Posterior shoulder instability: current concepts review.
Posterior shoulder instability (PSI) poses clinicians for a complex problem establishing a correct diagnosis and deciding on the optimal treatment options as several predisposing factors may be present in one patient.
Often patients with PSI have typical complaints: diffuse pain in the posterior shoulder commonly accompanied by mechanical symptoms (f.i. crepitations) – these may either be congenital (glenoid hypoplasia, posterior glenoid rim deficiency), the result of a trauma (reversed Bankart and other labral lesions, reversed Hill-Sachs fractures, rotator cuff tears) or develop due to overuse and associated microtrauma (stretched posterior capsule, rotator cuff tears).
In general, the most provocative position consists of combined flexion, adduction and internal rotation of the glenohumeral joint. The most widely utilized provocative tests, such as the jerk test and Kim test utilize this position, with the addition of posterior-directed axial force applied to the distal humerus.
The principal intervention for patients presenting with recurrent PSI is rehabilitation of the posterior rotator cuff, especially the infraspinatus muscle. Interestingly, strengthening exercises have proven to be more effective in posterior instability than in anterior instability – there are however cases that do not improve with exercise therapy. Surgical intervention is indicated in case of instability that can be attributed to mechanical factors, modifiable by surgery. > From: Van Tongel et al., Knee Surg Sports Traumatol Arthrosc 19 (2011) 1547-1553. All rights reserved to Springer-Verlag.
The Pubmed summary of the article can be found here.