The Pelvis and Hip Flashcards
What are the 4 regions of the lower limb?
- Gluteal region
- Thigh
- Leg
- Foot
What 3 important neurovascular spaces are found in the lower limb?
- Femoral triangle (groin)
- Popliteal fossa (behind knee)
- Tarsal tunnel (posterior to medial ankle)
What is the most commonly replaced joint in the body?
Hip
What bones make up the pelvis?
3 bones:
- Sacrum
- Right and left innominate bones (right and left ‘hip bones’)
How does the pelvis remain abnchored to the axial skeleton?
Via extremely strong and stable joints between the sacrum and each innominate bone: the sacroiliac joints
What does the head of the femur articulate with?
The acetabulum of the pelvis at the hip joint
Articulation between inomminate (hip) bone and sacrum
At the sacroiliac joint
Where do the 2 inomminate bones articulate with each other anteriorly?
At the pubic symphysis
What is this highlighted region?
Pelvic brim
Diagram of the iliac crest
What is the highlighted region?
Greater sciatic notch
What is the highlighted projection of bone?
Ischial spine
What are the highlighted regions?
superior and infreior pubic rami
Diagram of pelvis
What is the highlighted region?
Body of the pubis
Diagram of the pubic tubercle
Name the highlighted region
Obturator foramen (superior pubic ramus above it and inferior pubic ramus below it)
Label
Sacrum (orange)
Posterior aspect of iliac crest (light blue)
Greater sciatic notch (black)
Ischial spine (pink)
Ischial tuberosity (blue)
Bony landmarks of pelvis from lateral angle
What 3 bones come together during development and fuse to form the inomminate bone?
- Ilium (lies speriorly)
- Ishium (posterior)
- Pubic bone (anterior)
What is the point at which the ilium, ischium and pubic bone fuse?
Acetabulum
What are hip fractures?
Fractures of the neck of the femur
What is found below the head of the femur?
The neck of the femur
What does the proximal aspect of the femur articulate with?
The acetabulum of the pelvis to form the hip joint
What is the greater trochanter?
- The most lateral palpable projection of bone that originates from the anterior aspect, just lateral to the neck
- Site of attachment to many muscles in the gluteal region
i.e. similar to greater tubercle of humerus
What is the lesser trochanter?
Smaller than the greater trochanter. It projects from the posteromedial side of the femur, just inferior to the neck-shaft junction
Posterior diagram of femur
What is the intertrochanteric line?
A ridge of bone that runs in an inferomedial direction on the anterior surface of the femur, spanning between the two trochanters.
Name the highlighted landmarks
- Blue –> iliac crest
- Black –> neck of femur
- Pink –> iscial spine
- Yellow –> ischial tuberosity
- Purple –> inferior pubic ramus
- Pink –> greater trochanter
- Blue –> lesser trochanter
- Orange line –> intertrochanteric crest
What is the intertrochanteric crest?
Like the intertrochanteric line, this is a ridge of bone that connects the two trochanters but is located on the posterior surface of the femur
Difference between the intertrochanteric line and intertrochanteric crest?
Line –> anterior aspect
Crest –> posterior aspect
What is the trochanteric fossa?
What is the gluteal tuberosity?
Point of attachment of gluteus maximus
What type of joint is the hip joint?
Ball and socket –> very stable
Why is the hip joint so stable?
- Good fit
- Acetabular labrum
- Strong joint capsule
- Surrounding ligaments
- Muscles also add stability
What are the 2 bony ridges connecting the 2 trochanters?
- The intertrochanteris line anteriorly
- The trochanteric crest posteriorly
What is the acetabulr labrum?
Attaches from the acetabulum (pelvis) to the intertrochanteric line (proximal femur)
What is the purpose of the acetabular labrum?
Deepens the acetabulum
What are the 2 ligaments in the pelvis?
- Sacrospinous ligament
- Sacrotuberous ligament
Both are extremely strong
Where is the sacrospinous ligament?
Runs from sacrum to the ischial spine
What does the sacrospinous ligament form?
The greater sciatic foramen
Where is the sacrotuberous ligament?
Runs from the sacrum to the ischial tuberosity
What does the sacrotuberous ligament form?
The lesser sciatic foramen
What important nerve passes through the greater sciatic foramen?
The sciatic nerve (amongst other things)
Describe route of sciatic nerve
Passes from inside the pelvis out into the limb via the greater sciatc foramen
What are the 3 hip ligaments?
- Pubofemoral
- Iliofemoral
- Ischiofemoral
Attachments of the pubofemoral ligament (green)? What is its function?
- Between superior pubic rami and intertrochanteric line of the femur
- Reinforces capsule anteriorly and inferiorly
- Has a triangular shape
- Prevents excessive abduction and extension
Attachments of the iliofemoral (orange)? Function?
- From anterior inferior iliac spine, then bifurcates before inserting into the intertrochanteric line of the femur
- ‘Y shaped’ appearance
- Prevents hyperextension of the hip joint
- Supports superiorly and anteriorly
- Strongest ligament of the hip
Attachment of the ischiofemoral ligament (pink)? Function?
- Between body of ischium and greater trochanter of femur
- Reinforces capsule posteriorly
- Prevents hyperextension
- Holds femoral head in the acetabulum
- Weakest ligament
What are the movments at the hip joint?
- Flexion
- Extension
- Abduction
- Adduction
- Medial rotation
- Lateral rotation
- Circumduction –> combination movement achieved for very supple/fit/flexible people
Where do hip extensor muscles generally lie? Flexors?
Extensors generally lie posterior to hip joint
Flexors generally lie anteriorly
Where do abductors of the hip generally lie? Adductors?
Abductors –> lateral
Adductors –> medial
Where do medial and lateral rotators of the hip generally lie?
Medial rotators –> anterior/lateral
Lateral rotators –> posterior/lateral
What are most of the hip flexors innervated by?
Femoral nerve (L2-L4)
What muscle is the prime flexor of the hip?
Iliopsoas (lies within abdomen/pelvis)
What other muscles contribute to hip flexion?
- Iliopsoas
- Rectus femoris
- Sartorius
- Pectineus
What is iliopsoas made up of?
Made up of 2 muscles; psoas major and iliacus. These originate in different areas, but come together to form a tendon.
Where does iliopsoas insert?
On the lesser trochanter
Where does psoas major originate? Where does iliacus originate? Where do they both insert?
The psoas major originates from the lumbar vertebrae, and the iliacus originates from the iliac fossa of the pelvis. They insert together onto the lesser trochanter of the femur.
What structure does iliopsoas travel under?
Under the inguinal ligament
What are the attachments of the inguinal ligament?
ASIS to the pubic tubercle
What nerve travels between iliacus and psoas major and under the inguinal ligament?
Femoral nerve (purple)
Label diagram
- Inguinal ligament (black)
- Iliacus (yellow)
- Psoas major (blue)
- Femoral nerve
All travel under the inguinal ligament into the proximal part of the thigh.
What is the action of iliopsoas?
Flexes the thigh at the hip joint
Where do the other hip flexors lie?
In the anterior thigh
What is iliopsoas innervated by?
Psoas major is innervated by anterior rami of L1-L3
Iliacus is innervated by the femoral nerve
What are the attachments of pectineus?
It originates from the pectineal line on the anterior surface of the pelvis, and attaches to the pectineal line on the posterior side of the femur, just inferior to the lesser trochanter.
(shown in purple)
Action of pectineus?
Adduction and flexion at the hip joint
Innervation of pectineus?
Femoral nerve
What are the attachments of rectus femoris?
AIIS –> tibial tuberosity
(orange)
What are the actions of rectus femoris?
Flexes the thigh at the hip joint, and extends at the knee joint
What is the innervation of rectus femoris?
Femoral nerve
What are the attachents of sartorius?
Runs across the thigh in an interomedial direction and crosses knee.
- Originates from ASIS and attaches to the superior, medial turface of the tibia
- (shown in blue)
What are the actions of sartorius?
At the hip joint; it is a flexor, abductor and lateral rotator.
At the knee joint: it is a flexor.
Innervation of sartorius?
Femoral nerve
What are the attachments of tensor fascia latae?
Laterally positioned muscle.
- Originates from ASIS and inserting into the iliotibial tract
- Shown here laterally in green
What are the actions of tensor fascia latae?
Assists the gluteus medius and minimus in abduction and medial rotation of the lower limb. It also plays a supportive role in the gait cycle.
Innervation of tensor fascia latae?
Superior gluteal nerve
Label the highlighted muscles
- Purple: pectineus
- Orange: rectus femoris
- Blue: sartorius
- Green: tensor fascia latae
Where do extensors of the hip lie?
Behind the hip joint
What are the 2 main hip extensors?
- Gluteus maximum
- ‘Hamstrings’
Describe the gluteus maximus
The gluteus maximus is the largest of the gluteal muscles. It is also the most superficial, producing the shape of the buttocks.
What are the attachments of gluteus maximus?
Origin: Originates from the gluteal (posterior) surface of the ilium, sacrum and coccyx.
It slopes across the buttock at a 45 degree angle.
Inserts:
- Sends most fibres to insert onto the iliotibial tract
- Sends some fibres to insert onto the gluteal tuberosity of the femur
What is gluteus maximum innervated by?
Inferior gluteal nerve (L5, S1, S2)
What are the actions of gluteus maximum?
- Main extensor of the thigh
- Assists with lateral rotation (only when required e.g. running/climbing)
What is circled in black?
Ischial tuberosity
Where do the hamstring muscles originate?
Ischial tuberosity
Where do abductors of the hip lie?
Lie posterolateral to the joint (gluteal region)
Which muscles mainly abduct the hip?
Gluteus medius and gluteus minimus
What are gluteus medius and gluteus minimum innervated by?
Superior gluteal nerve (L4, L5, S1)
Attachments of gluteus medius?
- Originates from gluteal surface of ilium (shown in green)
- Insert onto lateral surface of greater trochanter
Actions of gluteus medius?
Abducts and medially rotates the lower limb. During locomotion, it secures the pelvis, preventing pelvic drop of the opposite limb
Attachments of gluteus minimus?
Deepest and smallest of the superficial gluteal muscles.
- Originates from ilium
- Converges to form a tendon, inserting to the anterior side of the greater trochanter (shown in pink)
Actions of gluteus minimus?
Abducts and medially rotates the lower limb. During locomotion, it secures the pelvis, preventing pelvic drop of the opposite limb.
Where do the adductors of the hip lie in relation to the joint?
Lie medial to the joint (thigh)
What are most of the adductors of the hip innervated by?
Mostly by obturator nerve (L2-L4)
What muscles make up the adductor group of the hip?
- Adductor brevis
- Adductor longus
- Adductor magnus (2 parts)
All insert on posterior aspect of the femur (different insertion points)
What other muscles make up the medial compartment of the thigh?
- Obturator externus
- Gracilis
- Pectineus
Where do the lateral rotators of the hip lie?
Lie deep in the gluteal region
Where do the lateral rotators of the hip insert?
Insert on the posterior aspect of the femur
What muscles in the shoulder region can the lateral rotators of the hip be compared to?
Shoulder cuff muscles
What muscles make up the lateral rotators (deep gluteal muscles)?
- Piriformis
- Obturator internus
- The Gemelli - superior and inferior
- Quadratus femoris
N.B. gluteus maximum also rotates
What is the most superior of the deep muscles in the gluteal region?
Piriformis
Attachments of piriformis?
- Originates from the anterior surface of the sacrum
- Travels inferolaterally through the greater sciatic foramen
- Inserts on the greater trochanter of the femur
What structure does piriformis travel through?
Greater sciatic foramen
Actions of piriformis?
- Lateral rotation
- Can contribute to abduction
Attachments of the gemelli?
Superior:
- originates from the ischial spine
- attaches to the greater trochanter of the femur
Inferior:
- originates from the ischial tuberosity
- attaches to the greater trochanter of the femur
Shown in orange
What lies between the superior and inferior gemelli?
Obturator internus
What are the actions of the gemelli?
Lateral rotation and abduction
What is the innervation of the gemelli?
Superior –> innervated by the nerve to obturator internus
Inferior –> innervated by the nerve to quadratus femoris
Attachments of obturator internus?
- Pubis and ischium at the obturator internus (membrane)
- Travels through the lesser sciatic foramen
- Inserts onto greater trochanter of the femur
- (seen in yellow)
What are the actions of obturator internus?
Lateral rotation (and abduction)
Innervation of obturator internus?
Nerve to obturator internus
Attachments of quadratus femoris?
The most inferior of the deep gluteal muscles.
- Originates from the lateral side of the ischial tuberosity
- Attaches to the quadrate tuberosity on the intertrochanteric crest
- (shown here in blue)
Action of quadratus femoris?
Lateral rotation
What muscles are the medial rotators of the hip?
- Pectineus
- Gluteus medius and minimus (anterior parts)
Attachments of pectineus?
- It originates from the pectineal line on the anterior surface of the pelvis
- Attaches to the pectineal line on the posterior side of the femur, just inferior to the lesser trochanter
What 2 vessels are the major contributors to the hip joint and anterior thigh?
- Obturator artery
- Femoral artery
Where does the obturator artery come from? Where does it pass through?
From the internal iliac artery –> passes through the obturator foramen to enter the medial thigh
Where does the femoral artery come from?
Is a continuation of the external iliac artery after it passes under the inguinal ligament to enter the thigh
What region does the femoral artery travel in?
In the femoral triangle, along with the femoral vein and femoral nerve
What forms the boundaries of the femoral triangle?
Superior: inguinal ligament
Medial: medial border of adductor longus muscle
Lateral: medial border of sartorius muscle
Floor: pectineus, iliopsoas and adductor longus
What are the contents of the femoral triangle (from lateral to medial)?
- Femoral nerve
- Femoral artery
- Femoral vein
- Femoral canal
What are the femoral artery, vein and canal contained within?
A fascial compartment known as the femoral sheath
Diagram of gluteal region
What are the major vessels of the gluteal region?
Internal iliac artery in the pelvis gives rise to the superior and inferior gluteal arteries
How do the gluteal arteries enter the gluteal region?
Through the greater sciatic foramen
Where does the superior gluteal artery emerge in relation to piriformis? How about the inferior gluteal artery?
Superior –> emerges above piriformis
Inferior –> emerges below piriformis
(2 black circles)
What is the dotted black outline? Where does it exit?
Sciatic nerve - exits greater sciatic foramen usually below piriformis
Diagram of gluteal region
What is the arterial supply to the hip joint largely delivered by?
- Branches of the profunda femoris artery (deep femoral artery)
- Gives rise to 2 vessels: medial and lateral circumflex artery
What happens to the medial and lateral circumflex femoral arteries?
Anastamose at the base of the femoral neck to form a ring, from which smaller arteries arise to supply the hip joint itself.
Which artery is responsible for the majority of the hip supply out of the medial and lateral circumflex arteries?
The medial circumflex femoral artery is responsible for the majority of the arterial supply (the lateral circumflex femoral artery has to penetrate through the thick iliofemoral ligament).
What other vessel gives a small contribution to the hip?
Obturator artery (from the internal iliac artery)
What vessels can femoral neck fractures damage? What can this result in?
Branches of medial circumflex artery –> can result in avascular necrosis of the femoral head
Normal AP pelvis and hip x-ray
What is Shenton’s line?
An imaginary curved line along the inferior border of the superior pubic ramus (superior border of the obturator foramen) and along the inferiomedial border of the neck of the femur. This line should be continuous and smooth.
Look for it during x-rays.
Especially important if worried about a fracture of the femoral neck
This 67 year old woman presented with right groin pain for the past 2 months after she had a fall.
Can you see anything abnormal?
- Small fracture in the superior pubic ramus
- Injury at the inferior pubic ramus
- White circle starting to form around it as bone tries to heal –> a callus (new bone formation)
This 25 year old man had a motorbike accident.
What injuries can you see? Potential complications?
This is an open book pelvic fracture –> a term used to describe any fracture that significantly disrupts the pelvic ring.
- Pubic symphysis has separated
- Fracture of inferior pubic ramus
- Likely to have serious injuries elsewhere; chest, head, abdomen
- Can damage vessels –> uncontrolled internal (concealed) haemorrhage
- Risk to organs; bladder, urethra
This 40 year old man fell onto concrete from a height of 1.5 metres and had severe pain in his left hip.
Can you see a problem with this X-ray?
- Fracture of the femoral neck
This 84 year old lady had fallen.
Can you see anything of concern?
- X-ray has been taken supine (lying down)
- Abnormality of lower part of lumbar spine
- Fracture of femoral neck
Can you see anything abnormal here?
- Osteoarthritis of the left hip
- Loss of joint space between femoral head and acetabulum
- Osteocytes
What type of hip injury has happened here? What structures could be injured here?
- Posterior dislocation of the hip
- Generally this injury happens due to force applied anteriorly to the femur, forcing the head of the femur out of the acetabulum
What is congenital hip dysplasia?
A condition where the “ball and socket” joint of the hip does not properly form in babies and young children. It has a wide range of severity:
- Sometimes the ligaments around the hip joint are loose, allowing the hip to subluxate
- Ball is no longer centered in the socket
- Other times, the ball is slightly or completely dislocated from the socket
What happens in congenital hip dysplasia?
Acetabulum isn’t deep enough for developing femoral head. As the child starts to move, the femoral head starts to dislocate out of the acetabulum. Once this has happened, the acetabulum doesn’t continue to develop properly as the head of the femur isn’t in it.
Checked for in newborn baby check.
What is the lumbosacral plexus?
The nerve network that innervates the lower limb, located in the abdomen and pelvis.
What segments of the spinal cord does the lumbosacral plexus come from?
Lumbar and sacral segments.
What 3 major branches does the lumbosacral plexus give rise to?
- Femoral (anterior thigh muscles)
- Obturator (medial thigh muscles)
- Sciatic (posterior thigh, leg and foot)
These provide most of the motor and sensory innervation of the lower limb.
What are the hip bones called?
Innominate bones
What are the 3 main articulations of the hip bones?
- Sacroiliac joint - articulation with the sacrum
- Pubic symphysis - articulation between right and left hip bones
- Hip joint - articulation with the head of the femur
What 3 parts comprises the hip bone?
- Ilium
- Pubis
- Ischium
Prior to puberty, the triradiate cartilage separates these parts – and fusion only begins at the age of 15-17.
Together, what sockets does the ilium, ischium and pubis form?
A cup-shaped socket known as the acetabulum
What articulates with the acetabulum?
The head of the femur to form the hip joint
Describe the ilium and its location. How does it contribute to the acetabulum?
- The widest and largest of the three parts of the hip bone,
- Is located superiorly
- The body of the ilium forms the superior part of the acetabulum (acetabular roof)
Describe the shape of the ilium immediately above the acetabulum
Immediately above the acetabulum, the ilium expands to form the wing (or ala).
What are the 2 surfaces of the wing of the ilium?
- Inner surface
- External surface
What does the superior margin of the wing of the ilium form?
The superior margin of the wing is thickened, forming the iliac crest
Where does the iliac crest extend from/to?
Frm the ASIS to the PSIS
What is the indentation on the posterior aspect of the ilium?
The greater sciatic notch
How does the the ASIS serve as an important anatomical landmark?
- Mid-inguinal point: halfway between the ASIS and the centre of the pubic symphysis. The femoral artery can be palpated here.
- Mid-point of the inguinal ligament: halfway between the ASIS and the pubic tubercle.
Describe the location of the pubis. What does it consist of?
The pubis is the most anterior portion of the hip bone. It consists of a body, superior ramus and inferior ramus (ramus = branch).
Where is the pubic body located? What does it articulate with?
Is ocated medially, it articulates with the opposite pubic body at the pubic symphysis. Its superior aspect is marked by a rounded thickening (the pubic crest), which extends laterally as the pubic tubercle.
Describe the superior and inferior pubic ramus
Superior - extends laterally from the body to form part of the acetabulum.
Inferior - projects towards the ischium.
Together, what do the superior and inferior rami enclose?
Part of the obturator foramen
Describe the location of the ischium.
The ischium forms the posteroinferior part of the hip bone. Much like the pubis, it is composed of a body, an inferior ramus and superior ramus.
What does the inferior ischial ramus combine with? What does this form part of?
The inferior ischial ramus combines with the inferior pubic ramus forming the ischiopubic ramus, which encloses part of the obturator foramen.
What does the posterorinferior aspect of the ischium form?
The ischial tuberosities and when sitting, it is these tuberosities on which our body weight falls.
Near the junction of the superior ramus and body is a posteromedial projection of bone. What is this called?
The ischial spine
What 2 ligaments attach to the ischium?
- Sacrospinous
- Sacrotuberous
Describe the location of the sacrospinous ligament. What foramen does this create?
Runs from the ischial spine to the sacrum, thus creating the greater sciatic foramen.
Describe the location of the sacrotuberous ligament. What foramen does this create?
Runs from the sacrum to the ischial tuberosity, forming the lesser sciatic foramen.
What 3 bones forms the pelvis?
- Sacrum
- Left innominate bone
- Right innominate bone
What is unique about the sacral vertebrae?
The individual vertebrae have been fused to form one bone
What is the purpose of the foramina found in the sacrum?
Allows for passage out of spinal canal of the spinal nerves
How is the sacrum connected to the innominate bones?
At the sacroiliac joints
Where are the innominate bones joined together?
Anteriorly at the pubic symphysis
What is the slightly shallow anterior surface of the ilium? What muscle is found here?
Iliac fossa –> this is where iliacus muscle is found
What bony projection is being pointed at?
Anterior superior iliac spine
What bony projection is being pointed to?
Anterior inferior iliac spine
What does ASIS provide attachment for?
a bony projection of the iliac bone which provides attachment for the inguinal ligament and the sartorius muscle.
What are the attachments of the inguinal ligament?
Superior: ASIS
Then courses obliquely in an inferomedial direction
Inferior: inserts on pubic tubercle of the pubic bone
What structures pass deep to the inguinal ligament?
- Iliacus
- Psoas major
- Pectineus
- Femoral nerve, artery, vein
Travel to anterior thigh
Superior and inferior pubic rami diagram
What part of the pubis is being pointed to? How does this articulate with the other side?
Body of the pubis - articulates with the opposite side at the pubic symphysis (i.e. this is part of the innominate bone)
What structure is being pointed to?
Obturator foramen
What passes through the obturator foramen?
The obturator artery, obturator vein, and obturator nerve all travel through the canal.
These travel out of the pelvis and into the lower limb.
What is being pointed to here?
Ischial tuberosity (posterior view too)
What is being pointed to here?
Acetabulum
How does the acetabulum compare to the glenoid fossa of the shoulder?
Acetabulum is much deeper –> much better fit
What is being pointed to here? What ligament is this an important attachment site for?
Ischial spine - attachment site for sacrospinous ligament
Attachments of sacrospinous ligament?
The sacrospinous ligament is thin, and triangular in form; it is attached by its apex to the ischial spine, and medially, by its broad base, to the lateral margins of the sacrum and coccyx in front of the sacrotuberous ligament
Attachments of the sacrotuberous ligament?
Lateral margins of the lower sacrum and upper coccyx and inserts into the ischial tuberosity
What notch is being pointed to?
Greater sciatic notch
What notch is being pointed to?
Lesser sciatic notch
What do the sacrospinous and sacrotuberous ligaments convert the greater and lesser sciatic notches into?
Greater and lesser sciatic foramina
What ligament is being pointed to here?
Inguinal ligament - spanning from ASIS to pubic tubercle
Most of the obturator foramen is covered over. What small gap remains?
Obturator canal - allows passageway out of pelvis
What ligament is being pointed to?
Sacrotuberous
What ligament is being pointed to?
Sacrospinous
Diagram of greater and lesser sciatic foramina
What is being pointed to here?
Femoral neck
Why is the femoral neck clinically important?
Commonly fractured (in elderly population)
What is being pointed to here?
Lesser trochanter
Posterior view of femur - what ridge of bone is being pointed to?
Intertrochanteric crest
What is the trochanteric fossa?
The medial surface of the greater trochanter has at its base a deep depression bounded posteriorly by the intertrochanteric crest, called the trochanteric fossa.
What inserts on the trochanteric fossa?
- Tendor of the obturator externus
- Obturator internus
- Superior gemellus
- Inferior gemellus
What is the gluteal tuberosity?
A vertical ridge of bone postero-laterally: some of the fibres of gluteus maximus insert here
What is an open book pelvic fracture?
Any fracture that significantly disrupts the pelvic ring. These injuries combine an anterior pelvic injury causing a widening of the pubic symphysis, and a posterior pelvic fracture or ligamentous injury.
Which deep gluteal muscle travels through the greater sciatic foramen?
Piriformis
Which deep gluteal muscle travels through the lesser sciatic foramen?
Obturator internus
What is the most superficial muscle of the buttocks?
Gluteus maximus
Why is gluteus maximus chosen for intramuscular injections? Where must the injection be placed?
Large and superficial muscle.
Outer upper quadrant of this area must be used to avoid any damage to the sciatic nerve.
Origin and insertion of gluteus maximus?
Origins:
- Sacrum and sacrotuberous ligament
- Most posterior part of iliac crest
- Fascia gluteus medius
Fibres extend down tiwards lateral aspect of thigh.
Insertions:
- Most fibres insert onto iliotibial tract
- Some fibres inserts onto gluteal tuberosity on posterior aspect
What is the iliotibial tract?
A thickening of the fascia lata on the lateral aspect of the thigh that extends all the way down to the tibia –> helps to stabilise the knee joint
What is the fascia lata?
The deep fascia of the thigh that encloses the thigh muscles
What is the tensor fascia lata?
Contracts to tighten and pull on the iliotibial tract which in turn stabilises the knee. Can also help to flex the hip (but not a strong flexor)
What area is being pointed to here?
Area of the greater trochanter (posterior view of thigh)
Where do gluteus medius and minimus insert?
On the greater trochanter
What are the gluteus medius and minimus innervated by?
Superior gluteal nerve
What is the gluteus maximus innervated by?
Inferior gluteal nerve
What muscle is being pointed to? What is its origin/insertion?
Piriformis
- Emerges from anterior surface of sacrum
- Travels through greater sciatic foramen
- Inserts on greater trochanter
What emerges superior to piriformis?
Superior gluteal nerve, artery and vein
What emerges inferior to piriformis?
Inferior gluteal artery, nerve and vein AND sciatic nerve
What is being pointed to?
Sciatic nerve
What ligament is being pointed to?
Sacrotuberous
Why is the ischial tuberosity recognisable in a prosection?
Is the bony landmark lying medially from which the hamstrings take origin
What muscle is being held?
Gluteus medius (has been cut from its attachment to the greater trochanter)
What muscle is being pointed to (gluteus medius has been reflected)?
Gluteus minimus
Identify piriformis in this prosection
What muscles laterally rotate the hip?
Deep lateral rotators –> group of smaller muscles that mainly act to laterally rotate the femur:
- Piriformis
- Gemellus superior and inferior
- Obturator internus
- Quadratus femoris
Diagram of superior and inferior gemelli. What lies in between them?
Tendon of obturator internus lies in between them
What structure does the tendon of obturator internus travel through?
Lesser sciatic foramen
Where do superior and inferior gemelli and the tendon of obturator internus insert?
Trochanteric fossa
What muscle is being pointed to?
Quadratus femoris
Origin and insertion of quadratus femoris?
It originates from the lateral side of the ischial tuberosity, and attaches to the quadrate tuberosity on the intertrochanteric crest.
Action of quadratus femoris?
Lateral rotation (and stabiliser)
Path of obturator internus
Diagram of obturator internus, sacrotuberous and sacrospinous ligament
Can see obturator internus passing through lesser sciatic foramen
Diagram of piriformis (highlighted deep in orange)
What tends to cause a posterior dislocation of the hip?
Impact when hip is:
- Flexed
- Internally rotated
- Adducted
i.e. seated position
Head of the femur is driven posteiorly, out of the acetabulum
What nerve injury may result from a posterior hip dislocation?
Sciatic nerve inury (L4-S3) may result. May be associated with acetabular fracture
What nerve is being pointed to?
Femoral nerve (passes under inguinal ligament)
What is being pointed to?
Right common iliac artery (accompanied by right common iliac vein)
What does the common iliac artery bifurcate into?
External and internal iliac artery
What is being pointed to here?
External iliac artery (and vein)
What is being pointed to here?
Internal iliac artery
Describe route of external iliac artery
Travels under inguinal ligament (with the femoral nerve) where it continues as the femoral artery
Describe the route of the internal iliac artery. What branches does it give off?
Travels into the pelvis and gives off many branches:
- Superior gluteal artery
- Inferior gluteal artery
These then travel through the greater sciatic foramen
What structures overly piriformis?
Nerves of the sacral plexus (sacrospinal nerves) –> these leave spinal canal through foramina, travel over piriformis and merge together to form the sciatic nerve
What muscle is being pointed to? What structure does it pass through?
Obturator internus (covers obturator foramen) and travels through the lesser sciatic foramen
What are the muscles of the anterior compartment of the thigh/hip?
- Iliopsoas
- Quadratus femoris
- Vastus Lateralis
- Vastus Intermedius
- Vastus Medialis
- Rectus Femoris
- Sartorius
- Pectineus
What are the muscles of the gluteal region?
Superior:
- Gluteus maximus
- Gluteus medius
- Gluteus minimus
- Tensor fascia lata
Deep:
- Piriformis
- Obturator internus
- The Gemelli
- Quadratus Femoris
What are the muscles of the medial thigh?
- Adductor magnus
- Adductor longus
- Adductor brevis
- Obturator externus
- Gracilis
What are all the muscles of the medial thigh innervated by? What is their arterial supply?
Innervated by the obturator nerve and arterial supply via the obturator artery
What is the main action of the muscles of the medial thigh?
Adduction
What is the main action of the deep muscles of the gluteal region?
The general action of these muscles is to laterally rotate the lower limb. They also stabilise the hip joint by ‘pulling’ the femoral head into the acetabulum of the pelvis.
