Femur

The thigh bone, in medical terminology short femur or the femur is the strongest bones and forms the basis of the thigh bone. He is the longest bone in the human body.

• 2.1 CCD angle
• 2.2 torsion

Anatomy

Head

At the upper end of the femur is to be the head (caput ossis femoris ) which forms a connection to the pelvic bone, and hence the hip joint with a roughly spherical articular surface. The head has at its center circumference a slight depression, called Hüftkopfgrube ( fovea capitis femoris). She's passage point for a band ( ligamentum capitis femoris ossis ) which surrounds the artery that supplies the femoral head.

Neck

If one follows the femur further down ( distal), joins the head to the neck ( collum femoris ossis ). Are at it sideways a large and centrally a small trochanter ( greater trochanter and lesser trochanter ), the ventral ( anterior ) through a flat, rough line ( intertrochanteric ) and move upward ( dorsal) by a sharp bar ( intertrochanteric crest ) are connected. The great trochanter serves as the approach of the gluteal muscles ( gluteus maximus, gluteus medius and gluteus minimus ), the small trochanter as an approach of the musculus iliacus and psoas major. Some mammals (eg, horses and rabbits) do not have a third trochanter ( trochanter tertius ). There is a recess ( trochanteric fossa ) between the greater trochanter and the femur neck. It serves as the approach for several muscles (musculus obturator internus muscle gemellus superior, inferior and musculus musculus gemellus obturator externus).

Malalignment of the femoral neck are:

• Coxa vara - miniaturized CCD angle
• Coxa valga - enlarged CCD angle
• Coxa antetorta - larger than normal anteversion
• Coxa retrotorta - anteversion of the femoral neck less than 0 °

Shaft

Below the rolling hills of the femoral shaft begins ( Corpus ossis femoris). He is almost cylindrical, but noticeably bent forward. About the posterior surface in humans draws a rough longitudinal line ( linea aspera ), which consists of two strips ( medial lip and labial lateral). - In animals (facies aspera ), these " lips " by a rough surface limited. - In the middle of the femoral shaft, the two bars are close together at both ends, they move away from each other ( diverge ). The sidebar widens towards the top ( proximal) in a longitudinal roughness ( gluteal tuberosity ). The central bar running flat out in the line between the rolling hills and ends just below the small trochanter, by a second, parallel line ( Linea pectinea ) is obtained directly. Next diverge above the two bars in two other lines ( Linea Linea supracondylar and medial supracondylar lateralis) which limit a nearly planar, triangular bone box (facies popliteal ). The lines and bars are used as starting points for the pre muscles ( adductors ).

Bottom

The thickened lower end of the femur bears two strongly outwardly curved (convex ) condyles ( medial condyle and lateral condyle ). They make up the knee joint with the shin plateau. The two condyles are separated by a pit ( intercondylar notch ). This is bounded behind by a flat bone line ( Linea intercondylar ). The cruciate ligament cave is located between the two knots (also known as intercondylar notch designated ). Front, the condyles merge into a common, transversely inwardly curved ( concave ), sagittal outwardly curved articular surface ( patellar surface ) for connection to the kneecap ( patella). The knots are each an essay, the little projects ( medial epicondyle and lateral epicondyle ). The lateral attachment has at his side a groove ( sulcus popliteus ).

Angle

CCD angle

The angle between the femoral neck ( collum ) and bone shaft called Centrum- collum - diaphyseal angle ( short CCD angle ).

The CCD angle decreases from 137 ° in the 4th to 5th month of the embryo up to 129 ° in the 9th month of pregnancy and reaches back to the birth of 137 °. The angle is 145 ° in infants, the child about 140 °, 130 ° from puberty when adult is about 126 ° and about 120 ° in the elderly.

Since the hip joint must transmit large forces, also the position of the acetabular cup is included for an assessment of axial ratios for example. So people also have larger CCD angle with steep joint sockets physiological manner. Case of pathologically high values ​​for the CCD angle, the clinical picture of the X- leg ( coxa valga ) is available (for example, immobility after muscle paralysis ), as the body weight exerts no mechanical pressure on the femoral neck. In a large load proportional to the femoral neck, there is an O- leg ( coxa vara ). This can (for example, rickets ) be the case with a reduced resistance, and therefore an increased flexibility of the bone.

Torsion angle

Under the torsion angle ( syn. antetorsion or anteversion angle) is defined as the rotation of the transverse axes of the distal and proximal end of the femur. The distal end of the femur is rotated about 12-20 degrees to the inward (towards the median plane ) as compared to the proximal. This angle is in the child's bones greater than in the adult (see: Najadensitz ).

Diseases

Fractures of the femur are relatively common, in particular femoral neck ( femoral neck fracture ) and shaft are affected.

The articular surface of the femoral head can be damaged due to wear phenomena such as arthrosis, mechanical failure stress, trauma, or inflammation. It can be replaced by an operation by a metal prosthesis (together with the femoral neck, if necessary ).

The knee joint side joint surfaces of the condyles are often damaged, so that a treatment or a surgical replacement may be necessary.