May 6, 2019
By: Dr. Michael O’Malley
The menisci are two c-shaped wedges that rest between the femur and tibia and serve as both shock absorbers and secondary stabilizers in the knee. They have fairly poor blood supply and are prone to injury in both the acute and chronic setting.
Injuries occur subsequent to a rotational or twisting injury to a planted leg. Traumatic tears are typically seen in an athletic or manual labor population. A sudden bend or twist to the knee causes the meniscus to tear. Degenerative tears occur as a result of the cartilage wearing down and weakening with age. Both types of tears can be symptomatic, especially in the setting of a torn tissue flap that causes mechanical symptoms such as locking or catching of the knee. With limited blood supply, the tissue is unable to heal itself.
Symptoms of a meniscal tear include pain over the inner or outer side of the knee where the tear occurred, swelling, stiffness, reduced range of motion, and even catching/locking of the knee. Following examination of the knee, an MRI is typically ordered if there is concern for tear.
In the acute setting, surgery may be recommended based on various patient factors, as well as on the type of tear, location and extent of the tear. In the degenerative setting, surgery is considered if conservative treatment options fail to relieve your knee pain or if mechanical symptoms persist. Surgical options include repair, meniscectomy, and even allograft transplantation.
Meniscal repair involves the use of sutures to fix and secure the meniscal tissue through an arthroscopic procedure. Repair depends on the extent of tear and the blood supply to the region. Although the recovery is longer, this is the preferred technique when possible to preserve the longevity of the compartment of the knee.
Meniscectomy involves removing either a portion (partial) or the entirety (total) of the torn meniscal tissue. The torn meniscus, or portion thereof, is removed and the remaining edges of the meniscus are smoothened so that there are no sharp ends or loose flaps. This procedure offers a much quicker recovery and aids in restoring and maintain knee stability, strength, and motion while decreasing pain.
In those patients who experience pain related to prior loos of meniscus tissue, an allograft transplant can be considered. This is usually either post-traumatic or related to prior meniscectomy. A size-matched cadaver meniscus replaces the deficient tissue in the affected compartment in an effort to alleviate pain and preserve the joint long term.
It is felt that preservation (if possible) or transplant of the tissue will help prevent the development or delay the progression of arthritis, and possibly eliminate the need for other surgery down the road.