MSK - Lower Limb Flashcards
What is the intertrochanteric line vs intertrochanteric crest of femur? What ligament attaches at the intertrohanteric line?
Intertrochanteric line is anterior
Intertrochanteric crest is at the posterior
Iliofemoral ligament - strong hip ligament
What else is down the posterior of the femur?
Gluteal tuberosity
Linea aspera
What is the artery damages in intracapsular prox femoral fracture? What can happen? What is the clinical presentation of this fracture and why?
Medial femoral circumflex artery
Avascular necrosis of femoral head
Shortened rotated leg
Distal fragment pulled up and rotated laterally
Find out why - put muscles that cause it here
Why does shaft of femur descend in medial direction?
To bring the knees closer to the body’s centre of gravity increasing stability
Do you get avascular necrosis in extra capsular fractures? How do these type of fractures present clinically?
No
Same as intra shortened and rotated
What does the linea aspera on the back of femur widen and become?
Floor of popliteal fossa
Are femoral shaft fractures common? Why? What nerve could be damaged? What usually happens alongside due to mechanism?
No as require a lot of force
Femoral nerve and artery damage
Soft tissue damage due to force required
What is the epiphyseal plate? What can occur in fast growing adolescents?
Growth plate
Hyaline cartilage
Allows long bone growth
Bone can grow faster than muscle - osteochondrosis
Two main functions of patella?
Leg extension
Protection of anterior aspect of knee joint from physical trauma
Where does patella sit? What happens in dislocation?
Is dislocation more commonly lateral or medial? What kind of mechanism can cause dislocation?
Femoropatella groove
Comes out
Lateral more common
High force impact on patella or sudden twisting
How do patella fractures occur? What happens if the patella separates into 2 fragments superior and inferior?
Normall direct trauma to bone
Or sudden contraction of quadriceps muscle
Prox fragment superiorly displaced by quadriceps tendon
Distal fragment inferiorly displaced by patellar ligament
Where does tibia articulate?
Knee and ankle joints
What is a role of the tibial bone?
Weight bearing - second biggest bone in body
What bone is the medial malleolus on?
Tibial
Where does the meniscus and ligaments of knee joint attach?
Intercondylar eminance
How does the femur attach to the tibia?
Via the intercodular tubercles fitting into the intercondyla fossa of the femur
What is a major feature of anterior surface of tibia?
Tibial tuberosity - attaches patellar ligament
What is a major feature of the posterior surface of the tibia?
Soleal line - where part of soleus muscle originates
How do the tibia and fibula bind together?
Via the interosseous membrane on the lateral border of the tibia - interosseous border
At distal end via fibular notch
What are the functions of the widenings at the prox and distal ends of tibia?
Helps with weight bearing
Where on the tibia is most vulnerable to injury?
Prox end - e.g. condylar fractures
What often goes with condylar fractures
Damage to ligaments of the knee
What happens with displacement if the fibular is NOT also fractured
Fibula supports tibia and therefore minimally displaced
How can you get a medial malleolus fracture?
Over inversion
Are tibia fractures common? In who/mechanism?
Usually trauma - middle aged
Common
Does the fibula articulate with the femur at the knee joint?
No
What is its main function
Attachment for muscles
Is it a weight bearer?
No
What are two types of fracture at the lateral malleolus and how do they occur?
Spiral - twisting - forced external rotation
Transverse - eversion - less common
What is the importance of the piriformis muscle?
Sciatic nerve enters the gluteal region directly behind it
Also it divides the superior and inferior parts of gluteal region
Above is super gluteal artery and nerve
Below is inferior gluteal artery and nerve
How can sciatic pain be caused by a muscle?
Some variants of sciatic nerve involve some or all of it going through piriformis muscle - can give sciatic pain if piriformis muscle contracts
Where does obturator arise from? What other nerve arises from here?
L2-L4
Femoral
Whats its course? What does it innervate (5)? What about cutaneous? What if it is damaged?
Runs with common iliac artery
Then goes through obturator foramen
Then supplies adductors, and obturator externus and gracilis
Cutaneous is medial aspect of thigh
Damage is pain paraesthesia in medial aspect and weak adduction or gait/posture problems
Where does the sciatic nerve originate from?
L4-S3
What is its course? What is an anatomical variant of bifurcation?
Arises inferior to piriformis muscle, passes posteriorly to the superior gemellus, obturator internus, inferior gemellus and quadrates femoris muscles
Enters thigh by passing deep to long head of biceps femoris
Bifurcates in popliteal fossa to tibial artery (central) and common peroneal (lateral) - these are technically in a sheath together making up the sciatic nerve so they can bifurcate anywhere up the lower limb
What does the sciatic nerve innervate? What does sensory?
Innervates posterior muscles of thigh - hamstrings
And hamstring portion of adductor magnus
Sensory - not directly but it’s branches do e.g. sural nerve (plus other branches) that comes off the tibial and common peroneal branches does the lateral side of leg and heel, dorsal and plantar surfaces of the foot.
What is piriformis syndrome?
Spasm of piriformis - can affect sciatic nerve esp if variant that goes through piriformis instead of inferior to it - can cause pain and parasthaesia in region of sciatic nerve
Where do IM gluteal injections and why?
Upper lateral quadrant to avoid sciatic nerve which is in lower medial quadrant
Which nerve innervates the posterior compartment of thigh?
Sciatic
Which nerve innervates the medial compartment of thigh? Which type of muscles are here?
Obturator
Adductors
Which muscles does the obturator innervate?
Obturator externus Adductor longus Adductor brevis Gracilis Adductor magnus (not hamstring portion)
What happens if obturator nerve damaged?
pain paraesthesia medial thigh and weak adduction
What femoral artery branch can be severed in intracapsular fracture?
Medial femoral circumflex artery
Where do you find femoral pulse? Where would you puncture for arterial blood test/coronary angioplasty etc
Mid inguinal point (MIPA)
1cm below that as that is in line with the ligament so need to go below to actually puncture the artery
What is the course from the femoral artery to LAD for coronary angioplasty?
Femoral artery External iliac artery Common iliac artery Abdominal aorta Thoracic aorta Aortic sinus Left coronary artery LAD
What does the femoral nerve innervate? Sensory?
Anterior muscles of thigh - hip flexors and knee extensors (and knee flexor sartorius)
Rectus femoris Vastus lateralis Vastus medialis Vastus intermidius Sartorius
Anteromedial part of thigh apart from small medial part that obturator innervates
Which muscle both flexes the hip and extends the knee
Biceps femoris
Which muscle both flexes the hip and flexes the knee
Sartorius
What are the roots of the femoral nerve?
L2-L4
What is the terminal cutaneous branches of the femoral nerve?
Saphenous nerve
What is the sensory distribution of the cutaneous branches of femoral nerve (thigh) /saphenous nerve (leg)
Anteromedial thigh and medial leg inc medial malleolus
What complication can occur with saphenous vein stripping?
Damage to saphenous nerve which runs with it. Does cutaneous part of medial lower leg so may get pain parasthaesia or complete loss of sensation there
When would you do a femoral nerve block (alongside sciatic nerve block?)
Patients who need operation but can’t tolerate general anaesthetic - e.g. too unwell etc
Also analgesia
What is the difference between the femoral sheath, canal, triangle?
Lymph nodes and lymph vessels make up canal
Canal artery and vein make up sheath
NAVEL makes up triangle
NERVE IS NOT in sheath
What are the borders of the femoral triangle?
Superior - inguinal ligament
Lateral - medial border or sartorius
Medial - medial border of adductor longus
Floor - rest of adductor longus, pectinius and iliopsoas.
Roof - fascia lata
Where does the inguinal ligament go to from? Where does the inguinal line go to from?
Ligament - from ASIS to pubis tubercle
Line - from ?ASIS to pubis symphysis (so is longer)
Where does femoral nerve run in comparison with femoral artery
Runs slightly laterally so is mid point of inguinal ligament whereas femoral artery is more mid inguinal point (of line)
What is the course of the femoral nerve?
From abdomen goes down through psoas major muscle roughly to midpoint of inguinal ligament then passes behind inguinal ligament through femoral triangle and down to branches
What pathology could you have in the femoral triangle?
Femoral hernia - bowl protruding into the femoral canal underneath the inguinal ligament
What three parts is the hip made up of? When do they fuse? Whats between them before this? What does the fusion form? What is the role of this thing?
Ilium
Ischium
Pubis
Separated with cartilage
Fuse at puberty
Forms acetabulum - head of femur articulates with acetabulum to form the hip joint
What are the three articulations of the hip?
Sacroiliac
Public symphysis
Hip - head of femur
Where does the femur articular with the pelvis?
Acetabulum
What is the posterior counterpart of the iliac crest (anterior)
Gluteal surface
What bony landmark are you sitting on when you sit down?
Ischial tuberosities
What are two important ligaments coming from the sacrum to the pelvis? What do they form?
Sacrospinous - from sacrum to ischial spine - creates greater sciatic foramen through which lower limb neurovasculature including sciatic nerve transcends
Sacrotuberous - from sacrum to ischial tuberosity - forms the lesser sciatic foramen
3 roles of pelvis?
Transfer of weight from upper skeleton
Attachment - for muscles ligaments
Protection - of abdo/pelvic organs
Is the gluteus minimums superior or inferior to piriformis?
Superior
What is the glut max, medius, minimus and piriformis innervated by?
Max - inferior gluteal
Medius - superior gluteal
Minimis - superior gluteal
Piriformis - nerve to piriformis
What three muscles are innervated by the superior gluteal nerve?
Gluteus maximus
Minimus
Tensor fascia lata
What does the tensor fascia lata do?
Abducts and medially rotates
What happens with damage to superior gluteal nerve? Why?
Trendlebergs sign - drop hip on opposite side to damage. But Trendleberg gait is called the side of the damage nerve
so right trendleberg gait is right superior gluteal nerve damage but left hip drop
Because loss of gluteus medius and minimus that have an important role in hip stabilisation during locomotion. They contract when the contralateral leg is raised to prevent the pelvis dropping on that side
What are the three ‘nerve - to’s of the gluteal region?
What do they innervate?
Nerve to piriformis - piriformis
Nerve to obturator internus - obturator internus and superior gemellus
Nerve to quadratus femoris - inferior gemellus and quadratus femoris
What do the superficial and deep muscles do of the gluteal region?
Superficial - abductors and extensors
Deep - lateral rotators (and extensors)
One of these muscles only does external rotation not abduction which is it
Piriformis Quadratus femoris Superior gemellus Inferior gemellus Obturator internus
Quadratus femoris only laterally rotates
What arises above the piriformis and what below?
Above - superior gluteal nerve and artery
Below - sciatic nerve interior gluteal nerve and artery
Which three bones articulate forming the knee?
Patella
Femur
Tibia
What kind of joint is the knee and what movements?
Synovial
Flexion extension
Small amount of lateral and medial rotation
What are the two articulations called at the knee? What are the roles of them?
Patellofemoral - allows for the biceps tendon to go directly over knee enhancing the efficiency of this muscle
Femorotibial - weight bearing articulation
What is the blood supply of the knee? Nerve supply?
Blood supply is genicular anastomoses from the femoral and popliteal arteries
Nerves are the ones of muscles around it - femoral, tibial and common fibular
What are the roles of the medial and lateral meniscus? What are they made of? What shape are they?
Fibrocartilagenous
They 1) deepen the articular surface of the tibia increasing stability of the knee joint
2) shock absorbers
Both C shaped as you look down on them from above one medial one lateral
Which of the menisci is attached to something else? What is it? What does this mean if damaged?
Medial meniscus is attached to the tibial collateral ligament - means if this ligament is damaged the medial meniscus will tear
What is a bursa? What’s their roles? How many in the knee? names?
A synovial fluid filled sac found between moving structures in a joint
Aim to reduce wear and tear on that joint
4
Infra patellar
Supra patella
Prepatellar
Semimembranosus
Name 5 ligaments of the knee and what they attach to
Patellar - continuation of quadriceps femoris tendon that attaches into the tibial tuberosity
Medial collateral - medial epicondyle of the femur to the medial surface of tibia
Lateral collateral - lateral epicondyle of the femur to the lateral surface of the tibia
Anterior cruciate - from anterior intercondylar region of tibia to posterior intercondylar fossa of femur
Posterior cruciate - from posterior intercondylar region of tibia to anterior intercondylar fossa of femur
What do the anterior and posterior cruciate ligaments do?
Anterior - prevents anterior dislocation of the tibia onto the femur
Posterior - prevents posterior dislocation of the tibia onto the femur
What locks and unlocks the knee
Locks - medial movement of the femur on the tibia
Pops - popliteus
What muscles do extension at the knee
Quadriceps femoris
Which muscles do flexion at the knee
Hamstrings
Gracilis
Sartorius
Popliteus
Which muscle does lateral rotation of the knee
Biceps femoris
Which muscles do medial rotation of the knee
Semimembranosis Semitendinosis Gracilis Sartorius Popliteus
What is the most common pathology to knee joint? How does this occur?
Collateral ligament damage
Force to side of knee when foot on ground
What is the unhappy triad?
ACL
Medial meniscus
Medial collateral
Which bursa is housemaids knee
prepatella
Which bursa is clergymans knee
infrapatella
