3. 5. Shoulder (glenohumeral) joint
dislocation.
? Synovial, multiaxial ball-and-socket joint formed by head of
humerus and the shallow glenoid fossa of the scapula.
? On AP radiograph, the articular surfaces of the humerus and
glenoid form parallel arcs.
4. Shoulder (GHJ) dislocation ¡
? Most common dislocated large joint , Male to female ratio 9:1,
? Weakest position is when abducted and externally rotated.
? Dislocation maybe associated with massive disruptive of labrum. Joint capsule,
supporting ligaments and muscles
? Classified into :
o Anterior 95%
o Posterior <4%
o Inferior <1%
o Superior - rare
5. Anterior GHJ dislocation
? Commonest by 95%
? humeral head lies anterior, medial and inferior to its normal
location and glenoid fossa.
? MOI: direct force to the arm causing force abduction,
external rotation and extension.
6. ? In anterior dislocation, the
humeral head strikes the
anterior-inferior glenoid
? This impaction may fracture
the humeral head, the glenoid,
or both, leads to :-
? Bankart lesion
? Hill sach lesion
7. Cont¡
? Bankart lesion- Injury of the anterior-inferior rim of the glenoid.
It usually involves the cartilaginous labrum only.
? A bony Bankart is a fracture of the bony glenoid.
? Hill sach lesion- Posterolateral compression fracture of humeral
head.
9. Posterior GHJ dislocation
? Rare -2-3%
? 50% are missed at time of initial examination and if only AP projected
radiograph are taken.
? An axillary view is a preferred view for diagnosis.
? MOI- Severe muscle spasm due to seizure or electrocution , the posterior
pulling muscles of the back are stronger than the anterior muscles.
? In posterior dislocation, typically the humeral head is forced posteriorly in
internal rotation while the arm is abducted.
10. Radiological features for posterior
shoulder dislocation
? Rim sign - widened glenohumeral joint >6 mm, due to lateral
displacement of the humeral head.
? Lightbulb sign - fixed internal rotation of the humeral head which
takes on a rounded appearance
? The Trough sign (reverse Hill¨CSachs) - Compression fracture of the
anteromedial aspect of the humeral head (dense vertical line in the
medial humeral head)
Cause : impaction of the humeral head on the posterior glenoid rim
13. Inferior GHJ dislocation
? AKA ¡°Luxatio erecta¡±
? Humeral head seen below the
glenoid fossa
? MOI ¨CDirect force to a fully
abducted arm
? Rotator cuff muscles are torn,
can cause injury to the axillary
artery or nerve
14. Sternoclavicular joint dislocation.
? Contribute 3% dislocation of the shoulder girdle
? Categorized into 2 based on the direction of medial clavicular displacement:
? MOI: anterior dislocation due to an indirect blow to the shoulder
? Its difficult to identify radiographically
? But AP view with 40-degree cephalic can be used to diagnose
? CT scan can confirm or excludes the diagnosis.
15. Clinical presentation of sternoclavicular
dislocation
Anterior dislocation
? A palpable deformity
Posterior dislocation
? May be occult on physical
examination
17. Radiological features
Anterior SCJ dislocation
? joint space widening at the
sternoclavicular joint
? joint space widening and asymmetry at
the sternoclavicular joint
? associated injuries of the mediastinum
Posterior SCJ dislocation
? Joint space widening
? Posterior displacement of medial
clavicle
20. 2.ACJ Dislocation
? Contributes 12% of the shoulder dislocation
? MOI: occurred due to downward blow to the lateral shoulder
? Cause rupture of the joint capsule and ligaments connecting
the clavicle to the superior aspect of the scapula
? The normal AC joint space <5mm and CC distance is <13mm
? Special views:¡°Weight bearing view¡±
23. Radiological features
? Widened of acromioclavicular joint space >5mm
? Widened of coracoclavicular space > 13 mm
? Displacement of clavicle
24. Classification of ACJ injury
? Grade l: AC ligament sprain, Radiograph are
normal.
? Grade ll: Disruption of the AC ligament and
intact CC ligaments.
? Grade lll: AC joint and CC ligamentous
disruption.CC interspace is < 25 mm
(100%crelative to the contralateral side.)
? Grade lV: Distal clavicle displaced posteriorly
into trapezius(seen on CT or axillary view)
? Grade V: Severe grade lll injury, with >100%
displacement relative to the other side.
? Grade VI: Inferior dislocation of the distal
clavicle.
28. Hip dislocation
? Is the displacement of the head of femur from its normal position
? The head of the femur displace in relation to the acetabulum from
severe trauma causing dislocation
29. Classification
1. According to direction of femoral head displacement;
A. Posterior dislocation
B. Anterior dislocation
C. Central dislocation
2. Other classification systems includes
D. Thompson and epstein
E. Stewart and Milfords
F. AO/ATO classification
30. Clinical features of hip fractures and
dislocation
? Loss of function/Pain with attempted motion of hip
? Deformity of the involved limb
? Pain to palpation of hip
? Possible neurological impairment
31. Hip fractures and dislocations imaging
modalities
? Conventional radiography
? CT Scan
? MRI
? Bone scintigraphy
32. Hip dislocation imaging features
A. Posterior dislocation
B. Anterior dislocation
C. Central dislocation
33. ? Almost always due to high-energy trauma
? Most commonly involve unrestrained occupants in MVAs
? Can also occur in pedestrian-MVAs, falls from heights,
industrial accidents and sporting injuries
? AP x-rays will usually be sufficient for the diagnosis
? The femoral head is displaced posterior, superior, and
slightly lateral to the acetabulum and is internally
rotated obscuring the lesser trochanter on AP view
Posterior dislocation
36. Anterior dislocation
? Mechanism of injury
? Forced abduction with external rotation of hip
? Anterior hip capsule is torn or avulsed
? Femoral head is levered out anteriorly
? Conventional radiography
? Head of the femur rests inferior and medial to its normal acetabular
position overlying the obturator foramen (inferior type of anterior
dislocation)
? There may be associated fractures of the anterosuperior aspect of the
femoral head (indentation fracture) or greater trochanter
37. °ä´Ç²Ô³Ù¡¯
? Computed tomography (CT Scan)
?Provides an accurate means of evaluating the dislocation and associated
fractures as well
38. °ä´Ç²Ô³Ù¡¯
The right femoral head (blue arrow) overlies the obturator
foramen, inferior and medial to its normal location in the
acetabulum (white arrow )
39. Central dislocation
? The femoral head dislocates centrally into the pelvis
? The acetabulum has to fracture and this is a severe injury that can
result in life threatening haemorrhage in pelvis
41. Also known as osteonecrosis is condition that occurs
when there is loss of blood to the bone.
The femoral head is the most common location for AVN
.
? Traumatic .
? chronic corticosteroid therapy
? Alcoholism
? hyperlipidaemia
AVASCULAR NECROSIS OF THE HIP
45. 3.Legg¨CCalv¨¦¨CPerthes Disease
? Legg-Calv¨¦-Perthes disease (LCPD) AKA Perthes disease is
idiopathic avascular necrosis (AVN) of the growing
femoral epiphysis seen in children.
? Diagnosis of exclusion (exclude other causes of AVN)
? LCPD is a childhood hip disorder initiated by a disruption of blood flow to
the ball of the femur called the femoral head
? A complex process of stages which can take up to 2-3 yrs.
? Occurs mostly unilateral and in boys 4-12yrs,
? Complication : hip deformities and severe degenerative arthritis
46. Signs and symptoms
i. Hip pain
ii. Knee pain (referred pain)
iii. Groin pain, exacerbated by hip/leg movement
iv. Reduced range of motion at the hip joint
v. Short limb length
48. Radiographic features
Radiographic findings are of AVN
Plain film-
Early signs
?asymmetrical femoral epiphyseal size (smaller on affected side)
?apparent increased density of the femoral head epiphysis
?widening of the medial joint space
?blurring of the physeal plate (stage 1)
?radiolucency of the proximal metaphysis
Late signs
?Eventually, the femoral head begins to fragment (stage 2), with subchondral lucency (crescent sign)
and redistribution of weight-bearing stresses leading to thickening of some trabeculae which
become more prominent.
?The typical findings of advanced burnt out (stage 4) Perthes disease are:
-femoral head deformity with widening and flattening
-proximal femoral neck deformity.
51. Staging (Waldenstr?m radiographic
stage)
Stage 1 ¨C initial or avascular necrosis
On x-rays, the femoral head looks more radiopaque and smaller than
the unaffected side due to the disruption of blood flow that
causes bone death. Early flattening of the top of the femoral head or
fracture line (called subchondral fracture or crescent sign) can be
seen. This stage generally lasts less than one year.
52. Stage 2- Fragmentation or Resorptive stage
?The femoral head looks
irregular and broken up
(fragmented) with a more
flattened appearance.
?The x-ray irregularities are due
to the dead bone being
removed by the healing process
creating areas without bone
(seen as dark areas on x-rays).
?The removal of the dead bone
is called resorption
?The femoral head can also
appear to be moving out of the
socket (called lateral
subluxation or extrusion).
?lasts 1 to 1 1/2 years.
53. Stage 3 ¨C Reparative (Reossification) stage
In this stage, new bone (seen as increased white
appearance of the femoral head) starts to fill in the
areas where the dead bone has been removed.
The newly-formed bone can be seen along the
outer perimeter of the femoral head that
gradually fills in towards the central area. Because
the new bone is filling in, this stage is called the
ossification stage.
This stage is usually the longest stage and can
take 2-3 years.
54. Stage 4 ¨C Healed stage
In this stage, the appearance of the
bone in the femoral head looks
similar to the normal side. It is
homogeneous and the irregular,
fragmented appearance is no longer
seen.
The affected femoral head and neck,
however, can be enlarged (called
coxa magna), flattened (coxa plana),
and have a short, broad neck (coxa
breva).
The final shape of the femoral head
at this stage (the degree of flattening
or deformity) and how it fits the
socket largely determines the long-
term outcome.
56. Arthrography
? Traditionally arthrography performed under general anesthesia with conventional
fluoroscopy is performed to assess congruency between the femoral head and the
acetabulum in a variety of positions.
? MRI is increasingly replacing this, in an effort to eliminate pelvic irradiation.
? Both arthrography and dynamic MRI asses three main features 3:
i. Deformity for the femoral head (also assessed on static x rays and MRI)
ii. Congruency - how well the femoral head contour matches that of the acetabulum
iii. Containment - the amount of lateral subluxation of the flattened femoral head out of
the acetabulum
58. Pelvic X-ray and MRI 5-
year-old boy with Legg-
Calve-Perthes disease
affecting one side.
The bony epiphysis on
the affected side is
smaller due to a growth
arrest.
MRI showed signal
changes in the whole
bony epiphysis.
#3: GHJ ¨C synovial multiaxial ball and socket joint.
wide range of motion.
inherent stability due to imbalance of forces from rotator cuff muscles.
articular surfaces form parallel arcs.
#4: .
CT and MR for assessing the subtle fracture., ligaments / tendeneous injury respectively.
Anterior and posterior are easy to detect, humeral head out of congruent of glenoid.
#5: .
When the humeral head is normally aligned, it will project centred over the centre of the Y formed by coracoid , blade of the scapula and spine of the scapula ( acromion)
Shoulder dislocation can also be associated with rotator cuff tears on the older group., incidence start to increase around age 40, high in patients above 60.
It is useful to determine whether the fracture is acute, chronic or recurrent.
#9: Rare , usually plain film series are sufficient, for extent of injury enquire cross sectional studies.
High index of suspicion is helpful.
Due to strength imbalances with in the rotator cuff muscles.
Posterior dislocation may go unnoticed especially in elderly.
#10: A Hill-Sachs defect is?a posterolateral humeral head depression fracture
Reversed Hill ¨C Sachs defect anterior medial humeral head depression.
#12: Light bulb appearance on scout view
Depression fracture anteriomedial to humeral head ¨CTrough line sign
#13: Which rotator cuff muscle(s) are more likely to be torn??
#14: Majority are anterior dislocation due to an indirect blow to the shoulder levering the medial end of clavicle forwards.
#16: Thoracic syndrome is a group of clinical syndromes resulting in compression of subclavian vessels and brachial plexus.
Neurogenic thoracic outlet syndrome
Venous thoracic outlet syndrome
Arterial venous syndrome
#17: more easily identified on an?angled view, on this view inferior displacement of the medial head of the clavicle is indicative of a posterior dislocation, whereas superior displacement of the clavicle indicates an anterior dislocation?6
difficult to determine anterior or posterior dislocation?
#20: a fall directly onto the acromion, with the arm adducted up against the body. When a person falls onto their shoulder, the force pushes the tip of the shoulder down.
they range in severity from a mild sprain to complete disruption.
Patients can present with non-specific shoulder pain and swelling
Male to female ratio 5:1
The AC joint injury typically occur in young athletic adults.
?
#24: Rockwood classification bases on
1 AC ligament 2. CC ligament 3. effect of trapezius muscle 4. effect of deltoid muscle
The Rockwood classification takes into account not only the?acromioclavicular joint?itself but also the?coracoclavicular ligament, the?deltoid, and?trapezius?muscles, whilst considering the direction of dislocation of the?clavicle?with respect to the?acromion. Essentially types IV, V, and VI are variants of type III?6.?
The Rockwood classification system is limited to describing soft tissue injuries and does not assess osseous injuries?8.?
#35: AP XR (A) before relocation shows the femur dislocated posterosuperiorly. No bony fragments are seen
CT images (B) Multiple fragments are seen, including a large intra-articular fragment. There is a fracture of the posterior acetabular wall
#57: Figure 1 - X-ray of a child's normal hip bone and a broken (fractured) hipbone from poor blood flow.
Figure 2 - MRI of a child's normal hip bone with fat in the growth center and an abnormal hipbone where the fat has been lost because of LCPD
