Left knee-joint from behind, showing interior ligaments Meniscal cartilage replacement therapy is surgical replacement of the meniscus of the knee as a treatment for where the meniscus is so damaged that it would otherwise need to be removed.

Anatomy

The

meniscus Meniscus may refer to: *Meniscus (anatomy), crescent-shaped fibrocartilaginous structure that partly divides a joint cavity *Meniscus (liquid) The meniscus (plural: ''menisci'', from the Greek for "crescent") is the curve in the upper surface ...

is a C-shaped piece of

fibrocartilage Fibrocartilage consists of a mixture of white fibrous tissue and cartilaginous tissue in various proportions. It owes its inflexibility and toughness to the former of these constituents, and its elasticity to the latter. It is the only type of ...

located at the peripheral aspect of the

knee joint In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia (tibiofemoral joint), and one between the femur and patella (patellofemoral joint). It is the largest joint in the hu ...

that offers lubrication and nutrition to the joint. Each knee has two menisci, medial and

lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral cons ...

, whose purpose is to provide space between the

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...

and the

femur The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with ...

, preventing friction and allowing for the diffusion of

articular cartilage Hyaline cartilage is the glass-like (hyaline) and translucent cartilage found on many joint surfaces. It is also most commonly found in the ribs, nose, larynx, and trachea. Hyaline cartilage is pearl-gray in color, with a firm consistency and has ...

. The majority of the meniscus has no blood supply. As a result, if the meniscus is damaged, from trauma or with age, it is unable to undergo the body’s normal healing process. Therefore, a torn piece can begin to move inside the joint, get caught between the bones, and cause pain, swelling, and decreased mobility. However, recent research has called into question whether many meniscus tears actually cause pain or are simply part of the normal degenerative process of aging. A 2008 study in the New England Journal of Medicine which shows that about 60% of meniscus tears cause no pain and are found in asymptomatic subjects. The three major treatments for a damaged meniscus are repair, removal, and transplantation. The surgery is often carried out

arthroscopic Arthroscopy (also called arthroscopic or keyhole surgery) is a minimally invasive surgical procedure on a joint in which an examination and sometimes treatment of damage is performed using an arthroscope, an endoscope that is inserted into the jo ...

ally.

Repair

During repair, the tissues are securely held together long enough for biological healing to occur. One procedure involves threading long needles into the meniscus and out an incision in the back of the knee through the aid of a guide tube called a

cannula A cannula (; Latin meaning 'little reed'; plural or ) is a tube that can be inserted into the body, often for the delivery or removal of fluid or for the gathering of samples. In simple terms, a cannula can surround the inner or outer surfaces ...

. The suture thread ends are tied together on the outside of the knee capsule layer to bring the tear together. Another procedure requires specially designed devices that employ multiple sutures and knot pusher instruments to allow surgeons to provide excellent meniscal repair with just a single 1 ½” incision. The majority of

meniscal tear A tear of a meniscus is a rupturing of one or more of the fibrocartilage strips in the knee called meniscus (anatomy), menisci. When doctors and patients refer to "torn cartilage" in the knee, they actually may be referring to an injury to a meni ...

s are not suitable for repair and instead the torn piece is removed, known as a meniscectomy. The torn portion of the meniscus is cut and sucked out of the joint, leaving behind as much normal meniscal cartilage as possible. The remaining meniscal rim is then rebalanced and contoured to provide a mechanically optimal shape.

Replacement

In some cases, the meniscal tear is so extensive that the entire meniscus must be removed, leaving the joint prone to constant pain and swelling. Removal of the meniscus cartilage leads to progressive, degenerative arthritis of the knee joint. Replacing the badly damaged or deficient meniscus with a

meniscus transplant A meniscus transplant or meniscal transplant is a transplant of the meniscus of the knee, which separates the thigh bone (femur) from the lower leg bone (tibia). The worn or damaged meniscus is removed and is replaced with a new one from a donor ...

from a human donor restores normal knee structure and helps protect the remaining joint surfaces. Meniscal transplantation is relatively uncommon, although it is gaining popularity. Meniscal transplantation was previously indicated for patients with mild arthritis who are younger than 50 years of age. The population for whom meniscal transplantation is appropriate has expanded. Survival data from a recent, long-term follow-up study shows that meniscal transplantation is also successful in older, arthritic patients with a success rate of 89.4% (42 of 47 transplants) at an average of 4.4 years. Meniscal transplantation offers patients with badly damaged cartilage an alternative to total joint replacement, and allows patients to pursue active lifestyles including impact sports.

References

{{reflist :* “Meniscal Transplants.” The American Academy of Orthopaedic Surgeons. http://orthoinfo.aaos.org. March 2003. :* Sapega, Alexander. “Meniscus Repair vs. Removal.” The Knee and Shoulder Centers of New Jersey and Pennsylvania. :* Pinkowski, John. “Meniscal Transplantation – A good choice for relieving pain and restoring mobility.” Orthopaedic and Rehabilitation Outlook :Quarterly. Fall Quarter 2004. :* Stone KR, Walgenbach AW, Turek TJ, Freyer A, Hill MD. “Meniscus allograft survival in patients with moderate to severe unicompartmental arthritis: a 2- to 7-year follow-up.” Arthroscopy. 2006 May;22(5):469-78. Orthopedic surgical procedures

Anatomy

Repair

Replacement

See also

References