Who needs a meniscus transplant?
Meniscus transplantation, or placing cartilage from a cadaver donor into a patient, has become a possible treatment for patients with a specific pattern of knee pain. The ideal patient is someone who had their meniscus removed, and subsequently begins to develop knee pain. The patient is too young and too active to consider a joint replacement. Yet all the other “usual” treatments (anti-inflammatory medications, physical therapy, Synvisc, cortisone, joint supplements, etc…) just aren’t doing the trick. The questions is, what is a reasonable treatment.
In the last decade, meniscus transplantation has become a reasonable treatment option to be considered for some patients with specific types of knee pain. The problem is, the number of patients for whom a meniscus transplant is a reasonable option is quite small.
What is the meniscus?
The meniscus is a complex structure that provides both cushioning and stability to the knee.
Without the meniscus present, patients are much more likely to develop accelerated degenerative changes to the knee joint. As this happens, the remaining cartilage that covers the ends of the bone, called the articular cartilage, is worn away, and bone is exposed.
For this reason, orthopedic surgeons attempt to preserve the meniscus when surgically treating a torn meniscus. During surgery, only the damaged portion of the meniscus is removed, or your surgeon will perform a meniscal repair if possible. Unfortunately, despite advances in arthroscopy, not all meniscus tears are amenable to repair. In some cases, in order to best treat the damaged meniscus, the entire meniscus must be removed.
What happens when the meniscus is removed?
When the meniscus is removed, the patient is left without much of the joint cushion. Initially, this tends not to be a problem. But over time, patients often develop pain where the meniscus was removed, and they can go on to develop accelerated arthritis in that part of the knee joint.
The hope of a meniscus transplant is that by restoring the normal joint support and cushioning of the meniscus, the pain will be alleviated and the degenerative changes will slow. It is important to understand, this is the goal of meniscus surgery, and while early studies show cause for optimism, it is not known that a meniscus transplant has any effect on protecting the joint from further degeneration!
Who is a good candidate for a meniscus transplant?
- A young to middle-age patient (20-50 years old)
- Underwent prior meniscectomy (removal of meniscus)
- Normal or limited damage to the articular cartilage (bone lining) of the joint
- Symptoms consistent with the absence of a meniscus
Unfortunately, finding a patient who fits these criteria is a difficult task. Many patients have undergone a prior meniscectomy (meniscus removal surgery), and many of these patients have persistent problems related to the removal of the meniscus. However, most people who become symptomatic because of the absence of a meniscus, already have developed damage to the cartilage that remains in the knee. Patients who have this accelerated degenerative change to their knee joint are not good candidates for meniscus transplant surgery.
As described previously, patients must fit specific criteria in order to be considered a good candidate for meniscus transplant surgery.
You are not a good candidate for a meniscus transplant if:
- You still have a significant portion of the meniscus remaining (this procedure is only for patients who had the bulk of the meniscus removed)
- You have degenerative changes within the joint (early arthritis)
- You have instability or malalignment of the knee joint
- You are unwilling to perform the lengthy rehabilitation from meniscus transplant surgery
What is the rehabilitation from meniscus transplant surgery?
This varies depending on the exact procedure your doctor will perform. Most surgeons have patients protect the knee with crutches for four to six weeks. Patients will not be able to squat, run, or perform athletic activities for at least several months. Most patients who have a successful outcome return to their usual activities by about six months from surgery.
What are the risks of meniscus transplant surgery?
The risks of every surgery must be carefully considered, but there are some unique risks to meniscal transplant that patients should be aware of.
Long-term results are lacking
Long-term results simply are not available because meniscus transplantation is a relatively new procedure. There are some mid-term (3-6 year) studies which show encouraging results, but no one knows for sure how well these knee will be working in 10 or 20 years.
More surgery may be coming
Studies have shown a significant number of these patients do require further surgery, about 30%. If you are looking for one-stop shopping, a procedure that you can confidently call your last, a meniscus transplant is not for you.
The transplant can fail
Not all transplants have healed into position, and some need to be removed because they end up causing more problems than they solved. Even if you undergo proper rehabilitation and therapy, there is a significant chance that your new meniscus will not heal into your knee.
There is a very small, but a very real risk of disease transmission when using another persons tissue in your body. These tissues are preserved and cleaned to destroy bacteria and viruses, but there are no guarantees. There is a theoretical risk of HIV, hepatitis, bacterial, or other infectious disease transmission with these grafts. Again, the risk is very small, but not zero.