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.
A ganglion cyst is a fluid-filled bump associated with a joint or tendon sheath. It most often occurs at the back of the wrist, followed by the front of the wrist.
The Achilles tendon or heel cord, also known as the calcaneal tendon, is a tendon at the back of the lower leg, and is the thickest in the human body. It serves to attach the plantaris, gastrocnemius (calf) and soleus muscles to the calcaneus (heel) bone. These muscles, acting via the tendon, cause plantar flexion of the foot at the ankle joint, and flexion at the knee.
Acute septic arthritis, infectious arthritis, suppurative arthritis, pyogenic arthritis, osteomyelitis, or joint infection is the invasion of a joint by an infectious agent resulting in joint inflammation. Generally speaking, symptoms typically include redness, heat and pain in a single joint associated with a decreased ability to move the joint. Onset is usually rapid. Other symptoms may include fever, weakness and headache. Occasionally, more than one joint may be involved, especially in neonates, younger children and immunocompromised individuals. In neonates, infants during the first year of life, and toddlers, the signs and symptoms of septic arthritis can be deceptive and mimic other infectious and non-infectious disorders.
The popliteal artery is a deeply placed continuation of the femoral artery opening in the distal portion of the adductor magnus muscle. It courses through the popliteal fossa and ends at the lower border of the popliteus muscle, where it branches into the anterior and posterior tibial arteries.
A shin splint, also known as medial tibial stress syndrome, is pain along the inside edge of the shinbone (tibia) due to inflammation of tissue in the area. Generally this is between the middle of the lower leg and the ankle. The pain may be dull or sharp, and is generally brought on by high-impact exercise that overloads the tibia. It generally resolves during periods of rest. Complications may include stress fractures.
Achilles tendon rupture is when the Achilles tendon, at the back of the ankle, breaks. Symptoms include the sudden onset of sharp pain in the heel. A snapping sound may be heard as the tendon breaks and walking becomes difficult.
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.
The plantaris is one of the superficial muscles of the superficial posterior compartment of the leg, one of the fascial compartments of the leg.
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.
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 popliteal artery entrapment syndrome (PAES) is an uncommon pathology that occurs when the popliteal artery is compressed by the surrounding popliteal fossa myofascial structures. This results in claudication and chronic leg ischemia. This condition mainly occurs more in young athletes than in the elderlies. Elderlies, who present with similar symptoms, are more likely to be diagnosed with peripheral artery disease with associated atherosclerosis. Patients with PAES mainly present with intermittent feet and calf pain associated with exercises and relieved with rest. PAES can be diagnosed with a combination of medical history, physical examination, and advanced imaging modalities such as duplex ultrasound, computer tomography, or magnetic resonance angiography. Management can range from non-intervention to open surgical decompression with a generally good prognosis. Complications of untreated PAES can include stenotic artery degeneration, complete popliteal artery occlusion, distal arterial thromboembolism, or even formation of an aneurysm.
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 knee bursae are the fluid-filled sacs and synovial pockets that surround and sometimes communicate with the knee joint cavity. The bursae are thin-walled, and filled with synovial fluid. They represent the weak point of the joint, but also provide enlargements to the joint space. They can be grouped into either communicating and non-communicating bursae or, after their location – frontal, lateral, or medial.
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.
Pseudothrombophlebitis is a clinical condition where there are signs and symptoms of phlebitis in the absence of a thrombophlebitis lesion. Symptoms include pain, swelling, erythema and tenderness evolving over hours or days. It is often associated with the rupture or dissection of a popliteal cyst otherwise known as a Baker's cyst, although it can be associated with other disorders such as the arthritides. It may also occur as an orthopaedic surgical complication, secondary to trauma or as a presentation of septic arthritis. It is crucial to differentiate this condition from deep vein thrombosis as the treatment for DVT can cause adverse effects in patients with pseudothrombophlebitis.
The calf is the back portion of the lower leg in human anatomy. The muscles within the calf correspond to the posterior compartment of the leg. The two largest muscles within this compartment are known together as the calf muscle and attach to the heel via the Achilles tendon. Several other, smaller muscles attach to the knee, the ankle, and via long tendons to the toes.
Knee pain is pain in or around the knee.
A tibial plateau fracture is a break of the upper part of the tibia (shinbone) that involves the knee joint. This could involve the medial, lateral, central, or bicondylar. Symptoms include pain, swelling, and a decreased ability to move the knee. People are generally unable to walk. Complication may include injury to the artery or nerve, arthritis, and compartment syndrome.
A popliteal artery aneurysm is a bulging (aneurysm) of the popliteal artery. A PAA is diagnosed when a focal dilation greater than 50% of the normal vessel diameter is found. PAAs are the most common aneurysm of peripheral vasculature, accounting for 85% of all cases. PAAs are bilateral in some 50% of cases, and are often (40-50%) associated with an abdominal aortic aneurysm.
