Today I am going to talk about meniscus tears. The meniscus is the piece of “shock absorber” cartilage in between the thigh bone (femur) and the shin bone (tibia) in the knee joint. It is made out of a tough, grissle-like fibrous type of cartilage that not only provides cushion and protection to the articular cartilage (“the tread on the tire”) but also provides some stability to the knee joint.

There are different types of meniscus tears and therefore different types of treatment as well as different expected outcomes. What I would like to concentrate on most are the differences and types of “meniscus” tears in different age groups. The vast majority of time, in a “younger” patient (30- to 40-year-old and younger), a meniscus tear is usually exactly that, i.e. a rip/tear/disruption of the fibers of the meniscus. It is usually a “clean” tear or at least it usually starts that way. Most of these types of meniscus tears are due to trauma i.e. a twisting injury such as in sports; an injury while squatting down or kneeling down, where a patient feels a specific pop and has immediate pain and relatively immediate swelling. These are in stark contrast to “degenerative” meniscus type tears.

The post traumatic/ “younger” type meniscus tears usually are isolated, and the remainder of the joint is in good condition. There is not a lot of softening of the cartilage “chondromalacia,” and there is not a lot of arthritis, which is an even more advanced form of chondromalacia. There is not a lot of chronic associated changes in the knee. There may or may not be an acute ligament injury which can complicate matters but the bottom line is that even with ligament injuries, many times if these are treated surgically the patients will overall recover and do well. It is certainly not an absolute but these types of tears definitely respond differently than the more “degenerative” meniscus tears.

As we get older, our body, including our joints, degenerate. There is wear and tear where the cartilage on the end of the bone starts to wear down, which is what arthritis is. There are different degrees of arthritis anywhere from some mild softening of the cartilage on the end of the bone to complete bone on bone wear and tear.

In addition to the articular cartilage degenerating, likewise the meniscus can also degenerate. As the articular cartilage degenerates from wear and tear over time, the surfaces become rougher and those rough surfaces rub on the meniscus cartilage increasing its own wear and tear. This can also work in reverse where a chronic meniscus tear can cause arthritis in the knee; but, in many patients 50, 60, 70 years of age and older, this degeneration can lead to pain, swelling and inflammation.

Sometimes there is even an actual traumatic injury that is the “straw that broke the camel's back” and even though the degenerative process was there prior to this injury (it takes years to occur) the traumatic injury caused the knee to become symptomatic.

Many times the patient will come to us with an MRI, but no X-rays taken with a diagnosis of a “meniscus tear.” We always order X-rays for completeness sake and especially weight bearing X-rays because many times these same patients will show a significant amount of narrowing of the joint space even up to and including bone on bone at times that is best seen on X-rays.

Therefore, it is not surprising that MRIs in these types of patients have many different abnormalities. Some of them may be pre-existing and “red herrings.” Some of them may be new or acute.

Either way, the presence of significant wear and tear/chondromalacia/arthritis in a joint bodes more poorly for post operative results than if the patient did not have degenerative changes/arthritis in the knee already.

This is one of the hardest things for me to get patients to understand is that even though they may truly have a “meniscus tear” on an MRI, it may or may not be the actual cause of their symptoms and even if it is, going in there and trimming out the torn degenerated portions of the meniscus does not change the fact that the patient has degeneration/arthritis in the knee and frequently these patients will continue to have pain despite surgical treatment.

Therefore, we do not rush immediately into surgical treatment for a “meniscus tear” in a patient who has degenerative changes in their knee without any mechanical symptoms. Certainly if the patient has symptoms with true locking, i.e. the knee is getting stuck and they have to shake it free, true significant catching and mechanical type pain, then we will strongly suggest a conservative treatment course of physical therapy, anti-inflammatories by mouth, possible cortisone injection, possible hyaluronic acid injections (artificial joint fluid injections).

The good news is that just as many people will get better with conservative treatment as they will with surgical treatment. Even the people who do have surgery, unfortunately, still usually have arthritic symptoms or at the least take quite a bit longer to get better than the patient that was previously discussed earlier in this article who has no degenerative changes in their knee and has “just” a meniscus tear.

Therefore the take home message in this article is that not all “meniscus tears” are created equal and if a patient has pre-existing chondromalacia “softening of the cartilage”/arthritis of the knee the results are far less predictable and far less successful than if they do not have degenerative changes.

Dr. Marc P. Pietropaoli is a board certified/fellowship trained orthopedic surgeon/sports medicine specialist and is president of Victory Sports Medicine & Orthopedics in Skaneateles.