Knee

From Wikipedia for FEVERv2
Jump to navigation Jump to search

This article is about the joint. Knee_sentence_0

For other uses, see Knee (disambiguation). Knee_sentence_1

Knee_table_infobox_0

KneeKnee_header_cell_0_0_0
DetailsKnee_header_cell_0_1_0
SystemKnee_header_cell_0_2_0 Musculoskeletal systemKnee_cell_0_2_1
NerveKnee_header_cell_0_3_0 femoral, obturator, sciaticKnee_cell_0_3_1
IdentifiersKnee_header_cell_0_4_0
LatinKnee_header_cell_0_5_0 Articulatio genusKnee_cell_0_5_1
MeSHKnee_header_cell_0_6_0 Knee_cell_0_6_1
TA98Knee_header_cell_0_7_0 Knee_cell_0_7_1
TA2Knee_header_cell_0_8_0 Knee_cell_0_8_1
FMAKnee_header_cell_0_9_0 Knee_cell_0_9_1

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). Knee_sentence_2

It is the largest joint in the human body. Knee_sentence_3

The knee is a modified hinge joint, which permits flexion and extension as well as slight internal and external rotation. Knee_sentence_4

The knee is vulnerable to injury and to the development of osteoarthritis. Knee_sentence_5

It is often termed a compound joint having tibiofemoral and patellofemoral components. Knee_sentence_6

(The fibular collateral ligament is often considered with tibiofemoral components.) Knee_sentence_7

Structure Knee_section_0

The knee is a modified hinge joint, a type of synovial joint, which is composed of three functional compartments: the patellofemoral articulation, consisting of the patella, or "kneecap", and the patellar groove on the front of the femur through which it slides; and the medial and lateral tibiofemoral articulations linking the femur, or thigh bone, with the tibia, the main bone of the lower leg. Knee_sentence_8

The joint is bathed in synovial fluid which is contained inside the synovial membrane called the joint capsule. Knee_sentence_9

The posterolateral corner of the knee is an area that has recently been the subject of renewed scrutiny and research. Knee_sentence_10

The knee is the largest joint and one of the most important joints in the body. Knee_sentence_11

It plays an essential role in movement related to carrying the body weight in horizontal (running and walking) and vertical (jumping) directions. Knee_sentence_12

At birth, the kneecap is just formed from cartilage, and this will ossify (change to bone) between the ages of three and five years. Knee_sentence_13

Because it is the largest sesamoid bone in the human body, the ossification process takes significantly longer. Knee_sentence_14

Articular bodies Knee_section_1

The main articular bodies of the femur are its lateral and medial condyles. Knee_sentence_15

These diverge slightly distally and posteriorly, with the lateral condyle being wider in front than at the back while the medial condyle is of more constant width. Knee_sentence_16

The radius of the condyles' curvature in the sagittal plane becomes smaller toward the back. Knee_sentence_17

This diminishing radius produces a series of involute midpoints (i.e. located on a spiral). Knee_sentence_18

The resulting series of transverse axes permit the sliding and rolling motion in the flexing knee while ensuring the collateral ligaments are sufficiently lax to permit the rotation associated with the curvature of the medial condyle about a vertical axis. Knee_sentence_19

The pair of tibial condyles are separated by the intercondylar eminence composed of a lateral and a medial tubercle. Knee_sentence_20

The patella also serves an articular body, and its posterior surface is referred to as the trochlea of the knee. Knee_sentence_21

It is inserted into the thin anterior wall of the joint capsule. Knee_sentence_22

On its posterior surface is a lateral and a medial articular surface, both of which communicate with the patellar surface which unites the two femoral condyles on the anterior side of the bone's distal end. Knee_sentence_23

Articular capsule Knee_section_2

Main article: Articular capsule of the knee joint Knee_sentence_24

The articular capsule has a synovial and a fibrous membrane separated by fatty deposits. Knee_sentence_25

Anteriorly, the synovial membrane is attached on the margin of the cartilage both on the femur and the tibia, but on the femur, the suprapatellar bursa or recess extends the joint space proximally. Knee_sentence_26

The suprapatellar bursa is prevented from being pinched during extension by the articularis genus muscle. Knee_sentence_27

Behind, the synovial membrane is attached to the margins of the two femoral condyles which produces two extensions similar to the anterior recess. Knee_sentence_28

Between these two extensions, the synovial membrane passes in front of the two cruciate ligaments at the center of the joint, thus forming a pocket direct inward. Knee_sentence_29

Bursae Knee_section_3

Main article: Knee bursae Knee_sentence_30

Numerous bursae surround the knee joint. Knee_sentence_31

The largest communicative bursa is the suprapatellar bursa described above. Knee_sentence_32

Four considerably smaller bursae are located on the back of the knee. Knee_sentence_33

Two non-communicative bursae are located in front of the patella and below the patellar tendon, and others are sometimes present. Knee_sentence_34

Cartilage Knee_section_4

Menisci Knee_section_5

The articular disks of the knee-joint are called menisci because they only partly divide the joint space. Knee_sentence_35

These two disks, the medial meniscus and the lateral meniscus, consist of connective tissue with extensive collagen fibers containing cartilage-like cells. Knee_sentence_36

Strong fibers run along the menisci from one attachment to the other, while weaker radial fibers are interlaced with the former. Knee_sentence_37

The menisci are flattened at the center of the knee joint, fused with the synovial membrane laterally, and can move over the tibial surface. Knee_sentence_38

The menisci serve to protect the ends of the bones from rubbing on each other and to effectively deepen the tibial sockets into which the femur attaches. Knee_sentence_39

They also play a role in shock absorption, and may be cracked, or torn, when the knee is forcefully rotated and/or bent. Knee_sentence_40

Ligaments Knee_section_6

The ligaments surrounding the knee joint offer stability by limiting movements and, together with the menisci and several bursae, protect the articular capsule. Knee_sentence_41

Intracapsular Knee_section_7

The knee is stabilized by a pair of cruciate ligaments. Knee_sentence_42

The anterior cruciate ligament (ACL) stretches from the lateral condyle of femur to the anterior intercondylar area. Knee_sentence_43

The ACL is critically important because it prevents the tibia from being pushed too far anterior relative to the femur. Knee_sentence_44

It is often torn during twisting or bending of the knee. Knee_sentence_45

The posterior cruciate ligament (PCL) stretches from medial condyle of femur to the posterior intercondylar area. Knee_sentence_46

Injury to this ligament is uncommon but can occur as a direct result of forced trauma to the ligament. Knee_sentence_47

This ligament prevents posterior displacement of the tibia relative to the femur. Knee_sentence_48

The transverse ligament stretches from the lateral meniscus to the medial meniscus. Knee_sentence_49

It passes in front of the menisci. Knee_sentence_50

It is divided into several strips in 10% of cases. Knee_sentence_51

The two menisci are attached to each other anteriorly by the ligament. Knee_sentence_52

The posterior and anterior meniscofemoral ligaments stretch from the posterior horn of the lateral meniscus to the medial femoral condyle. Knee_sentence_53

They pass posteriorly behind the posterior cruciate ligament. Knee_sentence_54

The posterior meniscofemoral ligament is more commonly present (30%); both ligaments are present less often. Knee_sentence_55

The meniscotibial ligaments (or "coronary") stretches from inferior edges of the mensici to the periphery of the tibial plateaus. Knee_sentence_56

Extracapsular Knee_section_8

The patellar ligament connects the patella to the tuberosity of the tibia. Knee_sentence_57

It is also occasionally called the patellar tendon because there is no definite separation between the quadriceps tendon (which surrounds the patella) and the area connecting the patella to the tibia. Knee_sentence_58

This very strong ligament helps give the patella its mechanical leverage and also functions as a cap for the condyles of the femur. Knee_sentence_59

Laterally and medially to the patellar ligament the lateral and medial retinacula connect fibers from the vasti lateralis and medialis muscles to the tibia. Knee_sentence_60

Some fibers from the iliotibial tract radiate into the lateral retinaculum and the medial retinaculum receives some transverse fibers arising on the medial femoral epicondyle. Knee_sentence_61

The medial collateral ligament (MCL a.k.a. "tibial") stretches from the medial epicondyle of the femur to the medial tibial condyle. Knee_sentence_62

It is composed of three groups of fibers, one stretching between the two bones, and two fused with the medial meniscus. Knee_sentence_63

The MCL is partly covered by the pes anserinus and the tendon of the semimembranosus passes under it. Knee_sentence_64

It protects the medial side of the knee from being bent open by a stress applied to the lateral side of the knee (a valgus force). Knee_sentence_65

The fibular collateral ligament (LCL a.k.a. "fibular") stretches from the lateral epicondyle of the femur to the head of fibula. Knee_sentence_66

It is separate from both the joint capsule and the lateral meniscus. Knee_sentence_67

It protects the lateral side from an inside bending force (a varus force). Knee_sentence_68

The anterolateral ligament (ALL) is situated in front of the LCL. Knee_sentence_69

Lastly, there are two ligaments on the dorsal side of the knee. Knee_sentence_70

The oblique popliteal ligament is a radiation of the tendon of the semimembranosus on the medial side, from where it is direct laterally and proximally. Knee_sentence_71

The arcuate popliteal ligament originates on the apex of the head of the fibula to stretch proximally, crosses the tendon of the popliteus muscle, and passes into the capsule. Knee_sentence_72

Muscles Knee_section_9

The muscles responsible for the movement of the knee joint belong to either the anterior, medial or posterior compartment of the thigh. Knee_sentence_73

The extensors generally belong to the anterior compartment and the flexors to the posterior. Knee_sentence_74

The two exceptions to this is gracilis, a flexor, which belongs to the medial compartment and sartorius, a flexor, in the anterior compartment. Knee_sentence_75

Extensors Knee_section_10

Knee_table_general_1

MuscleKnee_header_cell_1_0_0 OriginKnee_header_cell_1_0_1 InsertionKnee_header_cell_1_0_2 ArteryKnee_header_cell_1_0_3 NerveKnee_header_cell_1_0_4 ActionKnee_header_cell_1_0_5 AntagonistKnee_header_cell_1_0_6
Articularis genusKnee_cell_1_1_0 Distal end of anterior femoral shaftKnee_cell_1_1_1 Proximal extension of the joint capsule of the kneeKnee_cell_1_1_2 Femoral arteryKnee_cell_1_1_3 Femoral nerveKnee_cell_1_1_4 Pulling the suprapatellar bursa during extension of the kneeKnee_cell_1_1_5 Knee_cell_1_1_6
Quadriceps femorisKnee_cell_1_2_0 Combined rectus femoris and vastus musclesKnee_cell_1_2_1 Patella and Tibial tuberosity via the Patellar ligamentKnee_cell_1_2_2 Femoral arteryKnee_cell_1_2_3 Femoral nerveKnee_cell_1_2_4 Extension of the knee; flexion of the hip (rectus femoris only)Knee_cell_1_2_5 HamstringKnee_cell_1_2_6
Rectus femorisKnee_cell_1_3_0 Anterior inferior iliac spine and the exterior surface of the bony ridge which forms the iliac portion of the acetabulumKnee_cell_1_3_1 Patella and Tibial tuberosity via the Patellar ligamentKnee_cell_1_3_2 Femoral arteryKnee_cell_1_3_3 Femoral nerveKnee_cell_1_3_4 Extension of the knee; flexion of the hipKnee_cell_1_3_5 HamstringKnee_cell_1_3_6
Vastus lateralisKnee_cell_1_4_0 Greater trochanter, Intertrochanteric line, and Linea aspera of the femurKnee_cell_1_4_1 Patella and tibial tuberosity via the patellar ligamentKnee_cell_1_4_2 Femoral arteryKnee_cell_1_4_3 Femoral nerveKnee_cell_1_4_4 Extends and stabilizes kneeKnee_cell_1_4_5 HamstringKnee_cell_1_4_6
Vastus intermediusKnee_cell_1_5_0 Antero/lateral femurKnee_cell_1_5_1 Patella and tibial tuberosity via the patellar ligamentKnee_cell_1_5_2 Femoral arteryKnee_cell_1_5_3 Femoral nerveKnee_cell_1_5_4 Extension of the kneeKnee_cell_1_5_5 HamstringKnee_cell_1_5_6
Vastus medialisKnee_cell_1_6_0 FemurKnee_cell_1_6_1 Patella and tibial tuberosity via the patellar ligamentKnee_cell_1_6_2 Femoral arteryKnee_cell_1_6_3 Femoral nerveKnee_cell_1_6_4 Extension of the kneeKnee_cell_1_6_5 HamstringKnee_cell_1_6_6

Flexors Knee_section_11

Posterior compartment Knee_sentence_76

Knee_table_general_2

MuscleKnee_header_cell_2_0_0 OriginKnee_header_cell_2_0_1 InsertionKnee_header_cell_2_0_2 ArteryKnee_header_cell_2_0_3 NerveKnee_header_cell_2_0_4 ActionKnee_header_cell_2_0_5 AntagonistKnee_header_cell_2_0_6
SartoriusKnee_cell_2_1_0 Anterior superior iliac spineKnee_cell_2_1_1 Pes anserinusKnee_cell_2_1_2 superficial circumflex iliac artery, lateral femoral artery, deep femoral artery, descending geniculate artery, femoral arteryKnee_cell_2_1_3 femoral nerveKnee_cell_2_1_4 hip joint: flexion, lateral rotation and abduction. Knee joint: flexion and medial rotationKnee_cell_2_1_5 Quadriceps muscle (partly)Knee_cell_2_1_6
Biceps femorisKnee_cell_2_2_0 Long head: tuberosity of the ischium, short head: linea aspera on the femurKnee_cell_2_2_1 The head of the fibula which articulates with the back of the lateral tibial condyleKnee_cell_2_2_2 Inferior gluteal artery, perforating arteries, popliteal arteryKnee_cell_2_2_3 Long head: medial (tibial) part of sciatic nerve, short head: lateral (common fibular) part of sciatic nerveKnee_cell_2_2_4 Flexion of knee, laterally rotates leg at knee (when knee is flexed), extends hip joint (long head only)Knee_cell_2_2_5 Quadriceps muscleKnee_cell_2_2_6
SemitendinosusKnee_cell_2_3_0 Tuberosity of the ischiumKnee_cell_2_3_1 Pes anserinusKnee_cell_2_3_2 Inferior gluteal artery, perforating arteriesKnee_cell_2_3_3 Sciatic (tibial, L5, S1, S2)Knee_cell_2_3_4 Flexes knee, extends hip joint, medially rotates leg at kneeKnee_cell_2_3_5 Quadriceps muscleKnee_cell_2_3_6
SemimembranosusKnee_cell_2_4_0 Tuberosity of the ischiumKnee_cell_2_4_1 Medial surface of tibiaKnee_cell_2_4_2 Profunda femoris, gluteal arteryKnee_cell_2_4_3 Sciatic nerveKnee_cell_2_4_4 Flexes knee, extends hip joint, medially rotates leg at kneeKnee_cell_2_4_5 Quadriceps muscleKnee_cell_2_4_6
GastrocnemiusKnee_cell_2_5_0 Medial and lateral condyle of the femurKnee_cell_2_5_1 CalcaneusKnee_cell_2_5_2 Sural arteriesKnee_cell_2_5_3 Tibial nerve from the sciatic, specifically, nerve roots S1, S2Knee_cell_2_5_4 Minor flexion of knee and plantarflexionKnee_cell_2_5_5 Tibialis anterior muscleKnee_cell_2_5_6
PlantarisKnee_cell_2_6_0 Lateral supracondylar ridge of femur above lateral head of gastrocnemiusKnee_cell_2_6_1 Tendo calcaneus (medial side, deep to gastrocnemius tendon)Knee_cell_2_6_2 Sural arteriesKnee_cell_2_6_3 Tibial nerveKnee_cell_2_6_4 Flexes knee and plantar flexes footKnee_cell_2_6_5 Tibialis anterior muscleKnee_cell_2_6_6
PopliteusKnee_cell_2_7_0 Middle facet of the lateral surface of the lateral femoral condyleKnee_cell_2_7_1 Posterior tibia under the tibial condylesKnee_cell_2_7_2 Popliteal arteryKnee_cell_2_7_3 Tibial nerveKnee_cell_2_7_4 Medial rotation and flexion of kneeKnee_cell_2_7_5 Knee_cell_2_7_6

Medial compartment: Knee_sentence_77

Knee_table_general_3

MuscleKnee_header_cell_3_0_0 OriginKnee_header_cell_3_0_1 InsertionKnee_header_cell_3_0_2 ArteryKnee_header_cell_3_0_3 NerveKnee_header_cell_3_0_4 ActionKnee_header_cell_3_0_5 AntagonistKnee_header_cell_3_0_6
GracilisKnee_cell_3_1_0 Inferior pubic ramusKnee_cell_3_1_1 Pes anserinusKnee_cell_3_1_2 Obturator arteryKnee_cell_3_1_3 Anterior branch of obturator nerveKnee_cell_3_1_4 Flexion and medial rotation of knee; adduction of hip, flexion of hip,Knee_cell_3_1_5 Knee_cell_3_1_6

Blood supply Knee_section_12

The femoral artery and the popliteal artery help form the arterial network or plexus, surrounding the knee joint. Knee_sentence_78

There are six main branches: two superior genicular arteries, two inferior genicular arteries, the descending genicular artery and the recurrent branch of anterior tibial artery. Knee_sentence_79

The medial genicular arteries penetrate the knee joint. Knee_sentence_80

Function Knee_section_13

Knee_table_general_4

Maximum movements and musclesKnee_table_caption_4
Extension 5–10°Knee_header_cell_4_0_0 Flexion 120–150°Knee_header_cell_4_0_1
Quadriceps (with

some assistance from the Tensor fasciae latae)Knee_cell_4_1_0

(In order of importance)

Semimembranosus Semitendinosus Biceps femoris Gracilis Sartorius Popliteus GastrocnemiusKnee_cell_4_1_1

Internal rotation* 10°Knee_header_cell_4_2_0 External rotation* 30–40°Knee_header_cell_4_2_1
(In order of importance)

Semimembranosus Semitendinosus Gracilis Sartorius PopliteusKnee_cell_4_3_0

Biceps femorisKnee_cell_4_3_1
*(knee flexed 90°)Knee_cell_4_4_0

The knee permits flexion and extension about a virtual transverse axis, as well as a slight medial and lateral rotation about the axis of the lower leg in the flexed position. Knee_sentence_81

The knee joint is called "mobile" because the femur and lateral meniscus move over the tibia during rotation, while the femur rolls and glides over both menisci during extension-flexion. Knee_sentence_82

The center of the transverse axis of the extension/flexion movements is located where both collateral ligaments and both cruciate ligaments intersect. Knee_sentence_83

This center moves upward and backward during flexion, while the distance between the center and the articular surfaces of the femur changes dynamically with the decreasing curvature of the femoral condyles. Knee_sentence_84

The total range of motion is dependent on several parameters such as soft-tissue restraints, active insufficiency, and hamstring tightness. Knee_sentence_85

Extended position Knee_section_14

With the knee extended both the lateral and medial collateral ligaments, as well as the anterior part of the anterior cruciate ligament, are taut. Knee_sentence_86

During extension, the femoral condyles glide and roll into a position which causes the complete unfolding of the tibial collateral ligament. Knee_sentence_87

During the last 10° of extension, an obligatory terminal rotation is triggered in which the knee is rotated medially 5°. Knee_sentence_88

The final rotation is produced by a lateral rotation of the tibia in the non-weight-bearing leg, and by a medial rotation of the femur in the weight-bearing leg. Knee_sentence_89

This terminal rotation is made possible by the shape of the medial femoral condyle, assisted by contraction of the popliteus muscle and the iliotibial tract and is caused by the stretching of the anterior cruciate ligament. Knee_sentence_90

Both cruciate ligaments are slightly unwinded and both lateral ligaments become taut. Knee_sentence_91

Flexed position Knee_section_15

In the flexed position, the collateral ligaments are relaxed while the cruciate ligaments are taut. Knee_sentence_92

Rotation is controlled by the twisted cruciate ligaments; the two ligaments get twisted around each other during medial rotation of the tibia—which reduces the amount of rotation possible—while they become unwound during lateral rotation of the tibia. Knee_sentence_93

Because of the oblique position of the cruciate ligaments at least a part of one of them is always tense and these ligaments control the joint as the collateral ligaments are relaxed. Knee_sentence_94

Furthermore, the dorsal fibers of the tibial collateral ligament become tensed during extreme medial rotation and the ligament also reduces the lateral rotation to 45–60°. Knee_sentence_95

Clinical significance Knee_section_16

Knee pain is caused by trauma, misalignment, and degeneration as well as by conditions like arthritis. Knee_sentence_96

The most common knee disorder is generally known as patellofemoral syndrome.The majority of minor cases of knee pain can be treated at home with rest and ice but more serious injuries do require surgical care. Knee_sentence_97

One form of patellofemoral syndrome involves a tissue-related problem that creates pressure and irritation in the knee between the patella and the trochlea (patellar compression syndrome), which causes pain. Knee_sentence_98

The second major class of knee disorder involves a tear, slippage, or dislocation that impairs the structural ability of the knee to balance the leg (patellofemoral instability syndrome). Knee_sentence_99

Patellofemoral instability syndrome may cause either pain, a sense of poor balance, or both. Knee_sentence_100

Prepatellar bursitis also known as housemaid's knee is painful inflammation of the prepatellar bursa (a frontal knee bursa) often brought about by occupational activity such as roofing. Knee_sentence_101

Age also contributes to disorders of the knee. Knee_sentence_102

Particularly in older people, knee pain frequently arises due to osteoarthritis. Knee_sentence_103

In addition, weakening of tissues around the knee may contribute to the problem. Knee_sentence_104

Patellofemoral instability may relate to hip abnormalities or to tightness of surrounding ligaments. Knee_sentence_105

Cartilage lesions can be caused by: Knee_sentence_106

Knee_unordered_list_0

Any kind of work during which the knees undergo heavy stress may also be detrimental to cartilage. Knee_sentence_107

This is especially the case in professions in which people frequently have to walk, lift, or squat. Knee_sentence_108

Other causes of pain may be excessive on, and wear off, the knees, in combination with such things as muscle weakness and overweight. Knee_sentence_109

Common complaints: Knee_sentence_110

Knee_unordered_list_1

  • A painful, blocked, locked or swollen knee.Knee_item_1_8
  • Sufferers sometimes feel as if their knees are about to give way, or may feel uncertain about their movement.Knee_item_1_9

Overall fitness and knee injury Knee_section_17

Physical fitness is related integrally to the development of knee problems. Knee_sentence_111

The same activity such as climbing stairs may cause pain from patellofemoral compression for someone who is physically unfit, but not for someone else (or even for that person at a different time). Knee_sentence_112

Obesity is another major contributor to knee pain. Knee_sentence_113

For instance, a 30-year-old woman who weighed 120 lb at age 18 years, before her three pregnancies, and now weighs 285 lb, had added 660 lb of force across her patellofemoral joint with each step. Knee_sentence_114

Common injuries due to physical activity Knee_section_18

In sports that place great pressure on the knees, especially with twisting forces, it is common to tear one or more ligaments or cartilages. Knee_sentence_115

Some of the most common knee injuries are those to the medial side: medial knee injuries. Knee_sentence_116

Anterior cruciate ligament injury Knee_section_19

Main article: Anterior cruciate ligament injury Knee_sentence_117

The anterior cruciate ligament is the most commonly injured ligament of the knee. Knee_sentence_118

The injury is common during sports. Knee_sentence_119

Twisting of the knee is a common cause of over-stretching or tearing the ACL. Knee_sentence_120

When the ACL is injured a popping sound may be heard, and the leg may suddenly give out. Knee_sentence_121

Besides swelling and pain, walking may be painful and the knee will feel unstable. Knee_sentence_122

Minor tears of the anterior cruciate ligament may heal over time, but a torn ACL requires surgery. Knee_sentence_123

After surgery, recovery is prolonged and low impact exercises are recommended to strengthen the joint. Knee_sentence_124

Torn meniscus injury Knee_section_20

The menisci act as shock absorbers and separate the two ends of bone in the knee joint. Knee_sentence_125

There are two menisci in the knee, the medial (inner) and the lateral (outer). Knee_sentence_126

When there is torn cartilage, it means that the meniscus has been injured. Knee_sentence_127

Meniscus tears occur during sports often when the knee is twisted. Knee_sentence_128

Menisci injury may be innocuous and one may be able to walk after a tear, but soon swelling and pain set in. Knee_sentence_129

Sometimes the knee will lock while bending. Knee_sentence_130

Pain often occurs when one squats. Knee_sentence_131

Small meniscus tears are treated conservatively but most large tears require surgery. Knee_sentence_132

Fractures Knee_section_21

Knee fractures are rare but do occur, especially as a result of road accident. Knee_sentence_133

Knee fractures include a patella fracture, and a type of avulsion fracture called a Segond fracture. Knee_sentence_134

There is usually immediate pain and swelling, and a difficulty or inability to stand on the leg. Knee_sentence_135

The muscles go into spasm and even the slightest movements are painful. Knee_sentence_136

X-rays can easily confirm the injury and surgery will depend on the degree of displacement and type of fracture. Knee_sentence_137

Ruptured tendon Knee_section_22

Overuse Knee_section_23

Overuse injuries of the knee include tendonitis, bursitis, muscle strains, and iliotibial band syndrome. Knee_sentence_138

These injuries often develop slowly over weeks or months. Knee_sentence_139

Activities that induce pain usually delay healing. Knee_sentence_140

Rest, ice and compression do help in most cases. Knee_sentence_141

Once the swelling has diminished, heat packs can increase blood supply and promote healing. Knee_sentence_142

Most overuse injuries subside with time but can flare up if the activities are quickly resumed. Knee_sentence_143

Individuals may reduce the chances of overuse injuries by warming up prior to exercise, by limiting high impact activities and keep their weight under control. Knee_sentence_144

Varus or valgus deformity Knee_section_24

There are two disorders relating to an abnormal angle in the coronal plane at the level of the knee: Knee_sentence_145

Knee_unordered_list_2

  • Genu valgum is a valgus deformity in which the tibia is turned outward in relation to the femur, resulting in a knock-kneed appearance.Knee_item_2_10
  • Genu varum is a varus deformity in which the tibia is turned inward in relation to the femur, resulting in a bowlegged deformity.Knee_item_2_11

The degree of varus or valgus deformity can be quantified by the hip-knee-ankle angle, which is an angle between the femoral mechanical axis and the center of the ankle joint. Knee_sentence_146

It is normally between 1.0° and 1.5° of varus in adults. Knee_sentence_147

Normal ranges are different in children. Knee_sentence_148

Knee_unordered_list_3

  • Knee_item_3_12

Surgical interventions Knee_section_25

Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Knee.