Femur bone (Thigh bone) : Structure, Parts, Location, Side Determination, Anatomical Position, Attachments, Functions, Clinical Anatomy, Fracture, Pain, & Pictures
- Femur or thigh bone is the longest & the strongest bone of the body.
The bone has a shaft, and two ends, upper & lower.
Shaft of femur has following features :
- Cylindrical (more or less).
- Narrowest in the middle.
- More expanded inferiorly than superiorly.
- Convex forwards.
- Directed obliquely downwards and medially, because the upper ends of two femora are separated by the width of the pelvis, and their lower ends are close together.
Shaft, for convenience, can be divided into 3 parts :
Middle one-third : In the middle one-third, the shaft has three borders, medial, lateral and posterior and three surfaces, anterior, medial and lateral.
- Medial and lateral borders are rounded and ill-defined.
- Posterior border is in the form of a broad roughened ridge, called the linea aspera which has distinct medial and lateral lips.
Upper one-third : In the upper one-third, the shaft has four borders, medial, lateral, spiral line and the lateral lip of the gluteal tuberosity and four surfaces anterior, medial, lateral and posterior because two lips of the linea aspera diverge to enclose an additional posterior surface.
- Gluteal tuberosity is a broad roughened ridge present on the lateral part of the posterior surface.
Lower one-third : In the lower one-third also, the shaft has four borders, medial, lateral, medial supracondylar line and lateral supracondylar line and four surfaces, anterior, medial, lateral and popliteal because the two lips of the linea aspera diverge as supracondylar lines to enclose an additional, popliteal surface.
Upper end of the femur includes the following parts :
- Head : Forms more than half a sphere, and is directed medially, upwards and slightly forwards. It articulates with the acetabulum to form the hip joint. Roughened pit situated just below and behind the centre of the head is called the fovea.
- Neck : Connects the head with the shaft.
- Greater trochanter : Large quadrangular prominence located below junction of the neck with the shaft.
- Lesser trochanter : Conical eminence directed medially and backwards from the junction of the posteroinferior part of the neck with the shaft.
- Intertrochanteric line : Prominent roughened ridge which marks the junction of the anterior surface of the neck with the shaft of the femur.
- Intertrochanteric crest : Smooth-rounded ridge which marks the junction of the posterior surface of the neck with the shaft of the femur.
Lower end of the femur includes the following parts :
- Condyles (Lateral & Medial Condyle)
Lateral condyle is flat laterally, and is more in line with the shaft. It, therefore, takes greater part in the transmission of body weight to the tibia. The lateral aspect has a prominence called the Lateral epicondyle.
Medial Condyle is convex medially. The most prominent point on it is called the medial epicondyle.
- Intercondylar Fossa or Intercondylar Notch : Separates the lower and posterior parts of the two condyles.
- Articular Surface : The two condyles are partially covered by a large articular surface which is divisible into patellar and tibial parts.
- Upper end bears a rounded head
- Lower end is widely expanded to form two large condyles.
- Head is directed medially.
- Shaft (cylindrical) is convex forwards.
- Head is directed medially upwards and slightly forwards.
- Shaft is directed obliquely downwards and medially so that the lower surfaces of the two condyles of the femur lie in the same horizontal plane.
Attachments on Femur
- Provides attachment to the ligament of the head of femur or round ligament, or ligamentum teres.
2. Greater trochanter : It provides the attachment to the following :
- Gluteus minimus.
- Obturator internus.
- Obturator externus.
- Gluteus medius.
3. Lesser trochanter : It provides the attachment to the following :
- Psoas major.
4. Intertrochanteric line : It provides the attachment to the following :
- Capsular ligament of the hip joint.
- Upper band of the iliofemoral ligament in its upper part.
- Lower band of the iliofemoral ligament in its lower part.
It provide origin to the :
- Highest fibres of the vastus lateralis from the upper end.
- Highest fibres of the vastus medialis from the lower end of the line.
5. Quadrate tubercle : Insertion of the quadratus femoris.
6. Shaft :
Medial and popliteal surfaces are bare, except for a little extension of the origin of the medial head of the gastrocnemius to the popliteal surface.
Shaft provides the attachment to the following :
- Vastus intermedjus.
- Articularis genu.
- Suprapatellar bursa.
- Vastus lateralis.
- Vastus medialis.
- Deeper fibres of the lower half of the gluteus maximus.
- Adductor longus.
- Adductor brevis.
- Adductor magnus.
- Short head of the biceps femoris.
7. Lateral condyle : It provides the attachment to the following :
- Fibular collateral ligament of the knee joint.
- Lateral head of the gastrocnemius.
8. Medial condyle : It provides the attachment to the following :
- Tibial collateral ligament of the knee joint.
- Hamstring part or the ischial head of the adductor magnus.
9. Intercondylar notch : It provides the attachment to the following :
- Cruciate ligament (Anterior & Posterior).
- Capsular ligament.
- Oblique popliteal ligament.
Forced medial rotation of the thigh and leg may results in following type of inuries:
- Spiral fracture of the shaft of the femur : Usually in the persons below the age of 16 years.
- Bucket-handle tear of the medial meniscus : Usually between the ages of 14 and 40 years.
- Pott’s fracture of the leg : Usually between the ages of 40 and 60 years.
- Fracture of the neck of the femur : Usually over the age of 60 years.