7. Falls Flashcards
What is the proximal femur characterised by?
Head and neck and 2 large projections referred to as the greater and lesser trochanters residing on the superior shaft.
Describe the head of the proximal femur
2/3 of the head is spherical in nature, facilitating the articulation with the acetabulum of the pelvic bone as a ball-and-socket synovial joint (The hip joint). The hip joint is the articulation of the pelvis with the femur, connecting the axial skeleton with the lower extremity.
Describe the neck of the proximal femur
The neck is a cylindrical strut projecting superomedially from the shaft, forming a connection with the head of the femur. Despite being a site of structural weakness due to the narrow nature of the neck, the orientation of the neck increases the range of motion of the hip joint.
What does the shaft of the femur bear?
The greater and lesser trochanter, providing attachment for muscle that articulate the hip.
Describe the Greater trochanter
Extends superiorly from the femoral shaft, continuing posteriorly to the medial surface (Surface as a deep groove forming the trochanteric fossa).
What muscles attach to the greater trochanter?
Gluteus medius, gluteus minimus, piriformis, obturator externus and obturator internus.
Describe the lesser trochanter
A smaller, blunt conical shape that projects posteromedially from the femoral shaft inferior to the junction with the neck.
What muscles attach to the lesser trochanter?
Insertion of the tendon of the psoas major and iliacus muscle.
What is the inter-trochanteric line?
Resides on the anterior surface along the junction of the femoral neck and shaft traversing between the two trochanters.
N.B: Demarcates the inferior attachments of the hip capsule.
What does the hip capsule contain?
The acetabular notch which is spanned by the transverse acetabular ligament, the fossa contains fibro-fatty tissue, thus the articular surface is a horshoe shape to minimise contact stress with the acetabulum.
What is the hip capsule deepened by?
Rim of cartilage known as the acetabular labrum
What are the head of the femur and acetabular notch connected by?
Ligamentum teres from the transverse acetabular ligament and the fovea of the femoral head.
What does the hip capsule contains that perfuse the femoral head?
Retinacular vessels
What are retinacular vessels branches of?
Medial and lateral circumflex femoral arteries that extend to the head of the femur within the retinacular folds of the synovial membrane, penetrating the capsule of the hip joint at the intertrochanteric line (Intrascapular).
Origin and perfusion of the Medial circumflex artery
Originates proximally from the posteromedial aspect of the profunda femoris artery.
Passes over the superior margin of the adductor magnus.
Perfusion- The ascending branch of the medial circumflex artery supplies the blood supply to the head and neck of the femur.
Forms extracapsular arterial ring and extends as retinacular vessels to supply the head (intracapsular).
Origin and perfusion of the Lateral circumflex artery
Originates proximally from the lateral side of the profunda femoris artery.
Passes deep to the sartorius and rectus femoris muscles.
Perfusion- The ascending branch of the lateral circumflex artery connects with the branch of the medial circumflex to form a channel which circles the neck of the femur and supplies the femoral head. Forms extracapsular arterial ring and extends as retinacular vessels to supply the head (intracapsular).
Origin and perfusion of the Foveal artery
- Origin descends from the posterior branch of the obturator artery and attaches at the fovea.
- Perfusion- During skeletal development, this supplies the epiphysis. The artery is commonly disrupted with dislocation and forms the predominant blood supply
to the femoral head in children.
Intracapsular fractures
Origin and perfusion of the Metaphysical vessels
Origin- Ascending cervical arteries
Perfusion- Metaphyseal arteries contribute to the femoral head post skeletal maturity however are not a major source.
What can intracapsular fractures lead to?
Intracapsular fractures lead to a significant disruption to the vasculature of the femoral head and neck leading to avascular necrosis.
What do femoral neck fracture interrupt blood supply to?
Femoral head that is predominantly supplied by the extracapsular arterial ring formed by the branches of the medial and lateral circumflex femoral
arteries around the base of the femoral neck.
What do intrascapular features disrupt?
Penetrating retinacular arteries that supply the femoral head, ultimately manifesting as necrosis.
The foveal artery via the ligamentum teres contributes to supplying the femoral head.
Types of femoral fractures
- Intracapsular - fractures Above the inter-trochanteric line
- Extracapsular – fractures Below the intertrochanteric line
- Subcapital - fracture line that passes across the femoral head-neck junction → Highest risk of developing necrosis of the femoral head. Most common type of intrascapular fracture.
- Transcervical - fracture line passes through the mid-portion of the femoral neck.
- Basicervical - fracture line passes across the base of neck → Lowest risk of avascular femoral head necrosis.
What type of intracapsular fracture has greater risks of avascular necrosis?
Subcapital fracture along the head-neck junction (this type is also the most common).
Garden 1
Undisplaced
Incomplete fracture
Valgus impacted fracture
Garden 2
Undisplaced
Complete fracture
No disturbance of the medial trabeculae.
Garden 3
Partially displaced
Complete fracture
Femoral head tilts into varus position causing its medial trabeculae to be out of line with the pelvic trabeculae.
Garden 4
Completely displaced
Complete fracture
Femoral head aligned in the acetabulum; medial trabeculae are in line with the pelvic trabeculae.
Which type is there a minimal displacement in?
Garden Types I and II → therefore there is a lessened risk to the disruption of femoral head blood supply.
Which type is there a significant disruption of femoral head blood supply?
Garden types III and IV fracture displacement cause significant disruption to the femoral retinacular supply.
Neurological risk factors for falls
Confusion
Cognitive impairment
Depression
Poor vision, balance and co-ordination
Neuromuscular risk factors for falls
Muscle weakness
Gait disorder - Parkinson’s, hemiplegia, cerebellar disease, antalgic, normal pressure, hydrocephalus, proximaly myopathy.
Peripheral neuropathy, including sensory ataxia, foot drop.
Arthritis and joint disorders.