Radiographs Complete trauma series View Focus Shoulder AP Glenohumeral joint space, DJD Grashey view (True AP) Glenohumeral joint space, DJD, and proximal migration of humerus AP in ER Hill Sachs lesion AP in IR Hill Sachs lesion Axillary lateral Anterior and posterior dislocation, acromion Velpeau view Axillary lateral modification if unable to abduct the arm Scapular Y lateral Anterior and posterior dislocation Additional views View Focus Supraspinatous Outlet Allows classification of acromion (Type I-flat, Type II-curved, Type III-hooked). Hooked acromion is associated with impingement and rotator cuff pathology. Zanca Help visualize the AC joint. Shows AC joint disease and distal clavicle osteolysis. Stryker notch Hill-Sachs lesion West point axillary Anteroinferior glenoid, bony bankart, proximal humerus fx Garth Anteroinferior glenoid, bony bankart Hobbs Anterior and posterior sternoclavicular dislocation Serendipity Anterior and posterior sternoclavicular dislocation Computed Tomography Overview provides better detail of cortical and trabecular bone structures than MRI at cost of higher radiation exposure there for optimal for visualization of bony defects magnification artifacts that are associated with radiographs do not occur with CT Axial Shoulder Images useful to visulaize Reverse Hill Sachs Coronal Shoulder Images useful to visualize fractures Sagittal Shoulder Images useful to visualize anterior-inferior glenoid insufficiency 3D Reconstructions useful to visualize glenoid version for total shoulder arthroplasty Magnetic Resonance Imaging Overview MRI is best for evaluating soft tissue structures and evaluating bone contusions or trabelcular microfractures the stronger the magnet, the higher the intrinsic signal-to-noise ratio (e.g. a 3 Tesla MRI machine has 9x the proton energy of a 1.5 Tesla MRI machine) T1-weighted sequence uses a short repetition time (TR) and short echo time(TE) bright= fat dark= fluid, bone, ligament, bone marrow, and fibrocartilage often combined with MR arthrograms useful to visualize Hill Sachs Lesion T2-weighted sequence uses a long TR and long TE bright= fluid (inflammation) and bone marrow dark= bone, ligament, muscle, and fibrocartilage useful to visualize rotator cuff pathology full thickness tear Short tau inversion recovery (STIR) Fat saturation (e.g. suppression) technique technique that reduces signal from fat and increases signal from fluid and edema helps to determe edema versus fatty infiltration in the rotator cuff muscles useful to visualize rotator cuff pathology ABER (abduction external rotation) position sequence beyond the conventional 3 sequences (coronal, sagittal, and axial) patient places affected hand behind their head instead of a true 90-90 degree abduction-external rotation position position tensions the anteroinferior glenohumeral ligament and labrum and relaxes the capsule useful to visualize Bankart lesions partial- and full-thickness tears of the rotator cuff tendons internal impingement MR arthrogram commonly used to augment MRI to diagnose soft-tissue problems such as SLAP tears dilute gadolinium-containing solution is percutaneously injected into the joint. optimal for labral and ligament pathology Bankart lesion Superior labrum anterior-posterior tear (SLAP) Glenoid labral articular disruption (GLAD) Anterior labral periosteal sleeve avulsion (ALPSA) Humeral avulsion of the glenohumeral ligament (HAGL)