All about the Intrasubstance Tear
An intrasubstance tear is a partial tear of a tendon or cartilage. It is a tear that occurs in the middle layers of a tendon and not on the outside layers. An intrasubstance tear is most seen in the rotator cuff and the knee although it is possible in other tendons as well.
Since the advent of the MRI (magnetic resonance imaging), it is more likely that an intrasubstance tear will be diagnosed. In the rotator cuff, this is a tear between the middle layers of the rotator cuff but there are no changes which can be seen on the articular or bursal sides of the tendon.
Rotator cuff tears come in many different places and in many different sizes. A full thickness tear is often causes when there is a big trauma like a car accident or a fall or other injury. There is massive crushing. Other rotator cuff tears are less obvious. These, like the intrasubstance tear, can be more hidden and partial. In all cases, patients present with pain in their upper arm and shoulder and varying degrees of weakness and loss of range.
Rotator cuff tears can increase in size and get progressively worse. Once upon a time, rotator cuff tears were the problem of baseball pitchers, but today we are hearing more and more about shoulder impingement and dysfunction in people not involved in sports. Rotator cuff tears can be degenerative. Today they are much more common in people over the age of 60 and quite rare in people under the age of 40.
The knee is another spot where intrasubstance tears can take place. Here too, the most common kind are degenerative, or caused by wear from aging, but this kind of tear is also caused by injury, either a sport injury or another type of trauma. Because an intrasubstance tear is not a full-blown tear of the meniscus, surgery is not usually the first option.
An MRI would be completed to confirm diagnosis and you would most likely be treated with NSAIDs (non-steroidal anti-inflammatory drugs) and physical therapy. Very often a meniscal tear happens during sports. It is easy playing football to twist a knee from direct contact or from hitting the ground. It is very common for a meniscal tear to take place at the same time as an ACL (anterior cruciate ligament) tear. Today you often hear about these kinds of injuries from alpine skiers.
You could have an intrasubstance tear of the meniscus just because you are getting old. As tissue gets older it is more and more likely to tear. Just going from a sitting to a standing position can be enough for this tear in the knee. Treatment will depend somewhat on where the tear has occurred. Once again, surgery is not going to be the first recommendation, rather NSAIDs and physical therapy.
A study in rotator cuff tear surgeries determined that when surgery was undertaken, going in and repairing the partial tear was not the best answer. In all of these cases, both rotator cuff and knee, arthroscopic surgery is the most common type of surgery. In this particular study, it was determined that it was better to complete the tear and then repair the entire tear than to just try and repair a partial tear. There would be a higher success rate.
If your doctor should tell you that you have an intrasubstance tear, it is not the worst news in the world. But it does mean that you are going to have to take it easy until the tear heals or the doctors decide that surgery might be the best option after all.