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The anterior cruciate ligament (or ACL) is one of the four major ligaments of the knee. It connects from a posterio-lateral part of the femur to an anterio-medial part of the tibia. These attachments allow it to resist anterior translation of the tibia, in relation to the femur. More specifically, it is attached to the depression in front of the intercondyloid eminence of the tibia, being blended with the anterior extremity of the lateral meniscus. It passes up, backward, and laterally, and is fixed into the medial and back part of the lateral condyle of the femur. For other uses, see Latins and Latin (disambiguation). ...
The lateral condyle is one of the two projections on the lower extremity of femur. ...
The femur or thigh bone is the longest, most voluminous, and strongest bone of the mammalian bodies. ...
Between the articular facets of the upper extremity of the tibia, but nearer the posterior than the anterior aspect of the bone, is the intercondyloid eminence (spine of tibia), surmounted on either side by a prominent tubercle, on to the sides of which the articular facets are prolonged; in front...
This article is about the vertebrate bone. ...
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In anatomy, the term ligament is used to denote three different types of structures:[1] Fibrous tissue that connects bones to other bones. ...
For other uses, see Knee (disambiguation). ...
The femur or thigh bone is the longest, most voluminous, and strongest bone of the mammalian bodies. ...
This article is about the vertebrate bone. ...
Between the articular facets of the upper extremity of the tibia, but nearer the posterior than the anterior aspect of the bone, is the intercondyloid eminence (spine of tibia), surmounted on either side by a prominent tubercle, on to the sides of which the articular facets are prolonged; in front...
The lateral meniscus, also called the external semilunar fibrocartilage is a fibrocartilaginous band that spans the lateral knee. ...
Lateral condyle can refer to: Lateral condyle of tibia Lateral condyle of femur This is a disambiguation page: a list of articles associated with the same title. ...
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Diagram of the right knee Grays Fig. ...
Causes of Injury The ACL is the most commonly injured knee ligament [1]) and is commonly damaged by athletes. The ACL is often torn during sudden dislocation, torsion, or hyperextension of the knee and is usually quite painful. It is a very common injury in hockey, skiing, skating, soccer (and other field sports) and in less cases basketball, due to the enormous amount of pressure, weight, and torque the knee must withstand. Usually the injury occurs when someone tries to rapidly change direction with the leading leg out, twisting the knee. Or sudden high pressure contact, especially side on. A sportsperson (British and American English) or athlete (principally American English) is any person who participates regularly in a sport. ...
The known causes of ACL rupture can be divided into three major classifications:
- environmental
- anatomical
- hormonal [2]
Environmental Causes Sports which include running, jumping, and landing pose the most potential for injury to the athlete. Interestingly, the risk for rupture of the anterior cruciate ligament does not increase in contact sports (as opposed to noncontact sports). According to Maureen Madden, a physical therapist working with many ACL rupture patients, "the most encouraging aspect of the bad news about ACL tears is that 70 (percent) are noncontact injuries." [3]
Anatomical Causes ACL injuries are especially common in female athletes, due to many possible contributing factors. The most prevalent explanation relates to female athletes tending to land more straight-legged than men, removing the quadriceps' muscles shock-absorbing action on the knee. Often the knee on a straight leg can't withstand this and bends sideways.
Hormonal Causes High levels of specific hormones have been associated with an increased risk of ACL rupture. Estrogen is one of these hormones. Some anatomical and hormonal causes (such as high levels of estrogen) may put women at a higher risk for injury. [2]
Injury in Females Women are more susceptible to ACL rupture and new research shows that women may be up to 8 times more likely than men to rupture the ACL. Researchers continue to debate why women are more likely to tear their ACL than men. Most theories center on the "anatomical and hormonal differences among men and women." [3]A few of these differences include the following: Hormone is also the NATO reporting name for the Soviet/Russian Kamov Ka-25 military helicopter. ...
In human anatomy, a hamstring refers to one of the tendons that makes up the borders of the space behind the knee. ...
The quadriceps femoris, commonly the quadriceps, is a large muscle in the thigh, composed of the sections rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis. ...
Hormonal Levels According to Dr. Kurt Spinder, "Females have an increased frequency, or in other words a greater risk to tear their ACL at mid-cycle ovulation." [2] Spinder recently conducted a study focused on the stage of the menstrual cycle for 65 women with ACL injuries and his discovery may mean there is a correlation between a woman's hormones and her susceptibility to an ACL injury. Increased production of estrogen and other feminine hormones may cause a woman's motor skills to decrease and/or relax the ACL and surrounding ligaments.
Intercondylar Notch The intercondylar notch is a small groove located at the end of the femur, directly behind the patellar tendon. The location of the notch makes it a prime suspect for damage to the ACL, which has prompted many studies. One recent study using cadavers showed that the ACL comes in contact with the intercondylar notch when the leg is fully extended. [4] The fact that the notch is generally narrower in women than in men may contribute to the higher rate of ACL injuries in women.
Hamstring and Quadricep balance A third reason females are more susceptible to rupturing an ACL may be an imbalance between the quadriceps and hamstrings. The quadriceps and hamstrings are the muscles on the front and back of the thigh, around the femur. Many women have much stronger quadricep muscles than hamstrings, while men tend to have a more even distribution of muscle strength. This anatomical difference between men and women has led experts to believe it plays a role in knee stability. Doctors Boden, Griffin, and Garrett published this statement in "Etiology and Prevention of Noncontact ACL Injury" in a recent issue of The Physican and Sports Medicine: The quadriceps, as ACL antagonists, may contribute to ACL injury. Numerous investigators have reported that quadriceps contraction increases ACL strain between 10º and 30º of knee flexion. Because most noncontact ACL injuries occur with the knee close to full extension, it is possible that the quadriceps play an important role in ACL disruption...According to mechanical calculations, an eccentric quadriceps muscle contraction can produce forces beyond those required for ACL tensile failure. Hamstrings clearly play an important role in supporting the ACL. Thus, both men and women with weak hamstrings and strong quadriceps are at higher risk for an ACL tear.
Posture A final reason women are more likely to tear an ACL may be running and jumping posture. Since many ACL injuries are noncontact and occur while athletes are stopping, turning, running, and jumping, researchers have paid close attention to differences in men and women while exercising. Hundreds of studies have been conducted and show women tend to run in a more upright position than men, which may increase the stress on the ACL. Although the concept of posture increasing the risk for ACL injury is generally accepted in the medical community, it is important to note there is no conclusive evidence showing why the upright position is more dangerous. As research continues, more evidence can be gathered and more factors that increase the risk of ACL damage will, undoubtedly, be uncovered.
Diagnosis Several diagnostic maneuvers help clinicians diagnose an injured ACL. In the anterior drawer test, the examiner applies an anterior force on the proximal tibia with the knee in 90 degrees of flexion. The Lachman test is similar, but performed with the knee in only about twenty degrees of flexion, while the pivot-shift test adds a valgus (outside-in) force to the knee while it is moved from flexion to extension. Any abnormal motion in these maneuvers suggests a tear. A Lachman test is a medical test used for examining the Anterior Cruciate Ligament (ACL) in the knee for patients where there is a suspicion of a torn ACL. To do this, lie the patient supine on a bed. ...
In anatomy, Flexion is movement whereby bones or other objects are brought closer together. ...
The diagnosis is usually confirmed by MRI, the availability of which has greatly lessened the number of purely diagnostic arthroscopies performed. The mri are a fictional alien species in the Faded Sun Trilogy of C.J. Cherryh. ...
Arthroscopy (also called arthroscopic surgery) is a minimally invasive surgical procedure in which an examination and sometimes treatment of damage of the interior of a joint is performed using an arthroscope, a type of endoscope that is inserted into the joint through a small incision. ...
References - ^ Widuchowski, Widuchowski, Widuchowski (2007). "Articular cartilage defects: Study of 25,124 knee arthroscopies". PMID 17428666.
- ^ a b c Coggin, Amber.. "ACL Study Links Injury to Menstrual Cycle." The Reporter. 2 Feb. 2005. Vanderbilt Medical Center..
- ^ a b Madden, Maureen.. "Women and ACL Injuries: Taking the Bad News with the Good." The Stone Clinic..
- ^ Boden, Barry MD, Letha Y. Griffin MD, and William E. Garret, Jr MD.. "Etiology and Prevention of Noncontact ACL Injury" The Physician and Sports Medicine.
See also For other uses, see Knee (disambiguation). ...
Diagram of the knee The lateral collateral ligament (or LCL) is one of the four major ligaments of the knee. ...
The medial collateral ligament or MCL (or tibial collateral ligament) is one of the four major ligaments of the knee. ...
Diagram of the knee The posterior cruciate ligament (or PCL) is one of the four major ligaments of the knee. ...
Knees following ACL reconstruction surgery. ...
Additional images Right knee-joint, from the front, showing interior ligaments. Image File history File links Gray347. ...
| Left knee-joint from behind, showing interior ligaments. Image File history File links Gray348. ...
| Head of right tibia seen from above, showing menisci and attachments of ligaments. Image File history File links Gray349. ...
| Capsule of right knee-joint (distended). Posterior aspect. Image File history File links Gray352. ...
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External links | Joints and ligaments of lower limbs | | | Coxal/hip | | | | Knee-joint | | | | Tibiofibular | | | | Talocrural/ankle | | | | Foot - subtalar/talocalcaneal | | | | Foot - transverse tarsal | | | | Foot - distal intertarsal | Cuneonavicular: plantar - dorsal Cuboideonavicular: plantar - dorsal The State University of New York Health Science Center at Brooklyn, better known as SUNY Downstate Medical Center, is an academic medical center and is the only one of its kind in the Borough of Brooklyn in New York City. ...
The State University of New York Health Science Center at Brooklyn, better known as SUNY Downstate Medical Center, is an academic medical center and is the only one of its kind in the Borough of Brooklyn in New York City. ...
The State University of New York Health Science Center at Brooklyn, better known as SUNY Downstate Medical Center, is an academic medical center and is the only one of its kind in the Borough of Brooklyn in New York City. ...
eMedicine is an online clinical medical knowledge base that was founded in 1996. ...
For other uses, see Mnemonic (disambiguation). ...
Georgetown University is a Jesuit private university located in Georgetown, Washington, D.C. Father John Carroll founded the school in 1789, though its roots extend back to 1634. ...
For other uses, see Joint (disambiguation). ...
In anatomy, the term ligament is used to denote three different types of structures:[1] Fibrous tissue that connects bones to other bones. ...
In common usage, a human leg is the lower limb of the body, extending from the hip to the ankle, and including the thigh, the knee, and the cnemis. ...
In anatomy, the hip is the bony projection of the femur which is known as the greater trochanter, and the overlying muscle and fat. ...
The iliofemoral ligament (Y-ligament; ligament of Bigelow) is a band of great strength which lies in front of the hip joint; it is intimately connected with the joint capsule, and serves to strengthen the joint by resisting hyperextension. ...
The pubocapsular ligament (pubofemoral ligament) is a ligament on the inferior side of the of the hip joint. ...
The ischiocapsular ligament (ischiofemoral ligament, ischiocapsular band; ligament of Bertin) consists of a triangular band of strong fibers on the posterior side of the hip joint. ...
The ligament of the head of the femur is a triangular, somewhat flattened band implanted by its apex into the antero-superior part of the fovea capitis femoris; its base is attached by two bands, one into either side of the acetabular notch, and between these bony attachments it blends...
The Transverse Acetabular Ligament (transverse ligament) is in reality a portion of the acetabular labrum, though differing from it in having no cartilage cells among its fibers. ...
For other uses, see Knee (disambiguation). ...
The Patellar ligament (anterior ligament) is the central portion of the common tendon of the Quadriceps femoris, which is continued from the patella to the tuberosity of the tibia. ...
The oblique popliteal ligament (posterior ligament) is a broad, flat, fibrous band, formed of fasciculi separated from one another by apertures for the passage of vessels and nerves. ...
The arcuate popliteal ligament is an extracapsular ligament of the knee. ...
The medial collateral ligament or MCL (or tibial collateral ligament) is one of the four major ligaments of the knee. ...
The Fibular Collateral Ligament (external lateral or long external lateral ligament) is a strong, rounded, fibrous cord, attached, above, to the back part of the lateral condyle of the femur, immediately above the groove for the tendon of the Popliteus; below, to the lateral side of the head of the...
Diagram of the knee The posterior cruciate ligament (or PCL) is one of the four major ligaments of the knee. ...
In anatomy, a meniscus is a moon-shaped figure. ...
The medial meniscus is a fibrocartilage band that spans the medial knee, and lies on the head of the tibia. ...
The lateral meniscus, also called the external semilunar fibrocartilage is a fibrocartilaginous band that spans the lateral knee. ...
The superior tibiofibular articulation is an arthrodial joint between the lateral condyle of the tibia and the head of the fibula. ...
The anterior ligament of the head of the fibula (anterior superior ligament) consists of two or three broad and flat bands, which pass obliquely upward from the front of the head of the fibula to the front of the lateral condyle of the tibia. ...
The posterior ligament of the head of the fibula is a part of the knee. ...
The inferior tibiofibular articulation (tibiofibular syndesmosis) is formed by the rough, convex surface of the medial side of the lower end of the fibula, and a rough concave surface on the lateral side of the tibia. ...
The anterior ligament of the lateral malleolus (anterior tibiofibular ligament, anterior inferior ligament) is a flat, triangular band of fibers, broader below than above, which extends obliquely downward and lateralward between the adjacent margins of the tibia and fibula, on the front aspect of the syndesmosis. ...
The posterior ligament of the lateral malleolus (posterior tibiofibular ligament, posterior inferior ligament). ...
For a review of anatomical terms, see Anatomical position and Anatomical terms of location. ...
The medial ligament of talocrural joint (or deltoid ligament) is a strong, flat, triangular band, attached, above, to the apex and anterior and posterior borders of the medial malleolus. ...
The anterior talofibular ligament passes from the anterior margin of the fibular malleolus, forward and medially, to the talus, in front of its lateral articular facet. ...
The posterior talofibular ligament, runs almost horizontally from the depression at the medial and back part of the fibular malleolus to a prominent tubercle on the posterior surface of the talus immediately lateral to the groove for the tendon of the Flexor hallucis longus. ...
The calcaneofibular ligament is a narrow, rounded cord, running from the apex of the fibular malleolus downward and slightly backward to a tubercle on the lateral surface of the calcaneus. ...
For a review of anatomical terms, see Anatomical position and Anatomical terms of location. ...
The anterior talocalcaneal ligament (anterior calcaneo-astragaloid ligament) extends from the front and lateral surface of the neck of the talus to the superior surface of the calcaneus. ...
The posterior talocalcaneal ligament (posterior calcaneo-astragaloid ligament) connects the lateral tubercle of the talus with the upper and medial part of the calcaneus; it is a short band, and its fibers radiate from their narrow attachment to the talus. ...
The lateral talocalcaneal ligament (external calcaneo-astragaloid ligament) is a short, strong fasciculus, passing from the lateral surface of the talus, immediately beneath its fibular facet to the lateral surface of the calcaneus. ...
The medial talocalcaneal ligament (internal calcaneo-astragaloid ligament) connects the medial tubercle of the back of the talus with the back of the sustentaculum tali. ...
The interosseous talocalcaneal ligament forms the chief bond of union between the bones. ...
The transverse tarsal joint is formed by the articulation of the calcaneus with the cuboid, and the articulation of the talus with the navicular. ...
The Talocalcaneonavicular Articulation is an arthrodial joint: the rounded head of the talus being received into the concavity formed by the posterior surface of the navicular, the anterior articular surface of the calcaneus, and the upper surface of the planter calcaneonavicular ligament. ...
The dorsal talonavicular ligament is a broad, thin band, which connects the neck of the talus to the dorsal surface of the navicular bone; it is covered by the Extensor tendons. ...
The plantar calcaneonavicular ligament (also known as the spring ligament) is a ligament on the underside of the foot that connects the calcaneus with the navicular bone. ...
The bifurcated ligament (internal calcaneocuboid, interosseous ligament, bifurcate ligament) is a strong band, attached behind to the deep hollow on the upper surface of the calcaneus and dividing in front in a Y-shaped manner into a calcaneocuboid and a calcaneonavicular part. ...
Calcaneocuboid Articulation (articulation of the calcaneus with the cuboid). ...
The dorsal calcaneocuboid ligament (superior calcaneocuboid ligament) is a thin but broad fasciculus, which passes between the contiguous surfaces of the calcaneus and cuboid, on the dorsal surface of the joint. ...
The long plantar ligament (long calcaneocuboid ligament; superficial long plantar ligament) is a long ligament on the underside of the foot that connects the calcaneus with the cuboid bone. ...
The plantar calcaneocuboid ligament (short calcaneocuboid ligament; short plantar ligament) is a ligament on the bottom of the foot that connects the calcaneus to the cuboid bone. ...
The bifurcated ligament (internal calcaneocuboid, interosseous ligament, bifurcate ligament) is a strong band, attached behind to the deep hollow on the upper surface of the calcaneus and dividing in front in a Y-shaped manner into a calcaneocuboid and a calcaneonavicular part. ...
Intertarsal articulations are the joints of the tarsus. ...
Cuneonavicular Articulation (articulation of the navicular with the cuneiform bones). ...
The Plantar cuneonavicular ligaments are fibrous bands that connect the plantar surface of the navicular bone to the adjacent plantar surfaces of the three cuneiform bones. ...
Cuneonavicular Articulation (articulation of the navicular with the cuneiform bones). ...
Intercuneiform: plantar - dorsal - interosseous | | | Foot - other | | | | Arches of the foot | | | The interphalangeal articulations of the foot (articulations of the phalanges) are ginglymoid joints, and each has a plantar and two collateral ligaments. ...
In order to allow it to support the weight of the body in the erect posture with the least expenditure of material, the foot is constructed of a series of arches formed by the tarsal and metatarsal bones, and strengthened by the ligaments and tendons of the foot. ...
The Longitudinal arch of the foot can be broken down into several smaller arches: // The main arches are the antero-posterior arches, which may, for descriptive purposes, be regarded as divisible into two types—a medial and a lateral. ...
In addition to the longitudinal arches the foot presents a series of transverse arches. ...
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