PMR PG Teaching

1. Dr. S. K. Agrawal
Senior Professor & Head of the Department
Department of Radiodiagnosis & Modern Imaging
SMS Medical College, Jaipur
RADIOGRAPHIC EVALUATION OF THE
SHOULDER

2. INTRODUCTION
• There are many modern modalities available to evaluate to shoulder joint ie.
HR usg, CT scan & MRI. Specially usg & MRI are very useful.
• Plain Xray of shoulder is very important to evaluate to startwith..
• Accurate interpretation of shoulder radiographs can give many diagnosis, can
obviate the need for additional imaging & it gives baseline information before going
to other modility..

3. RADIOGRAPHIC TECHNIQUE
• Proper radiographic technique and positioning is important to understand the normal
appearances which can direct us the various abnormalities & diseases.
• A shoulder radiograph series may be needed for a particular condition, such as for
evaluation of arthritis, trauma, instability, or impingement.
• Additional views may be obtained in the search for specific abnormalities depending
on the clinical situation and area of concern.

4. SHOULDER IMAGING FOR VARIOUS CONDITIONS*
* Goud et al. Radiographic evaluation of the shoulder
European Journal of Radiology 68(2008) 2-15

5. SHOULDER RADIOGRAPH PROJECTIONS

6. RADIOGRAPHIC PROJECTIONS OF SHOULDER
ANTEROPOSTERIOR (AP) VIEW
ROCKWOOD VIEW
GRASHEY VIEW
AXILLARY VIEW
WEST POINT VIEW
SCAPULAR Y VIEW
SUPRASPINATUS OUTLET VIEW
STRYKER NOTCH VIEW

7. I. ANTEROPOSTERIOR (AP) VIEW
• The anteroposterior (AP) view is a key component of a basic shoulder series.
• Often, two AP projections are obtained:
• With the arm in external rotation: , the humeral head has the appearance of an
Indian axe.
• With the arm in internal rotation: the humeral head has the appearance of an
ice-cream cone.
• Since the glenohumeral joint is normally anatomically tilted 35–40 degree anteriorly,
this projection results in overlap of the glenoid and humeral head.
• These views allow for excellent visualization of the glenohumeral joint,
acromioclavicular (AC) joint, and the adjacent osseous structures including the distal
clavicle and scapula and thus are very helpful in the setting of acute trauma to
evaluate for fracture or dislocation and can also demonstrate abnormalities in the
setting of chronic shoulder pain, including calcific tendonitis or bursitis, and AC joint
arthritis.

8. ANTEROPOSTERIOR (AP) VIEW
• The AP projection is usually obtained with the patient in the upright or supine position
and with the coronal plane of the body parallel to the cassette.
• The beam is directed in a true AP direction relative to the body.
• This results in slight overlap of the glenoid rim and the humeral head as the
glenohumeral joint is tilted anteriorly approximately 40°.
• The lateral border of the scapula and the medial cortex of the proximal humerus form
a gentle, smooth convex arch, known as scapulohumeral or Moloney’s arch.

9. The beam is oriented in true AP view to the patient with the arm positioned in either neutral, internal, or
external rotation. The beam is centered on the coracoid process with the blade of the scapula
parallel to the film.

10. AP external rotation. There is overlap of the humeral head and the glenoid (ellipse). The anterior
(arrow) and posterior (thick dashes) margins of the glenoid are seen. The greater tuberosity (G) is
seen in profile. The acromiohumeral distance (line) is normal (>7 mm).

11. AP internal rotation. The humeral head is round in appearance with a smooth posterior contour. The
fat along the subacromial-subdeltoid bursa is seen as a lucent crescent (arrowheads).

12. AP VIEW IN EXTERNAL ROTATION: NORMAL ANATOMY
Moloney’s arch

13. II. ROCKWOOD VIEW
• The Rockwood view (AP with caudal angulation of the X-ray beam) is utilized in the
impingement series to evaluate the acromion and subacromial space.
• Angling the X-ray tube caudally or tilting the patient forward provides improved
visualization of the subacromial space.

14. ROCKWOOD VIEW
The Rockwood view is a modified AP view taken with 30 degree caudal angulation.

15. ROCKWOOD VIEW
Normally, a line (dashed) along the inferior aspect of the clavicle intersects the undersurface of the
acromion. Areas of bony prominence or osteophytes will extend below this line.

16. III. GRASHEY VIEW
• The Grashey view is a true anterior–posterior view of the shoulder.
• The overlap between the humerus and the glenoid seen on the AP view is removed
in the Grashey projection by rotating the patient posteriorly or angling the beam
laterally.
• The Grashey view is thus a true AP view of the shoulder joint and allows for better
evaluation of the glenohumeral cartilage space, joint congruity, and humeral head
subluxation.
• The addition of abduction and a weight provides an axial load to the shoulder joint
that may increase the ability to demonstrate articular cartilage loss.

17. The X-ray beam is tilted 45 degree laterally from the standard AP view. Alternatively, as shown
here, the patient may be rotated 45 degree towards the affected shoulder.
GRASHEY VIEW

18. GRASHEY VIEW
The glenohumeral joint is seen in profile (arrows) without overlap of the humerus and glenoid.

19. GRASHEY VIEW : NORMAL ANATOMY

20. IV. AXILLARY VIEW
• The axillary view is obtained with the patient supine and the arm abducted 90°.
• The beam is centred over the mid-glenohumeral joint and is directed in a distal-to-
proximal direction while tilted approximately 15° to 30° toward the spine.
• This results in a tangential view of the glenohumeral joint from below.
• Axillary view is an excellent method for evaluating for anterior or posterior
glenohumeral subluxation or dislocation and may also be helpful in the detection of
an osseous Bankart fracture involving the anterior glenoid rim.
• The radiographic quality is often very limited because of the rapid change of
overlying soft-tissue density.

21. AXILLARY VIEW
The axillary projection is obtained with the patient in the supine position and the arm placed in 90
degree of abduction. The angle of the Xray beam is approximately 30 degree towards the spine, with
the beam centred on the middle of the glenohumeral joint.

22. AXILLARY VIEW: NORMAL ANATOMY
The glenohumeral joint is seen in profile and is symmetrical. The humeral head is centred on
the glenoid.

23. V. WEST POINT VIEW
• The West Point View is a variation of the lateral axillary view that was developed to
improve detection of a Bankart fracture of the anterior glenoid rim.
• It is obtained by placing the patient in the prone position with the arm abducted 90°
from the long axis of the body with the elbow and forearm hanging off the side of the
table.
• The beam is directed 15° to 25° in an inferior-to-superior direction and tilted 25°
toward the spine.
• Although this projection improves detection of an osseous Bankart lesion, it can be
difficult to obtain in the setting of acute trauma.

24. WEST POINT VIEW
The patient is placed in the prone position with the shoulder resting on a cushion. The arm is abducted
90° and the patient’s forearm and hand are in pronation, hanging downwards off the edge of the table.

25. WEST POINT VIEW : NORMAL ANATOMY
The anteroinferior (arrow) portion of the glenoid is seen without overlap of the coracoid.
Glenoid
Head of Humerus

26. VI. SCAPULAR Y VIEW
• The scapular Y view is obtained with the patient upright or prone with the anterior
aspect of the affected side rotated 30° to 45° toward the cassette.
• The scapular body is seen in tangent and the glenoid fossa is seen en face as a Y-
shaped intersection of the scapular body, acromion process, and coracoid process.
• The humeral head should be centred over the glenoid fossa.
• This view can be very helpful in the setting of acute trauma to evaluate for anterior or
posterior dislocation as the patient can be imaged with little or no movement of the
arm and the projection obtains a lateral projection of the glenohumeral joint.
• This view is also useful for delineating fractures of the coracoid process, scapula,
acromion process, and proximal humeral shaft.
• The scapular Y view is also used to evaluate the contour of the undersurface of the
acromion process when “typing” the acromion.

27. SCAPULAR Y VIEW
The scapular “Y” view can be taken in the erect or supine position, in the PA direction, with the affected
shoulder rotated anteriorly 45°. The arm is positioned at the side, superimposed on the scapula.

28. SCAPULAR Y VIEW
Lines through the acromion, coracoid process, and body of the scapula intersect at the center
of the glenoid. The humeral head is centred on this intersection point.

29. SCAPULAR Y VIEW : NORMAL ANATOMY

30. VII. SUPRASPINATUS OUTLET VIEW
• The supraspinatus outlet view is useful for evaluating the acromion process and
subacromial abnormalities such as osteophytes that may cause impingement.
• It is similar to the Y-view but with caudal tube angulation.
• This view is taken with the patient turned as for the Y projection and the cassette
perpendicular to the body of the scapula and parallel to glenoid fossa.
• The X-ray is taken from a mediolateral projection along the axis of the scapular
spine, with X-ray beam angled 10–15° craniocaudally and centred on the
acromioclavicular joint.

31. SUPRASPINATUS OUTLET VIEW
This view is taken with the patient turned as for the Y projection and the cassette perpendicular to the
body of the scapula and parallel to glenoid fossa.

32. SUPRASPINATUS OUTLET VIEW: NORMAL ANATOMY
The subacromial space (arrows) and contour of the acromion (A) are well seen. The water density of
the supraspinatus muscle is shown (S).

33. VIII. STRYKER NOTCH VIEW
• The Stryker notch view can be obtained with the patient in the supine or upright
position.
• The arm is extended vertically overhead; elbow is flexed, and the hand is supported
on the back of the head.
• The beam is directed toward the mid axilla and is tilted 10° cephalic.
• This view nicely demonstrates the posterolateral aspect of the humeral head and is
excellent for depicting a Hill–Sachs deformity or flattening of the posterolateral
humeral head.
• Evaluation of glenoid rim fractures or subtle glenohumeral subluxation is limited on
this view.

34. STRYKER NOTCH VIEW
The Stryker notch view is obtained with the patient in the supine position with the arm externally
rotated and abducted and the X-ray beam angled 10° cephalad and centred on the coracoid process.
The patient’s hand supports the back of the head with the elbow pointed towards the ceiling.

35. STRYKER NOTCH VIEW: NORMAL ANATOMY

36. STRYKER NOTCH VIEW
The humeral head is normally smoothly round in appearance. A small contour defect in this case is
due to a Hill-Sachs impression fracture (arrow).

37. SPECIFIC UTILITY

38. APPROACH TO ANALYZING SHOULDER
RADIOGRAPH
• The general principles promulgated by Forrester and Nesson provide a useful
framework for evaluation of the shoulder.
• ABCs must be assessed:
 Alignment
 Bone density
 Cartilage spaces
 Soft Tissues

39. DISTURBANCE IN ALIGNMENT

40. 1. FRACTURES OF PROXIMAL HUMERUS
• Neer classification system is widely
used.
• It is a 4 segment system representing
the four anatomic components of the
proximal humerus.
• Fractures of the proximal humerus
occur between one or all of these four
major segments:
 the articular segment (at the level of
the anatomic neck)
 the greater tuberosity
 the lesser tuberosity
 humeral shaft (at the level of the
surgical neck).

41. • In minimally displaced fractures, there is no or minimal displacement between the
segments. The fragments are held together by the rotator cuff, the joint capsule, and
the periosteum.
• In a two-part fracture, there is displacement of one segment in relation to the three
non-displaced, nonangulated segments.
• In a three-part fracture there is involvement of either the lesser or greater tuberosity.
There may be anterior or posterior shoulder dislocation. The humeral head is rotated
by the pull of one of the rotator cuff tendons, which can be a source of blood supply
to the head.
• In a four-part fracture, there is involvement of both the greater and lesser
tuberosities and fracture of the surgical neck. There may be anterior or posterior
shoulder dislocation. There is typically impaired blood supply to the humeral head
due to lack of soft-tissue attachment, leading to the frequent development of humeral
head osteonecrosis.

42. Minimally displaced Neer fracture. There are fractures of the greater tuberosity and surgical neck
(arrows) but no significant displacement or angulation is present.

43. Two-part Neer fracture. Greater tuberosity (long arrow) is displaced greater than 1 cm from humeral
head fragment (short arrow), which remains in near anatomic position

44. 2. DISLOCATION OF SHOULDER
• Shoulder dislocation is the most common large joint dislocation presenting to the
Emergency Department.
• 3 types:
 Anterior shoulder dislocations are the most common, accounting for 95% of all
shoulder dislocations.
 Posterior shoulder dislocations account for less than 5% of all shoulder dislocations.
 Inferior or subglenoid dislocation (luxatio erecta) is very rare, occurring in
approximately 0.5% of cases.

45. ANTERIOR DISLOCATION
• Anterior shoulder dislocation is usually caused by trauma.
• These dislocations tend to recur, especially in young adults.
• The Bankart fracture( injury to anteroinferior part of glenoid labrum) and Hill-
Sachs deformity (posterolateral humeral head compression fracture ) have
been implicated as probable causes of recurrent shoulder dislocations.
• The characteristic feature of anterior shoulder dislocation is malposition of
the humeral head so that it lies anterior, medial and slightly inferior to the
glenoid fossa.
• This can be confirmed on the axillary view or the scapular Y-view.

46. AP view of glenohumeral joint demonstrates anterior dislocation of humeral head (arrow). Notice
that humeral head has moved medially and inferiorly and sits below coracoid process.
ANTERIOR DISLOCATION

47. (B) Axillary view and (C) scapular Y view demonstrate anterior dislocation of humeral head (arrow)
relative to glenoid fossa (arrowhead).

48. HILL SACHS LESION
• With anterior dislocation, the posterosuperior humeral head contacts the
anteroinferior glenoid rim, which may result in a wedge-shaped posterosuperior
humeral head impression fracture, termed a Hill-Sachs lesion.
• The Hill–Sachs defect is usually best depicted on the AP radiograph of the shoulder
with the arm in internal rotation and appears as an area of flattening or concavity of
the posterolateral aspect of the humeral head.
• The Stryker Notch view is also very useful in depicting a Hill–Sachs defect, whereas
the defect may be completely obscured on the axillary view or AP radiograph with
external rotation.
• Hill-Sachs lesions smaller than 20% of the articular surface are unlikely to be
clinically significant, lesions involving 20–40% have variable clinical significance, and
lesions larger than 40% are likely to contribute to recurrent dislocation.

49. (A) An internal rotation view shows the indentation (impression fracture, arrow) of the posterolateral
aspect of the humeral head. (B) The axillary view of another patient shows a Hill-Sachs lesion, (arrow)
causing deformity of the posterior humeral head. In this case the defect involves less than 20% of the
humeral articular surface. The Stryker notch view is also used to demonstrate Hill-Sachs lesions.
HILL SACHS LESION

50. BANKART LESION
• First-time dislocation in a young person (under 35 years of age) usually
results in a tear or avulsion of the anterior labroligamentous complex from
the inferior glenoid, referred to as a Bankart lesion.
• A Bankart fracture refers to an injury that includes not only an anterior labral
injury but also a fracture of the anteroinferior glenoid.
• Osseous Bankart lesions involving the inferior glenoid rim are often subtle
lesions that are best depicted on either the AP or the axillary view of the
shoulder.
• The West Point axillary view is a special adaptation of the axillary view that
was developed to accentuate detection of a Bankart lesion.

51. BANKART LESION
(A) Axillary view of glenohumeral joint demonstrates small fracture fragment (arrow) adjacent to
anterior glenoid. This fracture results from impaction injury of humeral head against
anteroinferior glenoid rim and can lead to recurrent instability of glenohumeral joint.
(B) Axial T1-weighted MR image with intraarticular gadolinium demonstrates minimally displaced
Bankart fracture (arrow).

52. POSTERIOR DISLOCATION
• Posterior dislocations are most often associated with a seizure or electrocution injury
and almost all bilateral posterior shoulder dislocations are due to a seizure.
• The mechanism of posterior shoulder dislocation is uneven muscle contraction with
the internal rotators of the shoulder contracting with greater force than the external
rotators, causing the humeral head(s) to move superiorly and posteriorly.
• Humeral head fractures can occur due to continuing pressure against the glenoid.
• The anteroposterior radiograph of the shoulder may appear nearly normal in patients
with posterior dislocation, contributing to a high misdiagnosis rate and delays in
treatment.
• The addition of axillary views raises the diagnosis rate to 100%.

53. • If axillary views cannot be obtained due to patient pain, a scapular “Y” view can be
obtained or CT, can demonstrate both the dislocation and any associated fractures.
• On the AP radiograph the humeral head is usually in internal rotation and higher than
normal. The posterior position of the humeral head can be shown on the scapular “Y”
view or axillary view.
• Often, the humeral head is subluxed, rather than completely dislocated. The anterior
humeral head can impact against the posterior glenoid rim, which can result in an
anterior humeral head impression fracture (reverse Hill-Sachs lesion, the trough
sign) and/or posterior glenoid rim fracture (reverse Bankart lesion).

54. Posterior dislocation. (A) The AP view shows the humeral head fixed in internal rotation and slightly
high in position with relation to the glenoid. An impression fracture (trough sign, arrow) is present.
(B) A rotated Y-view shows the apposition of the trough fracture line (arrows) and the posterior lip of
the glenoid. The displaced humeral head is posterior to the center of the glenoid (circle).

55. LUXATIO ERECTA
• Luxatio erecta is also called inferior or subglenoid dislocation.
• In this injury, the arm is raised, abducted and cannot be lowered.
• Causes of luxatio erecta include hyperabduction and extension during a fall and
attempting overhead shots in racket sports.
• Typical radiographic features of luxatio erecta include humeral head dislocation
inferior to the glenoid with the humerus locked in abduction.
• Associated injuries:
• 80% of the cases have associated greater tuberosity fracture or rotator cuff tear.
• 60% of the cases have some degree of neurological impairment, most frequently
to the axillary nerve.
• 3.3% of the cases have significant vascular compromise.

56. Luxatio erecta. The humeral head is displaced inferiorly and the arm is abducted.

57. Luxatio erecta. AP radiograph of shoulder demonstrates humeral head (arrow) to be displaced
directly inferiorly relative to glenoid fossa and arm is fixed in fully abducted position.

58. DISTURBANCE IN BONE DENSITY

59. AVASCULAR NECROSIS
• Common etiology:
• Post traumatic sequela
• Corticosteroid use
• Sickle cell disease.
• The typical radiographic findings of avascular necrosis depend on its stage, and can
progress through subtle lucency, sclerosis, fragmentation, sub-articular collapse, and
arthritis and joint destruction in the final stages.
• Classic descriptions of AVN include crescent-shaped sub-articular lucency (the
crescent sign) as well as the “snowcap sign” due to focal sub-articular sclerosis.

60. Avascular necrosis. This Grashey projection shows a lucency with surrounding sclerosis (arrows) in the
humeral head. In this case, there is no collapse of the humeral head and no crescent sign or cartilage
space narrowing is seen.

61. AP radiograph of shoulder demonstrates linear subchondral fracture (arrow) involving medial aspect
of subchondral bone of humeral head. Appearance and location are classic for advanced
osteonecrosis of humeral head.

62. DISTURBANCE IN CARTILAGE SPACES

63. RHEUMATOID ARTHRITIS
• The radiographic findings of RA of the shoulder consist of
 periarticular osteopenia
 marginal erosions develop at the bare area (the superolateral aspect of the
humeral head adjacent to the greater tuberosity) where articular cartilage is thin.
 uniform cartilage space narrowing in the absence of osteophytes
 subchondral sclerosis and bursitis.
• As the disease progresses, there is concentric erosion of the glenoid accompanied
by medial migration of the humeral head.
• Atrophy and tear of the rotator cuff with attendant superior migration of the humeral
head may follow and erosion and thinning of the undersurface of the acromion can
result.
• The resulting juxtaposition of the medial humeral shaft and the inferior glenoid
eventually produces a notch like defect of the humerus that predisposes to
pathologic fracture.

64. Rheumatoid arthritis. AP radiograph of shoulder demonstrates numerous marginal erosions of
proximal humerus, involving medial aspect of humeral head (arrowheads) and medial aspect of
proximal humeral shaft (long arrow). In addition, there are erosions and tapering of distal clavicle
(short arrow).

65. Rheumatoid arthritis. AP view shows deepening of the glenoid fossa owing to erosion. There is
also erosion of the humeral head

66. OSTEOARTHRITIS
• Since the shoulder is a nonweightbearing joint, primary osteoarthritis is unusual.
• Most cases of osteoarthritis are, therefore, secondary. Underlying causes include
prior trauma, systemic arthritis, chronic rotator cuff tear, congenital malformations,
and acromegaly.
• Typical of osteoarthritis are asymmetric cartilage space narrowing and osteophytes
that arise from the glenoid rim and the anatomic neck of the humerus.
• In acromegaly, the osteophytes are typically very large.
• As the articular cartilage of the glenohumeral joint deteriorates, subchondral
sclerosis and cysts develop.
• Unlike inflammatory conditions, bone density is preserved in patients with OA. In late
stages, posterior subluxation of the glenohumeral joint occurs.

67. Osteoarthritis in a patient with acromegaly. There is narrowing of the glenohumeral joint with large
osteophytes. Opacities overlying the scapula are ossified bodies in the subscapularis recess.

68. DISTURBANCE IN SOFT TISSUES

69. CALCIFIC TENDONITIS
• The shoulder is the most common site of calcific tendonitis or bursitis.
• About half of the cases involve the supraspinatus tendon.
• Radiography can localize calcification to a particular tendon and may indicate
whether the process is chronic or acute.
• Calcification within the supraspinatus tendon is seen in profile over the greater
tuberosity on radiographs obtained in external rotation.
• Because of their more posterior location, calcification in the infraspinatus or teres
minor tendons is best seen on internal rotation radiographs.
• Subscapularis calcification is located anteriorly adjacent to the lesser tuberosity and
is best seen on axillary views.
• Calcification of the long head of the biceps may occur at the musculotendinous
junction or at the tendon insertion on the superior glenoid labrum.

70. • Chronic calcification is usually sharply marginated and dense whereas acutely
inflamed deposits are less dense and may have surrounding edema causing
obliteration of adjacent fat planes.
• Correlation with clinical findings is necessary, however, to confirm the relevance of
radiographically detected calcification.
• Calcification in the rotator cuff may eventually rupture into the bursa and this can be
documented on radiographs by the location of the calcification.

71. Calcific tendonitis. (A) Calcific tendinitis of the long head of the biceps brachii. The calcification in
this case occurred at the musculotendinous junction (arrow).
(B) Calcific tendinitis and bursitis of the infraspinatus tendon with bone erosion. Calcification in the
infraspinatus tendon has extended into the subacromial-subdeltoid bursa (arrow) and has eroded
into the bone (white arrow)

72. ROTATOR CUFF TEARS
• In acute rotator cuff tears, radiographs are usually normal.
• A decreased acromiohumeral distance can be seen on films obtained with active
abduction. Accompanying atrophy of the supraspinatus muscle can be suspected on
the outlet view if there is flattening or poor definition of its normally convex upper
margin.
• Fatty replacement of the muscle can be seen as areas of low density fat replacing
the normally homogeneous muscle density.
• Eventually, due to the unopposed action of the deltoid, lack of humeral stabilization
by the supraspinatus, and lack of the mass of the supraspinatus tendon interposed
between the humerus and acromion, the humeral head will be elevated in relation to
the glenoid and the acromiohumeral interval will be narrowed to less than 7 mm.

73. • In chronic rotator cuff tears, remodeling of the humeral head and acromion may
occur (cuff tear arthropathy).
• Milwaukee shoulder syndrome (cuff tear arthropathy) is a rapidly destructive shoulder
arthropathy that causes severe destruction of the articular cartilage and subchondral
bone of the glenohumeral joint.
• Massive rotator cuff tear, recurrent noninflammatory joint effusion, and synovial
hyperplasia are present.

74. Chronic rotator cuff tear
The high position of the humeral head is evident from the small acromiohumeral distance.

75. Milwaukee shoulder. There is a rotator cuff tear with marked elevation of the humeral head
under the acromion. Bursal distension with splaying of the adjacent fat (arrows) is evident.

76. CPPD DEPOSITION DISEASE
• Calcium pyrophosphate dihydrate deposition is a crystal deposition
arthropathy that results from deposition of CPPD crystals into the hyaline
cartilage, labrum, and other soft-tissue structures of the shoulder.
• Radiographically, this results in the hallmark finding of chondrocalcinosis,
which is not as common within the shoulder as it is in the knee or wrist.
• Over time, CPPD results in secondary osteoarthritis of the glenohumeral
joint.
• With the exception of prior trauma, CPPD is the leading cause of secondary
osteoarthritis in the shoulder, especially if the OA is bilateral.

77. Calcium pyrophosphate deposition disease. AP radiograph of left shoulder shows linear collection of
chondrocalcinosis (arrows) within hyaline articular cartilage of humeral head.

78. SYNOVIAL OSTEOCHONDROMATOSIS
• Primary synovial chondromatosis is a benign, predominately monoarticular
disease.
• It results from synovial membrane proliferation and metaplasia forming
multiple cartilaginous nodules that may detach into the joint.
• As the chondroid fragments are bathed and nourished in the synovial fluid,
they can enlarge and ossify.
• When the intra-articular chondroid fragments are not calcified or ossified,
shoulder radiographs can appear normal.
• As the fragments ossify, well defined circular opacities are seen within the
joint or the bursae of the shoulder

79. Synovial osteochondromatosis. There are innumerable circular calcifications distributed in the
joint and the capsular recesses.