Lower extremity of femur
Encyclopedia
The lower extremity of the femur
(or distal extremity), larger than the upper extremity of femur
, is somewhat cuboid in form, but its transverse diameter is greater than its antero-posterior; it consists of two oblong eminences known as the condyles.
, is present between them.
The lateral condyle
is the more prominent and is the broader both in its antero-posterior and transverse diameters, the medial condyle
is the longer and, when the femur is held with its body perpendicular, projects to a lower level.
When, however, the femur is in its natural oblique position the lower surfaces of the two condyles lie practically in the same horizontal plane.
The condyles are not quite parallel with one another; the long axis of the lateral is almost directly antero-posterior, but that of the medial runs backward and medialward.
Their opposed surfaces are small, rough, and concave, and form the walls of the intercondyloid fossa.
This fossa is limited above by a ridge, the intercondyloid line, and below by the central part of the posterior margin of the patellar surface.
The posterior cruciate ligament
of the knee-joint is attached to the lower and front part of the medial wall of the fossa and the anterior cruciate ligament
to an impression on the upper and back part of its lateral wall.
.
The medial epicondyle is a large convex eminence to which the tibial collateral ligament of the knee-joint is attached.
At its upper part is the adductor tubercle, already referred to, and behind it is a rough impression which gives origin to the medial head of the Gastrocnemius.
The lateral epicondyle
, smaller and less prominent than the medial, gives attachment to the fibular collateral ligament of the knee-joint.
Directly below it is a small depression from which a smooth well-marked groove curves obliquely upward and backward to the posterior extremity of the condyle.
This groove is separated from the articular surface of the condyle by a prominent lip across which a second, shallower groove runs vertically downward from the depression.
In the fresh state these grooves are covered with cartilage.
The Popliteus arises from the depression; its tendon lies in the oblique groove when the knee is flexed and in the vertical groove when the knee is extended.
Above and behind the lateral epicondyle is an area for the origin of the lateral head of the Gastrocnemius, above and to the medial side of which the Plantaris arises.
Its front part is named the patellar surface and articulates with the patella; it presents a median groove which extends downward to the intercondyloid fossa
and two convexities, the lateral of which is broader, more prominent, and extends farther upward than the medial.
The lower and posterior parts of the articular surface constitute the tibial surfaces for articulation with the corresponding condyles of the tibia
and menisci.
These surfaces are separated from one another by the intercondyloid fossa and from the patellar surface by faint grooves which extend obliquely across the condyles.
The lateral groove is the better marked; it runs lateralward and forward from the front part of the intercondyloid fossa
, and expands to form a triangular depression.
When the knee-joint is fully extended, the triangular depression rests upon the anterior portion of the lateral meniscus, and the medial part of the groove comes into contact with the medial margin of the lateral articular surface of the tibia in front of the lateral tubercle of the tibial intercondyloid eminence.
The medial groove is less distinct than the lateral.
It does not reach as far as the intercondyloid fossa and therefore exists only on the medial part of the condyle; it receives the anterior edge of the medial meniscus when the knee-joint is extended.
Where the groove ceases laterally the patellar surface is seen to be continued backward as a semilunar
area close to the anterior part of the intercondyloid fossa
; this semilunar area articulates with the medial vertical facet of the patella in forced flexion of the knee-joint.
The tibial surfaces of the condyles are convex from side to side and from before backward. Each presents a double curve, its posterior segment being an arc of a circle, its anterior, part of a cycloid.
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
(or distal extremity), larger than the upper extremity of femur
Upper extremity of femur
The upper extremity of femur contains the following structures:* Femur head* Femur neck* Greater trochanter* Lesser trochanter* Tubercle of the femur* Intertrochanteric line* Intertrochanteric crest* Linea quadrata...
, is somewhat cuboid in form, but its transverse diameter is greater than its antero-posterior; it consists of two oblong eminences known as the condyles.
Condyles
Anteriorly, the condyles are slightly prominent and are separated by a smooth shallow articular depression called the patellar surface. Posteriorly, they project considerably and a deep notch, the Intercondylar fossa of femurIntercondylar fossa of femur
In front, the condyles are but slightly prominent, and are separated from one another by a smooth shallow articular depression called the patellar surface; behind, they project considerably, and the interval between them forms a deep notch, the intercondylar fossa ....
, is present between them.
The lateral condyle
Lateral condyle of femur
The lateral condyle is one of the two projections on the lower extremity of femur. It is the more prominent and is the broader both in its antero-posterior and transverse diameters....
is the more prominent and is the broader both in its antero-posterior and transverse diameters, the medial condyle
Medial condyle of tibia
The medial condyle is the medial portion of the upper extremity of tibia.It is the site of insertion for the Semimembranosus muscle....
is the longer and, when the femur is held with its body perpendicular, projects to a lower level.
When, however, the femur is in its natural oblique position the lower surfaces of the two condyles lie practically in the same horizontal plane.
The condyles are not quite parallel with one another; the long axis of the lateral is almost directly antero-posterior, but that of the medial runs backward and medialward.
Their opposed surfaces are small, rough, and concave, and form the walls of the intercondyloid fossa.
This fossa is limited above by a ridge, the intercondyloid line, and below by the central part of the posterior margin of the patellar surface.
The posterior cruciate ligament
Posterior cruciate ligament
The posterior cruciate ligament is one of the four major ligaments of the knee. It connects the posterior intercondylar area of the tibia to the medial condyle of the femur...
of the knee-joint is attached to the lower and front part of the medial wall of the fossa and the anterior cruciate ligament
Anterior cruciate ligament
The anterior cruciate ligament is a cruciate ligament which is one of the four major ligaments of the human knee. In the quadruped stifle , based on its anatomical position, it is referred to as the cranial cruciate ligament.The ACL originates from deep within the notch of the distal femur...
to an impression on the upper and back part of its lateral wall.
Epicondyles
Each condyle is surmounted by an elevation, the epicondyleEpicondyle
Epicondyle may refer to:...
.
The medial epicondyle is a large convex eminence to which the tibial collateral ligament of the knee-joint is attached.
At its upper part is the adductor tubercle, already referred to, and behind it is a rough impression which gives origin to the medial head of the Gastrocnemius.
The lateral epicondyle
Lateral epicondyle of the femur
The lateral epicondyle of the femur, smaller and less prominent than the medial epicondyle, gives attachment to the fibular collateral ligament of the knee-joint. Directly below it is a small depression from which a smooth well-marked groove curves obliquely upward and backward to the posterior...
, smaller and less prominent than the medial, gives attachment to the fibular collateral ligament of the knee-joint.
Directly below it is a small depression from which a smooth well-marked groove curves obliquely upward and backward to the posterior extremity of the condyle.
This groove is separated from the articular surface of the condyle by a prominent lip across which a second, shallower groove runs vertically downward from the depression.
In the fresh state these grooves are covered with cartilage.
The Popliteus arises from the depression; its tendon lies in the oblique groove when the knee is flexed and in the vertical groove when the knee is extended.
Above and behind the lateral epicondyle is an area for the origin of the lateral head of the Gastrocnemius, above and to the medial side of which the Plantaris arises.
Articular surface
The articular surface of the lower end of the femur occupies the anterior, inferior, and posterior surfaces of the condyles.Its front part is named the patellar surface and articulates with the patella; it presents a median groove which extends downward to the intercondyloid fossa
Intercondyloid fossa
Intercondyloid fossa can refer to:* Anterior intercondyloid fossa* Posterior intercondyloid fossa* Intercondylar fossa of femur...
and two convexities, the lateral of which is broader, more prominent, and extends farther upward than the medial.
The lower and posterior parts of the articular surface constitute the tibial surfaces for articulation with the corresponding condyles of the tibia
Tibia
The tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....
and menisci.
These surfaces are separated from one another by the intercondyloid fossa and from the patellar surface by faint grooves which extend obliquely across the condyles.
The lateral groove is the better marked; it runs lateralward and forward from the front part of the intercondyloid fossa
Intercondyloid fossa
Intercondyloid fossa can refer to:* Anterior intercondyloid fossa* Posterior intercondyloid fossa* Intercondylar fossa of femur...
, and expands to form a triangular depression.
When the knee-joint is fully extended, the triangular depression rests upon the anterior portion of the lateral meniscus, and the medial part of the groove comes into contact with the medial margin of the lateral articular surface of the tibia in front of the lateral tubercle of the tibial intercondyloid eminence.
The medial groove is less distinct than the lateral.
It does not reach as far as the intercondyloid fossa and therefore exists only on the medial part of the condyle; it receives the anterior edge of the medial meniscus when the knee-joint is extended.
Where the groove ceases laterally the patellar surface is seen to be continued backward as a semilunar
Semilunar
Semilunar can refer to:* Semilunar valves* An older name for the Lunate bone* In neurology, the semilunar fasciculus....
area close to the anterior part of the intercondyloid fossa
Intercondyloid fossa
Intercondyloid fossa can refer to:* Anterior intercondyloid fossa* Posterior intercondyloid fossa* Intercondylar fossa of femur...
; this semilunar area articulates with the medial vertical facet of the patella in forced flexion of the knee-joint.
The tibial surfaces of the condyles are convex from side to side and from before backward. Each presents a double curve, its posterior segment being an arc of a circle, its anterior, part of a cycloid.