Bones And Joints Of The Proximal Lower Limb Flashcards
What composes the pelvis
A bony ring formed by the articulation of the left and right innominate (hip) bones and the sacrum
Acetabulum
Where the 3 bones of the hip fuse
3 bones of the hip
Pubic bone
Ilium
Ischium
What do the hip bones articulate with anteriorly
Each other at the pubic symphysis
What do the hip bones articulate with posteriorly
The sacrum at the sacroiliac joints
What surrounds the obturator Foramen
Superior and inferior pubic rami
Obturator canal
A small gap in the membrane and muscles that cover the obturator Foramen that allows vessels and nerves to pass between the pelvis and thigh
Iliac crest
Uppermost part of the ilium
2 key bony prominences of the ischium
Ischial spine
Ischial tuberosity
Ischial spine
Where the Sacrospinous ligament attaches
Ischial tuberosity
Where the sacrotuberous ligament attaches as well as muscles of the posterior thigh
Where do muscles of the posterior thigh attach to
Ischial tuberosity
What forms the greater and lesser sciatic foramina
Greater and lesser sciatic notches of ischium
Sacrotuberous and Sacrospinous ligaments
Function of the greater and lesser sciatic foramina
Allow structures to pass between the pelvis and the gluteal region and perineum
What is the long bone of the thigh
Femur
Parts of the femur
Head
Neck
Shaft
2 condyles at distal end
What does the head of the femur articulate with
Acetabulum of the pelvis = hip joint
Location of neck of femur
Extends laterally and distally from the head
Greater and lesser trochanters of femur
Located distal to neck
Sites of muscle attachment
Intertrochanteric line
Between the greater and lesser trochanters on anterior surface of femur
Linea aspera
Bony vertical ridge on posterior aspect of shaft of femur
Site of muscle attachment
Gluteal tuberosity
Located just inferior to the trochanters in posterior aspect of femur
Site of muscle attachment
What are the sites of muscle attachment on the femur
Linea aspera
Gluteal tuberosity
Greater and lesser trochanters
Medial and lateral femoral condyles
Distal end of femur
Articulate with the proximal tibia
Adductor tubercle location
Superior to the medial femoral condyle
Patella location
Anterior to knee joint
What type of joint is the hip joint
Synovial ball and socket
Which bones form the hip joint
Articulation between the acetabulum of the hip (innominate) bone and the femoral head
Stability of the hip joint
Stable as the acetabulum is deep and a good fit between it and the femoral head
Acetabular labrum
Ligaments
Acetabular labrum
A rim of fibrocartilage which deepens the acetabulum for even more stability at the hip joint
Ligament of the head of the femur
A weak ligament that attaches the femoral head to the centre of the acetabulum
Arteries to the hip joint
Medial and lateral circumflex femoral arteries
What do the medial and lateral circumflex femoral arteries arise mainly from
Profunda femoris
What do the medial and lateral circumflex femoral arteries give rise to
Retinacular arteries
Retinacular arteries
Run along the neck of the femur to supply the femoral head
Which muscles of the thing flex the hip joint
Anterior
Which muscles of the thing adduct the hip joint
Medial
Which muscles of the thing extend the hip joint
Posterior
Which muscles of the thing extend, abduct and rotate the hip joint
Gluteal region
Which ligaments stabilise the hip joint
Iliofemoral
Pubofemoral
Ischiofemoral
Which hip ligaments are anterior
Iliofemoral
Pubofemoral
Which hip ligaments are posterior
Ischiofemoral
What type of joint is the knee joint
Synovial hinge joint
Which bones form the knee joint
Femoral condyles and tibial condyles
Tibial plateaus
Flat surface on the most superior aspect of the tibial condyles
When is the best fit of the knee joint achieved
When knee is extended
What helps us stand for long periods of time
Femur rotates slightly as the knee reaches full extension
Knee ‘locks’ in place and becomes very stable
What muscle is responsible for unlocking the knee and rotating the femur back again
Popliteus
What contributes to stability of the knee joint
Muscles
Tendons
Cartilage
Ligaments
Iliotibial tract
Where does the iliotibial tract attach
Lateral aspect of tibia
Menisci
C-shaped cartilage that sit in the tibial plateaus
Wedge-shaped with the thickest part at the periphery and thinnest part in the centre
Menisci function
Act to deepen the tibial condyles for articulation with the femoral condyles- improving the fit
Medial meniscus
Attached to the joint capsule along its peripheral margin and is attached to the medial collateral ligament
Lateral meniscus
Not attached to the lateral collateral ligament (fibular)
Which meniscus is more prone to injury
Medial if knee is twisted due to attachments
Ligaments of the knee
Collateral
Cruciate
Function of medial and lateral collateral ligaments
Support the knee and resist sideways movement of the tibia on the femur
What does the medial collateral ligament connect
Femur to tibia
What does the lateral collateral ligament connect
Femur to fibula
Attachment of the anterior cruciate ligament
Anterior part of intercondylar area of the tibia
Medial aspect of the lateral condyle of the femur
Function of anterior cruciate ligament
Prevents the tibia moving anteriorly relative to the femur
Attachments of the posterior cruciate ligament
Posterior part of the intercondylar area of the tibia
Lateral aspect of the medial condyle of the femur
Function of posterior cruciate ligament
Prevents the tibia moving posteriorly relative to the femur
Important in stability of knee when walking downhill or downstairs
Neck of femur fracture
A ‘fractured hip’ refers to a fracture of the femoral neck. This is very common in the elderly population and can be caused even by a low energy fall. Osteoporosis is often a contributing factor. Patients typically have pain in the groin and are unable to bear any weight on the affected leg. The typical finding on examination is shortening and external rotation of the affected limb compared to the uninjured limb. The fracture may tear the vessels that supply the femoral head and neck, leading to avascular necrosis of the femoral head.
Patellar dislocation
Dislocation of the patella is common. Dislocation is almost always lateral because the femur is angled obliquely relative to the tibia and so the angle of the pull of quadriceps is also oblique. The distal fibres of vastus medialis are arranged horizontally and these usually resist lateral movement of the patella. Additionally, the patellofemoral joint has a larger ridge laterally in an attempt to resist to lateral dislocation. Dislocated patellae are relatively easy to relocate and often simply require extension of the leg at the knee, and a small push on the patella.
Osteoarthritis of the hip and knee joints
Osteoarthritis of the hip joint and knee joint is very common. It causes progressive pain and limited mobility. Hip and knee replacements are two of the most common surgical procedures undertaken in the UK.
Posterior dislocation of the hip
Dislocation of the hip requires significant force because the joint is very stable. Posterior dislocation of the femoral head tends to occur in car accidents when the knee forcibly impacts the dashboard. The force is transmitted along the femur and the head is forced posteriorly. The acetabulum may fracture. A posterior dislocation risks injury to the sciatic nerve, which is located just behind the hip joint.
Meniscal and ligament injuries at the knee
The menisci can be torn by twisting injuries of the knee. Tears of the medial (tibial) collateral ligament result from a lateral blow to the knee or twisting injuries. Because it is attached to the medial meniscus, the meniscus may also tear. Anterior cruciate injury is typically also caused when there is a lateral blow to a partially flexed knee. In some cases, all three of these structures can be damaged in a single injury, and this is known as the ‘unhappy triad of the knee’. It is most often seen as a sporting injury, particularly amongst those who play football or rugby. Ligament injuries cause instability of the joint.
- Which vessels supply blood to the head of the femur? What results if these vessels are disrupted by a fracture of the femoral neck?
Medial and lateral circumflex arteries
Artery of Ligamentum teres
-head undergoes avascular necrosis
- What are the functions of the cruciate ligaments?
Stability of the knee
Anterior- resists anterior movement of tibia relative to femur
Posterior- resists posterior movement of tibia relative to femur
- Which ligaments prevent sideways forces to the knee?
Medial and lateral collateral ligaments
- Which movements of the knee are the anterior and posterior cruciate ligaments supposed to prevent?
Anterior - hyperextension
Posterior- hyperflexion
What are the names of the two large ligaments on the posterior pelvis? What do that attach to?
Sacrospinous ligament- sacrum to spine of ischium
Sacrotuberous ligament - sacrum to Ischial tuberosity
- What is the name of the foramen formed by the ilium and the sacrospinous ligament?
Greater sciatic foramen
- What is the ‘textbook’ resting position of the lower limb in a patient with a fractured neck of femur?
Shortened and laterally rotated
- What mechanisms resist dislocation of the patella? (Lateral movement)
Distal fibres of the vastus medialis are orientated almost horizontally pulling the patella medially
Lateral part of the patella groove of the femur is more prominent than the medial part
Why does the knee tend to dislocate laterally
Femur is orientated obliquely relative to the tibia
Pull of quadriceps is lateral
