 | This article includes a list of references, related reading or external links, but its sources remain unclear because it lacks inline citations .(January 2017) |
Meniscal cyst is a well-defined cystic lesion located along the peripheral margin of the meniscus, a part of the knee, nearly always associated with horizontal meniscal tears.
Pain and swelling or focal mass at the level of the joint. The pain may be related to a meniscal tear or distension of the knee capsule or both. The mass varies in consistency from soft/fluctuant to hard. Size is variable, and meniscal cysts are known to change in size with knee flexion/extension.
Various etiologies have been proposed, including trauma, hemorrhage, chronic infection, and mucoid degeneration. The most widely accepted theory describes meniscal cysts resulting from extrusion of synovial fluid through a peripherally extended horizontal meniscal tear, accumulating outside the joint capsule. They arise more commonly from the lateral joint margin, and occur most often in 20- to 40-year-old males.
Magnetic resonance imaging is the modality of choice for diagnosis of meniscal cysts. In their most subtle form, meniscal cysts present as focal areas of high signal intensity within a swollen meniscus. It is not uncommon for radiologists to miss this type of meniscal cyst because the signal intensity is not quite as great as fluid on T2 weighted sequences.2 When this fluid is extruded into the adjacent soft tissues, the swollen meniscus subsequently assumes a more normal shape, and the extruded fluid demonstrates a higher T2 signal typical of parameniscal cysts.
Medial meniscus horizontal tear extending into a meniscal cyst.
Sagittal T2 images of a medial meniscus horizontal tear extending into a meniscal cyst.
Large medial meniscus cyst.
Treatment of meniscal cysts consists of a combination of cyst decompression (intraarticular decompression versus open cystectomy) and arthroscopic repair of any meniscal abnormalities. Success rates are significantly higher when both the cyst and meniscal tear are treated compared to treating only one disease process.
In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia, and one between the femur and patella. It is the largest joint in the human body. The knee is a modified hinge joint, which permits flexion and extension as well as slight internal and external rotation. The knee is vulnerable to injury and to the development of osteoarthritis.
Arthroscopy 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 joint through a small incision. Arthroscopic procedures can be performed during ACL reconstruction.
A Baker's cyst, also known as a popliteal cyst, is a type of fluid collection behind the knee. Often there are no symptoms. If symptoms do occur these may include swelling and pain behind the knee, or knee stiffness. If the cyst breaks open, pain may significantly increase with swelling of the calf. Rarely complications such as deep vein thrombosis, peripheral neuropathy, ischemia, or compartment syndrome may occur.
The Segond fracture is a type of avulsion fracture from the lateral tibial plateau of the knee, immediately below the articular surface of the tibia.
A meniscus is a crescent-shaped fibrocartilaginous anatomical structure that, in contrast to an articular disc, only partly divides a joint cavity. In humans they are present in the knee, wrist, acromioclavicular, sternoclavicular, and temporomandibular joints; in other animals they may be present in other joints.
The McMurray test, also known as the McMurray circumduction test is used to evaluate individuals for tears in the meniscus of the knee. A tear in the meniscus may cause a pedunculated tag of the meniscus which may become jammed between the joint surfaces.
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. The meniscus to be transplanted is taken from a cadaver, and, as such, is known as an allograft. Meniscal transplantation is technically difficult, as it must be sized accurately for each person, positioned properly and secured to the tibial plateau. As of 2012, only a few surgeons have significant volume of experience in meniscus transplantation worldwide.
The medial meniscus is a fibrocartilage semicircular band that spans the knee joint medially, located between the medial condyle of the femur and the medial condyle of the tibia. It is also referred to as the internal semilunar fibrocartilage. The medial meniscus has more of a crescent shape while the lateral meniscus is more circular. The anterior aspects of both menisci are connected by the transverse ligament. It is a common site of injury, especially if the knee is twisted.
The lateral meniscus is a fibrocartilaginous band that spans the lateral side of the interior of the knee joint. It is one of two menisci of the knee, the other being the medial meniscus. It is nearly circular and covers a larger portion of the articular surface than the medial. It can occasionally be injured or torn by twisting the knee or applying direct force, as seen in contact sports.
The knee examination, in medicine and physiotherapy, is performed as part of a physical examination, or when a patient presents with knee pain or a history that suggests a pathology of the knee joint.
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.
Knee effusion, informally known as water on the knee, occurs when excess synovial fluid accumulates in or around the knee joint. It has many common causes, including arthritis, injury to the ligaments or meniscus, or fluid collecting in the bursa, a condition known as prepatellar bursitis.
The unhappy triad, also known as a blown knee among other names, is an injury to the anterior cruciate ligament, medial collateral ligament, and meniscus. Analysis during the 1990s indicated that this 'classic' O'Donoghue triad is actually an unusual clinical entity among athletes with knee injuries. Some authors mistakenly believe that in this type of injury, "combined anterior cruciate and medial collateral ligament disruptions that were incurred during athletic endeavors" always present with concomitant medial meniscus injury. However, the 1990 analysis showed that lateral meniscus tears are more common than medial meniscus tears in conjunction with sprains of the ACL.
The Posterior meniscofemoral ligament is a small fibrous band of the knee joint. It attaches to the posterior area of the lateral meniscus and crosses superiorly and medially behind the posterior cruciate ligament to attach to the medial condyle of the femur.
A tear of a meniscus is a rupturing of one or more of the fibrocartilage strips in the knee called menisci. When doctors and patients refer to "torn cartilage" in the knee, they actually may be referring to an injury to a meniscus at the top of one of the tibiae. Menisci can be torn during innocuous activities such as walking or squatting. They can also be torn by traumatic force encountered in sports or other forms of physical exertion. The traumatic action is most often a twisting movement at the knee while the leg is bent. In older adults, the meniscus can be damaged following prolonged 'wear and tear'. Especially acute injuries can lead to displaced tears which can cause mechanical symptoms such as clicking, catching, or locking during motion of the joint. The joint will be in pain when in use, but when there is no load, the pain goes away.
The transverse or [anterior] meniscomeniscal ligament is a ligament in the knee joint that connects the anterior convex margin of the lateral meniscus to the anterior end of the medial meniscus.
Spontaneous osteonecrosis of the Knee, is the result of vascular arterial insufficiency to the medial femoral condyle of the knee resulting in necrosis and destruction of bone. It is often unilateral and can be associated with a meniscal tear.
Discoid meniscus is a rare human anatomic variant that usually affects the lateral meniscus of the knee. Usually a person with this anomaly has no complaints; however, it may present as pain, swelling, or a snapping sound heard from the affected knee. Strong suggestive findings on magnetic resonance imaging includes a thickened meniscal body seen on more than two contiguous sagittal slices.
In medicine, joint locking is a symptom of pathology in a joint. It is a complaint by a person when they are unable to fully flex or fully extend a joint. This term is also used to describe the mechanism of lower limb joints held in full extension without much muscular effort when a person is standing.
Knee pain is pain in or around the knee.