Lower limb Flashcards
What does the pelvic girdle consist of?
The two hip bones and the sacrum
What are the main functions of the pelvic girdle?
Transfer forces from axial skeleton to lower limb, provide attachment for muscles, protect the pelvic area
What are the three bones that form the pelvic bone? Roughly at what age are they fused? How are they connected before this?
Illium, ischium, pubis; 18; triradiate cartilage connects them in the acetabulum
Which is the most superior of the three pelvis bones?
Illium
Describe the location of the iliac fossa; what purpose does it serve?
Found on the anterior, medial side of the illium, this is a concave surface; the iliacus muscle originates from here
Describe the location of the gluteal surface
Found on the posterior side of the illium
What is the iliac crest?
The superior margin of the illium thickens to form a crest that the muscles and fascia of the abdomen attach to
Which bone of the pelvic bone is found posteriorly and inferiorly?
The ischium
What does the ischium consist of?
A body and a ramus; the body forms part of the acetabulum and joins with the ilium superiorly; the ischial ramus projects medially to join with the laterally projecting ramus of the pelvis
Describe the location of the ischial tuberosity
Large projection of bone on the body of the ischium, in the posterior and inferior direction
What does the pubis consist of?
Body: articulates with body of other pubis, at the pubic symphysis
Superior ramus: joins with the ilium and ischium at the acetabulum, helping to form it
Inferior ramus: joins with the ramus of the ischium, helping it form the obturator foramen
What is the most common way of fracturing the pelvis?
Direct trauma e.g. traffic collision, fall on feet (force transmitted to pelvis)
Where do fractures of the pelvis occur?
At weaker points; the superior and inferior pelvic rami, the acetabulum or in the region of the sacroiliac joint
What is a common complication of pelvic fractures?
Soft tissue injury; the bladder and urethra are relatively close
How does avulsion of the hip bone commonly occur?
Sports requiring sudden acceleration or deceleration forces, such as sprinting, or kicking a football
What is an ‘avulsion’?
A small part of bone with a piece of tendon or ligament attached is ‘avulsed’. These fractures occur at apophyses (bony projections that lack secondary ossification centres); they occur where muscles are attached
What is the main function of the femur?
Transmit forces from tibia to hip joint
What is the purpose of the depression on the medial surface of the head of the femur?
Attachment of the ligament of the head
Describe the greater trochanter
Projection of bone originating from anterior shaft, just lateral to where the neck joins; it is angled superiorly and posteriorly, and can be found on both the anterior and posterior sides of the femur
What is the function of the greater trochanter?
Site of attachment of the abductor and lateral rotator muscles of the leg
Describe the lesser trochanter; what is its function?
Much smaller than greater trochanter, projects from the posteromedial side, just inferior to the neck-shaft junction; the psaos major and illiacus muscles attach here
What is the intertrochanteric line?
Ridge of bone running in inferomedial direction on the anterior surface of the femur, connecting the two trochanters together; site of attachment of iliofemoral ligament
What is the intertrochanteric line known as after passing the lesser trochanter on the posterior surface?
Pectineal line
What is the intertrochanteric crest?
Similar to intertrochanteric line, it is a ridge of bone connecting the two trochanters; it is located on the posterior surface of the femur
What is the rounded tubercle on the superior half of the intertrochanteric crest?
The quadrate tubercle; place of attachment of quadratus femoris
What is the name of the projection of bone that runs down the femur on the posterior side?
The linea aspera
What do the medial and lateral borders of the proximal femur become as they descend?
Medial becomes pectineal line, lateral becomes gluteal tuberosity (where gluteus maximus attaches)
What happens to the linea aspersa distally?
It widens and forms the floor of the popliteal fossa, and the medial and lateral supracondylar ridges
What are the medial and lateral condyles of the femur?
Rounded areas at the distal end of the femur; the posterior and inferior surfaces articulate with the tibia and menisci of the knee, while the anterior surface articulates with the patella
What are the medial and lateral epicondyles of the femur?
Bony elevations on the non-articular areas of the condyles; they are the area of attachment of some muscles and collateral ligaments of the knee
What is the intercondylar fossa?
Depression found on the posterior surface of the femur, it lies in between the two condyles; it contains facets for attachment of internal knee ligaments (anterior and posterior cruciate)
Describe the facet for attachment of the posterior cruciate ligament
Found on the medial wall of the intercondylar fossa; it is a large rounded flat face, where the posterior cruciate ligament attaches
Describe the facet for attachment of the anterior cruciate ligament
Found on the lateral wall of the intercondylar fossa, it is smaller than the facet on the medial wall, and is where the anterior cruciate ligament of the knee attaches
In what direction does the shaft of the femur descend?
Slightly medially
What are the two common types of fractures at the neck of the femur?
Subcapital, trochanteric
Who are subcapital fractures common in? How do they often occur?
Elderly, especially women; result of minor trip or stumble
What happens in a subcapital fracture?
The distal fragment is pulled upwards and rotated laterally; this can be seen clinically by a shorter left leg, and toes pointing laterally
What is a dangerous complication of a subcapital fracture of the femur?
The head can undergo avascular necrosis as its blood supply is disrupted by the fracture
Who are trochanteric fractures common in? What is the difference between trochanteric and subcapital fractures?
Young and middle aged people; fracture occurs extracapsularly and so no avascular necrosis can occur; like the subcapital facture, the leg is shortened and laterally rotated
Describe the position of the fragments of a fracture of the upper third of the femoral shaft
Proximal fragment: flexed, abducted and laterally rotated
Distal fragment: adducted, laterally rotated and elevated
Describe what is seen with a fracture of the middle third of the femoral shaft
Limb shortening occurs, due to the distal fragment being pulled upwards
Describe what is seen with a fracture of the lower third of the femoral shaft; why can blood supply to the leg and foot be compromised?
Limb shortening occurs, due to the distal fragment being pulled upwards; the distal fragment is also rotated inferiorly due to the gastrocnemius muscle- this can interfere with the popliteal artery
What are the two groups of muscles in the gluteal region?
Deep lateral rotators, and the superficial abductors and extensors
Name the deep lateral rotator gluteal muscles
Quadratus femoris, piriformis, gemellus superior, gemellus inferior and obturator internus
Name the superficial abductor and extensor muscles
Gluteus minimus, gluteus medius, gluteus maximus; it also contains the fascia latae, which acts on the knee joint
Which is the largest and most posterior region in the gluteal region?
Gluteus maximus; makes up most of the shape of the buttocks
What is the action of the gluteus maximus?
It is the main extensor of the thigh, and assists with lateral rotation; however it is only used when force is required, such as running or climbing
What is the innervation of the gluteus maximus?
Inferior gluteal nerve
Describe the position of the gluteus medius relative to the other superficial muscles of the gluteal region
Lies deep to the gluteus maximus, but above the gluteus minimus
What is the action of the gluteus medius?
Performs abduction and also prevents pelvis drop; with the hip flexed, the gluteus medius is a medial rotator
What is the innervation of the gluteus medius?
Superior gluteal nerve
What is the action of the gluteus minimus?
Performs abduction; it also prevents pelvis drop; with the hip flexed the gluteus minimus is a stronger medial rotator than the gluteus medius
What is the innervation of the gluteus minimus?
Superior gluteal nerve
What is the action of the piriformis? What is its innervation?
Acts to laterally rotate and abduct the thigh; nerve to piriformis
Which deep muscles of the gluteal region pull the head of the femur into the acetabulum, stabilising it?
Obturator internus, the gemelli, and the quadratus femoris
What is the action of the obturator internus? What is its innervation?
It acts to laterally rotate and abduct the thigh; nerve to obturator internus
What are the gemelli?
Two, narrow triangular muscles (superior and inferior), separated by the obturator internus tendon
What is the action of the gemelli?
Act to laterally rotate and abduct the thigh
What is the innervation of the gemelli?
Superior: nerve to obturator internus
Inferior: nerve to quadratus femoris
What is the quadratus femoris?
Square shaped muscle, found inferior to the gemelli and obturator internus
What is the action of the quadratus femoris? What is its innervation?
Laterally rotates the thigh; innervated by the nerve to quadratus femoris
What is the common insertion of the deep muscles of the gluteal region? Which one is the exception?
Greater trochanter; the quadratus femoris inserts into the quadrate tubercle of the thigh
What will happen if the superior gluteal nerve is injured?
The gluteus minimus and medius are paralysed
How can the function of the superior gluteal nerve be tested clinically?
By testing for pelvis drop (Trendelenburg’s sign); for example, if the left nerve is damaged then when the patient raises their right leg, the pelvis will drop on the right side; the patient will also walk with what is known as gluteal gait – where the pelvis falls towards the unaffected leg on each step
What is the importance of the piriformis in the gluteal region?
As it travels through the greater sciatic foramen, it effectively divides it into an inferior and superior part; this determines the names of the vessels and nerves in this region; superior gluteal nerves and vessels, inferior gluteal nerves and vessels (and sciatic nerve)
Name the muscles in the anterior compartment of the thigh
Iliopsoas (psaos major, iliacus), quadriceps femoris (vastus medialis, vastus intermediuam vastus lateralis, rectus femoris), sartorius, pectineus
What is the general action of the muscles in the anterior compartment of the thigh? What is their innervation? Which muscle is an exception?
Mainly flexors at the hip, and extensors at the knee; innervation is by the femoral nerve (psaos major is anterior rami L1-L3)
Why are the iliacus and psaos major commonly referred to as one muscle? What is the name of the common muscle?
They originate in different areas but come together to form a tendon; the iliopsoas
What is the action of the iliopsoas?
Powerful flexor of lower limb at the hip joint, can also assist in lateral rotation
What is the innervation of the iliopsoas?
Psoas major is innervated by anterior rami L1 to L3, while the iliacus is innervated by the femoral nerve
What is the quadriceps femoris?
Consists of four parts; three vastus muscles and the rectus femoris, found in the anterior compartment of the thigh they all attach to the patella and are one of the most powerful muscles in the body
What are the vastus muscles? What are their relative positions within the anterior compartment of the thigh?
Vastus medialis, intermedius, and lateralis; medialis is medial, lateralis is lateral, intermedius is found deep to the medialis, lateralis and rectus femoris
What is the action of the vastus muscles? What is their innervation?
They extend at the knee joint; innervation is by the femoral nerve
What is unique about the rectus femoris amongst the quadriceps?
It is the only one to cross both the hip and knee joint
What is the action of the rectus femoris? What is its innervation?
Extends at the knee joint, and also flexes at the hip; innervation is by the femoral nerve
How would you test the function of the quadriceps femoris? (or the femoral nerve)
Ask the patient to extend the leg, and resist movement; the quadriceps femoris should contract and be observable
What is the longest muscle in the body? Describe its location
Sartorius; runs across the anterior thigh in an inferomedial direction, superfifical to the other muscles
What is the action of the sartorius?
What is its innervation?
At the hip it is a flexor, abductor and lateral rotator; at the knee it is also a flexor; femoral nerve
Why can the pectineus muscle be classified in the anterior or medial compartments of the thigh?
Innervation is by the femoral nerve (anterior characteristic), actions (adduction and flexion at hip) are typical of the medial compartment
What is the importance of the pectineus with respect to the femoral triangle?
It forms the base
What is the action of the pectineus muscle? What is its innervation?
It act to adduct and flex at the hip joint; femoral nerve
What are the five muscles in the medial compartment of the thigh?
The gracilis, obturator externus, adductor brevis, adductor longus, and adductor magnus
What is the importance of the adductor longus with respect to the femoral triangle?
Lateral border is medial border of femoral triangle
What is the action of the adductor longus? What is the innervation of the adductor longus?
Adducts and medially rotates the thigh; obturator nerve (L2-L4)
Describe the location of the adductor brevis relative to the adductor longus and pectineus
Posterior
What is the action of the adductor brevis? What is its innervation?
Adduction of the thigh; obturator nerve (L2-L4)
Which is the largest muscle in the medial compartment of the thigh?
The adductor magnus; lies posteriorly to the other muscles (part of it is in the posterior compartment)
What is the action of the adductor magnus?
Both parts (adductor and hamstring components) adduct the thigh; the adductor component also flexes the thigh, with the hamstring component extending the thigh
What is the innervation of the adductor magnus?
Adductor part is obturator nerve (L2-L4), hamstring part is tibial nerve (L4-S3)
Which is the most superior of the muscles in the medial compartment of the thigh?
The obturator externus
What is the action of the obturator externus? What is its innervation?
Laterally rotates the thigh; obturator nerve (L2-L4)
What is the most superficial and medial of the medial thigh muscles? What is unique about it?
Gracilis; only muscle of the group to cross both the hip and knee joints
What is the action of the gracilis muscle? What is its innervation?
Adducts the thigh at the hip, flexes the leg at the knee; innervation is by the obturator nerve (L2-L4)
What is the general origin of the muscles of the medial compartment of the thigh?
The pubis
What is the blood supply of the muscles in the medial compartment of the thigh?
Obturator artery
What are the muscles in the medial compartment of the thigh also known as?
The adductors
What type of joint is the hip? Which structures are involved?
Synovial ball and socket; acetabulum of pelvis and head of femur (covered in articular cartilage)
Name the four important ligaments of the hip joint
Ligament of head of femur, pubofemoral, iliofemoral, ischiofemoral
Describe the location of the ligament of head of femur
Attaches from the acetabular fossa to the fovea of the femur
What structure is important in respect to the ligament of head of femur?
The ligament encloses a branch of the obturator artery, which contributes a small proportion of the blood supply to the hip joint
Describe the position of the pubofemoral ligament in the hip joint
Found anteriorly and inferiorly, it attaches at the pelvis to the iliopubic eminence and obturator membrane, and then blends with the articular capsule
What is the function of the pubofemoral ligament in the hip joint?
Prevents excessive abduction
Describe the position of the iliofemoral ligament at the hip joint
Found anteriorly, it originates from the ilium, just inferior to the anterior inferior iliac spine; it attaches to the intertrochanteric line, thickening in two places to give a Y shaped appearance
`What is the function of the iliofemoral ligament of the hip joint
Prevents hyperextension of the joint during standing (screws head of femur into acetabulum)
Describe the position of the ischiofemoral ligament of the hip joint
Main posterior ligament, attaches to the ischium and greater trochanter
What is the function of the ischiofemoral ligament of the hip joint
Prevents hyperextension (screws head of femur into acetabulum)
How does the structure of the acetabulum contribute to the stability of the hip joint?
It is deep, encompassing nearly all of the head of the femur, decreasing the probability of the head slipping out of the acetabulum
What increases the depth of the acetabulum?
A fibrocartilaginous collar; increases the articular surface, and hence the stability, of the joint
Describe the orientation of the ligaments and joint capsule at the hip joint that contributes to the stability of the joint
Spiral orientation, which causes them to become tighter when the joint is extended, adding to stability and also means that less energy is needed to maintain a standing position
Describe the reciprocal fashion of action of the muscles and ligaments of the hip joint
Anteriorly, where the ligaments are strongest, the medial flexors (anterior) are fewer and weaker; posteriorly, where the ligaments are weakest, the medial rotators are greater in number and stronger; they effectively pull the head of the femur into the acetabulum
What movements are possible at the hip joint?
Flexion, extension, abduction, adduction and medial/lateral rotation
Why is greater flexion possible at the hip joint when the knee is flexed?
When the knee is flexed the hamstrings are relaxed
Which muscles produce flexion at the hip joint?
Iliosoas, rectus femoris, Sartorius
Which muscles produce extension at the hip joint?
Gluteus maximus, semimembranosus, semitendinous and biceps femoris
Which muscles produce abduction at the hip joint?
Gluteus medius, gluteus minimus, and deep gluteals (piriformis, obturator internus, gemelli, quadratus femoris)
Which muscles produce adduction at the hip joint?
Adductors longus, brevis and magnus, pectineus and gracillis
Which muscles produce lateral rotation at the hip joint?
Biceps femoris, gluteus maximus, and the deep gluteals (piriformis, obturator internus, the gemelli, quadratus femoris)
Which muscles produce medial rotation at the hip joint?
Gluteus medius and minimus, semitendinous and semimembranosus
Which arteries supply the hip joint?
Medial and lateral femoral circumflex arteries, and the artery to the head of femur
Which artery supplies the greatest proportion to the hip joint? What can disruption cause? Why is the alternative supply not as good?
Medial circumflex; disruption can cause avascular necrosis of the femoral head and neck; the lateral circumflex artery has to penetrate through the thick iliofemoral ligament to reach the joint, and so supplies less blood
Which nerves supply the hip joints, and which aspects? How is this worked out?
Femoral nerve; anterior aspect Obturator nerve; inferior aspect Nerve to quadratus femoris; posterior Superior gluteal nerve; superior aspect Hilton’s law
What is Hilton’s law?
The nerves supplying muscles extending directly across and acting at a given joint also innervate the joint
What is a fracture of the femoral neck also known as?
Subcapital fracture
What happens in a surgical hip replacement?
The acetabulum is replaced with a plastic socket, a stainless steel femoral stem replaces the femur
What is congenital dislocation of the hip? What are common symptoms?
During development the femoral head is not placed within the acetabulum, resulting in a dislocated joint; common symptoms include inability to abduct at the hip joint, affected limb shorter, positive Trendelenburg sign
Why are acquired dislocations of the hip quite uncommon? How do they usually occur? What are the two types? Which is more common?
The hip joint is strong and stable; usually occur during traumatic incidents; posterior and anterior dislocations; posterior is more common
Describe a posterior dislocation of the hip; what happens to the affected limb?
Femoral head is forced posteriorly, and tears through the inferior and posterior part of the joint capsule, where it is at its weakest; the affected limb becomes shortened and medially rotated
Which structure is at risk with a posterior dislocation of the hip joint? What would damage cause?
Sciatic nerve runs posteriorly to the hip joint; damage would cause paralysis of the hamstrings, the muscles distal to the knee (all of which are supplied by the sciatic nerve)
What are anterior dislocations of the hip a consequence of? Describe what happens to the femoral head
Extension, abduction and lateral rotation; the femoral head ends up inferior to the acetabulum, and often pulls the acetabular labrum with it
What is the second largest bone in the body? What is its function?
The tibia; it is the main bone of the leg, forming what is more commonly known as the shin; it bears all of the weight of the axial skeleton (the fibula is not a weight bearer)
What are the two prominent structures that cause the widening of the proximal end of the tibia? What is their function?
The medial and lateral condyles; they form a flat surface (good for weight) bearing for articulation with the condyles of the femur; this is known as the tibial plateau
What is the region between the condyles of the proximal end of the tibia known as? What is its function?
The intercondylar eminence; consists of two tubercles and roughened areas; provides attachment for ligaments and menisci of knee
What structure accommodates the tubercles of the intercondylar eminence during movement of the knee?
The intercondylar fossa
What is found immediately inferior to the condyles on the anterior surface of the tibia? What is its function?
The tibial tuberosity; this is where the patella ligament attaches
What are the three surfaces of the tibia? Which one is palpable and where?
Medial, posterior and lateral; the medial surface is palpable down the anterior surface of the leg as the shin
Describe the prominent feature of the posterior surface of the tibia
There is a ridge called the soleal line, which crosses inferomedially, where it merges with the medial border
What does the lateral surface of the tibia give rise to?
The interosseous membrane; binds the tibia and fibula together
What is the advantage of the widenings at the ends of the tibia?
Aid in weight bearing
What is the medial malleolus? What is its function?
Bony projection continuing inferiorly on the medial side of the tibia; it articulates with the tarsal bones to form part of the ankle joint
Where is the fibula notch found? What is its function?
Found laterally, on the distal end of the tibia; place where fibula is bound to tibia
Who are fractures of the tibia most common in? What is the importance of the fibula not being fractured with a tibial fracture?
Middle aged/elderly; if the fibula is not fractured, it supports the tibia and displacement of fragments is minimal
Which part of the tibia is most vulnerable to damage? How does fracture commonly occur?
The proximal end, often due to trauma; the condyles may be broken and it is not uncommon for there to be injury to the ligaments of the knee
What part of the tibia is fractured at the ankle? Describe what occurs
The medial malleolus; this is caused by the ankle being twisted inwards (overinversion) – the talus is forced against the medial malleolus and fractures it
What is the main function of the fibula?
It doesn’t articulate with the knee joint; main function is to act as an attachment for muscles, and not as a weight bearer
Describe the proximal end of the fibula
Enlarged head, which contains a facet for articulation with the lateral condyle of the tibia
What structure can be found passing round the lateral condyle of the tibia and the neck of the fibula
The common fibular nerve
What are the surfaces of the fibular shaft?
The anterior, lateral and posterior; each faces its respective compartment of the leg
What is the lateral malleolus? Where can it be palpated?
A continuation of the lateral surface of the tibia inferiorly; it is more prominent than the medial malleolus and can be palpated at the ankle on the lateral side of the leg
Which part of the fibula is prone to fracture?
The lateral malleolus
What are the two ways in which the lateral malleolus can be fractured?
External rotation of the ankle; the force of the talus against the bone causes a spiral fracture of the lateral malleolus
Eversion of the ankle (less common); the talus presses against the lateral malleolus, causing a transverse fracture
Name the tarsals
Proximal (talus, calcaneus), intermediate (navicular), distal (cuboid, and three cuneiforms; lateral, intermediate and medial)
What does the talus articulate with? What is its main function?
Most superior or tarsals, it articulates with the lateral and medial malleoli and with the tibia; it transmits the weight of the body from the tibia to the foot
Which bone forms the heel? What is its function?
The calcaneus; it lies partially underneath the talus, transmitting most of the force from the body to the ground
Which two parts of the talus are most liable to fracture?
The neck or body
How do fractures of the neck of the talus usually occur?
Excessive dorsiflexion; the neck is pushed into the tibia
How do fractures of the body of the talus usually occur?
Jumping from a height; the two malleoli act to hold the two fragments together, and so there is little displacement
How is the calcaneum commonly fractured? What happens?
It transmits the weight of the body- it is most commonly fractured by jumping form a height; the talus is usually driven into the bone, crushing it; it appears shorter and fatter
What is the root of the name of the navicular bone? What does it articulate with?
Shaped like a boat; articulates with the talus posteriorly, the cuneiform bones anteriorly and the cuboid laterally
Which is the most lateral tarsal bone in the distal group? Which muscle attaches to it?
The cuboid; the fibularis longus attaches here
What are the three cuneiforms? What do they articulate with?
Three wedge shaped tarsal bones in distal group (lateral, intermediate, medial); they articulate with the navicular posteriorly and the metatarsals anteriorly
In which direction are the metatarsals numbered? Which is the shortest and widest?
Medially to laterally; the big toe (metatarsal I) is the shortest and widest
What do the metatarsals articulate with?
At their base, the cuneiforms and cuboid bone; at their distal end with the phlanges of the toes
What happens to metatarsal V during excessive inversion of the foot?
The fibularis brevis muscle can pull off the base of metacarpal V
What common injury affects most commonly metatarsals II, III and IV?
Stress fractures; incomplete fractures caused by repeated stress to the bone (athletes; footballers)
How many phlanges are there in the foot?
Great toe has a proximal and distal, all the rest also have an intermediate, so there is a total of 14
Name the muscles in the posterior compartment of the thigh
The hamstrings; biceps femoris, semitendinosus, semimembranosus, (and part of the adductor magnus)
Describe the structure of the biceps femoris
Two heads, which come together to form a tendon which inserts into the fibula
What is the action of the biceps femoris?
Main action is flexion at the knee; it also extends at the hip, and laterally rotates at the hip and knee
What is the innervation of the biceps femoris?
Sciatic nerve
Describe the position of the semitendinosus muscles relative to the other hamstrings
Medial to the biceps femoris, lies on top (posteriorly) of the semimembranosus
What is the action of the semitendinosus muscle?
Acts to flex at the knee joint, also extends at the hip and medially rotates at the hip and knee
What is the innervation of the semitendinosus muscle?
Sciatic nerve
What is the action of the semimembranosus muscle?
Flexes the leg at the knee, extends the thigh at the hip, medially rotates at the hip and knee
What is the innervation of the semimembranosus muscle?
Sciatic nerve
What is the femoral triangle?
A deep hollow in the anterior thigh region, the path of important neurovascular structures from the abdomen into the lower limb
What is the superior border of the femoral triangle?
Inguinal ligament; runs from the superior iliac spine to the pubis tubercle
What is the lateral border of the femoral triangle?
Medial border of the sartorius muscle
What is the medial border of the femoral triangle?
Lateral border of the adductor longus muscle
What forms the roof and floor of the femoral triangle?
Roof; the fascia lata
Floor; medially the pectineus, and laterally the iliopsoas
What are the contents of the femoral triangle? (lateral to medial)
NAVEL; femoral nerve, femoral sheath containing femoral artery, femoral vein, empty space and lymph nodes/vessels
What is the purpose of the empty space in the femoral triangle?
Allows the veins and lymph to distend, so they can cope with different levels of flow
Describe the palpation of the femoral pulse
Just inferior to where the femoral artery crosses the inguinal ligament, exactly midway between the pubic symphysis and anterior superior iliac spine
What happens to cause a femoral hernia?
Part of the bowel pushes into the femoral canal, underneath the inguinal ligament; manifests clinically as a lump or bulge in the area of the femoral triangle
What is the popliteal fossa?
Diamond shaped area found on the posterior side of the knee, it is the main path in which structures move from the thigh into the leg
What is the superior medial border of the popliteal fossa?
Semimembranosus muscle
What is the superior lateral border of the popliteal fossa?
Biceps femoris
What is the inferior medial border of the popliteal fossa?
Medial head of gastrocnemius
What is the inferior lateral border of the popliteal fossa?
Lateral head of gastrocnemius and plantaris
What is the floor of the popliteal fossa?
Formed by the posterior surface of the knee joint capsule, and the posterior surface of the femur
What forms the roof of the popliteal fossa?
Two layers; the popliteal fascia (continuous with fascia lata) and skin
What are the main contents of the popliteal fossa?
Popliteal artery, popliteal vein, small saphenous vein, tibial nerve, common fibular nerve
Which are the most superficial contents of the popliteal fossa?
The tibial and common fibular nerves (branches of sciatic)
What does the small saphenous vein empty into? Where?
The popliteal vein in the popliteal fossa
Which is the deepest structure in the popliteal fossa?
The popliteal artery, a continuation of the femoral artery
Why does a popliteal aneurysm have consequences for other contents of the popliteal fossa?
The popliteal fascia is tough and non-extensible, and an aneurysm will not be able to expand outwards – it will compress the other contents
Which structure is particularly sensitive to compression by a popliteal aneurysm?
The tibial nerve; damage will present as anaesthesia in the leg or loss of motor function
How is a popliteal aneurysm detected?
Obvious palpable pulse and abnormal arterial signs
What type of joint is the knee? What movements does it allow?
Synovial hinge; flexion and extension (and a small amount of medial and lateral rotation)
What are the articulations of the knee joint?
Medial and lateral condyles of femur articulate with tibia (tibiofemoral), and anterior distal portion of femur articulates with the patella (patellofemoral)
Which tendon is the patella formed within?
The patella is formed within the tendon of the quadriceps femoris; it’s presence minimises wear and tear on the tendon
What are the menisci of the knee made of?
Fibrocartilage
What is the function of the menisci of the knee?
They deepen the articular surface of the tibia, increasing stability, and they also act as shock absorbers
What is the medial meniscus attached to?
The intercondylar area of the tibia, the tibial collateral ligament and the joint capsule
What is the lateral meniscus attached to?
The intercondylar area of the tibia; nowhere else, meaning it is fairly mobile
What are the three important bursae of the knee joint?
Suprapatella, prepatella, and infrapatellar
Where is the suprapatella bursa of the knee found?
It is an extension of the synovial cavity of the knee, between the quadriceps femoris and femur
Where is the prepatella bursa of the knee found?
Found between the apex of the patella and the skin
Where is the infrapatella bursa of the knee found?
Between the tibial tuberosity and the skin
What are the five major ligaments of the knee joint?
The patellar ligament, collateral ligaments (tibial and fibular), cruciate ligaments (anterior and posterior)
Describe the location of the patellar ligament of the knee
A continuation of the quadriceps femoris tendon distal to the patella, it attaches to the tibial tuberosity
What is the function of the collateral ligaments of the knee joint?
Stabilise the hinge-like motion of the knee, preventing any medial or lateral movement
Describe the location of the tibial collateral ligament of the knee joint?
Wide and flat, found on the medial side of the joint; proximally it attaches to the medial epicondyle of the femur, distally it attaches to the medial surface of the tibia
Describe the location of the fibular collateral ligament of the knee joint?
Thinner and rounder than the tibial, it attaches proximally to the lateral epicondyle of the femur, distally to the a depression on the lateral surface of the fibular head
In which directions do cruciate ligaments pass from the tibia to the femur?
PAM’s APpLes; posterior passes anteriorly, inserts medially, anterior passes posteriorly, inserts laterally
Describe the attachments of the anterior cruciate ligament and its function
Anterior intercondylar region of the tibia, lateral intercondylar fossa of the femur; prevents anterior dislocation of the tibia
Describe the attachments of the posterior cruciate ligament and its function
Posterior intercondular region of the tibia, medial intercondylar fossa of the femur; prevents posterior dislocation of the tibia
Which muscles perform extension at the knee joint?
Quadriceps (vastus medialis, lateralis, intermedialis, rectus femoris)
Which muscles perform flexion at the knee joint?
Hamstrings (biceps femoris, semitendinosus, semimembranosus), gracilis, sartorius, popliteus
How is lateral rotation of the knee achieved?
Achieved through contraction of the biceps femoris, when the knee is flexed
How is medial rotation of the knee achieved?
Five muscle (when the knee is flexed): semimembranosus, semitendinosus, gracilis, sartorius, popliteus
What is the most common injury affecting the knee joint? What causes it?
Injuries to collateral ligaments; force applied to the side of the knee when the foot is placed on the ground
How can damage to the collateral ligaments of the knee joint be tested?
Ask patient to medially and laterally rotate the leg; pain on medial rotation indicates damage to medial collateral ligament, and same with lateral
What is also likely to be damaged with a tear of the tibial collateral ligament of the knee?
Medial meniscus, due to their attachment
How is the anterior cruciate ligament damaged?
Large force applied to back of knee with the joint partly flexed; hyperextension
How can you test for anterior cruciate ligament damage?
Anterior draw test; with knee flexed, you attempt to pull the tibia in an anterior direction; if it moves the ligament has been torn
How is the posterior cruciate ligament damaged?
Hyperextension of joint, damage to upper part of tibial tuberosity, or ‘dashboard injury’ (large force to shins)
How can you test for posterior cruciate ligament damage?
Posterior draw test; with knee flexed, you attempt to push the tibia in a posterior direction; if it moves the ligament has been torn
What is housemaid’s knee?
Friction between skin and patella causes the prepatella bursa to become inflamed, producing a swelling on the anterior side of the knee
What is clergyman’s knee?
Friction between the skin and patella can cause the infrapatella bursa to become inflamed, resulting in what is known as clergyman’s knee
What is a baker’s cyst?
Abnormal fluid filled sacs in region of popliteal fossa
What causes a baker’s cyst?
Chronic knee joint effusion, or herniation of a bursa (gastrocnemius or semimembranosus)
What are the four muscles in the anterior compartment of the leg?
Tibialis anterior, extensor digitroum longus, extensor halluces longus, fibularis tertius
Which muscle of the anterior compartment of the leg is most medial?
Tibialis anterior; lies against the lateral surface of the tibia
What is the action of the tibialis anterior?
Performs dorsiflexion and inversion of the foot
What is the innervation of the tibialis anterior?
Deep fibular nerve
Which is the most lateral muscle of the anterior compartment of the leg?
Extensor digitorum longus
What is the action of the extensor digitorum longus?
Extends the lateral four toes, dorsiflexes the foot
What is the innervation of the extensor digitorum longus?
Deep fibular nerve
Describe the location of the extensor hallucis longus
Lies between the extensor digitorum longus and the extensor hallucis longus; most of its surface is covered by these two muscles
What is the action of the extensor hallucis longus?
Extends the great toe, and dorsiflexes the foot
What is the innervation of the extensor hallucis longus?
Deep fibular nerve
What is sometimes considered to be part of the extensor digitorum longus?
The fibularis tertius
What is the action of the fibularis tertius?
Everts the foot, but also a weak dorsiflexor
What is the innervation of the fibularis tertius?
Deep fibular nerve
What are the muscles in the lateral compartment of the leg? What are they also known as?
The fibularis longus and fibularis brevis; peroneal longus and peroneal brevis
What is the common function of the fibularis longus and brevis? What is their ‘actual function’?
Eversion of the foot (only a few degrees from anatomical position); the fix the medial margin of the foot during running, preventing excessive inversion
What is the action of the fibularis longus? What is its innervation?
Eversion and plantarflexion of the foot; superficial fibular (peroneal) nerve
Which nerve is found passing under the proximal fibularis longus?
Common fibular nerve; splits into superficial and deep branches
What is the action of the fibularis brevis muscle?
It is a weak evertor of the foot
What is the innervation of the fibularis brevis?
Superficial fibular nerve
Name the muscles of the posterior compartment of the leg
Superficial: gastrocnemius, plantaris, soleus
Deep (separated from superficial by a band of fascia): flexor digitorum longus, flexor hallucis longus, popliteus, tibialis posterior
What are the general actions of the muscles of the posterior compartment of the leg? What is their common innervation?
Plantarflexion, inversion of the foot, flexion of the toes; tibial nerve
What is the common insertion of the superficial muscles in the posterior leg?
They all form the calcaneal (Achilles) tendon, and insert into the calcaneus
Which is the most superficial muscle in the posterior compartment of the leg?
The gastrocnemius
What muscle fibre type is the gastrocnemius predominantly made up of?
Fast twitch muscle fibres; produces forceful, quick movements such as running and jumping
What is the action of the gastrocnemius? What is it innervation?
Plantarflexion of the foot, and also crosses the knee so flexes there; tibial nerve
What can the plantaris tendon be mistaken for?
A nerve; the tendon is long and thin (plantaris is absent in 10% of the population)
What is the action of the plantaris? What is its innervation?
Plantarflexion at the ankle, and crosses the knee so is a flexor there; it is not a vital muscle for these movements; tibial nerve
What is the root of the name of the ‘soleus’ muscle?
It is large and flat, looking like a sole (flat fish); it is found deep to the gastrocnemius
What is the action of the soleus? What is its innervation?
Plantarflexion at the foot; tibial nerve
Which is the most superior of the deep muscles in the posterior compartment of the leg? What is its relevance to the popliteal fossa?
The popliteus; it’s fascia forms part of the floor of the popliteal fossa, along with the joint capsule and popliteal surface of the femur
What is the action of the popliteus? What is its innervation?
Acts to laterally rotate the femur on the tibia, ‘unlocking’ the joint so that flexion at the knee joint can occur; innervation is by the tibial nerve
Which is the deepest muscle in the posterior compartment of the leg?
The tibialis posterior; it lies between the flexor digitorum longus and flexor hallucis longus
What is the action of the tibialis posterior? What is its innervation?
Inverts and plantarflexes the foot, maintaining the medial arch; tibial nerve
Where is the flexor digitorum longus found?
Medially in the deep posterior compartment of the leg, it is smaller than the flexor hallucis longus
What is the action of the flexor digitorum longus? What is its innervation?
Flexes the lateral four toes; tibial nerve
Where is the flexor hallucis longus found?
Laterally in the deep posterior compartment of the leg (opposite side to great toe)
What is the action of the flexor hallucis longus? What is its innervation?
Flexion of the great toe; tibial nerve
When does the external iliac artery become the femoral artery?
When it crosses under the inguinal ligament and enters the femoral triangle
Which artery arises from the femoral artery in the femoral triangle?
The profunda femoris, the deep artery of the thigh; it is derived from the lateral and posterior aspect of the femoral artery, and travels posteriorly
What are the three general branches given off by the profunda femoris artery?
Perforating branches, lateral femoral circumflex artery, medial femoral circumflex artery
What are the perforating branches of the profunda femoris?
Three or four arteries that perforate the adductor magnus, supplying some of the muscles in the medial and posterior thigh
Describe the lateral femoral circumflex artery
Wraps around the anterior, lateral side of the femur, supplying some of the muscles in the lateral side of the thigh
Describe the medial femoral circumflex artery
Wraps around the posterior side of the femur, supplying the neck and head; in a fracture of the femoral neck, this artery can be easily damaged, and avascular necrosis of the femoral head can occur
Describe the path of the femoral artery after crossing underneath the inguinal ligament, to the adductor hiatus
Travels through the femoral triangle in the femoral canal; after exiting the femoral triangle it continues down the anterior surface of the thigh in the adductor canal; here is supplies the anterior thigh muscles; the adductor canal ends at an opening in the adductor magnus (the adductor hiatus)
When does the femoral artery become the popliteal artery?
After passing through the adductor hiatus; the artery moves around to the posterior face of the limb; at this point, just proximal to the knee, it becomes known as the popliteal artery
What is the blood supply of the knee?
Popliteal artery gives off genicular branches
Where does the popliteal artery terminate? What to?
At the lower border of the popliteus, divides into anterior and posterior tibial arteries
Describe the anterior tibial artery; path, supply, termination
The anterior tibial artery passes anteriorly, between the tibia and fibula, through a gap in the interosseous membrane; it supplies all the muscles in the anterior compartment of the leg, and into the foot, where it becomes the dorsalis pedis artery
Describe the posterior tibial artery
Remains on the posterior side of the leg, giving rise to the fibular artery; they supply the posterior and lateral sides of the leg respectively; the posterior tibial artery gives rise to the medial and lateral plantar arteries, supplying the foot
What is the other main artery in the thigh, not derived from the femoral artery? Where does it come from?
The obturator artery; it splits off from the internal iliac artery, descending down into the pelvic region via the obturator foramen, entering the medial thigh
What happens to the obturator artery when it enters the medial thigh?
It bifurcates into two branches; the anterior branch supplies the medial compartment of the thigh, the posterior branch supplies some of the distal, deep gluteal muscles
What are the three main pulse points in the lower limb?
Femoral, popliteal, dorsalis pedis
Describe the location of the palpation of the femoral pulse
When it enters the femoral triangle; midway between the ASIS and pubic symphysis, just distal to the inguinal ligament
How is the popliteal pulse palpated?
Deep in the popliteal fossa; requires deep palpation, assisted by patient flexing the leg, relaxing the fascia of the popliteal fossa
Describe the location of the dorsalis pedis pulse
Dorsum of the foot, just medial to the first extensor pollicis longus tendon, lateral to extensor hallucis longus tendon
Which deep veins drain the foot and leg?
Anterior tibial vein, and medial and lateral plantar veins which form posterior tibial and fibular veins respectively; they all combine to form the popliteal vein at the knee
Apart from the femoral vein, what is the other deep vein of the lower limb?
The deep vein of the thigh
What are the two most clinically important superficial veins of the lower limb?
The great and small saphenous veins
Describe the course of the great saphenous vein of the leg
Arises from the medial side of the dorsal venous arch in the foot; it ascends up the medial side of the leg, passing anteriorly to the medial malleolus at the ankle, and posteriorly to the medial condyle at the knee; it drains into the femoral vein just distal to the inguinal ligament
Describe the course of the small saphenous vein
Derived from the lateral side of the dorsal venous arch in the foot; it moves up the posterior side of the leg, passing posteriorly to the lateral malleolus, along the lateral border of the calcaneal tendon; it moves between the two heads of the gastrocnemius muscle, emptying into the popliteal vein in the popliteal fossa
Why do varicose veins form?
A result of incompetent valves, the superficial veins in the leg become dilated ; various soft tissue changes can occur, due to increased venous pressure; this can damage the cells causing blood to extrude into the skin, and result in a brown pigmentation and ulceration.
What nerve roots is the femoral nerve derived from?
L2-L4, from the lumbar plexus
What is the motor function of the femoral nerve?
Anterior thigh muscles; pectineus, iliacus, sartorius, quadriceps femoris
What is the sensory function of the femoral nerve?
Gives cutaneous branches to the anteromedial thigh and a terminal cutanaeous branch supplies the medial side of the leg and foot (saphenous)
What is the name of the nerve that supplies sensory function to the medial side of the leg and foot?
Saphenous nerve (branch of the femoral)
Describe the course of the femoral nerve
Descends from the lumbar plexus in the abdomen, through the psoas major muscle; it then travels through the pelvic region entering the femoral triangle behind the inguinal ligament, lateral to the femoral vessels; it splits into anterior and posterior divisions in the thigh
Describe the course of the saphenous nerve
Travels with the femoral artery and vein through the adductor canal; then descends with the great saphenous vein
What would be indicated as analgesia in patients requiring lower limb surgery who cannot tolerate a general anaesthetic?
Femoral and sciatic nerve blocks
What is the origin of the sciatic nerve?
L4-S3, sacral plexus
Describe the course of the sciatic nerve
Enters the gluteal region via the greater sciatic foramen inferior to the piriformis (can be through or over in some people) and deep to the gluteus maximus; it descends into the posterior thigh deep to the biceps femoris, bifurcating into the tibial and common fibular nerves at the apex of the popliteal fossa
What is the motor function of the sciatic nerve?
Supplies no muscles in the gluteal region; supplies all the muscles in the posterior compartment of the thigh (tibial division supplies all but the short head of biceps, supplied by the common fibular division)
Where would you inject for a sciatic nerve block?
Midpoint of the line joining the PSIS and superior border of the greater trochanter
What is piriformis syndrome?
Pain in the buttock resulting in compression of the sciatic nerve by the piriformis muscle; women and individuals in sports requiring gluteal muscles are likely to be affected
What would occur if there was complete section of the sciatic nerve?
It is uncommon; if this occurs, leg is useless because extension of the hip is impaired, as is flexion of the leg, and all of the movements of the ankle and foot
Describe the site of an intragluteal injection
Superolateral quadrant of the buttock; approximated by placing index finger on ASIS, fingers spread posteriorly along the iliac crest until the tubercle of the iliac crest is felt by the middle finger; an IG injection can be made safely in the triangular region between the fingers
Why is the intragluteal injection site safe?
The muscles are thick and large; substantial volume for absorption by intramuscular veins; sciatic nerve or other neurovascular structures not at risk
Describe the course of the tibial nerve
Forms as the sciatic bifurcates at the apex of the popliteal fossa, which is descends through; lies on top of the popliteus, runs inferiorly on the tibialis posterior with posterior tibial vessels; terminates beneath the flexor retinaculum by dividing into medial and lateral plantar nerves
What is the supply of the tibial nerve?
Posterior muscles of the leg and knee joint; sensory function to sole of foot
Describe the course of the common fibular (peroneal nerve)
Forms as the sciatic bifurcates at the apex of the popliteal fossa and follows the medial border of the biceps femoris and its tendon; passes over the posterior aspect of the head of the fibula and then winds around the neck of the fibula deep to the fibularis longus where it divides into deep and superficial fibular nerve
What is the supply of the common fibular nerve?
Supplies skin on lateral part of posterior aspect of leg via the lateral sural cutaneous nerve; also supplies the knee joint via its articular branch
Describe the course of the superficial fibular nerve
Arises between the fibularis longus and neck of fibula and descends in the lateral compartment of the leg; it pierces fascia on the distal third of the anterior surface of the leg and dorsum of the foot
What is the supply of the superficial fibular nerve?
Supplies fibularis longus and brevis and skin on the distal third of anterior surface of the leg and dorsum of the foot
Describe the course of the deep fibular nerve
Arises between the fibularis longus and neck of fibula; passes through extensor digitorum longus and descends on interosseous membrane; crosses distal end of tibia and enters dorsum of foot
What is the supply of the deep fibular nerve?
Supplies anterior muscles of leg, and those in the dorsum of the foot, as well as the skin of the first interdigital cleft; it sends articular branches to joints it crosses
Describe the course of the sural nerve
Usually arises from both tibial and common fibular nerves; descends between the heads of gastrocnemius and becomes superficial at the middle of the leg; it descends with the small saphenous vein and passes inferior to the lateral malleolus to the lateral side of the foot
What is the supply of the sural nerve?
Supplies skin on the posterior and lateral aspects of the leg and lateral side of the foot
How can the tibial nerve be damaged? What would happen?
Deep lacerations or posterior dislocation of the knee joint; severance would produce paralysis of the flexor muscles; this presents as an inability to platarflex the ankle or flex the toes
Which nerve is most commonly injured in the lower limb, why and how?
Common fibular nerve, due to its subcutaneous winding around the fibular neck, leaving it vulnerable to direct trauma (e.g. coffee table)
What does severance of the common fibular nerve result in?
Flaccid paralysis of all the muscles in the anterior and lateral compartments of the leg (dorsiflexion and eversion), resulting in footdrop; this is further exacerbated by unopposed inversion
Which muscle does an intra-gluteal injection predominantly enter?
The gluteus medius
What are the five stages of walking?
Heel-strike, support, toe-off, leg lift, swing
What happens during the ‘heel-strike’ stage of walking?
Foot hits the ground, heel first; gluteus maximus acts on the hip to decelerate flexion, quadriceps maintain the extended position of the knee, muscles in the anterior compartment of the leg keep the ankle dorsiflexed
What happens during the ‘support’ stage of walking?
Other leg lifts off ground, so the weight of the body must be supported by one leg; quadriceps maintains extended knee, ankle kept stable by balanced contraction of invertors and evertors, pelvis is prevented by gluteus medius, minimus and tensor fascia latae
What happens during the ‘toe-off’ stage of walking?
The foot prepares to leave the ground heel first, toes last; ; the hamstring muscles extend the leg at the hip, the quadriceps maintain the extended position of the knee, and the ankle is plantarflexed by the muscles in the posterior compartment of the leg
What happens during the ‘leg lift’ stage of walking?
The lower limb and foot are raised in preparation for the swing phase; the iliopsoas and rectus femoris flex the lower limb at the hip, the knee is flexed by the hamstings, the ankle is dorsiflexed by the muscles in the anterior compartment of the leg
What happens during the ‘swing’ phase of walking?
This phase is where the forward motion of the walk occurs; the iliopsoas and rectus femoris keep the hip flexed, the knee is now extended by the quadriceps, the ankle is still dorsiflexed by the muscles in the anterior compartment of the leg
Describe Trendelenburg gait
During walking, a weakness in the abductor muscles gives rise to a characteristic gait; as the pelvis drops on one side, the trunk lurches to the opposite side, in an effort to maintain a steady pelvic level
Describe foot drop gait
Suggests deep fibular nerve damage; if damaged, the foot cannot be dorsiflexed, and drags along the ground during the swing phase
What might also be seen in a patient with foot drop gait?
Eversion flick; to try and dorsiflex the foot during the swing phase, the patient may evert the foot in a sudden movement
What is antalgic gait?
A gait where the stance phase is significantly shortened for one limb, as a result of pain (less time spent on limb, less pain)
Which myotome performs flexion of the hip?
L1, L2
Which myotome performs extension of the knee?
L3, L4
Which myotome performs flexion of the knee?
Mainly L5 to S2
Which myotome performs plantarflexion of the foot?
S1, S2
Which myotome performs adduction of the digits of the foot?
S2, S3
Which spinal level is tested by a tap on the patellar ligament?
L3 and L4
Which spinal level does a tap on the calcaneal tendon posterior to the ankle test?
S1 and S2
What is the function of the femoral canal?
The empty space in the femoral triangle, it contains no discrete structures other than a lymph or two; it allows the distension of the femoral vein, particularly during heavy exercise, to accommodate venous return from the limb
What is the purpose of the smooth fascial covering of the rectus femoris muscle?
It helps the muscle to move smoothly over the adjacent muscles
Why does the vastus medialis have horizontal fibres to the patella?
They help to prevent lateral displacement of the patella during movements of the knee; the lateral condyle is at a slightly higher elevation compared to the medial epicondyle, assisting stability
How would you locate the femoral vein?
Locate pulsations of femoral artery, the vein is medial
What structure can be damaged during stripping of the long saphenous vein for varicosities?
The saphenous nerve, a branch of the femoral, which innervates the medial side of the leg and foot
Which parts of the skeleton would you X-ray of someone who has fallen from a height and landed on their feet?
X-rays of the whole of the upper limb and vertebral column; any weight bearing joints and bones can be affected, e.g. calcaneal, acetabular and vertebral fractures
Which muscle lies anterior to the sacroiliac joint?
The psoas major and minor (in ~50% of people)
How would you test the power of knee extension?
Ask the patient to sit on a chair and extend the knee against resistance
Which nerve supplies sensory function to the lateral side of the thigh?
Lateral (femoral) cutaneous nerve of the thigh, derived from the lumbar plexus
Which nerve supplies sensory function to the anterior and medial sides of the thigh?
Anterior femoral cutaneous (from the femoral nerve)
Which nerve supplies sensory function to the posterior side of the thigh?
Posterior femoral cutaneous branch of the femoral nerve
Which nerves run close to the sacroiliac joint and can be damaged by a fracture here?
Femoral and obturator nerves, derived from the lumbar plexus
Why is hip extension limited to only about 15 degrees?
Iliofemoral ligament, anteriorly placed, becomes very taut in extension of the hip
What is the structural basis for classifying a hip fracture as intra or extra capsular?
Whether the fracture involves bone within the margins of the capsule are intracapsular; the capsule joins proximally to the acetabulum, distally to the neck of femur, anteriorly to the intertrochanteric line and posteriorly to the intertrochanteric crest
How do you measure the length of the whole lower limb?
ASIS to medial malleolus
How do you measure size of the hip?
ASIS to greater trochanter
How do you measure the size of the femur?
(ASIS or) greater trochanter to knee joint line
How do you measure length of the tibia?
Knee joint line to medial malleolus
What is mensuration of the lower limb?
Measuring of the lower limb
Why is there shortening of the limb with a fracture neck of femur?
The strong muscles of the thigh (flexors, adductors and extensors) pull the distal fragment of the femur upwards; thus the leg is shortened
Why is there lateral rotation of the foot with a fracture to the neck of the femur?
Fractured neck allows shaft to move independently of hip joint; the axis of rotation of the femur normally passing through the head shifts to pass through the greater trochanter and along the axis of the femoral shaft. The iliopsoase, which would normally act as a medial rotator, now acts as a lateral rotator of the femur due to the fractured neck
Why is there shortening of the leg of a patient with a dislocation of the hip?
The head of the femur is pulled upwards by the strong flexors, extensors and adductors, causing limb shortening
Describe the location of the head of the femur after a posterior dislocation
The femoral head is pushed backwards over the posterior margin if the acetabulum; comes to lie on the lateral surface of the ilium
Which bony landmarks are used to determine the course of the sciatic nerve?
The sciatic nerve emerges from the pelvis cavity midway between the PSIS and ischial tuberosity; it then descends into the thigh vertically at the midpoint between the ischial tuberosity and greater trochanter
Which injury to the hip joint could cause damage to the sciatic nerve?
Posterior dislocation would stretch or severly damage the sciatic nerve e.g. during a dashboard injury
What is the iliotibial tract?
A specialised condensation of the fascia lata of the lateral thigh; it crosses the knee joint to attach to the tibia
What is the function of the iliotibial tract?
It helps to steady the femur on the tibia during standing by supporting and keeping the knee joint in extension
Which ligament forms the greater sciatic foramen with the greater sciatic notch?
The sacrospinous ligament
Which ligament forms the lesser sciatic foramen with the lesser sciatic notch?
Sacrotuberous ligament
What is the role of the sacrospinous and sacrotuberous ligaments in the erect position?
They limit rotation (upward movement) of the inferior part of the sacrum during transmission of weight of the body down the vertebral column in erect posture
Where do the gluteal nerves originate from?
Sacral plexus; superior L4-S1, inferior L5-S2
What course do the gluteal nerves take to reach the muscles they innervate?
They leave the pelvis via the greater sciatic foramen; superior gluteal nerve passes superior to the piriformis while the inferior gluteal nerve passes inferior
Where would you measure between to give an indication of true leg length?
Greater trochanter and medial malleolus
What is the difference between true and apparent limb shortening?
Causes of apparent limb shortening include fixed joint deformity or pelvic tilt; actual limb shortening involves actual loss of bone length
Which movement causes the ‘locking’ of the knee?
Medial rotation of the femur on the tibia; enables lower limb to become solid column, enabling muscle relaxation
Which movement causes the ‘unlocking’ of the knee?
Contraction of the popliteus muscle, which rotates the femur laterally on the tibia, so that flexion of the knee can take place
What shape are the menisci?
Crescent
Which collateral ligament of the knee is the stronger?
The fibular collateral ligament (strong round band of tissue, compared to broad tibial)
Why might a ‘locked’ knee be the presenting symptom of a torn meniscus?
A torn meniscus may result in it becoming dislodged and becoming trapped with the knee joint, causing ‘locking’
What occurs in a ‘pulled hamstring’?
There is tearing (part/complete) of the tendinous attachments of the hamstrings to the ischial tuberosity, resulting in rupture of blood vessels supplying the muscles
Where would you palpate for the posterior tibial pulse?
Behind the medial malleolus
What are the 6 ‘P’s of acute limb ischaemia?
Pain, paraesthesia, pallor, perishingly cold, ‘pulselessnes’, paralysis (weakness)
What is the general function of the retinacula around the ankle?
Binds down the tendons of the muscles in the antero-lateral compartments and prevents them from bowstringing during movements at the ankle
What is compartment syndrome?
Sustained rise in compartment pressure (e.g. due to blood vessel rupture), bound by fascia, above arterial pressure, causing ischaemia to muscles and nerves; ischaemia casues release of factors which increase capillary permeability and worsen the situation
Why is there sensory loss before motor loss in compartment syndrome?
Cutaneous nerve fibres are affected by ischaemia more than motor nerves
Why does a ‘kick on the shin’ hurt so much?
The medial surface of the tibia has only subcutaneous soft tissue; the bone is covered in periosteum which has a rich nerve supply
Differentiate between the mid-point of the inguinal ligament, and the mid-inguinal point, naming the structures located at each
Mid-point of the inguinal ligament is the midpoint of the line from the ASIS to the pubic tubercle; this is where the femoral nerve is. The mid-inguinal point is the midpoint of the line from the ASIS to the pubic symphysis; this is where the femoral artery is
Which nerves supply sensory function to the lateral side of the leg and the dorsum of the foot?
Common fibular proximally, superficial peroneal nerve distally on leg and dorsum of foot; deep fibular supplies lateral side of great toe and medial side of 2nd toe, and interdigital cleft here
Which nerve supplies sensory function to the posterior leg and lateral side of the foot (but not distal phalanxial area of little toe)
Sural nerve
Which nerve supplies sensory function to the heel?
Tibial nerve
Which nerve supplies the medial side of the sole of the foot?
Medial plantar, branch of the tibial; supplies 3½ digits
Which nerve supplies the lateral side of the sole of the foot?
Lateral plantar, branch of the tibial; supplies later 1½ digits
What is the arrangement, anterior to posterior, of the structures passing posteriorly around the medial malleolus?
Tibialis posterior, flexor digitorum longus, posterior tibial artery, posterior tibial vein, tibial nerve, flexor hallucis longus
Which area of the leg commonly has skin ulcers? Why?
Subcutaneous antero-medial surface of the tibia where cutaneous blood supply is relatively poor; stagnation of blood in the skin of the lower limb results in the skin being poorly nourished, and so when subject to even minor trauma it can breakdown to an ulcer
Why can stripping of the short saphenous vein for varicose veins leave the patient with tingling in the little toe?
The sural nerve runs alongside the nerve, supplying skin on the posterior and lateral sides of the leg and on the lateral side of the foot
Which nerves form the sural nerve?
The sural nerve is formed by union of the medial sural cutaneous branch of the tibial nerve and the fibular communicating branch of the common fibular nerve
Where would you hope to find the great saphenous vein in a patient who requires an IV line inserted urgently?
Venous cut-down; in front (anterior) of the medial malleolus; the anatomical positioning of the vein is relatively constant; another site is one hand’s breadth posterior to the patella
Why is the lower part of the calcaneal often a point of weakness?
It has a poor blood supply
Which muscles perform dorsiflexion at the ankle?
Tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis tertius (lateral muscles weakly so)
Which muscles perform plantarflexion at the ankle joint?
Gastrocnemius, soleus, plantaris, tibialis posterior, flexor hallucis longus, flexor digitorum longus
In severe sprain of the ankle, why is it not uncommon to find that the patient has an avulsion of the fifth metatarsal tuberosity?
Fibularis brevis tendon is attached to the tuberosity of the 5th metatarsal
At which joint does the movement of inversion and eversion of the foot occur?
At the subtalar and calcaneocuboid joint
What is the functional significance of the capacity of the foot to be able to undertake the movements of inversion and eversion?
The movements allow one (a biped) to walk on uneven surfaces
Which muscles hold up the medial longitudinal arch of the foot?
Tibialis anterior and posterior (attached the 1st metatarsal and medial cuneiform), fibularis longus and flexor hallucis longus
Which muscles hold up the lateral longitudinal arch of the foot?
That calcaneus, cuboid and lateral two metatarsals from the lateral arch mainly; the fibularis brevis may help in holding it up
What causes flat foot? How does it occur?
Caused due to ‘fallen arches’, usually the medial parts of the longitudinal arches. During standing, the plantar ligaments and plantar aponeurosis stretch under body weight; if these ligaments become abnormally stretched, the calcaneonavicular ligament can no longer support the head of the talus; the talus displaces inferomedially, causing flattening of the medial longitudinal arch
Why does the foot in a child appear to be flat?
Arches are not developed fully and also due to presence of the subcutaneous adipose tissue in the sole of the foot
What is the anterosuperior border of the femoral canal?
Inguinal ligament
What is the posterior border of the femoral canal?
Pectineal ligament
What is the medial border of the femoral canal?
Lacunar ligament
What is the lateral border of the femoral canal?
Femoral vein
What is the entrance to the femoral canal known as?
The femoral ring
Why might there be a swelling the femoral triangle?
Expanded lymph, tumour, femoral hernia
What is a hernia?
A protrusion of an organ through the wall of the cavity that normally contains it
Which nerve innervates the skin over the femoral canal?
The lumboinguinal, a branch of the genitofemoral nerve
What gives the sensory supply to the skin over the gluteal region?
Mostly the superior and middle cluneal nerves
