity in ligaments and tendons must be
recognized to avoid misdiagnosis and improper treatment.
MR imaging has provided us with new insights into the difficult
anatomy of the wrist by allowing improved visualization of the
relationship of the muscles, ligaments , tendons and bone.
Its multiplaner and exquisite soft tissue contrast capabilities
allow for the depiction of the subtle osseous and soft tissue
pathology.

199. Normal osseous anatomy.
Sagittal T2-weighted image
with fat saturation shows
normal relationship between
the radius (R), lunate (L),
capitate (C), and the base of
third metacarpal.3 dditional
structures shown: dorsal
intercarpal ligament (di), dorsal
radiocarpal ligament (drc),
radioscaphocapitate ligament
(rsc), short radiolunate ligament
(srl), flexor retinaculum (fr),
flexor digitorum superficialis
(fds), flexor digitorum profundus
(fdp), and pronator quadratus
muscle (p).

200. Volar ligaments. (A) Sagittal T2-weighted image with fat saturation shows
radioscaphocapitate (rsc) and short radiolunate (srl) ligaments. Capitate
(C) and lunate (L) are labeled. (B) Coronal GRE image shows
radiolunotriquetral (rlt) and radioscaphocapitate (rsc) ligaments.

201. Thank You.