Session 3: Pelvic Osteology Flashcards
1
Q
What are the three main articulations in the hip bone?
A
Sacroiliac joint - with sacrum Pubic symphysis - between pubis (left and right hip bones) Hip joint - head of the femur
2
Q
The hip bone is comprised of three parts. Which? Where are they?
A
Ilium (superior) Pubis (medial) Ischium (lateral)
3
Q
What is the triradiate cartilage?
A
Only found in children. Cartilage between ilium, pubis and ischium. Fusion begins around 15 and ends around 25.
4
Q
What is the acetabulum?
A
The ilium, pubis and ischium forms a socket where the femur of the head will articulate.
5
Q
Label the image.
A
6
Q
Label the image.
A
7
Q
Explain features of the internal surface of the hip bone.
A
Concave shape
8
Q
Explain the shape of the external surface.
A
Convex shape.
9
Q
Which muscle originates from the iliac fossa?
A
Iliacus muscle
10
Q
Which muscles attach at the external muscle?
A
Gluteus muscles.
11
Q
What parts does the pubis consist of?
A
A body
Superior ramus
Inferior ramus
12
Q
What kind of cartilage does the pubic symphysis consist of?
A
Fibrocartilage
13
Q
Where is the superior pubic ramus?
A
Extends laterally from the pubic body to the acetabulum.
14
Q
Where is the inferior pubic ramus?
A
Extends laterally from the pubic body and joins with the inferior ischial ramus.
15
Q
What passes through obturator foramen?
A
The obturator nerve, artery and vein to reach the lower limb.
16
Q
What encloses the obturator foramen?
A
The pubis and the ischium.
17
Q
What attaches to the ischial tuberosities?
A
Hamstring muscles except short biceps.
Sacrotuberous ligament.
18
Q
There are important ligaments attached to the ischium. Which? and where?
What do they do?
A
Sacrospinous ligament from ischial spine to the sacrum. It forms the greater sciatic foramen.
Sacrotuberous ligament from ischial tuberosity to the sacrum. Forms the lesser sciatic foramen.
Both of the ligaments together make up the lesser sciatic foramen.
19
Q
What are the roles of the ligaments (spinous and tuberous)?
A
Limit rotation of the inferior part of the sacrum during transmission of weight of the body down the vertebral column in the erect position.
20
Q
What is the greater sciatic foramen made up of?
What is the lesser sciatic foramen made up of?
A
Greater sciatic notch and sacrospinous ligament.
Lesser sciatic notch and sacrotuberous ligament along with sacrospinous ligament.
21
Q
Explain the features of the hip joint. What kind is it?
What is its primary function?
A
A ball and socket synovial joint.
Articulation between the head of the femur and the pelvic acetabulum.
To enable mobility of the lower limbs without weakening the ability of the lower limbs to support the weight of the body.
22
Q
What is the acetabular labrum? What is its function.
A
A fibrocartilaginous collar that attaches to the acetabulum.
Increases the articular contact area by 10% which makes more than 50% of the head of the femur to fit into the acetabulum.
23
Q
What is the fovea capitis?
A
A small depression in the head of the femur which in utero and children is the entrance for the ligamentum teres and its artery to supply the head of the femur. This is not used very much in adults.
24
Q
What is the acetabular notch?
How is it strengthened?
A
A small notch where there is no ‘capsule’ of the socket.
By the tranverse acetabular ligament.
25
Label the diagram.
26
What is the ligamentum teres? What does it do?
Attaches at the fovea capitis and contains the artery of the ligamentum teres which somewhat supplies the head of the femur.
27
What is the site of insertion of the gluteus maximus?
The gluteal tuberosity.
28
Label the diagram.
29
What are the major extracapsular ligaments of the hip joint?
Iliofemoral
Pubofemoral
Ischiofemoral
30
What is the intracapsular ligament?
The ligamentum teres
31
The longitudinal retinacula?
Blood vessels ascending the femoral neck to the head of the femur.
32
What is the role and structure of the:
Iliofemoral ligament
Pubofemoral ligament
Ischiofemoral ligament
IFL: Strongest ligament in the body. Inverted Y shape. Attached to anterior inferior iliac spine and to the intertrochanteric line anteriorly. Prevents the trunk from falling backward. Prevents hyperextension of the hip.
PFL: Attached to the superior pubic ramus and apex to the inferior part of the intertrochanteric line anteriorly. Prevents excessive abduction and extension of the hip joint.
IFL: Smallest of the three. Attaches to the greater trochanter of the femur and to the body of the ischium posteriorly. Prevents excessive internal/medial rotation.
33
What is the transverse acetabular ligament.
Formed by the acetabular labrum and brides the acetabular notch. Converts the notch into a tunnel through which blood vessels and nerve enter the hip joint.
34
What does the synovial membrane line? Where is it attached and what does it ensheath?
The capsule.
Attached to the margins of the articular surface.
Ensheathes the ligamentum teres and covers the pad of fat contained in the acetabular fossa.
35
What factors act to increase stability of the joint?
Cup-shaped acetabulum
Acetabular labrum (deepens acetabulum)
The capsule
The ligamentum teres
Extracapsular ligaments
Muscles surronding the hip joint.
36
Flexion of hip.
Iliopsoas
Assisted by rectus femoris, sartorius and pectineus.
37
Extension of hip.
Gluteus maximus and hamstrings (semimembranous, semitendinou,biceps femoris (long head))
38
Abduction of the hip.
Gluteus medius and gluteus minimus.
Assisted by sartorius and tensor fascia lata.
39
Adduction of the hip.
Adductor longus, adductor brevis, adductor magnus.
40
Lateral rotation of the hip.
Obturator externus. Piriformis,obturator internus, superior and inferior gemelli and quadratus femoris.
Assisted gluteus maximus and sartorius
41
Medial rotation
Anterior fibres of gluteus medius and minimus and tensor fascia lata.
Assisted by adductor muscles.
42
What is Hilton's law?
The nerves supplying the join capsule also supply the mscules moving the joint and the skin overlying the insertions of these muscles.
43
What is the hip joint innervated by?
Anteriorly:
Posteriorly:
Inferiorly:
Anteriorly: Femoral nerve
Posteriorly: Sciatic nerve
Inferiorly: Obturator nerve
SOFPIA
44
What do the femoral and sciatic nerves also innervate?
Skin around the knee as well which is why pain can be referred to the knee from the hip as well.
45
The hip joint gets innervation from to additional nerves. Which and where?
Which muscles do they innervate?
Superior gluteal nerve superiorly - Gluteus minimus and gluteus medius.
Nerve to quadratus femoris posteriorly - Quadratus femoris
Inferior gluteal nerve - Gluteus maximus
46
Where is the extracapsular arterial ring and what is it formed posteriorly and anteriorly?
What does it give rise to?
Base of the femoral neck.
Posterior: Medial femoral circumflex artery MFCA
Anterior: Lateral femoral circumflex artery LFCA
Gives rise to ascending cervical branches that are also called retinacular arteries.
47
Where are the retinacular arteries found?
They travel proximally under the hip capsule and continue along the femoral neck deep to the synovial membrane and toward the femoral head.
48
Label the diagram.
49
There's another artery that supplies the femoral head except for the retinacular arteries. Which?
The ligamentum teres which goes from the fovea capitans to the acetabulum. In children it is the primary supply to the head of the femur.
50
What is the lumbar component of the lumbosacral plexus?
Anterior rami of the L1 to L4 nerves.
51
What does the L5 anterior ramus form?
The lumbosacral trunk. Also contributes axons to the sacral plexus.
52
What does the posterior part of the lumbar plexus innervate?
The anterior thigh.
53
What is the root value of ilioinguinal nerve?
What does it innervate?
L1 root value
Skin of genitalia and the upper medial thigh
54
What is the root value of the genitofemoral nerve?
What does it branch into?
L1-L2
Genital branch and femoral branch.
55
What is the root value of the lateral cutaneous nerve of the thigh?
What does it innervate?
L2-L3 (posterior roots)
Innervates anterolateral thigh as far inferiorly as the knee.
Enter the thigh at the lateral aspect of the inguinal ligament.
56
What is the root value of the obturator nerve?
What does it innervate?
L2-L4.
The skin over the medial thigh and the nerve of the medial compartment of the thigh.
Obturator externus, pectineus, adductor longus/brevis/magnus and gracilis muscles.
57
What is the root value of the femoral nerve?
What does it innervate?
L2-L4
Innervates the skin of the anterior thigh via its anterior femoral cutaneous branch.
Innervates the skin of the medial leg via its saphenous branch.
Innervates muscles: Iliacus, pectineus, sartorius, rectus femoris, vastus lateralis, vastus medialis intermedius.
58
What are the nerves of the lumbar plexus?
I get lots of fanny.
Ilioinguinal
Genitofemoral
Lateral femoral cutaneous
Obturator
Femoral
59
What nerves is the sacral plexus formed by?
Anterior rami of S1-S5 and also contribution from L4 and L5.
60
The nerves of the sacral plexus have two main destinations. Which?
The lower limb: and the pelvic muscles, organs and perineum.
61
Where does the superior gluteal nerve leave the pelvis and enter the gluteal region?
What is its root value?
What does it innervate?
Exits: greater sciatic foramen
Enter gluteal region: above the piriformis muscle.
Root value: L4-S1
Innervates gluteus medius, gluteus minimus and tensor fascia lata.
It has no sensory branches.
62
Where does the inferior gluteal nerve exit the pelvis and enter the gluteal region?
What is its root value?
What does it innervate?
Exit via the greater sciatic foramen.
Enters the gluteal region below the piriformis muscle.
Root value: L5-S2
Innervates only the gluteus maximus.
63
Where does the posterior cutaneous nerve of the thigh (posterior femoral cutaneous nerve) exit the pelvis and enter the gluteal region?
Root value.
Innervation.
Exit via the greater sciatic foramen below the piriformis muscle.
S1-S3. Posterior S1-S2. S2-S3 Anterior.
Innervates the skin of the posterior thigh and leg.
64
What nerves are in the sacral plexus?
Salmon is so perfectly pink.
Superior gluteal
Inferior gluteal
Sciatic
Posterior femoral
Pudenal
65
Label the diagram.
66
Label the diagram.
67
Which structures exit the pelvis via the greater sciatic foramen *inferior* to the piriformis?
Sciatic nerve
Inferior gluteal
Posterior femoral cutaneous nerve
Nerve to quadratus femoris
Nerve to obturator internus
68
Which structures exit via the lesser sciatic foramen?
Tendon of obturator internus
Nerve to obturator internus
Pudendal nerve
Internal pudendal vessel
69
What exits via the greater sciatic foramen *above* piriformis?
Superior gluteal nerve
70
What is the root value of the sciatic nerve?
L4-S3
71
Explain where the sciatic emerge.
Horizontally from the pelvic cavity, inferior to the piriformis muscle, mid-way between the posterios superios iliac spine and the ischial tuberosity.
It has no branches in the gluteal region.
72
How does the sciatic nerve descend the thigh?
Passes midway between the greater trochanter of the femur and the iscial tuberosist of the pelvis to enter the posterior compartment of the thigh.
In the posterior thigh the sciatic nerve is on the posterior surface of the adductor magnus muscle and is corssed bby the long head of the biceps fermoris muscle.
73
What does the sciatic nerve divide into and where?
Tibial nerve and common peroneal nerve at the superior end of the popliteal fossa.
They are both mixed sensory and motor nerves.
74
What does the tibial nerve innervate?
All of the hamstring muscles:
Semitendinous
Semimembranous
Biceps femors long head
Ischial part of the adductor magnus in the posterior thigh
75
What does the common peroneal nerve supply?
Short head of biceps femoris in the posterior thigh
76
Where do you administer intramuscular injection of the gluteal region?
Why are there two sites?
Dorsogluteal site or ventrogluteal site.
You want to get away from the sciatic nerve. In children over the age of three years.
In children over the age of seven or in adults you tend to go for the ventrogluteal site.
77
What is the deep fascia of the thigh called?
Fascia lata
78
What does the fascia lata do?
Encloses the thigh muscles and is a site of attachment for the intermuscular septae which...:
Divides thigh into three compartments:
Anterior
Medial
Posterior
Continuous with fascia of the abdominal wall and perineal region superiorly.
Continuous with the deep fascia of the leg inferiorly.
79
What is the role of the saphenous opening in the fascia lata just below the inguinal ligament?
It serves as an entry point for the saphenous vein and for lymphatic vessels which drain into the superficial inguinal lymph nodes.
80
What is the iliotibial tract? Where is it?
A thickening of the lateral aspect of the fascia lata. Runs from the iliac crest to the lateral tibial condyle at the knee.
81
Where does the tensor fascia lata and insert?
What is it innervated by?
Originate:
Anterior superior iliac spine
Insert:
Between the two layers of the iliotibial tract of the fascia lata.
Innervation:
Superior gluteal nerve (L5,S1)
82
Label the diagram.
83
What happens when you pull on the iliotibial tract?
Tensor fascia lata helps to stabilise the hip in extension.
84
What happens by tightening the iliotibial tract in the standing position?
Tensor fascia lata and gluteus maximus help to stabilise the knee by steadying the condyles of the femur on the articular surfaces of the tibia.
85
The tensor fascia lata also has a minor action. Which?
Hoists the fascia lata upwards which has the effect of the tightening of the compartments of the thigh and compression of the deep veins. Improving venous return from the lower limbs.
86
What are complications of being seated for the iliotibial tract?
It is in a shortened position while seated and becomes tight easily leading to lateral knee pain, patellar instability and other issues.
87
The gluteal muscles can be broadly divided into two groups which?
Which muscles are in these two groups?
Superficial: Gluteus maximus, gluteus minimus, gluteus medius and tensor fascia lata muscles.
Deep: Inferior and superior gemellus, piriformis, obturator internus and quadratus femoris. *Obturator externus is sometimes included here.*
88
Which arteries supply most of the gluteal muscles?
Superior and inferior gluteal arteries which are branches of the internal iliac artery.
89
Where does the gluteus maximus originate?
Where does it insert?
Origination: Posterior gluteal surface of the ilium, sacrum and coccyx.
Insertion:
Superior and most superficial fibres insert into iliotibial tract.
Inferior and deeper fibres insert into the gluteal tuberosity of the femur.
90
What would be the complication of having a paralysed gluteus maximus?
Climbing stairs and running will become difficult. Other muscles can still extend the hip.
91
Insertion and origination of the Gluteus medius.
Origin: Gluteal surface of the ilium
Insertion: Lateral surface of the greater trochanter
92
What does the gluteus medium and minimus assist in walking?
Secures the pelvis in a horisontal alignment preventing a downward tilt towards the unsupported limb.
93
Origin and insertion of the gluteus minimus.
Origin: From the ilium
Insertion: Anterior aspect of the greater trochanter
94
What are the consequences of injury in the superior gluteal nerve?
What is the Trendelenburg sign?
It supplies the gluteus minimus and medius.
Leads to weakness in abducting the thigh at the hip.
When a person with a superior gluteal nerve injury is asked to stand on their injured lower limb the pelvis on the unsupported side descends. This is a positive Trendelenburg sign.
95
How can the superior gluteal nerve get injured?
Hip surgery
Injection to buttocks
Fracture of greater trochanter
Dislocation of the hip joint (usually posterior)
96
Why is the piriformis a key landmark in the gluteal region?
Because the sciatic nerve emerges from the pelvis inferior to it.
97
Origin, innervation and insertion of the piriformis.
Origin: Anterior surface of the sacrum.
Travels inferolaterally through the greater sciatic foramen.
Insertion: Into the posterosuperior aspect of the greater trochanter of the femur.
Innervation: Nerve to piriformis
98
Origin, insertion and innervation of the Obturator internus.
Origin: Medial surface of the obturator membrane (fills the obturator foramen) and travels through the lesser sciatic foramen.
Insertion: Posterior aspect of the greater trochanter of the femur below the insertion of the piriformis and superior gemellus muscles.
Innervation: Nerve to obturator internus.
99
Origin, insertion and innervation of the superior and inferior gemelli.
Origin (superior): Ischial spine
Origin (inferior): Ischial tuberosity
Insertion (superior and inferior): posterior aspect of greater trochanter below the insertion of obturator internus respectively.
Innervation (superior): obturator internus
Innervation (inferior): quadratus femoris
100
Origin, insertion and innervation of the quadratus femoris.
Origin: lateral aspect of the ischial tuberosity
Insertion: quadrate tubercle located on the intertrochanteric tuberosity
Innervation: Nerve to quadratus femoris
101
Origin, insertion and innervation of obturator externus.
Origin: External surface of the obturator membrane that occupies the obturator foramen
Passes posertior to the neck of femur
Insertion: Posterior aspect of the greater trochanter
Innervation: Obturator nerve (L2-L4)
102
Label the diagram.
103
Origin, insertion and innervation of the two heads of biceps femoris.
Origin (long head): Ischial tuberosity of the pelvis
Origin (short head): Linea aspera on poserior surface of the femur
Insertion (long head and short head): Form a common tendon inserting into head of the fibula
Innervation (long head): Tibial part of the sciatic nerve
Innervation (short head): Common peroneal (common fibular) part of the sciatic nerve
104
Origin, insertion and innervation of the semitendinous muscle.
Origin: Ischial tuberosity
Insertion: Upper medial aspect of the tibia as part of the pes anserinus
Innervation: Tibial part of the sciatic nerve
105
Origin, insertion and innervation of the semimembranous muscle.
Origin: Ischial tuberosity.
Insertion: Medial tibial condyle and does not form part of the pes anserinus.
Innervation: Tibial part of the sciatic nerve
106
Label the diagram
107
