The anatomy of Femur features and attachments.pptx

anatomy of femur

1. The Femur   T high bone Dr M Idris Siddiqui

2. The Femur The Femur  is the longest, heaviest and strongest bone of the body, present in the thigh. It is around 18 inches ( 45cm long), i.e ., about quarter of the height of the individual. At the upper end it articulates with the  hip bone  to create the  hip joint . A t the lower end it articulates with the   patella  and  tibia . The femur conducts body weight from the  hip bone  to the  tibia  in standing position.

3. PARTS The femur is is composed of 3 parts : Upper end, Shaft . Lower end. The upper end contains: The head, The neck . The lesser and greater trochanter . The shaft of the femur is gradually convex anteriorly with maximum convexity in the middle third where the shaft is narrowest. The lower end of the femur is enlarged to create Medial condyle . Lateral condyle . Intercondylar fossa Both condyles project backwards and are divided by the intercondylar fossa . The most notable points on the condyles are named epicondyles .

4. SIDE DETERMINATION The upper end bears a rounded head whereas the lower end is widely expanded to form two large condyles . The head is directed medially. The cylindrical shaft is convex forwards

5. ANATOMICAL POSITION The head is directed medially upwards and slightly forwards. The 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.

6. HEAD It creates about two-third of a sphere and articulates with the  acetabulum  of the hip bone to create the hip joint . It is covered with catilage except a central pit, fovea. It presents a small pit, the fovea, just below and behind the center, where ligament of the head of femur ( ligamentum teres femoris ) attaches.

7. NECK It is 5 cm long and attaches the head with all the shaft. It is directed upward, medially, and somewhat forwards. The angle between its lower border and the medial border of shaft is termed neck-shaft angle(110-120⁰).

8. GREATER TROCHANTER It is a quadrilateral elevation, projecting upward from the lateral aspect of the junction of neck and shaft . Its upper & posterior part is bent backwards & medially and overhangs the neck. Its lateral surface has an oblique rough ridge which separates 2 smooth areas.

9. Greater trochanter It has the following features: Its lateral surface is convex. Its upper & posterior borders are free. Its highest point is in its posterosuperior angle. Its medial surface has a deep depression called the trochanteric fossa for insertion of  obturator externus .. Its posterior part presents the apex or tip of greater trochanter , which gives connection to the  piriformis .

10. Greater trochanter A shallow depression above and in front of trochanteric fossa for insertion of obturator internus together with the gemellus superior and gemellus inferior. It is quadrilateral and split diagonally by an oblique ridge into the upper and lower triangular regions. The ridge gives connection to the gluteus medius muscle. The triangular regions- anterior and posterior to the ridge are associated with the trochanteric bursae of the gluteus medius and  gluteus maximus , respectively.

11. LESSER TROCHANTER It is a conical projection rising from the posteromedial surface of the neck-shaft angle. It is directed medially. Its apex gives connection to the  psoas major . Iliacus  is connected to its base on the front . Three lines radiate from the lesser trochanter One runs upwards & medially below the neck. 2 nd is pectineal line; it runs downwards & gives attachment to the aponeurosis of the pectineal muscle. 3 rd line runs upwards & laterally and forms the lower half of the “ Intertrochanteric crest”

12. The junction between the neck and shaft It presents 4 features. The greater trochanter ……………..……….laterally The lesser tronchater …………………………medially & somewhat posteriorly The trochanteric line…..……………………..in front The trochanteric crest……………………….. behind

13. Bony ridges in between tronchaters Intertrochanteric line  Intertrochanteric crest 

14. TROCHANTERIC LINE A ridge of bone that runs in an inferomedial direction on the anterior surface of the femur, connecting the two trochanters together.  After it passes the lesser trochanter on the posterior surface, it is known as the pectineal line of femur. It continues downward and medially below the lesser trochanter on the posterior aspect of femur as spiral line. It gives connection to : 2 ligaments and Capsule of the hip joint. Iliofemoral ligament  (strongest ligament in the body). 2 muscles: Vastus lateralis  to its upper end. Vastus medialis  to its lower end.

15. TROCHANTERIC CREST This is a ridge of bone that connects the two trochanters together. It is located on the posterior surface of the femur. There is a rounded tubercle on its superior half, this is called the quadrate tubercle. It gives insertion to the quadratus femoris .

16. UPPER END

17. Points to be Noticed Angle of inclination of femur : It is an angle between the long axes of neck and shaft of the femur thus also named neck-shaft angle. The normal neck-shaft angle is 125 ° in adults and 160 ° in youngsters. It is less in female. Angle of femoral torsion : It is an angle between long axis of the head and neck of femur, and transverse axis of the femoral condyles . It measures about 7 ° in men and 12 ° in female ) Angle of anteversion : The neck of femur is also tilted forwards slightly as it passes proximally to the head.(10⁰-15⁰)

18. Blood supply of the head of the femur Blood ascends upwards from the shaft along the cancellous bone. Blood from the vessels in the capsule of the hip joint; reflected to the neck in longitudinal bands called capsular retinaculae ( retinacular supply). These arise from the lateral femoral circumflex artery . Blood from the artery in the ligament teres .

19. SHAFT of femur

20. FEATURES of the shaft of femur Essentially the shaft of femur presents: Cylindrical in the mid, expands in upper 1/3 rd and flattened in lower 1/3 rd . 3 surfaces: Anterior , Medial , and Lateral Upper posterior, and Lower posterior ( popliteal surface).

21. the shaft of femur The middle third of posterior border is represented by a thick ridge termed linea aspera . The linea aspera presents inner and outer lips and an intermediate area. When the upper end of linea aspera is tracked upward, its inner and outer lips diverge and enclose a triangular posterior surface in the upper one-third of the shaft. The inner (medial) lip passes above to form the spiral line which winds around the medial aspect of the upper part of the shaft and then below the lesser trochanter to reach the anterior surface of the shaft where it ends at the lower part of intertochanteric line.

22. The Shaft On the posterior surface of the femoral shaft, there are roughened ridges of bone, these are called the  linea aspera   . Proximally, the medial border of the linea aspera becomes the  pectineal line.  The lateral border becomes the  gluteal tuberosity,  where the gluteus maximus attaches. Distally, the linea aspera widens and forms the floor of the  popliteal fossa , the medial and lateral borders form the medial and lateral supracondylar lines . The medial supracondylar line stops at the  adductor tubercle , where the adductor magnus attaches.

23. the shaft of femur When the lower end of linea aspera is followed downward, its inner and outer lips, diverge below, and enclose a triangular popliteal surface in the lower one-third of the shaft. The inner (medial) lip becomes constant with the medial supracondylar line, which finishes at the adductor tubercle. The outer (lateral) lip becomes constant with Lateral supra condylar line.

24. BORDERS AND SURFACES OF THE SHAFT OF FEMUR Part of femur Borders Surfaces Middle 1/3rd of the shaft Medial border Anterior surface Lateral border Medial surface Posterior border ( linea aspera ) Lateral surface Upper 1/3rd of the shaft Medial border Anterior surface Lateral border Medial surface Spiral line Lateral surface Gluteal tuberosity Posterior surface Lower 1/3rd of the shaft Medial border Anterior surface Lateral border Medial surface Medial supracondylar line Lateral surface Lateral supracondylar line Popliteal surface

25. ATTACHMENTS of the shaft The shaft of femur gives connection to these intermuscular septa: Attachments of intermuscular septa: 1 . Medial intermuscular septum is connected to the medial lip of linea aspera . 2 . Lateral intermuscular septum is connected to the lateral lip of the linea aspera .

26. Linea aspera The arrangement of 9 structures connected to the linea aspera : From medial to lateral side, these are: Vastus medialis . Medial intermuscular septum. Adductor brevis  (in the upper) and  Adductor longus  (in the lower part). Adductor magnus . Short head of  biceps femoris . Posterior intermuscular septum. Vastus lateralis . Vastus intermedius .

27. Muscle attachments of the shaft Origins Vastus intermedius  appears from the upper three fourth of anterior surface and adjoining lateral surface. Articularis genu  originates by few small slides from the lower quarter of anterior surface immediately below the vastus intermedius . Vastus lateralis appears in a linear manner from the upper part of intertrochanteric line, anterior and inferior edges of greater trochanter , lateral margin of gluteal tuberosity, and lateral lip of linea aspera . Vastus medialis appears in a linear manner from the lower part of intertrochanteric line, coil line, and the medial lip of linea aspera and the upper 1 fourth of medial supracondylar line.

28. Muscle attachments of the shaft Insertions: Adductor longus  is added into the medial lip of linea aspera . Pectineus  is added into a line going from the lesser trochanter to the upper end of linea aspera . Adductor brevis  is added into a line going from the lesser trochanter to the upper part of linea aspera . Adductor magnus  is added into the medial margin of gluteal tuberosity, linea aspera , medial supracondylar line, and adductor tubercle.

29. Gluteal tuberosity The lateral ridge of the  linea aspera  is very rough, and runs almost vertically upward to the base of the  greater trochanter . It is termed the  gluteal tuberosity , and gives attachment to part of the  Glutæus maximus : its upper part is often elongated into a roughened crest, on which a more or less well-marked, rounded tubercle, the  third trochanter .

30. LOWER END

31. The Distal end The distal end is characterised by the presence of the medial and lateral condyles , which articulate with the tibia and patella, forming the knee joint. Medial and lateral condyles   Medial and lateral epicondyles  

32. Medial Condyle Its most notable point is named medial epicondyle , which gives connection to the upper end of  medial collateral ligament . A projection posterosuperior to the medial epicondyle is known as adductor tubercle, which gives insertion to the ischial head of adductor magnus . Its lateral surface creates medial boundary of intercondylar fossa.

33. Lateral Condyle It is stouter and more powerful in relation to the medial condyle but less notable. Its lateral surface presents a bulge referred to as lateral epicondyle which gives connection to the fibular collateral ligament of the  knee joint . Smooth opinion above and behind the lateral epicondyle there is an origin to the lateral head of gastrocnemius . A groove below and behind the lateral epicondyle gives connection to  popliteus  in its anterior part. Tendon of popliteus takes up the posterior part of the groove during total flexion in the  knee joint . Its medial surface creates the lateral boundary of intercondylar fossa.

34. Intercondylar fossa Intercondylar fossa  –  A depression found on the posterior surface of the femur, it lies in between the two condyles . It contains two facets for attachment of internal knee ligaments. Facet for attachment of the posterior cruciate ligament  –  Found on the medial wall of the intercondylar fossa, it is a large rounded flat face, where the posterior cruciate ligament of the knee attaches. Facet for attachment of anterior cruciate ligament   –  Found on the lateral wall of the intercondylar fossa, it is smaller than the facet on the medial wall, and is where the anterior cruciate ligament of the knee attaches.

35. Distal end of femur

36. Muscle attachments of the lower end Gastrocnemius : The medial head originates from the popliteal surface just above the  medial condyle . The lateral head originates primarily from the  lateral condyle  but also stretches over the lower end of lateral supracondylar line. Plantaris (if present)arises from the lower end of lateral supracondylar line just above the lateral head of gastrocnemius Popliteus arises (inside knee joint) by a tendon from the anterior end of a groove below the lateral epicondyle .

37. Intercondylar Fossa ( Intercondylar Notch) It is a deep notch, which divides 2 condyles posteriorly. It is restricted posteriorly above by intercondylar path. It presents medial and lateral walls and floor. Medial wall of the fossa gives attachments to the upper end of posterior cruciate ligament in its anteroinferior part. Lateral wall of the fossa gives connection to the upper end of anterior cruciate ligament in its posterosuperior part. Mnemonic: LAMP = Lateral condyle gives connection to Anterior cruciate ligament and Medial condyle to Posteriorcruciate ligament

38. ARTICULAR SURFACE on distal end of femur The lower end of femur presents a V-shaped articular surface having the anterior, inferior, and posterior surfaces of both condyles . The apex of ‘V’ is referred to as patellar surface which inhabits the anterior surfaces of 2 condyles and articulates with the  patella . The patellar surface is saddle-shaped. Its lateral portion is wider and extends to a higher level in relation to the medial portion, corresponding to articular outermost layer of the patella.

39. Distal end of femur Connection of fibrous capsule at the lower end of femur: Posteriorly , it is connected to the intercondylar line and articular margins. Anteriorly , it is deficient for communication of suprapatellar bursa together with the synovial cavity of knee joint. Laterally and medially , it is connected along a line 1 cm above the articular margins. It is essential to note the groove for popliteus is intracapsular . The connection of fibrous capsule at the upper end of femur: Anteriorly it is connected to the intertrochanteric line but posteriorly it is connected about 1 cm medial to the intertrochanteric crest. Thus, the lateral part of the posterior outermost layer of the neck of femur is extracapsular and its medial half is intracapsular

40. Clinical Relevance: Proximal Femur Fractures Fractures of the proximal femur can broadly be classified into two main groups: Intracapsular Fracture Intracapsular fractures are more common in the elderly, especially  women . They are a result of a minor trip or stumble. This fracture occurs within the  capsule  of the hip joint. It can damage the medial  femoral circumflex artery –  and cause avascular necrosis of the femoral head. The distal fragment is pulled  upwards  and rotated  laterally . This manifests clinically as a shorter leg length, with the toes pointing laterally Extracapsular Fractures Extracapsular fractures are more common in young and middle aged people. In these fractures, the blood supply to the head of femur is  intact , and so no avascular necrosis can occur.  Like the subcapital fracture, the leg is shortened and laterally rotated.

41. Intracapsular # of femur

42. CLINICAL SIGNIFICANCE FRACTURE NECK OF FEMUR It is quite common in aged especially in women because of osteoporotic changes in the neck. TYPES OF FRACTURE The fracture might be intracapsular ( subcapital , transverse cervical) or extracapsular (basal, intertrochanteric , and subtrochanteric ). In intracapsular fracture, the retinacular boats- the main source of blood supply to the head- are injured. This results in delayed healing or nonunion of fracture, or even avascular necrosis of the head of femur. In intracapsular fracture of the neck of femur, the affected limb is shortened and characteristically held in laterally rotated position with the toes pointing laterally.

43. Clinical Relevance: Fractures of the Femoral Shaft Fractures of the  femoral shaft  are relatively uncommon, and require a lot of force. They are usually a consequence of a  traumatic  injury, such as a vehicular accident. They can often occur as a  spiral  fracture, which causes leg  shortening . The loss of leg length is due the bony fragments overriding, pulled by their attached muscles. As the method of injury is typically high energy, the surrounding soft tissues may also be damaged. As in any fracture, it is important to assess the  neurovascular supply  to the affected limb, as they femoral nerve or artery may have been damaged in the injury.

44. OSSIFICATION The femur ossifies from 5 centers: 1 primary and 4 secondary centers. The primary center appears in the midshaft . 3 secondary centers show up in the upper end 1 secondary center in the lower end.

45. CLINICAL SIGNIFICANCE Medicolegal importance of ossification center at the lower end of femur: The secondary center at the lower end of femur is exceptional in the meaning it seems during beginning/ just before arrival (ninth month of IUL). It is of medicolegal significance because its look in radiograph signifies maturity of the fetus.