Rockwood Adults CH34

1074

SECTION TWO • Upper Extremity

A, B

C

Figure 34-15.  A: The sulcus sign is used for inferior instability and laxity. A: With the patient in the sitting position. B: A downward force is applied to the arm with the elbow bent. A positive sulcus sign is seen with inferior translation of the humeral head at least 1 to 2 cm from the acromion ( arrow ). C: The same test is also done with the arm in maximum external rotation to evaluate for laxity in the rotator interval.

Increased external rotation may imply anterior hyperlaxity (Fig. 34-14A), and asymmetric hyperabduction greater than 15 degrees of difference from the contralateral shoulder (Gagey test) with scapular stabilization may indicate incompetency of the inferior glenohumeral ligament complex (IGHLC) (Fig. 34-14B). Additional special tests include the sulcus sign for inferior insta- bility, and the anterior and posterior load and shift. The sulcus test assesses inferior instability and is tested by applying inferior traction with the arm at the side (Fig. 34-15A). 84 A positive test results in inferior translation of at least 1 to 2 cm. This can cause the appearance of a skin dimpling ( arrow ) inferior to the lateral aspect of the acromion (Fig. 34-15B). A positive sulcus sign is also noted ( arrow ) then with the arm taken into external rotation (Fig. 34-15C). A sulcus sign that persists with the arm past 45 degrees external rotation is thought to represent an increased spectrum of inferior instability related to a widened or incom- petent rotator interval. 183 Apprehension and Jobe relocation tests are considered the most diagnostic for identifying anterior shoulder instability, with a positive predictive value of 96%. 128 The Jerk test, Kim test, and push–pull examination maneuvers

will help exclude posterior instability and, in combination with the above described testing, the diagnosis of MDI may be elic- ited. Furthermore, pathology of the biceps–superior labral com- plex (SLAP) may also be assessed with the O’Brien test, Crank test, dynamic labral shear test, and Yergason test. IMAGING AND OTHER DIAGNOSTIC STUDIES FOR GLENOHUMERAL INSTABILITY Radiography Patients presenting with shoulder instability and dislocations are initially imaged with standard radiographs. Radiographs provide an overview of the bony anatomy, orientation of the humeral head in relation to the glenoid, and initial assessment for both bony Bankart and Hill–Sachs lesions among other associated pathologies. Given the orientation of the glenohumeral joint, radiographs can be obtained relative to the body or aligned to the scapula. Anteroposterior (AP), Grashey (true AP view), Y, and axillary views are typically obtained (Fig. 34-16). The AP view is aligned with the body (Fig. 34-17A) while the Grashey view

A

B

Figure 34-16.  A: Anterior–posterior radiographic view of the shoulder. B: Grashey true view.