Meniscus Injury Overview
The medial and lateral menisci of the knee are very important cushions to protect the cartilage and prevent the development of osteoarthritis. In addition, the menisci also serve to provide extra stability to the knee. Thus, they are an essential part of the anatomy and the loss of the menisci can result in early onset osteoarthritis and can also result in an unstable knee, especially if there is a concurrent ligament reconstruction performed.
The menisci are fibrocartilage and have a very limited blood supply. Thus, a meniscal tears at the edges of the meniscus on the inside of the knee have a very low chance of healing. However, meniscal tears closer to the joint lining, commonly called meniscocapsular separations, have a much higher chance of healing. Meniscal tear treatment will usually be administered surgically.
Description of Meniscus Surgery
In general, Dr. LaPrade will always try to preserve the meniscal tissues to prevent further development of osteoarthritis, especially if there is a concurrent ACL reconstruction performed to prevent the graft from stretching out over time. He has found the use of multiple inside-out sutures allows the meniscus to be put back into its anatomic position and also provides extra stability to the meniscus such that early range of motion can be implemented.
In the case of a non-repairable tear, Dr. LaPrade will try to preserve as much meniscal tissue as possible and will trim and contour the area of the tear such that it has a lower risk of tearing further over time. In all patients who have meniscal tissue removed, they must be educated to make sure if they have any problems with pain or swelling that they return to be evaluated. This is because the early signs of osteoarthritis are pain and swelling with activities. It is important to have a proper assessment to evaluate if the patient has post-meniscectomy arthritis developing to the point where the use of an unloader brace, osteotomy or meniscus transplant surgery may be necessary to slow the further progression of osteoarthritis.
Dr. LaPrade recommends patients be periodically observed with Rosenberg x-ray views to look for joint space narrowing and alignment x-rays to determine if they are malaligned for that particular compartment where the meniscus has been removed.
Dr. LaPrade will typically do a repair of peripheral tears of the meniscus, large horizontal tears, root detachments and occasionally for radial tears, especially of the lateral meniscus, in young athletic patients. He performs the majority of meniscal tear treatments using an inside-out approach with a surgical incision on the inside or outside of the knee with needles placed into the tear which are then pulled outside the joint and tied directly over the joint lining. The use of non-absorbable sutures in this circumstance are incorporated because of the reports of higher risks of tearing a meniscus repair over time in patients who have absorbable sutures utilized.
Our preferred technique is a vertical mattress suture repair for a meniscal tear. Biomechanically, these have been shown to be the strongest type of suture repair. In some circumstances, a horizontal mattress suture may be required, especially for undersurface meniscal tears to pull it back to a more anatomic position, and also for radial tears of the lateral meniscus where horizontal mattress sutures are required to hold meniscal tissue back into place.
The rehabilitation program for postoperative meniscus surgery depends upon the other concurrent surgeries. It has been well demonstrated for patients with a meniscus repair and a concurrent ACL reconstruction that one can start early weight bearing and range of motion and have a very high chance of healing. We believe this is because of the growth factors and stem cells that are released from drilling the ACL reconstruction tunnels.