PTP 521Musculoskeletal Diseases and Disorders

Spring/Summer 2012

Musculoskeletal Diseases and Disorders: Shoulder Girdle Complex

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Objectives

• By the end of this presentation, students will be able to: • Identify common bone presentation on radiographs• Identify common positions for radiographic shoulder

studies• Differentiate between an MRI, CT, and US of the Shoulder• Discuss common fractures of the clavicle, scapula, and

humerus• Discuss necessary information to obtain on a surgical

history to assist in clinical decisions for patients with post operative shoulder conditions

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Epidemiological Data

• According to the Centers for Disease Control and Prevention: Nearly 1.5 million Americans went to ER for shoulder injury in 2006

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Anatomy Review

• Joints of the shoulder Girdle– Acromioclavicular– Sternoclavicular– Scapulothoracic– Glenohumeral

AcromioClavicular Joint

• AP view• Alignment: distal clavicle

aligns with the acromian• Joint should be less than 6

mm wide• Bone density: check distal

end for any fractures or osteophytes

• Cartilage and Soft Tissue: not evaluated with this view

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Radiographic Imaging: AP View

• Anteroposterior positioning

• View position of humerus in relation to the glenoid cavity

• Clavicle to the acromion

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Three views:

Internal Rotation External Rotation Neutral

What anatomy do you see on the internal differently from external and neutral?What parts of the scapula overlap the humeral head. It helps to know the positionof the arm when you review shoulder radiographs. You really have to keep the shoulderAnatomy in mind. These are all normal (no pathology) views.

emedicine.medscape.com/article/328253-overview7

Anterior Posterior View of GH joint

Search StrategyA: alignmentB: bone densityC: cartilage spaceS: soft tissue

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Radiographs: Anterior Posterior External Rotation View

• Humerus is in external rotation

• View position of humerus in relation to the glenoid cavity

• Clavicle to the acromion• Exposes the greater

tuberosity more than the lesser tuberosity

home.comcast.net/~wnor/radiographsul.htm

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• Alignment: – Relationship of the

humeral head to the glenoid

– Is there an overlap by more than 7-8 mm between the superior portion of the humeral head and the inferior surface of the acromian?

• Rotator cuff tear: < 7 mm may indicate a subluxation of the humeral head through rotator cuff muscles into the acromian

emedicine.medscape.com/article/1261152-overview10

Bone Density

• Look for consistent trabecular lines

• Consistent cancellous patterns in both the humeral head and the glenoid

• Are there areas of increased or decreased density?– Snow cap indicating

avascular necrosis

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Cartilage

• Normal cartilage: –

• Soft Tissue:– May want to assess

lung as well as the soft tissue that might be seen around the glenoid and humeral head

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Scapular Y view

• Position of the humerus in relation to the glenoid, acromian and coracoid process

• True lateral view of the scapula

http://www.e-radiography.net/technique/shoulder/Shoulder_scapula_normal_lateral.jpg 13

Lateral View or Transcapular View

• Alignment: position of the humeral head within the Y

• Humeral head should be within the notch

cme.medscape.com/viewarticle/416588_214

ALSO Called: Anterior Oblique: Scapular Lateral (Y) view

• So, many names, same view• This is important when

determining shoulder dislocations. Look for the humeral head to be outside the notch, posterior to or anterior to the Y when the shoulder is dislocated

www.rcsed.ac.uk/.../shoulder/overview.htm 15

“eye” sign• The “eye” sign is just posterior to the

glenoid.

• If this eye is not present, the anterior glenoid edge will be obliqued by the superior or inferior glenoid edge - which may mask severe defects that only a properly aligned axillary view will reveal.

• If the "eye" is not seen on the axillary view, this shot should be redone.

• This view may also show decreased joint space, fractures, osteophytes, dislocations, Hill Sachs and reverse Hill Sachs Lesions.

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Axial Shoulder

• Difficult view as it requires the patient to be in abduction.

• Patient sitting, arm in abduction, film cassette below joint.

• X-ray beam directed from superior to inferior at an angle of 5-10 dg toward the elbow. http://classes.kumc.edu/som/radanatomy/

image.asp?Image=6102-001.jpg&Film=6102&Features=1

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Variations of the Axillary View:

• Lawrence View• Arm abducted to 90

dg• Patient supine• Beam directed

inferior to superior with angulation medial and superior through the axilla

• West Point View• Arm abducted to 90 dg• Patient prone• Film against the superior

aspect of the shoulder• Beam directed inferior

to superior angled toward the axilla ~ 25 dg in frontal plane and ~ 25 dg posterior to joint.

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West Point View

• Similar to an Axillary view, patient is prone instead of supine

• Determine glenoid fractures

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CT Scans

• MRI have virtually replaced them

• Will still see them taken to have a reformatted view of a shoulder fracture

• Also common to use CT scan to determine if a patient will have a total shoulder or Reverse total shoulder surgery

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CT Scan of the Shoulder

• CT scan of a normal shoulder.

• For surgeons to consider replacement surgery, the glenoid bone should be at least 2 cm in depth

www.bosshin.com/owners_manual_instability/ 21

• Dysplasia of the shoulder

• Posterior aspect of the glenoid did not develop well

www.bosshin.com/owners_manual_instability/ 22

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Bankart Lesion

Lesions of the glenoid fossa

Erosion of the glenoid

www.bosshin.com/owners_manual_instability/

Arthroscopic Positioning

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• MRI of theShoulder throughthe posterior portal

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MRI Images

• Coronal Oblique– Infraspinatus muscle and

tendon– Supraspinatus muscle and

tendon– Acromioclavicular joint– Acromion– Glenohumeral joint– Subacromial/subdeltoid

bursa– Labrum – superior and

inferior portions

fat suppressed T2 wt images and proton density weighted images

wheelessonline.com

MRI

• Images soft tissue around the shoulder joint

• Deltoid Tendon

stemcelldoc.wordpress.com/.../27

Sagittal ViewT1-weighted view. 1. Coracobrachialis muscle 2. Subscapularis muscle and

tendon. 3. Humeral head. 4. Coracoid process 5. Deltoid muscle (Anterior part). 6. Coracoacromial ligament.7. Acromion. 8. Supraspinatus tendon. 9. Infraspinatus tendon. 10. Deltoid muscle (Posterior part).

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Rotator Interval• Triangular space

– coracoid process coming between the subscapularis and supraspinatus muscles and tendons.

• Floor of the rotator cuff interval is the cartilage of the humeral head

• Roof of the rotator cuff interval is the rotator interval capsule,

which links the subscapularis and supraspinatus tendons and is

composed of two layers: the CHL on the bursal side and the fasciculus obliquus on the articular side.

Fig. 1. —Drawing, according to Gohlke et al.of rotator cuff interval in sagittal plane, with superior capsular complex (in green), bridging subscapularis tendon (SSC), superior glenohumeral ligament (SGHL), and long portion of biceps tendon (LPB) and passing beneath deep fibers of supraspinatus (SSP). (Courtesy of F. Gohlke, Wuerzburg, Germany)

http://www.ajronline.org/cgi/content/full/184/5/1490

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Axial View

Axial T2-weighted FATSAT view. (mid shoulder)

1. Deltoid muscle (Anterior part).2. Biceps tendon, long head. 3. Coracobrachialis muscle. 4. Subscapularis muscle and

tendon. 5. Glenoid. 6. Humeral head. 7. Infraspinatus muscle.8. Deltoid muscle.

www.info-radiologie.ch/shoulder-mri.php

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Ultrasound

http://www.med.umich.edu/rad/muscskel/mskus/index.html

http://www.biij.org/2006/4/e58/e58.pdf

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Shoulder Pain:

Fractures of the shoulder girdle complex

Clavicle: 75% occur in children under 13• Proximal fracture

– Rare, differentiate from epiphyseal injuries

• Middle Third fracture- Most common, 80%

– Usually displaced upward by pull of the sternocleidomastoid muscle

• Distal fracture– Displaced downward by the

weight of the arm.

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• MOI: – Fall on the lateral aspect

of the shoulder

– Fall on outstretched arm (FOOSH)

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• RX: – Arm sling

• For the first 1-2 weeks • To support the weight of the

arm.– Figure of eight

• Figure of eight bandage, intent is to reduce the motion at the fracture site.

• Worn for a period of at least 6 weeks (adults) or 4 weeks (child).

• Can use the arm as wanted & symptoms allow.

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Scapular Fractures

• 1% of all fractures• High energy: fall or direct blow• Associated Injuries

– Ipsilateral rib fractures– Pulmonary trauma– Clavicular fractures– Brachial plexus injuries– Subclavian artery injuries

• Classified according to location

Scapula:• Type I: fractures of scapular

body 2• Type II: fractures of

apophyseal regions including acromion and coracoid process 3,4

• Type III: fracture of superolateral angle including glenoid neck and fossa 1

• RX: generally minimal treatment. Surgery only in most drastic, displaced fractures.

Donatelli RA, 198737

Scapular Fractures requiring surgery

• Acromion or scapular spine fractures with a doward tilting of the lateral fragment and subacromial narrowing

• Coracoid fractures that extend into the glenoid fossa

• Glenoid rim and intra-articular glenoid fractures associated with glenohumeral instability

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Rx of Scapular Fractures

• Sling 7-10 days• Progressive regimen of pendulum and gentle

ROM exercises• Progressive AROM and strengthening

exercises

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Humeral Head Fractures

Fracture Dislocations

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Proximal: A. Greater Tuberosity

More commonly seen in older individuals.

B. Lesser TuberosityRare, usually avulsion fractures

C. Neck of the HumerusCommon fractures, transverse, comminuted, impacted

D. Shaft of the Humerus

• MOI: significant force applied directly or indirectly to shoulder region

• Rx: depends upon the type of fracture, age of the patient

Fractures Associated with Shoulder Dislocations

Hill-Sachs lesion:– depression fracture of

the posterior/lateral humeral head.

– Area of soft cancellous bone which is compressed against the glenoid rim.

– Occurs in 77% of traumatic anterior dislocations

http://www.athleticadvisor.com/Injuries/UE/Shoulder/shoulder_dislocation.htm

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Bankart Lesion

– Defined as a detachment of the labrum from the glenoid rim

– occur in 87% of the traumatic dislocations

– the most common reason for recurrent instabilities

www.sportsortho.co.uk/article.asp?article=86

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• Quality of the Tissue– Good tissue quality: heal

faster, less functional issues

– Poor tissue quality: will the repair hold, takes longer to heal, more functional deficits after surgery

• Specifics of the Case:– Did it involve the Biceps

Tendon or not?– Removal of any bone?– Other?

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Rotator Cuff Dysfunction Resulting in Impingement

• Key pathophysiological factors– Primary or secondary

impingement– Tensile overload– Macrotraumatic tendon

failure– Posterior or

undersurface impingement

• Key Muscles and Force Couples– Deltoid Rotator cuff

force couple• Deltoid force: • Rotator Cuff force:

– Trapezius and Serratus anterior

– Anterior posterior rotator cuff force couple

• Concavity-compression mechanism

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Rotator Cuff Impingement

• Primary Compressive Disease: Primary Impingement– Compression of rotator cuff tendons between the

humeral head and the overlying anterior third of the acromion, coracoacromial ligament, coracoid or AC joint

– Subacromial space• Normals:

6mm-14mm

• Patients with shoulder pain: 7mm-13mm

Neer Classification

Stage I: characterized by edema, inflammation, hemorrhage in the subacromial space. Swelling is responsible for the impingement – Risk Factors: age 25 or less – SX: dull ache in the shoulder after activity, pain may

interfere with ADL’s

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Signs: painful arc in abduction - between 60 and 120 dg, pain free – PROM, resisted tests are strong but painful for abduction– Palpation: tender over the greater tuberosity and the anterior edge of

the acromian– Special tests: + Neer impingement test, + Kennedy and Hawkins test.

– This stage is easy to reverse if the person rests from aggravating activities and changes some work or play postures, strengthens weak muscles

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Stage II:

Characterized by aggravation of the subacromial contents creating a thickness in the bursae and fibrosis of the tendons.

• Risk Factors: 25 to 40 years of age • SX and Signs: similar but increased in intensity from

Stage I • Impairments: more limitation in the PROM and with

Hawkins and Kennedy test there is a catching sensation with the return from an elevated position.

• More difficult to reverse than Stage I 49

Stage III:More complicated:

– get a partial or full thickness tendon tear, – changes in the bony configuration of the humeral head

and acromion, – osteophytes

• Risk Factor: 40 years of age or greater • SX: increase in intensity of symptoms, interferes with

daily activities • Signs: AROM more limited than PROM, resisted tests

show weakness in abduction and external rotation

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• X-Rays: cystic changes in the greater tuberosity, underside of the acromian or at the AC joint

• RX: surgery if conservative treatment doesn’t work. Repair of the torn muscles would occur with all of the surgical options.

• Surgical Options: 1. coracoacromial ligament resection

2. anterior acromioplasty 3. distal clavicle resection (Mumford procedure) 4. AC joint inferior osteophyte resection

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Mechanical Impingement:• Abnormal shape of the

acromion. • 3 types of acromion, flat,

curved and hooked. • There is a close

association with a hooked acromion (70%) with full thickness rotator cuff tears; 80% association with impingement syndrome

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Secondary Compressive Disease

• Due to underlying instability of the GH joint– Anterior instability – overhead athletes, throwing

athletes– Increase in anterior translation, biceps tendon and

rotator cuff become impinged– Continual loss of GH stability– Leads to rotator cuff tears

Tensile Overload

• Repetitive intrinsic tension overload– Occurs during deceleration

and follow through – High load placed on

posterior rotator cuff muscles

– Pathological changes of angiofibroblastic hyperplasia – early tendon stages, progresses to tears

• Tendinosis injuries– Degenerative process

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Macro traumatic Tendon Failure

• Single traumatic event or a previous traumatic event

• Forces are greater than the tendon can handle

• Normal tendons don’t tear

• 30% damaged to produce a substantial reduction in strength

• Full thickness tears• Bony avulsions• May have had

repeated microtraumatic insults and degeneration over time

• Failure over one heavy load

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Posterior impingement

• Undersurface– In 90 dg of abduction

and 90 dg of Ext rotation– Supraspinatus tendon

and infraspinatus tendon rotate posteriorly and get pinched between the humeral head and the posterior-superior glenoid rim

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• Add anterior translation of the humeral head causes mechanical fraying on undersurface of the rotator cuff tendons

• Halbrecht et al studied baseball pitchers with MRI of shoulder

• Paley et al studied 41 professional throwing athletes – all had this problem

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