This week I received an inquiry regarding shoulder instability which had been ongoing several months after a shoulder replacement. It prompted me to provide a response to the question: "What are the options if you have a shoulder replacement that is unstable?"
Visit this link for my answer:
http://www.rearmyourself.com/questio...0is%20unstable
Early diagnosis of instability after shoulder replacement is critical because it may reflect a disruption of the subscapularis tendon repair. In order to perform a shoulder replacement, the subscap tendon needs to be divided (to gain exposure) and then repaired. It takes about 6 weeks to heal, which is why we keep patients in a sling for 6 weeks and limit the degree of external rotation after surgery. Usually xrays will be checked immediately after the operation and then again within 5-6 weeks. Both physical assessment of subscapularis function and xrays are helpful in determining whether the subscap has healed.
When anterior instability occurs, one may feel a slip out the front or there may be a subtle change on xray.
The point that I want to emphasize is the following: although there are numerous potential causes of instability after anatomic shoulder replacement (see the above link), instability acutely may reflect a subscap problem---as evidenced by the attached xrays. This may be fixable--but it must be performed within 4-6 weeks to increase the liklihood of success.