What is a meniscus transplant? The simplest answer is it’s a surgery to remove your damaged, irreparable meniscus and replace it with a new one from a donor. This surgery is a consideration when you are missing the normal function of your meniscus, usually from significant meniscus damage or surgical removal of a large portion. There are other criteria to be met, which are mentioned later in the article.
Is this different from a meniscectomy? Yes, a meniscectomy involves trimming the torn portion of the meniscus. A partial removal maintains some residual function, but a complete removal results in high risk of developing arthritis. Ideally a meniscus may be repaired to preserve its function, but in many cases it cannot be repaired and a partial removal is performed.
Basic anatomy: Just a basic anatomy lesson to help you understand what we are talking about in this article. The meniscus is a C-shaped piece of “rubbery” cartilage. It sits between your femur (thighbone) and tibia (shin) and acts as a shock absorber.
Below is an illustration of knee anatomy and an operative picture of a normal meniscus
Who can have a meniscus transplant? Are there specific criteria that need to be met?
There are some factors that make you a candidate for a meniscal transplant. You’re a candidate if:
- You are missing a major portion of your meniscus
- Your knee must have little to no arthritis-if your cartilage is too worn away it can damage the transplant
- Your knee must have proper alignment and stable ligaments- again proper knee anatomy if crucial to the success of your transplant
- This surgery works best in people under 50 years of age, and not that we want this to be a determining factor, but insurance will rarely approve this surgery in anyone over the age of 50.
This is an operative picture of a damaged meniscus that's missing a large portion
What steps need to be taken to prepare for surgery?
Before a meniscal transplant is considered, you will undergo a formal examination by an orthopedic surgeon. You will also have an MRI performed to assess the integrity of your meniscus and determine whether it is repairable or could possibly be managed by performing a meniscectomy. If a meniscal transplant is determined to be the best option, you will then have sizing x-rays taken. The sizing x-rays are very important because you need to be matched with a compatible donor’s size.
Where does to donor meniscus come from? The meniscus comes from a cadaver donor. This is a very safe process as the donor is assessed for communicable diseases and any active infections. The donors tend to be young and healthy because the graft must be taken from a non-arthritic knee. The graft also goes through several safety steps such as an antibiotic soak, ionizing radiation and sterile processing- it is then frozen until needed. We use licensed tissue banks that adhere to the strictest standards in the industry.
The picture on the left is how the donor meniscus arrives. The picture on the right demonstrates a trimmed graft with bone plugs and suture in place. It is ready for implantation.
What happens during the procedure?
A meniscal transplant takes place during a knee arthroscopy. You will have 3-4 small incisions (portals) in your knee which provide access for surgical instruments. A camera is inserted to visualize the knee along with very small surgical tools. Your damaged meniscus is trimmed away, and a small trough is made in the tibia (shin bone) for the transplant and its bone plug to sit in and the meniscus is then stitched into place.
The transplanted menicus with stiches in place
What is the recovery time?
This is an outpatient surgery, and you will go home the same day. You will be placed in a range of motion (ROM) brace and use crutches for protection of the transplant.
You will remain in the ROM brace for 4-6 weeks following surgery. The brace will need to be locked with your leg in full extension when you are standing for protection of the implant. You will also need to remain non-weightbearing for 6 weeks after surgery with gradual return to bearing weight. If you start walking on it too soon, the transplant could move or cause you to tear the stitches holding it in place. Your body weight can cause the meniscus to “squish” out of place.
You will attend physical therapy following surgery to strengthen the muscles in your knee and work on regaining full range of motion.
Can I resume full activities following surgery?
You need to be patient following surgery to allow your knee to heal and recover from the “trauma” of surgery. You can resume physical activities about 6-12 months post-op depending on how strenuous they are.
This surgery is performed for joint preservation and our goal is to return you to full activities.