mri of the shoulder: labrum - sprmn.pt of glenohumeral... · • rotator cuff dysfunction – long...
TRANSCRIPT
MRI of the Shoulder:
Labrum
Donald J. Flemming, M.D.
Radiology Department
Penn State Hershey Medical Center
Glenohumeral Instability
• Acute Traumatic Instability
– cartilaginous labrum
– glenohumeral ligaments/ capsule
• Multidirectional instability
– atraumatic
• Developmental
– humeral and glenoid version
– glenoid hypoplasia or humeral dysplasia
Glenohumeral Instability
• Rotator Cuff Dysfunction
– long head biceps tendon
• Scapulothoracic Dysfunction
– serratus anterior
– long thoracic nerve palsy
Glenoid Labrum
• Fibrocartilaginous ring
• Deepens glenoid
• Attachment for capsule
• Superior meniscal configuration
– Long head biceps attachment
• Variable morphology
Glenoid Labrum
Radiologic Evaluation
• Plain radiographs
– Hill-Sachs and bony Bankart
• CT arthrography
• MR
– Noncontrast
– Direct MR arthrography
– Indirect Arthrography
MR Technique
• Need dedicated shoulder coil
• Neutral to external rotation
– Tightens capsule
– Tightens long head biceps tendon
• ABER Position
– Tightens anterior inferior capsule
– Axial oblique
• Axial, Coronal oblique, Sagittal oblique
MR Technique- ABER
Anterior/Inferior
Noncontrast MR
• Noncontrast
– Fat-saturated FSE Proton
– GRE
– T2 (SE or FS)
• Inexpensive/ Little risk
• Poor sensitivity
Noncontrast MRI Accuracy
Labral Pathology
Sensitivity Specificity
Ianotti 88% 93%
Garneau 66.7% 77.8%
Tuite 50% 90%
Legan 95% 86%
Flemming* 0% 0%
* Unpublished data
Indications for Arthrography
• History of instability
• Concern for labral pathology
• Any patient < 35(40) years?
• Direct vs Indirect Arthrography
Direct MR Arthrography
• Improves diagnostic accuracy
• Increases cost
• Requires access to fluoroscopy
• Decreased schedule flexibility
• Increases physician time
• It hurts
Indirect MR Arthrography
• Increases diagnostic accuracy
• Relatively inexpensive
• Technologist can perform exam
• Lack of capsular distension
• Anaphylaxis
• Requires fat saturation
• Enhancement may mimic pathology
Technique
• Inject 15 minutes prior to exam
– 0.1 mmole/kg dose
• Exercise for 10 minutes after injection
• Synovial membrane permeable to
gadolinium
Normal Labrum
• Triangular focus of low signal
• Capsular insertion
– Variable anterior – labrum to neck of glenoid
– Posterior – labrum – less variability
• Glenohumeral ligaments
Normal Labrum
Labral Clock
Shoulder Arthroscopy
• Posterior Portal
– Through Infraspinatus
– Optimum look at anterior-inferior glenoid
– Poor look at posterior/inferior
• Requires experience
• Not a perfect “Gold Standard”
Shoulder Arthroscopy
Humerus
Glenoid
Labrum
Normal Labrum
• Normal variants
• Sublabral foramen
• Buford complex
Sublabral Foramen
Ant/Sup 12:00 – 3:00
No Man’s Land
Sublabral Foramen
No Man’s Land
Buford Complex
• Absent superior
labrum
• Thick middle
glenohumeral ligament
Capsulolabral “Tear”
• Bankart
• Perthes
• ALPSA
• GLAD
• SLAP
• Bennett
• HAGL
• BHAGL
Labral “Tear”
• Antero-inferior most common
– Axial
– Remember to look at coronals
• Superior (SLAP) - not uncommon
• Posterior/inferior most difficult
• Look for second tear 1800
Labral Pathology
• Contrast/signal under labrum
• Abnormal morphology
• Perilabral cyst
• Pitfalls
– Normal variants
– Sublabral foramen
Bankart
Bankart
Bankart
Intralabral Signal
Abnormal Labrum/ Capsule
Associated Findings
• Hill-Sachs Defect
– Posterior humeral head
– First axial cuts (above level of coracoid)
– Seen on internal rotation
– Significant - >30% of articular surface
• Peri-labral cyst
– “100%” association with tears
– Usually chronic/degenerative tears
Hill-Sachs
Perilabral Cyst
Perthes
• Detached labrum with
periosteum intact
• May be missed at MR
without ABER
Perthes
ALPSA
• Anterior Labral Periosteal Sleeve Avulsion
• Periosteal sleeve rolls down on glenoid neck
• May be missed at arthroscopy
ALPSA
GLAD
• Glenoid Labral Articular Disruption
• Hyaline cartilage injury +/- Bankart
Bennett
• Reverse Perthes with ossification
Posterior Labral Tear
• Common in weightlifters
• Extension from superior labral tear
• Retroverted glenoid
• Perilabral cysts
• Easy for arthroscopist to miss
– Look from anterior portal
Posterior Labral Tear
HAGL/BHAGL
• Humeral Avulsion Glenohumeral Ligament
– Add “B” if bony fragment avulsed
• Rare injury
• Easy to miss on arthroscopy and MR
HAGL
HAGL
Superior Labral Anterior to
Posterior
• Type I - fraying
• Type II - detached
• Type III – bucket-handle
• Type IV – extension into biceps
SLAP Tears
• External rotation important
• Type I and II most common
– Differentiate from sublabral foramen
– Difficult to differentiate I from II
– Look for branching signal
• ↑ Signal on T2W is high PPV
• Look for anterior/posterior extension
• Type III and IV – Look for Bankart
Normal Superior Labrum
Type II
SLAP with Extension
Hyaline Cartilage Defects
• 3D volume SPGR with contrast aids
detection
Radiology Report
• Tear – describe location by clock face
– Anterior – 12:00 to 6:00
• Remember equator low
• Look for second labral lesion –1800 away
• Look for hyaline cartilage defect
• Look for rotator cuff tear
• CORRELATE!!!!
Thanks!!