Femur bone lec3

Anatomy of Femur bone

1. feMUR The femur is also called the thigh bone and is the longest and strongest bone of the body. It is composed of upper end, lower end and a shaft . The upper e nd bears a rounded head , whereas the lower end is widely expanded to from two large condyles . The head is directed medially.

2. Upper end of Femur The upper end of the femur includes the: head, the neck, the greater trochanter, the lesser trochanter, the intertrochanteric line, and the intertrochanteric crest.

3. Head of Femur Head articulates with acetabulum to form a hip joint. It is more than half a sphere, and is directed medially, upwards and slightly forwards. Fovea is a roughened pit just below and behind the center of the head. Head, in its most part is covered by cartilage.

4. Neck of Femur 3-3.5 cms long and connects head with shaft. Forms an angle with shaft, known as neck shaft angle and is about 125 in adults [lesser in females]. The angle facilitates movements of the hip joint. The neck has two borders and two surfaces The upper border , concave and horizontal, meets the shaft at the greater trochanter. The lower border , straight and oblique, meets the shaft near the lesser trochanter. The anterior surface is flat and meets the shaft at the intertrochanteric line. Anterior surface of femoral neck is entirely interacapsular . Upper part of this surface may be covered by articular cartilage . The posterior surface is convex from above downwards and concave from side to side. It meets the shaft at the intertrochanteric crest.

5. Greater Trochanter Greater trochanter is a large quadrangular prominence located at the upper part of the junction of the neck with shaft. The greater trochanter has an upper borde r with an apex, and 3 surfaces ( anterior,  medial  and  lateral ). The apex is the in turned posterior part of the posterior border. The anterior surface is rough in its  lateral   part. The   medial  surface presents a rough impression, above and a deep trochanteric fossa, below. The   lateral  surface is crossed by an oblique ridge directed downwards and forwards.

6. Lesser Trochanter It is a conical eminence directed medially and backwards from the junction of the posterior part of the neck with the shaft.

7. Intertrochanteric Line It marks the junction of neck with the femur. It is a roughened ridge from anterosuperior angle of the greater trochanter (as a tubercle )

8. Intertrochanteric Crest It marks the junction of the posterior surface of the neck with the shaft of the femur. It   is smooth rounded ridge which begins above at the posterior  superior  angle of the greater trochanter and ends at the lesser trochanter. The rounded elevation, a little above its middle is called the quadrate tubercle.

9. Shaft of Femur The shaft is almost a cylindrical structure wide superiorly and inferiorly and narrowest in the middle. It is convex forwards and is directed obliquely downwards and medially . The shaft in middle one-third has three borders - medial ,  lateral  and posterior. The  medial  and  lateral  borders are rounded and ill- defined, but the posterior border is in the form of a broad roughened ridge, called the linea aspera . Linea aspera is an important landmark in orthopedics surgeries involving reduction of femoral fractures. The Linea aspera has distinct  medial  and  lateral  lips. The  medial  and  lateral  surfaces are directed more backwards than to sides.

10. shaft The shaft in middle one-third has three borders - medial ,  lateral  and posterior. The  medial  and  lateral  borders are rounded and ill- defined, but the posterior border is in the form of a broad roughened ridge, called the linea aspera . Linea aspera is an important landmark in orthopedics surgeries involving reduction of femoral fractures. The Linea aspera has distinct  medial  and  lateral  lips. The  medial  and  lateral  surfaces are directed more backwards than to sides.

11. shaft The shaft possesses 3 surfaces as well – anterior,  medial  and  lateral . The gluteal tuberosity is a broad roughened ridge on the  lateral  part of the posterior surface.

12. Lower end

13. Lower End of Femur The lower end of the femur is wide and expanded. It has two large condyles –   medial and   lateral . Anteriorly, the two condyles are united and are in a line with the front of the shaft. Posteriorly, they are separated by a deep gap, termed the interocondylar fossa or intercondylar notch, and project backwards much beyond the plane of the popliteal surface.

14. condyles The  lateral  condyle is flat laterally, less prominent than  medial  condyle and stouter than it. It has a prominence  called the  lateral  epicondyle. Below it lies the popliteal groove with deeper anterior part and a shallower posterior part. Medial condyle is  convex medially. It also bears a prominent point called the  medial epicondyle . Adductor tubercle is a projection posterosuperior to the epicondyle which serves as an important landmark.  The epiphyseal line for the lower end of the femur passes through it.

15. Interondylar fossa or notch Interondylar fossa or notch separates the lower and posterior parts of the two condyles. Intercondylar line separates notch from the popliteal surface. Anteriorly, the notch is limited by patellar articular surface. The two condyles are partially covered by a large articular surface. Anteriorly, the condyles articulate with patella and this articualtion extends more on the  lateral condyle than on the  medial . Between the two condyles, the surface is grooved vertically.  Two faint grooves separate the patellar articualtion surface from tibial surfaces. Tibial articulation surface over the   lateral  condyle is short and straight anteroposteriorly whereas the part over the  medial  condyle is longer and is convex medially.

16. Attachments on the Femur

17. Head of Femur The fovea on the head of the femur provides attachment to the ligamentum teres .

18. Greater Trochanter INSERTIONS: The piriformis The gluteus minimus The obturator internus and the two gemelli The obturator externus The gluteus medius The trochanteric  bursa  of the gluteus medius lies in front of the ridge, and the trochanteric  bursa  of the gluteus maximus lies behind the ridge.

19. Lesser Trochanter INSERTION: The psoas major The iliacus Gluteus minimus   bursa  lies deep to the upper horizontal fibrres of the adductor magnus .

20. Intertrochanteric Line Capsular ligament of the hip joint Iliofemoral ligament Highest fibres of the vastus lateralis from the upper end Highest fibres of the vastus medialis from the lower end Quadratus femoris attached on quadrate tubercle

21. Shaft of Femur Vastus intermedius Vastus lateralis Vastus medialis Gluteal tubersosity receives insertion of deeper fibres of the lower half of the gluteus maximus Adductor longus

22. Shaft of Femur INSERTION: Adductor brevis U pper part of the adductor longus Adductor magnus Pectineus ORIGIN: Short head of the biceps femoris The lower end of the  lateral  supracondylar line gives origin to the plantaris above and the upper part of the  lateral  head of the gastrocnemius below.

23. Lateral Condyle Fibular collateral ligament of the knee attaches to the  lateral   epicondyle. The popliteus aries from the deep anterior part of the popliteal groove. origin to the  lateral head of the gastrocnemius

24. Medial Condyle Tibial collateral ligament of the knee –  medial  epicondyle Hamstring part of the adductor magnus – adductor tubercle

25. Intercondylar Notch Anterior cruciate ligament – posterior part of the  medial  surface of the  lateral condyle . The intercondylar line provides attachment to the capsular ligament and laterally to the oblique popliteal ligamemt .

26. Significance of Femur Femur is a common bone to be injured Coxa valga is a condition where the femoral neck shaft angle is more than normal. ( 135 degrees) Coxa vara is a condition where the neck shaft angle is less than normal (120 degrees)