Femur Flashcards
What is the femur?
The only bone in the thigh
What is the femur classed as?
A long bone
What is the main function of the femur?
To transmit forces from the tibia to the hip joint
What does the femur act as?
The place of origin and attachment of many muscles and ligaments
What can the femur be split into?
Three areas, proximal, shaft, and distal
What does the proximal area of the femur form?
The hip joint with the pelvis
What does the proximal area of the femur consist of?
A head and neck
Two bony processes called trochanters
Bony ridges connecting the trochanters
What does the head of the femur have?
A smooth surface, with a depression on the medial surface
What is the depression on the head of the femur for?
Attachment of the ligament of the head
What happens to the head of the femur at the hip joint?
It articulates with the acetabulum of the pelvis
What does the neck of the femur do?
Connects the head of the femur with the shaft
What shape is the neck of the femur?
Cylindrical
In what direction does the neck of the femur project?
Superior and medial
What does the angle of projection of the neck of the femur allow for?
An increased range of movement at the hip joint
What is the greater trochanter?
A projection of bone
Where does the greater trochanter originate from?
The anterior shaft, just lateral to where the neck joins
How is the greater trochanter angled?
Superiorly and posteriorly
Where can the greater trochanter be found?
Both on the anterior and posterior sides of the femur
What is the greater trochanter the site of?
Attachment of the abductor and lateral rotator muscles of the leg
How does the lesser trochanter differ from the greater trochanter?
It is much smaller
Where does the lesser trochanter project from?
The posteromedial side of the shaft, just inferior to the neck-shaft junction
What is the lesser trochanter the site of?
Attachment of the psoas major and iliacus muscles
What is the intertrochanteric line?
A ridge of bone
Where does the intertrochanteric line run?
In an inferomedial direction on the anterior surface of the femur, connecting the two trochanters together
What attaches to the intertrochanteric line?
The iliofemoral ligament
What is the iliofemoral ligament?
A very strong ligament of the hip joint
What happens after the intertrochanteric line passes the lesser trochanter on the posterior surface?
It becomes known as the pectineal line
What is the intertrochanteric crest?
A ridge of bone that connects the two trochanters together
Where is the intertrochanteric crest located?
On the posterior surface of the femur
What is found on the intertrochanteric crest?
A rounded tubercle on its superior half, called the quadrate tubercle
What is the quadrate tubercle the site for?
Attachment of the quadratus femoris
Why are fractures of the femoral neck a very good predictor of mortality?
Within a year, 1/3 of people with a hip fracture will die
What can fractures of the femoral neck be classified into clinically?
Intracapsular fracture
Extracapsular fracture
Who are intracapsular fractures more common in?
The elderly, especially women
What are intracapsular fractures the result of?
A minor trip or stumble
Where does an intracapsular fracture occur?
Within the capsule of the hip joint
What can an intracapsular fracture cause?
Damage to the medial femoral circumflex artery and therefore avascular necrosis of the femoral head
What happens in an intracapsular fracture?
The distal fragment is pulled upwards, and rotated laterally
How can an intracapsular fracture manifest clinically?
Shorter leg length, with toes pointing laterally
Who are extracapsular fractures more common in?
Young and middle aged people
What happens in an extracapsular fracture?
The leg is shortened and laterally rotated
The blood supply to the head of the femur is intact, and so no avascular necrosis can occur
How does the shaft of the femur descend?
In a slight medial direction
What is the result of the medial descent of the femur shaft?
It brings the knees closer to the body’s centre of gravity, increasing stability
What is found on the posterior surface of the femoral shaft?
Roughened ridges of bone called the linea aspera
What does the linea aspera become?
The medial border becomes the pectineal line
The lateral border becomes the gluteal tuberoisty
Where does the linea aspera become the pectineal line and gluteal tuberosity?
Proximally
What happens at the gluteal tuberosity?
The gluteus maximus attaches
What happens to the linea aspera distally?
It widens and forms the floor of the popliteal fossa
The medial and lateral borders form the medial and lateral supracondylar lines
Where does the medial supracondyle line stop?
At the adductor tubercle
What happens at the adductor tubercle?
The adductor magnus attaches
How common are fractures of the femur shaft?
Relatively uncommon
What do fractures of the femur shaft require?
A lot of force
What are fractures of the femoral shaft usually a result of?
Traumatic injury
Give an example of a classification of femoral shaft fracture
Spiral fracture
How can a spiral fracture present?
Leg shortening
What is the loss of leg length in spiral fractures due to?
The fragments overriding, pulled by the attached muscles
What is the result of the mechanism of spiral fracture injury usually being high energy?
The surrounding soft tissues may also be damaged
Give an example of a possible sequelae of a femoral shaft fracture?
A femoral nerve palsy
What is important to ensure when the femoral shaft is fractured?
To ensure the blood supply from the femoral artery hasn’t been compromised
What is the distal end of the femur characterised by?
The presence of the medial and lateral condyles
What do the medial and lateral condyles articulate with?
The tibia and patella
What is formed by the articulation of the condyles and the tibia and patella?
The knee joint
What are the medial and lateral condyles of the femur?
Rounded areas at the end of the femur
What do the posterior and inferior surfaces of the medial and lateral condyles articulate with?
The tibia and menisci of the knee
What do the anterior surfaces of the medial and lateral condyles articulate with?
The patella
What are the medial and lateral epicondyles of the femur?
Bony elevations on the non articular areas of the condyles
What are the medial and lateral epicondyles the site of?
Attachment of some muscles and collateral ligaments of the knee
What is the intercondylar fossa?
A depression found on the posterior surface of the femur
Where is the intercondylar fossa?
Between the two condyles
What does the intercondylar fossa contain?
Two facets for attachment of internal knee ligaments
Where is the facet for attachment of the posterior cruciate ligament?
Medial wall of the intercondylar fossa
What is the facet for attachment of the posterior cruciate ligament?
A large, rounded, flat face where the posterior cruciate ligament of the knee attaches
Where is the facet for attachment of the anterior cruciate ligament found?
The lateral wall of the intercondylar fossa
How does the facet for attachment of the anterior cruciate ligament differ from the posterior?
It is smaller
