Shoulder Instability:
What is shoulder instability?
Shoulder instability occurs whenever the humerus (the ball of the shoulder joint) pops out of the glenoid (the socket). There is a wide spectrum of this - from subluxation (the humerus slides off the glenoid, but not completely) to dislocation (the humerus completely slides off the glenoid and then gets stuck in that abnormal position). Subluxations usually pop back into place on their own. Often, dislocations need to be put back into place by someone else.
Is it possible to have shoulder instability and not know it?
Because there is such a wide range of instability, it is possible to have a shoulder that is unstable and not realize that the the shoulder is coming out of joint. Symptoms usually consist of pain, especially when the arm is put into various positions. For example, swimmers can often stretch their joint capsule (the balloon around the joint) because of repeated activity. This can lead to subluxation; although the swimmer only notes pain at a certain position in their stroke.
What types of instability are there?
Instability is usually classified by the direction the head pops out of the socket. Anterior instability refers to the head coming out the front; posterior instability refers to the head coming out the back. Inferior instability is usually combined with anterior instability - the head falls out below the socket. Multidirectional instability means that the head is very loose and can subluxate out the socket in more than one direction.
What is the difference between traumatic and atraumatic instability?
Traumatic instability occurs whenever there is a violent injury that causes the shoulder to dislocate (eg. a skiing accident). Atraumatic instability is caused by a repetitive injury that stretches out the ligaments of the shoulder joint (eg. volleyball or swimming). Generally speaking, people with traumatic instability experience dislocations while people with atraumatic instability experience subluxations.
I dislocated my shoulder skiing. Now what?
If this is the first time you've dislocated your shoulder, we will usually recommend that after the shoulder is reduced, your shoulder should be placed in an immobilizer for a few weeks (the exact duration depends on your age). The purpose of this is to allow the shoulder ligaments to heal. After the shoulder has rested for an appropriate length of time, strengthening exercises are prescribed. The goal is to strengthen your muscles to regain the strength you've lost after the dislocation and prevent the shoulder from dislocating again.
What is the chance of me dislocating my shoulder again?
The chance of you dislocating your shoulder again is primarily related to your age. Young people (less than 20) have a very high rate of re-dislocating their shoulder - 90% or higher. The older you get, the less chance there is of re-dislocating.
What happens if my shoulder dislocates again?
Usually after the first traumatic dislocation, the force necessary to dislocate the shoulder again is much less. People who are going to have re-dislocations (called "recurrent dislocations") can often get them with very minor movements, even sometimes in their sleep depending on the position they put their arms when they sleep. Obviously, this can be very painful and annoying. In addition, many dislocations can wear the cartilage of the shoulder joint and put you at risk for arthritis.
Sometimes, physical therapy to strengthen the rotator cuff can help with these recurrent dislocations. But usually this depends on the patient's age - if the patient is young and active, chances are that therapy is not going to prevent future dislocations. In these cases, we advise the patients to undergo a surgical repair.
What does surgery accomplish?
The ultimate goal is to stop your shoulder from dislocating again. This is accomplished by tightening up the ligaments that prevent your shoulder from dislocating. The two major things we do is: 1) repair the labrum - this is an "O-ring" on the glenoid that acts as a bumper to keep the head from sliding out; and 2) tighten the glenohumeral ligaments.
What are the types of surgery?
There are many different types of shoulder dislocation surgery. However, the one that we perform, and that most others in the country do also, is called the Bankart repair. Actually, there are many different versions of this, with slightly different names and modifications (eg. "anterior capsulo-labral reconstruction") but they all basically accomplish the same thing.
There are two ways to do this surgery - "open" and "arthroscopic". Open surgery involves an incision in the front of the shoulder about 2 inches in length. The joint is viewed directly and the repair performed using suture and suture anchors (small devices used to attach the stitches to bone). Arthroscopic surgery involves doing the same thing through a scope - the incisions are much smaller.
What is the difference between arthroscopic and open Bankart procedures?
This is a hotly debated subject amongst shoulder surgeons. People can agree on certain things: arthroscopic reconstructions are generally less painful and use smaller incisions than open reconstructions. Rehabilitation is often easier after arthroscopic repair, and there is less loss of motion after surgery. Many "open" shoulder surgeons argue, however, that the results for open shoulder surgery are more successful than arthroscopic - arthroscopic repairs are often more "delicate" and they are also harder to perform. They point to studies that state that open repairs have a success rate of 90-95%, whereas arthroscopic repairs have success rates of 80-90%.
Personally, I believe that the arthroscopic repair is the best option for most people. It is much less painful, more cosmetic, and there is less limitation of motion. I think that the reason that such repairs have a wider variability of success is that they are much harder to perform than open repairs. Most orthopedic surgeons are not trained in the arthroscopic technique; hence their ability to perform this complicated procedure can be limited, unless they have had special experience. The technique I use, in the hands of master arthroscopists, has a success rate of 93% - this is as good as any open repair. Indeed, I think that with the latest arthroscopic techniques, one may see an even higher success rate (studies are being done now to test this). Finally, I do not think one loses anything by trying the arthroscopic technique first - if it does not work, we can always go back and do the bigger, more invasive, open surgery.
What's this new "thermal" procedure?
Thermal capsulorraphy is a relatively new arthroscopic technique that can be utilized in the repair of some types of instability. It allows us to "shrink" some of the tissues within the shoulder to tighten loose ligaments or decrease the volume of the capsule. For more information, see our page on thermal capsular shrinkage.
What can I expect after surgery?
After a surgical reconstruction, your pain will depend on exactly what needed to be done and whether the repair was "open" or "arthroscopic" (arthroscopic procedures generally have less pain). Cryotherapy is very useful to help decrease swelling and relieve pain. Most patients will find this useful for several days, if not longer, after surgery. Your arm is immobilized for a period of time, depending on the reconstruction. Finally, physical therapy is usually prescribed to help you regain motion, then strength.
- Dr. Laith Farjo
Telephone:
(810) 299-8550