Frozen Shoulder: 2. How It Develops
The origins of Adhesive capsulitis (a.k.a. Frozen shoulder) involve many factors, and may include an injury to the biceps muscle, and the development of inflammation in various shoulder joint components. Dr. Michael Buna's explanation helps identify the how frozen shoulder develops and why movements are restricted as a result.
Video Transcript: Frozen Shoulder - How It Develops
Now I want to talk about when patients attend their doctors and they come up with confusing diagnoses. The reason being is that doctors tend to oversimplify things. We want to just give one label because if we give it two labels then people think, ‘Oh, they’re really sick.’ Or if we give it three labels they think ‘Really we’re going down.’ But what actually happens is that most conditions are more complex that we make them out to be. That is classic in the frozen shoulder.
So one of the conditions that we get in the shoulder, and everybody gets, is tendonitis, where the tendon in the biceps comes inflamed. So you will attend the Dr. and he will call it tendonitis. Then there is another condition you can get where the bursa, that I talked about before in the anatomy portion, becomes inflamed and you end up with bursitis. And in our shoulder as I said earlier, we have two bursas and they can both become inflamed. Now a third thing that you have in your shoulder is the capsule, the bag. So we can get capsulitis too. And the ultimate thing that we end up with in shoulders is Adhesive capsulitis.
Now what really happens usually, in most people, is they do something with their arm, and their bicep tendon becomes inflamed. So, then you have tendonitis. Now the shoulder is also an unusual joint, in that the biceps tendon penetrates the capsule, and hooks on inside the joint. So, when the biceps tendon becomes inflamed, the place where it penetrates the capsule, the capsule now becomes inflamed. Now once the capsule is inflamed, then two bursas that live inside, they become inflamed. So now you have tendonitis, you have capsulitis, and you have bursitis.
An unusual thing that happens in the shoulder, as I described earlier, is that the capsule hangs down allowing for the abduction action. But what happens when the capsule becomes inflamed, is the inner linings of the capsule become sticky, so they adhere to themselves. So instead of it looking like this when your arm is down, the capsule actually looks like that. And when you go to abduct your arm, instead of it going like this, it goes like that because this is not letting go of it. And therefore another term that is used is Adhesive capsulitis. That's the true term that should be used in a true frozen shoulder. You do have tendinitis. You do have bursitis. But you actually have Adhesive capsulitis.
There you go.