The hip, buttock and thigh

Question 1

Describe the twisting of the lower limb during development

Answer 1

permanent pronation at the mid-thigh level makes the terminology in the lower limb confusing

Thing that were supposed to be posterior are now anterior

Why flexion of the knee is in posterior direction, whereas flexion of the elbow is anterior

Question 2

What are the two major regions of the lower limb

Answer 2

The gluteal region (part of the trunk)
and
the “free lower limb” (thigh, leg and foot)

Question 3

Summarise the bones of the region

Answer 3

The pelvis (the “hip bone”)
Ischium
Ilium
pubis
The femur

Question 4

What is the difference between the thigh and leg

Answer 4

Thigh- hip and knee

Leg- knee and ankle

Question 5

What type of bone is the patella

Answer 5

Sesamoid bone- does not form part of the knee joint
Formed within a tendon of a muscle
Patella is important as it helps maintain arrangement and minimise friction when a muscle is moving over the surface of a joint- to prevent damage to the muscle or the bone.

Question 6

What 3 bones contribute to the hip joint

Answer 6

Each pelvic bone is formed by three bones (ilium, ischium, and pubis), which fuse during childhood. The ilium is superior and the pubis and ischium are anteroinferior and posteroinferior, respectively.

Question 7

Describe how the pelvis is joined to the vertebral column

Answer 7

The ilium articulates with the sacrum. The pelvic bone is further anchored to the end of the vertebral column (sacrum and coccyx) by the sacrotuberous and sacrospinous ligaments, which attach to a tuberosity and spine on the ischium.

Question 8

Summarise the relationship of the pelvis with the other parts of the body

Answer 8

The outer surface of the ilium, and the adjacent surfaces of the sacrum, coccyx, and sacrotuberous ligament, are associated with the gluteal region of the lower limb and provide extensive muscle attachment. The ischial tuberosity provides attachment for many of the muscles in the posterior compartment of the thigh, and the ischiopubic ramus and body of the pubis are associated mainly with muscles in the medial compartment of the thigh. The head of the femur articulates with the acetabulum on the lateral surface of the pelvic bone.

Question 9

Describe the key features of the ilium

Answer 9

The upper fan-shaped part of the ilium is associated on its inner side with the abdomen and on its outer side with the lower limb. The top of this region is the iliac crest, which ends anteriorly as the anterior superior iliac spine and posteriorly as the posterior superior iliac spine. A prominent lateral expansion of the crest just posterior to the anterior superior iliac spine is the tuberculum of the iliac crest.
The anterior inferior iliac spine is on the anterior margin of the ilium, and below this, where the ilium fuses with the pubis, is a raised area of bone (the iliopubic eminence).

Question 10

What is the name given to the surface of the hipbone that articulates with the sacrum

Answer 10

Auricular surface

Question 11

Describe the gluteal surface of the ilium

Answer 11

The gluteal surface of the ilium faces posterolaterally and lies below the iliac crest. It is marked by three curved lines (inferior, anterior, and posterior gluteal lines), which divide the surface into four regions:

Question 12

Describe the inferior gluteal line

Answer 12

The inferior gluteal line originates just superior to the anterior inferior iliac spine and curves inferiorly across the bone to end near the posterior margin of the acetabulum—the rectus femoris muscle attaches to the anterior inferior iliac spine and to a roughened patch of bone between the superior margin of the acetabulum and the inferior gluteal line.

Question 13

Describe the anterior gluteal line

Answer 13

▪
The anterior gluteal line originates from the lateral margin of the iliac crest between the anterior superior iliac spine and the tuberculum of the iliac crest, and arches inferiorly across the ilium to disappear just superior to the upper margin of the greater sciatic foramen—the gluteus minimus muscle originates from between the inferior and anterior gluteal lines.

Question 14

Describe the posterior gluteal line

Answer 14

The posterior gluteal line descends almost vertically from the iliac crest to a position near the posterior inferior iliac spine—the gluteus medius muscle attaches to bone between the anterior and posterior gluteal lines, and the gluteus maximus muscle attaches posterior to the posterior gluteal line.

Question 15

Where is the ischial tuberosity located

Answer 15

The ischial tuberosity is posteroinferior to the acetabulum and is associated mainly with the hamstring muscles of the posterior thigh (Fig. 6.23). It is divided into upper and lower areas by a transverse line.

Question 16

Describe the upper parts of the ischial tuberosity

Answer 16

The upper area of the ischial tuberosity is oriented vertically and is further subdivided into two parts by an oblique line, which descends, from medial to lateral, across the surface:
▪
The more medial part of the upper area is for the attachment of the combined origin of the semitendinosus muscle and the long head of the biceps femoris muscle.
▪
The lateral part is for the attachment of the semimembranosus muscle.

Question 17

Describe the lower parts of the ischial tuberosity

Answer 17

The lower area of the ischial tuberosity is oriented horizontally and is divided into medial and lateral regions by a ridge of bone:
▪
The lateral region provides attachment for part of the adductor magnus muscle.
▪
The medial part faces inferiorly and is covered by connective tissue and by a bursa.
When sitting, this medial part supports the body weight.
The sacrotuberous ligament is attached to a sharp ridge on the medial margin of the ischial tuberosity.

Question 18

Summarise the ischipubic ramus and pubic bone

Answer 18

The external surfaces of the ischiopubic ramus anterior to the ischial tuberosity and the body of the pubis provide attachment for muscles of the medial compartment of the thigh (Fig. 6.23). These muscles include the adductor longus, adductor brevis, adductor magnus, pectineus, and gracilis.

Question 19

What are the two parts of the ischiopubic ramus

Answer 19

Inferior ramus of pubis

Ramus of ischium

Question 20

What is the acetabulum

Answer 20

The large cup-shaped acetabulum for articulation with the head of the femur is on the lateral surface of the pelvic bone in the region where the ilium, pubis, and ischium fuse

Question 21

Describe the margins and walls of the acetabulum

Answer 21

The margin of the acetabulum is marked inferiorly by a prominent notch (acetabular notch).
The wall of the acetabulum consists of nonarticular and articular parts:
▪
The nonarticular part is rough and forms a shallow circular depression (the acetabular fossa) in central and inferior parts of the acetabular floor—the acetabular notch is continuous with the acetabular fossa.
▪
The articular surface is broad and surrounds the anterior, superior, and posterior margins of the acetabular fossa.

Question 22

Compare the lunate surface to the acetabular fossa

Answer 22

The smooth crescent-shaped articular surface (the lunate surface) is broadest superiorly where most of the body’s weight is transmitted through the pelvis to the femur. The lunate surface is deficient inferiorly at the acetabular notch.
The acetabular fossa provides attachment for the ligament of the head of the femur, whereas blood vessels and nerves pass through the acetabular notch.

Question 23

Describe the consequences of a pelvic fracture

Answer 23

The pelvic bones, sacrum, and associated joints form a bony ring surrounding the pelvic cavity. Soft tissue and visceral organ damage must be suspected when the pelvis is fractured. Patients with multiple injuries and evidence of chest, abdominal, and lower limb trauma should also be investigated for pelvic trauma.
Pelvic fractures can be associated with appreciable blood loss (concealed exsanguination) and blood transfusion is often required. In addition, this bleeding tends to form a significant pelvic hematoma, which can compress nerves, press on organs, and inhibit pelvic visceral function

Question 24

Describe some other types of pelvic fracture

Answer 24

Other types of pelvic ring injuries include fractures of the pubic rami and disruption of the sacro-iliac joint with or without dislocation. This may involve significant visceral pelvic trauma and hemorrhage.
Other general pelvic injuries include stress fractures and insufficiency fractures, as seen in athletes and elderly patients with osteoporosis, respectively.

Question 25

When is synostosis of the hip bone complete and what is the acetabulum initially

Answer 25

Around 9 years | Acetabulum is a triradiate cartilage which closes when synostosis is complete

Question 26

Summarise the femur

Answer 26

The femur is the bone of the thigh and the longest bone in the body. Its proximal end is characterized by a head and neck, and two large projections (the greater and lesser trochanters) on the upper part of the shaft

Question 27

Describe the head of the femur

Answer 27

The head of the femur is spherical and articulates with the acetabulum of the pelvic bone. It is characterized by a nonarticular pit (fovea) on its medial surface for the attachment of the ligament of the head. The head of the femur is covered in hyaline cartilage

Question 28

Describe the neck of the femur

Answer 28

The neck of the femur is a cylindrical strut of bone that connects the head to the shaft of the femur. It projects superomedially from the shaft at an angle of approximately 125°, and projects slightly forward. The orientation of the neck relative to the shaft increases the range of movement of the hip joint. The upper part of the shaft of the femur bears a greater and lesser trochanter, which are attachment sites for muscles that move the hip joint.

Question 29

Describe the greater trochanter

Answer 29

The greater trochanter extends superiorly from the shaft of the femur just lateral to the region where the shaft joins the neck of the femur (Fig. 6.26). It continues posteriorly where its medial surface is deeply grooved to form the trochanteric fossa. The lateral wall of this fossa bears a distinct oval depression for attachment of the obturator externus muscle.

Question 30

Describe the key features of the greater trochanter

Answer 30

The greater trochanter has an elongate ridge on its anterolateral surface for attachment of the gluteus minimus and a similar ridge more posteriorly on its lateral surface for attachment of the gluteus medius. Between these two points, the greater trochanter is palpable. On the medial side of the superior aspect of the greater trochanter and just above the trochanteric fossa is a small impression for attachment of the obturator internus and its associated gemelli muscles, and immediately above and behind this feature is an impression on the margin of the trochanter for attachment of the piriformis muscle

Question 31

Describe the lesser trochanter and its key features

Answer 31

The lesser trochanter is smaller than the greater trochanter and has a blunt conical shape. It projects posteromedially from the shaft of the femur just inferior to the junction with the neck (Fig. 6.26). It is the attachment site for the combined tendons of psoas major and iliacus muscles. Extending between the two trochanters and separating the shaft from the neck of the femur are the intertrochanteric line and intertrochanteric crest.

Question 32

Describe the intertrochanteric line

Answer 32

The intertrochanteric line is a ridge of bone on the anterior surface of the upper margin of the shaft that descends medially from a tubercle on the anterior surface of the base of the greater trochanter to a position just anterior to the base of the lesser trochanter (Fig. 6.26). It is continuous with the pectineal line (spiral line), which curves medially under the lesser trochanter and around the shaft of the femur to merge with the medial margin of the linea aspera on the posterior aspect of the femur.

Question 33

Describe the intertrochanteric crest

Answer 33

The intertrochanteric crest is on the posterior surface of the femur and descends medially across the bone from the posterior margin of the greater trochanter to the base of the lesser trochanter (Fig. 6.26). It is a broad smooth ridge of bone with a prominent tubercle (the quadrate tubercle) on its upper half, which provides attachment for the quadratus femoris muscle.

Question 34

Describe the angle of the shaft of the femur

Answer 34

The shaft of the femur descends from lateral to medial in the coronal plane at an angle of 7° from the vertical axis (Fig. 6.27). The distal end of the femur is therefore closer to the midline than the upper end of the shaft.

Question 35

Describe the middle third of the shaft of the femur

Answer 35

The middle third of the shaft of the femur is triangular in shape with smooth lateral and medial margins between anterior, lateral (posterolateral), and medial (posteromedial) surfaces. The posterior margin is broad and forms a prominent raised crest (the linea aspera).

Question 36

Describe the linea aspera

Answer 36

The linea aspera is a major site of muscle attachment in the thigh. In the proximal third of the femur, the medial and lateral margins of the linea aspera diverge and continue superiorly as the pectineal line and gluteal tuberosity, respectively (Fig. 6.27): ▪ The pectineal line curves anteriorly under the lesser trochanter and joins the intertrochanteric line. ▪ The gluteal tuberosity is a broad linear roughening that curves laterally to the base of the greater trochanter. The gluteus maximus muscle is attached to the gluteal tuberosity. The triangular area enclosed by the pectineal line, the gluteal tuberosity, and the intertrochanteric crest is the posterior surface of the proximal end of the femur.

Question 37

What is the angle of inclination

Answer 37

The angle that the long axis of the shaft makes with the long axis of the head and neck

Question 38

What determines the size of the angle between the long axis of the shaft and the vertical plane?

Answer 38

The width of the hips

Question 39

What is the anterior protrusion between the ilium and the pubis called?

Answer 39

Ilipoubic eminence

Question 40

Describe femoral neck fractures

Answer 40

Femoral neck fractures (Fig. 6.28) can interrupt the blood supply to the femoral head. The blood supply to the head and neck is primarily from an arterial ring formed around the base of the femoral neck. From here, vessels course along the neck, penetrate the capsule, and supply the femoral head. The blood supply to the femoral head and femoral neck is further enhanced by the artery of the ligamentum teres, which is generally small and variable. Femoral neck fractures may disrupt associated vessels and lead to necrosis of the femoral head.

Question 41

Describe intertrochanteric fractures

Answer 41

In these fractures, the break usually runs from the greater trochanter through to the lesser trochanter and does not involve the femoral neck. Intertrochanteric fractures preserve the femoral neck blood supply and do not render the femoral head ischemic

Question 42

Describe femoral shaft fractures

Answer 42

An appreciable amount of energy is needed to fracture the femoral shaft. This type of injury is therefore accompanied by damage to the surrounding soft tissues, which include the muscle compartments and the structures they contain.

Question 43

What structures form the greater and lesser sciatic foramina?

Answer 43

Sacrospinuous ligament Sacrotuberous ligament Structures (nerves and vessels) pass through these foramina to pass between the posterior buttock and the interior of the pelvis.

Question 44

Summarise the fascia of the region

Answer 44

There are two layers of fascia Superficial fascia – i.e. subcutaneous tissue Deep fascia – in the thigh called fascia lata Fascia lata extends like a stocking beneath the skin (holding all the muscle compartments in place) A lateral thickened area of it is called the ilio-tibial tract ( important for function of muscles)

Question 45

What is the fascia lata

Answer 45

The outer layer of deep fascia in the lower limb forms a thick “stocking-like” membrane, which covers the limb and lies beneath the superficial fascia (Fig. 6.39A). This deep fascia is particularly thick in the thigh and gluteal region and is termed the fascia lata.

Question 46

Describe the boundaries of the fascia lata

Answer 46

The fascia lata is anchored superiorly to bone and soft tissues along a line of attachment that defines the upper margin of the lower limb. Beginning anteriorly and circling laterally around the limb, this line of attachment includes the inguinal ligament, iliac crest, sacrum, coccyx, sacrotuberous ligament, inferior ramus of the pubic bone, body of the pubic bone, and superior ramus of the pubic bone. Inferiorly, the fascia lata is continuous with the deep fascia of the leg.

Question 47

What is the ilio-tibial tract

Answer 47

The fascia lata is thickened laterally into a longitudinal band (the iliotibial tract), which descends along the lateral margin of the limb from the tuberculum of the iliac crest to a bony attachment just below the knee

Question 48

Describe the different regions of the ilio-tibial tract

Answer 48

The superior aspect of the fascia lata in the gluteal region splits anteriorly to enclose the tensor fasciae latae muscle and posteriorly to enclose the gluteus maximus muscle: ▪ The tensor fasciae latae muscle is partially enclosed by and inserts into the superior and anterior aspects of the iliotibial tract. ▪ Most of the gluteus maximus muscle inserts into the posterior aspect of the iliotibial tract.

Question 49

Describe the key functions of the ilio-tibial tract

Answer 49

The tensor fasciae latae and gluteus maximus muscles, working through their attachments to the iliotibial tract, hold the leg in extension once other muscles have extended the leg at the knee joint. The iliotibial tract and its two associated muscles also stabilize the hip joint by preventing lateral displacement of the proximal end of the femur away from the acetabulum.

Question 50

What is the saphenous opening

Answer 50

Saphenous opening: prominent aperture on anterior aspect just inferior to medial end of inguinal ligament - allowing great saphenous vein to pass from superficial to deep fascia to connect with femoral vein The margin of the saphenous opening is formed by the free medial edge of the fascia lata as it descends from the inguinal ligament and spirals around the lateral side of the great saphenous vein and medially under the femoral vein to attach to the pectineal line (pecten pubis) of the pelvic bone.

Question 51

Outline the borders of the femoral triangle

Answer 51

Superiorly – the inguinal ligament Medially – adductor longus Laterally - sartorius

Question 52

Describe the different regions of the femoral triangle

Answer 52

▪ The base of the triangle is the inguinal ligament. ▪ The medial border is the medial margin of the adductor longus muscle in the medial compartment of the thigh. ▪ The lateral margin is the medial margin of the sartorius muscle in the anterior compartment of the thigh. ▪ The floor of the triangle is formed medially by the pectineus and adductor longus muscles in the medial compartment of the thigh and laterally by the iliopsoas muscle descending from the abdomen. ▪ The apex of the femoral triangle points inferiorly and is continuous with a fascial canal (adductor canal), which descends medially down the thigh and posteriorly through an aperture in the lower end of one of the largest of the adductor muscles in the thigh (the adductor magnus muscle) to open into the popliteal fossa behind the knee.

Question 53

What are the contents of the femoral triangle (medial to lateral)

Answer 53

Deep inguinal lymph nodes Femoral Vein Femoral Artery Femoral Nerve The femoral artery can be palpated in the femoral triangle just inferior to the inguinal ligament and midway between the anterior superior iliac spine and the pubic symphysis.

Question 54

Describe the passage of the structures in the femoral triangle

Answer 54

The femoral nerve, artery, and vein and lymphatics pass between the abdomen and lower limb under the inguinal ligament and in the femoral triangle (Fig. 6.42). The femoral artery and vein pass inferiorly through the adductor canal and become the popliteal vessels behind the knee where they meet and are distributed with branches of the sciatic nerve, which descends through the posterior thigh from the gluteal region.

Question 55

Describe the femoral sheath

Answer 55

In the femoral triangle, the femoral artery and vein and the associated lymphatic vessels are surrounded by a funnel-shaped sleeve of fascia (the femoral sheath). The sheath is continuous superiorly with the transversalis fascia and iliac fascia of the abdomen and merges inferiorly with connective tissue associated with the vessels.

Question 56

Which structures are found in the femoral sheath

Answer 56

Each of the three structures surrounded by the sheath is contained within a separate fascial compartment within the sheath. The most medial compartment (the femoral canal) contains the lymphatic vessels and is conical in shape. The opening of this canal superiorly is potentially a weak point in the lower abdomen and is the site for femoral hernias. The femoral nerve is lateral to and not contained within the femoral sheath.

Question 57

Summarise the clinical uses of the femoral artery

Answer 57

Vascular access to the lower limb Deep and inferior to the inguinal ligament are the femoral artery and femoral vein. The femoral artery is palpable as it passes over the femoral head and may be easily demonstrated using ultrasound. If arterial or venous access is needed rapidly, a physician can use the femoral approach to these vessels. Many radiological procedures involve catheterization of the femoral artery or the femoral vein to obtain access to the contralateral lower limb, the ipsilateral lower limb, the vessels of the thorax and abdomen, and the cerebral vessels. Cardiologists also use the femoral artery to place catheters in vessels around the arch of the aorta and into the coronary arteries to perform coronary angiography and angioplasty. Access to the femoral vein permits catheters to be maneuvered into the renal veins, the gonadal veins, the right atrium, and the right side of the heart, including the pulmonary artery and distal vessels of the pulmonary tree. Access to the superior vena cava and the great veins of the neck is also possible.

Question 58

What is the margin of the saphenous opening called

Answer 58

The falciform margin.

Question 59

What are the other names for the adductor canal

Answer 59

Hunter’s Canal, Subsartorial Canal

Question 60

Describe the boundaries of the adductor canal

Answer 60

Extends along the medial aspect of the thigh Formed by: Vastus medialis (anteriorly) Adductor longus and adductor magnus (posteriorly) Sartorius (medially)

Question 61

What are the contents of the adductor canal

Answer 61

Femoral artery Femoral vein Saphenous nerve (major branch of the femoral nerve)

Question 62

When does the femoral nerve give off most of its branches

Answer 62

Upon entering the femoral triangle.

Question 63

What is the key difference between the greater sciatic foramen and the lesser sciatic foramen

Answer 63

Greater sciatic foramen: structures passing from the pelvis to the thigh Lesser sciatic foramen: structures passing from the pelvis to the perineum

Question 64

Describe the margins of the greater sciatic foramen

Answer 64

The margins of the foramen are formed by: ▪ the greater sciatic notch, ▪ parts of the upper borders of the sacrospinous and sacrotuberous ligaments, and ▪ the lateral border of the sacrum. The piriformis muscle passes out of the pelvis into the gluteal region through the greater sciatic foramen and separates the foramen into two parts, a part above the muscle and a part below:

Question 65

Describe the marigns of the lesser sciatic foramen

Answer 65

The lesser sciatic foramen is inferior to the greater sciatic foramen on the posterolateral pelvic wall (Fig. 6.34). It is also inferior to the lateral attachment of the pelvic floor (levator ani and coccygeus muscles) to the pelvic wall and therefore connects the gluteal region with the perineum:

Question 66

Summarise the passage of the sciatic nerve

Answer 66

Passes from pelvis to buttock via greater sciatic notch/foramen In the buttock, lies in the inferior and medial quadrant Passes along posterior aspect of the thigh Divides into the tibial nerve and the common peroneal nerve (inconstant level) Supplies all the hamstring muscles and all the muscles below the level of the knee If injecting in the buttock, use the superior and lateral quadrant

Question 67

Describe how the sciatic nerve normally enters the gluteal region

Answer 67

The sciatic nerve normally enters the gluteal region inferiorly to piriformis muscle, but can be superior or pierce the muscle itself. Variations of the emergence of the sciatic nerve from the pelvis interior to the gluteal region. For this reason, care must be taken to avoid the nerve during intramuscular injection.

Question 68

Describe how the gluteal region can be divided into different regions

Answer 68

The gluteal region can be divided into quadrants by two imaginary lines positioned using palpable bony landmarks (Fig. 6.48). One line descends vertically from the highest point of the iliac crest. Another line is horizontal and passes through the first line midway between the highest point of the iliac crest and the horizontal plane through the ischial tuberosity.

Question 69

Explain the safe place for intramuscular injecitons

Answer 69

It is important to remember that the gluteal region extends as far forward as the anterior superior iliac spine. The sciatic nerve curves through the upper lateral corner of the lower medial quadrant and descends along the medial margin of the lower lateral quadrant. Occasionally, the sciatic nerve bifurcates into its tibial and common fibular branches in the pelvis, in which case the common fibular nerve passes into the gluteal region through, or even above, the piriformis muscle. The superior gluteal nerve and vessels normally enter the gluteal region above the piriformis and pass superiorly and forward. The anterior corner of the upper lateral quadrant is normally used for injections to avoid injuring any part of the sciatic nerve or other nerves and vessels in the gluteal region. A needle placed in this region enters the gluteus medius anterosuperior to the margin of the gluteus maximus.

Question 70

How can we demonstrate this safe region clinically

Answer 70

Index finger on ASIS Middle finger on tubercle of iliac crest Safe region is area between these two fingers.

Question 71

What test is used to asses the function of the hip abductors

Answer 71

Trendelenberg test When a patient lifts one foot off the floor, their hip abductors (gluteus medius and gluteus minimus) should contract to keep the pelvis level despite the extra weight of the raised foot on the opposite side

Question 72

Describe the trendelenberg test

Answer 72

Trendelenburg’s sign occurs in people with weak or paralyzed abductor muscles (gluteus medius and gluteus minimus) of the hip. The sign is demonstrated by asking the patient to stand on one limb. When the patient stands on the affected limb, the pelvis severely drops over the swing limb. Positive signs are typically found in patients with damage to the superior gluteal nerve. Damage to this nerve may occur with associated pelvic fractures, with space-occupying lesions within the pelvis extending into the greater sciatic foramen, and in some cases relating to hip surgery during which there has been disruption of and subsequent atrophy of the insertion of the gluteus medius and gluteus minimus tendons on the greater trochanter. In patients with a positive Trendelenburg’s sign, gait also is abnormal. Typically during the stance phase of the affected limb, the weakened abductor muscles allow the pelvis to tilt inferiorly over the swing limb. The patient compensates for the pelvic drop by lurching the trunk to the affected side to maintain the level of the pelvis throughout the gait cycle.

Question 73

Summarise the hip joint

Answer 73

The hip joint is a synovial articulation between the head of the femur and the acetabulum of the pelvic bone (Fig. 6.29A). The joint is a multiaxial ball and socket joint designed for stability and weight-bearing at the expense of mobility. Movements at the joint include flexion, extension, abduction, adduction, medial and lateral rotation, and circumduction.

Question 74

Describe the impact of the orientation of the femur on the movements of the hip joint

Answer 74

When considering the effects of muscle action on the hip joint, the long neck of the femur and the angulation of the neck on the shaft of the femur must be borne in mind. For example, medial and lateral rotation of the femur involves muscles that move the greater trochanter forward and backward, respectively, relative to the acetabulum

Question 75

Describe the articular surfaces of the hip joint

Answer 75

The articular surfaces of the hip joint are: ▪ the spherical head of the femur, and ▪ the lunate surface of the acetabulum of the pelvic bone. The acetabulum almost entirely encompasses the hemispherical head of the femur and contributes substantially to joint stability. The nonarticular acetabular fossa contains loose connective tissue. The lunate surface is covered by hyaline cartilage and is broadest superiorly. Except for the fovea, the head of the femur is also covered by hyaline cartilage.

Question 76

Describe the fibrocartilaginous collar of the hip joint

Answer 76

The rim of the acetabulum is raised slightly by a fibrocartilaginous collar (the acetabular labrum). Inferiorly, the labrum bridges across the acetabular notch as the transverse acetabular ligament and converts the notch into a foramen (acetabular foramen)

Question 77

Describe the ligament of the head of the femur

Answer 77

The ligament of the head of the femur is a flat band of delicate connective tissue that attaches at one end to the fovea on the head of the femur and at the other end to the acetabular fossa, transverse acetabular ligament, and margins of the acetabular notch (Fig. 6.30B). It carries a small branch of the obturator artery, which contributes to the blood supply of the head of the femur.

Question 78

Describe the synovial membrane of the hip joint

Answer 78

The synovial membrane attaches to the margins of the articular surfaces of the femur and acetabulum, forms a tubular covering around the ligament of the head of the femur, and lines the fibrous membrane of the joint (Figs. 6.30B and 6.31). From its attachment to the margin of the head of the femur, the synovial membrane covers the neck of the femur before reflecting onto the fibrous membrane

Question 79

Describe the fibrous membrane of the hip joint

Answer 79

The fibrous membrane that encloses the hip joint is strong and generally thick. Medially, it is attached to the margin of the acetabulum, the transverse acetabular ligament, and the adjacent margin of the obturator foramen (Fig. 6.32A). Laterally, it is attached to the intertrochanteric line on the anterior aspect of the femur and to the neck of the femur just proximal to the intertrochanteric crest on the posterior surface

Question 80

What is important to remember about the capsule of the hip joint

Answer 80

Extends further anteriorly than posteriorly Within capsule runs the blood supply of the femur head Hip fractures are classified intracapsular and extracapsular

Question 81

What is the acetabular fossa made up of

Answer 81

Fibrous-fatty tissue

Question 82

Describe the ilio-femoral ligament

Answer 82

▪ The iliofemoral ligament is anterior to the hip joint and is triangular shaped (Fig. 6.32B). Its apex is attached to the ilium between the anterior inferior iliac spine and the margin of the acetabulum and its base is attached along the intertrochanteric line of the femur. Parts of the ligament attached above and below the intertrochanteric line are thicker than the part attached to the central part of the line. This results in the ligament having a Y appearance.

Question 83

Describe the pubofemoral ligament

Answer 83

▪ The pubofemoral ligament is anteroinferior to the hip joint (Fig. 6.32B). It is also triangular in shape, with its base attached medially to the iliopubic eminence, adjacent bone, and obturator membrane. Laterally, it blends with the fibrous membrane and with the deep surface of the iliofemoral ligament.

Question 84

Describe the ischiofemoral ligament

Answer 84

▪ The ischiofemoral ligament reinforces the posterior aspect of the fibrous membrane (Fig. 6.32C). It is attached medially to the ischium, just posteroinferior to the acetabulum, and laterally to the greater trochanter deep to the iliofemoral ligament.

Question 85

How are the fibres of the ligaments of the hip join orientated and describe the importance of this arrangement

Answer 85

The fibers of all three ligaments are oriented in a spiral fashion around the hip joint so that they become taut when the joint is extended. This stabilizes the joint and reduces the amount of muscle energy required to maintain a standing position. When the hip is flexed, these ligaments are relaxed When the hip is extended (e.g. when standing) the ligaments wind, which pulls the head of the femur into the acetabulum and helps stabilise the joint when in the standing position

Question 86

Summarise the vascular supply of the hip joint

Answer 86

Vascular supply to the hip joint is predominantly through branches of the obturator artery, medial and lateral circumflex femoral arteries, superior and inferior gluteal arteries, and the first perforating branch of the deep artery of the thigh. The articular branches of these vessels form a network around the joint

Question 87

Describe the blood supply of the femur

Answer 87

The main blood supply is via the medial circumflex femoral artery and the lateral circumflex femoral artery (both from profunda femoris) There is a small blood supply from the artery of the head of the femur (branch of obturator artery - this is more important in children) - acetabular branch Lateral circumflex gives off ascending, transverse and descending branch.

Question 88

What type of hip fracture is most likely to need a hip replacement and why?

Answer 88

Intracapsular – this is more likely to disrupt the blood supply and cause avascular necrosis of the head of the femur

Question 89

What does the abdominal aorta give off

Answer 89

Arterial supply: abdominal aorta produces common iliac arteries that divide to the external and internal iliacs

Question 90

When does the external iliac artery become the femoral artery

Answer 90

The femoral artery is the continuation of the external iliac artery and begins as the external iliac artery passes under the inguinal ligament to enter the femoral triangle on the anterior aspect of the upper thigh

Question 91

When does the femoral artery become the popliteal artery

Answer 91

The femoral artery passes vertically through the femoral triangle and then continues down the thigh in the adductor canal. It leaves the canal by passing through the adductor hiatus in the adductor magnus muscle and becomes the popliteal artery behind the knee. Femoral artery continues as the superficial femoral artery and subsequently as the popliteal artery

Question 92

name four small branches of the femoral artery

Answer 92

A cluster of four small branches—superficial epigastric artery, superficial circumflex iliac artery, superficial external pudendal artery, and deep external pudendal artery—originate from the femoral artery in the femoral triangle and supply cutaneous regions of the upper thigh, lower abdomen, and perineum.

Question 93

What is the largest branch of the femoral artery

Answer 93

The largest branch of the femoral artery in the thigh is the deep artery of the thigh (profunda femoris artery), which originates from the lateral side of the femoral artery in the femoral triangle and is the major source of blood supply to the thigh produces the medial and lateral circumflex arteries to form the arterial ring around the neck and to supply the head; also produces perforating arteries to supply shaft

Question 94

Describe the obturator artery

Answer 94

The obturator artery originates as a branch of the internal iliac artery in the pelvic cavity and enters the medial compartment of the thigh through the obturator canal (Fig. 6.65). As it passes through the canal, it bifurcates into an anterior branch and a posterior branch, which together form a channel that circles the margin of the obturator membrane and lies within the attachment of the obturator externus muscle. Vessels arising from the anterior and posterior branches supply adjacent muscles and anastomose with the inferior gluteal and medial circumflex femoral arteries. In addition, an acetabular vessel originates from the posterior branch, enters the hip joint through the acetabular notch, and contributes to the supply of the head of the femur.

Question 95

Summarise the arteries of the gluteal region

Answer 95

Two arteries enter the gluteal region from the pelvic cavity through the greater sciatic foramen, the inferior gluteal artery and the superior gluteal artery (Fig. 6.49). They supply structures in the gluteal region and posterior thigh and have important collateral anastomoses with branches of the femoral artery. Inferior gluteal anastomoses with perforating branches of femoral Superior gluteal anstamoses with inferior gluteal artery as well as medial and lateral circumflex Superior- from posterior trunk of internal iliac (above piriformis) Inferior- from anterior trunk (below piriformis)

Question 96

Summarise the venous drainage of the thigh

Answer 96

Venous drainage: superficial drainage by the great saphenous vein which joins the femoral vein at the sapheno-femoral junction; deep drainage starts with small saphenous vein which joins tibial veins to form the popliteal, then femoral vein Then becomes external iliac-vein

Question 97

Summarise the deep veins of the thigh

Answer 97

``` Popliteal vein Femoral vein External iliac vein Sapheno-femoral junction Venae comitantes of the profunda femoris artery ```

Question 98

Describe the veins of the gluteal region

Answer 98

Inferior and superior gluteal veins follow the inferior and superior gluteal arteries into the pelvis where they join the pelvic plexus of veins. Peripherally, the veins anastomose with superficial gluteal veins, which ultimately drain anteriorly into the femoral vein.

Question 99

When does the femoral vein become the popliteal vein

Answer 99

The femoral artery and vein pass from the anterior compartment to the posterior of the knee (the popliteal fossa) through the hiatus of adductor magnus muscle. After passing posteriorly, they are named the popliteal artery and vein.

Question 100

What other veins drain into the saphenous vein before it enters the sapheno-femoral junction?

Answer 100

Superficial circumflex iliac Superficial epigastric Superficial external pudendal Deep external pudendal vein

Question 101

Summarise the lymphatic drainage

Answer 101

Lymph flows with the superficial and deep veins Superficial inguinal lymph nodes Deep inguinal lymph nodes External iliac lymph nodes Deep lymphatic vessels of the gluteal region accompany the blood vessels into the pelvic cavity and connect with internal iliac nodes. Superficial lymphatics drain into the superficial inguinal nodes on the anterior aspect of the thigh.

Question 102

Which spinal roots are responsible for different movements of the hip

Answer 102

``` Hip Flexors L23 Hip Extensors L45 Knee Extensors L34 Knee Flexors L5S1 ``` Lateral rotation of hip- L5, L1 Medial rotation of hip- L1-3 Adductin- L1-4 Abduction- L5,S1 Dorsiflexion- L4,5 Plantar flexion- S1,2

Question 103

Summarise the nerves of the anterior and medial compartments

Answer 103

Anterior Compartment of the Thigh Femoral Nerve Posterior divisions of lumbar plexus (L234) Medial Compartment of the Thigh Obturator Nerve Anterior divisions of the lumbar plexus (L234)

Question 104

Summarise the nerves of the posterior compartment

Answer 104

Sciatic n. (or its terminal branches Tibial and Common Peroneal ns.) supply the remaining compartments (i.e. post. thigh, ant. and post. leg, foot) L345S12)

Question 105

Sumamarise the nerves of the gluteal compartment of the thigh

Answer 105

Gluteal Compartment of the Thigh Superior gluteal nerve (L45S1) – gluteus medius and minimus Inferior gluteal nerve (L5S12) – gluteus maximus

Question 106

Summarise the sensory segmental supply

Answer 106

Dermatomal distribution Front of the thigh : T12, L123 Back of the thigh : S123 Buttock S234

Question 107

List the nerves involved in the sensory peripheral supply

Answer 107

Subcostal nerve (T12) Ilio-hypogastric nerve (L1) Ilio-inguinal nerve (L1) Genito-femoral nerve (L12) Lateral cutaneous nerve of the thigh (L23) Sensory branches of the femoral nerve (L234) Sensory branches of the obturator nerve (L234) Posterior cutaneous nerve of the thigh (S23) Saphenous nerve (L234) Buttock nerves from the scaral plexus (L1-S3)