AP of Shoulder: in the scapular plane

- See:
      - Anterior Dislocation
      - Posterior Dislocations:

- Discussion:
    - note: w/ true AP of shoulder there should be no overlap of the humerus over the glenoid;

- Greater Tuberosity and Acromio Humeral Interval;
    - AP in ext. rot. brings greater tuberosity into clear prominence;
    - this x-ray taken w/ pts arm at side, hand supinated, & elbow extended;
    - gives good visualization of the greater tuberosity;
    - measurement of the acromiohumeral interval also can be done more accurately on the external rotation view;

- Calcific Tendonitis:
    - AP w/ arm in internal rotation is taken with the arm at the side, elbow extended, and the forearm pronated;
    - may also be helpful in calcific tendinitis, esp in the supraspinatus;

- AC Joint View: (see AC joint)
    - AP w/ arm in 100 deg of abduction provides best view of AC joint;
    - this projection allows the AC joint to clear the overlying scapular or acromial neck, so degeneration or osteophytes can be seen better;
    - this view is a useful one in pts with true adhesive capsulitis;

- Technique:
    - taken w/ pt's back flat on cassette & x-ray beam at right angles to this plane and centered on the shoulder;
    - the scapula sits obliquely on the chest wall, and the glenoid surface is tilted approx. 35 to 40 deg anteriorly;
    - the posterior aspect of the affect shoulder is placed up against the x-ray plate & opposite shoulder is rotated out approx. 40 deg;
    - angled AP radiograph (body turned 35-40 toward cassette), shows glenoid fossa in profile

- Note Neck Shaft angle:
    - angle created at intersection of lines that are perpendicular to anatomic neck and parallel to shaft of humerus;
    - avg angle 143 deg (134 to 166) - angle is less in external rotation and angle is more in internal rotation

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Sunday, June 24, 2012 3:45 pm