Jumper’s knee Health Dictionary

The joint formed by the FEMUR, TIBIA and patella (knee-cap). It belongs to the class of hinge-joints, although movements are much more complex than the simple motion of a hinge, the condyles of the femur partly rolling, partly sliding over the ?at surfaces on the upper end of the tibia, and the acts of straightening and of bending the limb being ?nished and begun, respectively, by a certain amount of rotation. The cavity of the joint is very intricate: it consists really of three joints fused into one, but separated in part by ligaments and folds of the synovial membrane. The ligaments which bind the bones together are extremely strong, and include the popliteal and the collateral ligaments, a very strong patellar ligament uniting the patella to the front of the tibia, two CRUCIATE LIGAMENTS in the interior of the joint, and two ?brocartilages which are interposed between the surfaces of tibia and femur at their edge. All these structures give to the knee-joint great strength, so that it is seldom dislocated. The cruciate ligaments, although strong, sometimes rupture or stretch under severe physical stress such as contact sports or athletics. Surgical repair may be required, followed by prolonged physiotherapy.

A troublesome condition often found in the knee – and common among athletes, footballers and other energetic sportspeople – consists of the loosening of one of the ?bro-cartilages lying at the head of the tibia, especially of that on the inner side of the joint. The cartilage may either be loosened from its attachment and tend to slip beyond the edges of the bones, or it may become folded on itself. In either case, it tends to cause locking of the joint when sudden movements are made. This causes temporary inability to use the joint until the cartilage is replaced by forcible straightening, and the accident is apt to be followed by an attack of synovitis, which may last some weeks, causing lameness with pain and tenderness especially felt at a point on the inner side of the knee. This condition can be relieved by an operation

– sometimes by keyhole surgery (see MINIMALLY INVASIVE SURGERY (MIS)) – to remove the loose portion of the cartilage. Patients whose knees are severely affected by osteoarthritis or rheumatoid arthritis which cause pain and sti?ness can now have the joint replaced with an arti?cial one. (See also ARTHROPLASTY; JOINTS, DISEASES OF.)... knee

Knock-knee, or genu valgum, is a deformity of the lower limbs in such a direction that when the limbs are straightened the legs diverge from one another. As a result, in walking the knees knock against each other. The amount of knock-knee is measured by the distance between the medial malleoli of the ankles, with the inner surfaces of the knee touching and the knee-caps facing forwards. The condition is so common in children between the ages of 2–6 years that it may almost be regarded as a normal phase in childhood. When marked, or persisting into later childhood, it can be corrected by surgery (osteotomy).... knock-knee

See REFLEX ACTION.... knee jerk

A surgical operation to replace a diseased – usually osteoarthritic – KNEE with an arti?cial (metal or plastic) implant which covers the worn cartilage. As much of the original joint as possible is retained. The operations, like hip replacements, are usually done on older people (there is some restriction of movement) and about 90 per cent are successful.... knee-joint replacement

An in?ammation of the bursa in front of the knee-cap, often mistaken for some disease in the joint itself (see BURSITIS).... housemaid’s knee

Inflammation of the bursa that cushions the pressure point over the tibial tubercle (the bony prominence just below the knee) caused by prolonged kneeling (see bursitis).... clergyman’s knee

See patella.... kneecap

A temporary inability to move the knee joint. A locked knee may be caused by a torn cartilage or by loose bodies in the joint.... locked knee

A popular term for accumulation of fluid within or around the knee joint. The most common cause is bursitis. (See also effusion, joint).... water on the knee

(prepatellar bursitis) inflammation and resultant swelling of the bursa in front of the kneecap, usually due to repetitive friction and pressure over the kneecap, as from frequent episodes of prolonged kneeling. Treatment includes pressure bandaging, *NSAIDs, and avoidance of kneeling. See bursitis.... housemaid’s knee

(patellar tendinitis) a form of *tendinitis that is common in athletes and dancers. Repeated sudden contracture of the quadriceps muscle at take-off causes inflammation of the attachment of the patellar tendon to the lower end of the patella. Treatment includes rest, physiotherapy, and anti-inflammatory medication.... jumper’s knee

the buttocks-up position assumed by patients undergoing anorectal examinations, now commonly performed in the left lateral position. It is useful for helping patients dispel excess flatus following colonoscopy.... knee-elbow position