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