What happens to a joint during a shoulder dislocation?
During a shoulder dislocation, the ball part of the joint, the humerus, completely loses contact with the socket or with the glenoid. The most common dislocation is called an anterior dislocation of the shoulder.
This is where the ball goes forward then off the front of the socket. Least commonly we have posterior dislocations where the ball goes backwards, and most uncommonly we have inferior dislocations.
With an inferior dislocation the ball completely loses contact with the socket. The two are no longer touching each other.
Whereas in a subluxation (partial dislocation) the ball partially dislocates, slides forward or back, but it never loses contact with the socket. It’s like a part dislocation.
What’s the difference between a shoulder dislocation and instability?
A shoulder dislocation is usually an acute injury where the shoulder comes out of the joint completely. The humerus may relocate of its own accord or you may need to go to hospital or to an A & E to have it relocated under sedation or pain relief.
Shoulder instability is what can develop in the months or years following a dislocation. This is a result of ligament injuries to the shoulder. Your shoulder continues to either sublux, which is partially dislocate, or continues to dislocate and this instability requires surgery.
Is it possible to dislocate your shoulder without knowing it?
Yes, it is. A lot of the instability that we see is a result of dislocations or significant subluxations that have occurred as a result of injuries, possibly meaning years before.
Often the patient just felt they had a bit of a shoulder sprain. They were not really particularly worried about it. It recovered after a couple of weeks and they carried on playing or working normally.
It’s only a couple of months to a couple of years later that they start to notice issues with the shoulder as a result of the ongoing instability of the shoulder.
How will I know if it is dislocated?
Usually it is traumatic. Most common patterns of injury we see in New Zealand are due to contact sports such as rugby, in rugby league or as a result of trauma such as a fall or a slip/fall.
The shoulder is painful. It often looks funny. There is a squaring off of the shoulder, so the arm looks like it’s down and the normal rounded contour of the shoulder is gone. It looks square, is painful to move the shoulder.
People often report a dead-arm feeling where they feel as though the arm is paralyzed or someone is giving them a charley-horse type punch.
Often it is a case of the arm feeling completely flaccid. Occasionally, if it spontaneously relocates, people will feel a thunk or a squelching noise as the shoulder goes back into the joint itself.
If I think it is dislocated but gone back into place, should I still see a doctor?
Yes. For any significant shoulder injury, you should probably see a doctor or physiotherapist for assessment.
Part of that process is to get that injury logged with ACC so they are aware an injury has occurred, so if you need further treatment down the track, it should be funded by them.
Also, they can acess you for other injuries that can be associated with what people often feel are dislocations such as rotator cuff tears or significant shoulder sprains.
Does shoulder instability feel the same as a dislocation?
No. When you dislocate your shoulder it is often painful, but instability is often felt as a sense of apprehension.
So if people go to do an activity where the shoulder begins to sublux and they feel as though they shouldn’t do that activity. They feel fear of doing that activity because they think something bad is going to happen.
So they may lift their arm up overhead to pull a big heavy box down from a shelf and they immediately go, “No, I can’t do that. My shoulder won’t cope.”
Or they bring their arm back to throw and they feel a sudden pain or pinch at the front of the shoulder, and sometimes a bit of a clunk, and that is when they know they have this instability pattern.
Can a traumatic dislocation cause other damage to my shoulder joint?
The labrum is the tissue around the front of the shoulder that helps to deepen the socket and acts as a little bumper to help stop the shoulder dislocating, but importantly, it also has the shoulder ligaments attached to it labrum.
When it becomes torn from the socket, the ligaments become lax and those lax ligaments allow the shoulder to sublux and maybe dislocate again. That often is the condition with a younger patient, whereas with older patients, there is a greater risk of damage to the rotator cuff at the same time.
Other associated injuries, things such as damage to the cartilage or the wear surface of the shoulder or fractures of the shoulder at the same time, such as breaking a piece off the socket, which is called a bony Bankart injury.
The socket is more likely to fracture. What happens to the ball is that as it rolls forward and ends up sitting on the front of the socket, it can get a little impaction fracture on the back. Imagine putting your finger into a pavlova. When you pull your finger out there is a depression left.
The same thing happens on the back of the head. The bone is a bit softer so a divot or a depression gets left in the back of the head.
The problem is that Hill-Sachs impaction injury acts as a lever later on for patients and can increase the risk of further dislocation as can the fractures at the front of the glenoid because they decrease the diameter or the front to back distance of the glenoid so there is less distance for the shoulder to travel before it falls out of joint.
Which sports are more prone to dislocations?
In this country it is primarily contact sports. So rugby league, rugby union, but other sports such as basketball, netball are all associated with dislocation as are sports where falls or things happen at great velocities such as waterskiing, wake boarding, cycling, mountain biking.
If I had it previously, am I at more risk of it happening again?
Yes, particularly if you were young. Most studies looking at instability have been done on a young population.
Quoted figures of re-dislocation in a young male athlete who is involved in a contact sport sometimes seem to approach 100%, meaning if you have a traumatic dislocation in your teens through to your early 30s and you continue to play contact sports such as rugby, rugby union, your chances of dislocating again are almost 100%.
How are dislocations diagnosed?
In the first instance, an x-ray is taken and if the shoulder is frankly dislocated, or the ball is no longer in the socket, then the shoulder will be relocated.
Often, however, shoulders spontaneously relocate or it is just a subluxation episode, in which case x-rays will often be normal or will show bony injuries we mentioned above, the Bankart lesion and the Hill-Sachs fractures.
But even then, they are difficult to pick up on a normal x-ray, so that is when we use an MR arthrogram to look at what is going on with the ligaments.
There are certain tests we can perform when we examine the patient that indicate they are unstable.
If it does continue to dislocate, will I need surgery?
Most likely, yes. I can’t say that for 100% of people because some people are prepared to change their activities to prevent it dislocating.
So if they are coming to the end of their rugby career, they might want to give up rugby and take up coaching.
But if they are young, if they are at the start of their careers, then yes, they are more likely to want surgery. The problem here is if it is dislocating as a result of rugby trauma, fine, change your activity.
But if it is dislocating just when you are in bed at night or when you do simple tasks like drying yourself or putting on a shirt, then yes, you most likely will require surgery to fix the dislocation.
Otherwise, you will develop further posttraumatic arthritis in the shoulder.
How many times should I let it happen before I see a shoulder specialist?
That is a question that is up for debate. Most people nowadays would say that if your shoulder dislocates once you should probably be seeing at least a physiotherapist, if not a shoulder specialist to have your shoulder assessed.
Particularly if you are young, particularly if you are involved in contact sports.
Am I at risk of arthritis of my shoulder as I get older?
Yes you are. If your shoulder continues to be unstable, you are at increased risk of arthritis in the shoulder because of the fact the shoulder is not moving normally.
Like a joint on your car or anywhere, it needs to move correctly if it wants to last a long time.
The minute it starts to move abnormally, then it will start to wear out a little bit quicker.
My shoulder feels like it is slipping and it sometimes happens when I am asleep. What should I do?
You need to see a general practitioner or physiotherapist to have an initial workup done, which will usually be an x-ray and a physical examination, then most likely you will be referred on to a shoulder specialist.
If I need surgery, what do you do to stop it from happening again?
There are a number of things we can do to stop shoulders dislocating.
If it as simple as damage to the labrum at the front of the shoulder and the bony injury is fairly minor. Then we will repair the labrum, those ligaments back to the front of the shoulder or what laymen refer to as a shoulder tightening operation where we snug the ligaments back down onto the shoulder.
If there is significant bone damage or bone loss, we have to make up for that bone loss, so we sometimes have to attach a piece of bone to the front of the shoulder to rebuild the shoulder socket to increase that distance from front to back again.
That can be in combination with ligament repairs and reconstructions as well. If you are a little bit older and you have a rotator cuff injury, we will repair the rotator cuff at the same time.
If there is cartilage damage, we cannot rebuild cartilage but we can do various techniques to try and encourage scar cartilage to form to try and preserve the joint for as long as possible.
That is a graft taken from you. There is one of two procedures that can be done.
One is called a Latarjet, which is where the coracoid process, which is the spikey bone at the front of the shoulder, is detached and moved to the front of the shoulder and that is the operation I prefer.
But there are also operations with pieces of bone from the top of your pelvis that can be used purely as a bone block procedure.
What can I expect in the 24 to 48 hours following surgery?
For the first 18 to 24 hours your shoulder will be completely numb because most operations are done under a block.
The shoulder is not usually too uncomfortable after this particular operation because it is done keyhole for the most part, occasionally done open if there is a need for the bone block procedure, or if there are unexpected findings at the time of surgery.
Your shoulder can be uncomfortable for up to six to eight weeks afterwards but usually that is manageable just with simple analgesics like paracetamol.
How long until I can begin my rehab?
For the first four weeks you are in a sling. We get you doing some simple exercises to keep your shoulder moving.
At the six-week mark we begin a little bit of active movement so we get you moving your shoulder under muscle power, and then at 12 weeks we begin some strengthening activities.
Depending on your occupation depends on when you get back to work. If you are desk bound or a sedentary worker, and you have transport support, then you could be back at work within a week or so.
If you are a heavy manual worker or particularly work overhead such as a builder, you may not be back to work for several months, and you won’t be back to contact sports like rugby, rugby league for 5-1/2 to 6 months.
If I don’t rehab properly, can my shoulder dislocate again?
Yes. Simple as that. The surgery is reasonably straightforward in most people’s cases, but adherence to the rehabilitation and properly managing the shoulder afterwards allows that surgery to heal.
Surgery is designed to put things back where they came from, but your body still has to heal them back there and that still takes time.
If I don’t need surgery, will I be able to return to weights and playing contact sports again?
Yes, if you have properly rehabbed your shoulder and it is considered to be stable, then you should be able to return to those; however, there is always a risk that you will dislocate again, and if you do, that may push the issue of surgery a little bit harder.
However if you do need surgery to stop further instability, then in most part yes, there is no reason you cannot retutn to those activities. Provided you have rehabilitated correctly.
What is multidirectional instability to the shoulder and is it different to a dislocation?
The dislocations we have talked about up until now have been traumatic dislocations as a result of an injury. Traumatic dislocations run along a spectrum from your basic anterior dislocation as a result of an accident, in which case we will repair it – that is an operation, right through the spectrum to people who are born with unstable or lax shoulders who can often dislocate voluntarily.
They can pop the shoulder out themselves. Multidirectional instability is a shoulder that is unstable in multiple directions, front or back and often down as well.
It can be as a result of trauma, but often there is a hereditary or congenital part to play in that as well. The operations for that vary slightly and sometimes in those patients it is less about an operation and more about appropriate rehab and counseling education.
Can MDI be fixed with physical rehab?
It depends on what multidirectional instability you have. Some MDI we can fix with physical rehab, some of it requires surgery, but it depends very much on the individual.
If you are experiencing any of the symptoms mentioned in this guide please contact Mr Durrants clinic on (09) 523 2765 for more information. If you are in pain from a recent injury please seek immediate medical attention from your nearest accident and emergency clinic.