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the area around the knee joint, a hinge joint that is one of the largest joints of the body, sustaining great pressure. The knee is formed by the proximal portion of the tibia, the distal end of the femur, and the patella, or kneecap. The bones are joined by ligaments, and the patella is secured to the adjacent bones by powerful tendons. The fibula is attached at the side of the knee to the tibia. Two crescent-shaped pads of cartilage, one medial and one lateral, called menisci, lying on top of the tibia cushion it from the femur and form the gliding surfaces of the joint in motion. Further cushioning is supplied by bursae, which are located around the main joint, between it and the patella and on the outside of the patella. A capsule of ligaments binds the whole assembly together. The capsule is lined with synovial membrane, which secretes a lubricating synovial fluid that makes possible a smooth, gliding motion. Traumatic disorders of the knee are common and include dislocation, sprain, and fracture.
Left: Knee joint, front view. Right: Knee joint, flexed in profile.
knee jerk (knee reflex) a kick reflex produced by sharply tapping the patellar ligament. To test this reflex, the lower part of the leg is allowed to hang relaxed (such as by crossing the legs at the knees) and the examiner taps the ligament below the patella with a small rubber hammer. The normal reaction is contraction of the quadriceps muscle, causing involuntary extension of the lower leg. This is a stretch reflex; striking the patellar ligament stretches the quadriceps muscle at the front of the thigh and causes it to contract. Two nerves are involved; one receives the stimulus and transmits the impulse to the spinal cord, and the other, a motor nerve, receives the impulse and relays it to the quadriceps muscle. Inadequate response to the knee jerk test may mean that the reflex mechanism involved is in some way impaired. In some people with normal reflexes the jerk of the knee is so light as to be nearly imperceptible, and the examiner must make other tests to check the reflex mechanism. Called also patellar or quadriceps reflex.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


(), [TA]
1. Synonym(s): genu (1)
2. Any structure of angular shape resembling a flexed knee.
[A.S. cneōw]
Farlex Partner Medical Dictionary © Farlex 2012


a. The joint between the thigh and the lower leg, formed by the articulation of the femur and the tibia and covered anteriorly by the patella.
b. The region of the leg that encloses and supports this joint.
2. An analogous joint or part of a leg of a quadruped vertebrate.
3. The joint between the femur and the tibia in an insect leg.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


() [TA]
1. Synonym(s): genu (1) .
2. Any structure of angular shape resembling a flexed knee.
[A.S. cneōw]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


Enlarge picture
Enlarge picture
1. The articulations formed by the distal femur, proximal tibia, and the patella. See: illustration
2. Any structure shaped like a semiflexed knee. Synonym: geniculum

Brodie knee

See: Brodie, Sir Benjamin Collins

carpetlayer's knee

Prepatellar bursitis.

game knee

A colloquial term for internal derangement of the knee joint, characterized by pain or instability, locking, and weakness. It is usually the result of a torn internal cartilage, a fracture of the tibial spine, or an injury to the collateral or cruciate ligaments.

First Aid

The knee should be immobilized with a posterior splint.


Arthroscopy and/or magnetic resonance imaging may be necessary for a definitive diagnosis.

housemaid's knee

Prepatellar bursitis.

knee of internal capsule

The curve at the meeting place of the anterior and posterior limbs of the internal capsule of the brain.

jumper's knee

A colloquial term for an overuse syndrome, marked by chronic inflammation and infrapatellar tendonitis, resulting from repetitive jumping or leg extension exercises. The usual treatment is nonsteroidal anti-inflammatory drugs, rest, and phonophoresis.

locked knee

A condition in which the leg cannot be extended. It is usually due to displacement of meniscal cartilage or dislocation of the patella.

posterolateral corner knee

The ligamentous, capsular, and muscular structures that stabilize the knee against varus, external rotation, and anterior/posterior forces. Disruption of these structures can result in posterolateral rotary instability of the knee.

replacement of knee

Orthopedic implantation of a prosthetic knee joint, particularly useful in treating patients with severe disabling arthritis of the knee. See: arthroplasty

roofer's knee

Prepatellar bursitis.

runner's knee

A colloquial term for several overuse conditions resulting from excessive exercise of the lower extremities. These may involve the extensor mechanism and other musculotendinous insertions. Patellar tendonitis (jumper's knee), patellofemoral dysfunction, iliotibial band syndrome, and pes anserinus tendonitis or bursitis have all been called by this term.

valgus knee

A medial alignment of the femur and tibia of less than 180°.
Synonym: bandy leg; bowleg; genu valgum; tibia valga See: valgus

varus knee

A lateral alignment of the femur and tibia of greater than 195°.
Synonym: genu varum See: varus
Medical Dictionary, © 2009 Farlex and Partners


The hinge articulation between the lower end of the thigh bone (FEMUR) and the upper end of the main lower leg shin bone (TIBIA). The knee cap (PATELLA) is a flat bone lying within the massive tendon of the thigh muscles and is not an intrinsic part of the joint.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005


  1. the joint between the femur and tibia of the posterior limb in higher vertebrates.
  2. a stem joint in grasses.
  3. a root emerging above ground or water level in trees inhabiting wet areas.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005


() [TA]
1. Synonym(s): genu (1) .
2. Any structure of angular shape resembling a flexed knee.
[A.S. cneōw]
Medical Dictionary for the Dental Professions © Farlex 2012

Patient discussion about knee

Q. Can knee pain at childhood be connected to osteoarthritis? My mother is suffering from osteoarthritis (OA). She is 72 years old and the OA is a major problem in her life. My son is 10 years old. He has a relapsing knee pain. His pain occurs mostly at day time but can wake him from sleep. The pain is in both legs. Is my son in a risk group for OA?

A. Osteoarthritis is a disease that is most commonly caused by weight gain. The problem is that weigh gain has an important genetic factor. So, it doesn't matter if your son has knee pain right now, he is in a risk group for OA. If your mom is fat, she can start a program to lower her fat rate. I used this program for me. In the beginning it was too hard so cut her some slack!

Q. how to treat knee pain nothing

A. to treat it properly you need to define it and understand the cause. to help you do that there is a wonderful site that does a short servy and help you define where your knee pain comes from:

hope it helps!

Q. I have a reccurent ache just below my knee. what can it be? I am a 18 years old healthy guy. I never go to my physician, because i never need him, but in the past 4 month i recognized a strange pain just under my knee. The area is tender to palpation and the pain excruciate during walking and running. What can it be? What can I do to prevent it? P.S. I play collage basketball and this pain ruins my games...

A. Hi mate.
I am a 21 collage student and i play soccer.
It sure sounds like something i suffered from. Go see your GP and don't worry. if it is what i had he will probably tell you that
you can take any NSAID you want, and if you will give yourself a break from competitive sport for a month or so you will be just like new :)

More discussions about knee
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References in classic literature ?
And, resolutely, still on his knees, he wiggled through the hole in the wall.
He crawled a little farther on his knees, then turned right round and said:
And Galazi the Wolf struggled to his knees and for the last time shook the Watcher about his head, then fell again and died.
"No, you've never seen him," the old man was saying: "you couldn't, you know, he's been away so long--traveling from land to land, and seeking for health, more years than you've been alive, little Sylvie!" Here Bruno climbed upon his other knee, and a good deal of kissing, on a rather complicated system, was the result.
Here he rested on one knee, while the referee raced off the seconds.
Most of the indications in our study belongs to Osteoarthritis (41 knees) and rheumatoid Arthritis (6 knees).
Osteoarthritis of knees and obesity in Eastern Saudi Arabia.
"Minimally invasive technology in knee replacement surgery ensures efficacy, simplicity and more flexion in knees as compared to conventional surgeries.
Gregg Klein, orthopedic surgeons at HUMC are two of the developers of ROSA.On April 29 and 30, Levine and Klein successfully performed New Jersey's first cases of robotic-assisted total knee arthroplasty using the Zimmer Biomet ROSA Knee robot.A 60-year-old patient suffered from osteoarthritis in both knees.
Your knee joint is made up of bones, cartilage, tendons, and ligaments, so when you do exercises to strengthen your knees, you are actually exercising the muscles that support and stabilize your knees, including the large muscles of your upper thighs--your quadriceps and hamstrings--among others.
Bilateral Knee Replacement If you suffer from painful arthritis in both knees, you may be looking at a second replacement surgery three to six months after your first.
When a person with knock-knees is standing with their knees together, there's a large gap between their feet.