The thigh and leg Flashcards
Where are they hamstrings located?
What is their main function?
Which muscles are included?
Posterior thigh To extend the hip and flex the knee Semimembranosus Semitendinosus Biceps femoris
Which nerve innervate most of the hamstrings?
What’s the exception?
The tibial (medial) division of the sciatic nerve
The short head of the biceps femoris is innervated by the common fibular/peroneal division (because it’s more lateral)
Which muscle has a hamstrings component, but is not classed as belonging to the hamstrings?
Why is this the case?
Adductor magnus
- Shares the same common embryonic origin as the hamstrings
- the hamstrings component originates from the ischial tuberosity
What’s the common origin of the hamstrings?
What’s the exception?
Ischial tuberosity
The short head of the biceps femoris originates form the linea aspera on the back of the femur
Which tendon can be palpated laterally at the back of the knee?
Common (insertion) tendon of the long and short head of biceps femoris
Where do semimembranosus and semitendinosus insert?
Which action do they perform in addition to the shared role of the quadriceps?
The medial tibial condyle
Medially rotate the thigh at the hip and the leg at the knee
Which muscles
extend the knee
flex the knee
quadriceps extend the knee
hamstrings flex the knee
Which muscle of the hamstrings is part of pes anserinus?
What is this?
What does it literally mean?
Where is it?
semitendinosus
it means goose’s foot and refers to the common insertion of three muscles by their conjoined tendons
- sartorius
- gracilis
- semitendinosus
anteromedial aspect of the tibia
How can sprinting without warming up cause an avulsion?
Sprinting, lunging and jumping engage the hamstrings muscles which extend the hip and flex the knee
Sudden tension can cause a complete tear from the ischial tuberosity and a fragment of bone to be torn off when the tendon is ripped free
How do tendons and ligaments attach?
tendon- muscle to bone
ligament- bone to bone
What causes osteoarthritis?
How is it defined clinically?
Breakdown of hyaline cartilage coating the articular surfaces of synovial joints
Joint pain with limited function and a reduced quality of life
Primary vs secondary osteoarthritis?
Primary has an unknown cause
Secondary is caused by a pre-existing condition. E.g obesity, infection, malalignment or inflammatory arthritis
How can haemophilia cause osteoarthritis?
bleeding into the joints
What is charcot joint?
What is ankylosing spondylitis?
Progressive degeneration of a weight bearing joint (usually the foot) due to neuropathy and loss of sensation
Type of inflammatory arthritis characterised by bony fusion across the joints (bamboo spine)
Crepitus is a common symptom of OA, what is it?
grinding of the joint
4 signs of OA on an X-ray?
- subchondral sclerosis (very white due to increased bone density) - reduced joint space - osteophytes - bone cysts
What is eburnation?
What do osteophytes develop from?
process where the subchondral bone becomes thickened and denser at areas of pressure. (Ebony-like)
Seen as subchondral sclerosis on X ray
connective tissue along the edges of the joint (articular margins) undergoes osseous metaplasia
Why do subchondral bone cysts develop in OA?
(fluid filled sacs)
- Either due to osseous necrosis due to chronic impaction
- or intrusion of synovial fluid as the subchondral bone is damaged
Explain how the cartilage is gradually worn away in osteoarthritis
- precipitating risk factors causes excessive or uneven loading of the joint
- damages the hyaline cartilage
- chondrocytes increase proteoglycan synthesis and in number. The cartilage is swollen
- eventually the proteoglycan content falls and cartilage softens and loses elasticity. Flaking and fibrillation of cartilage
- cartilage is eroded down to the subchondral bone, causing loss of joint space
Osteorthritis of the hip is most common in who?
What are the symptoms?
What is the cure?
Men over 40 years old
Mechanical pain- worse with movement Stiffness Crepitus (grinding) Reduced mobility Pain in the hip radiating to knee (obturator nerve)
The only cure is a hip replacement
Note; hemiarthroplasty is the femoral head only
How can orthotic footwear help an osteoarthritic hip?
Why is weight loss important if the patient is obese?
Rebalance a misaligned load through the joint
A force equivalent to 6x body weight passes through the hips and knees
What do steroid injections do in OA?
What is viscosupplementation?
They reduce inflammation/ swelling in the joint to ease pain and stiffness
Injections of hyaluronic acid to increase lubrication of the joint
NOF means?
fractured Neck Of Femur
- fracture in the proximal femur (the inferior margin is 5cm below the lesser trochanter)
Two types of extracapsular neck of femur fractures?
Avascular necrosis of the femoral head is extermely likely in _____ ___-capsular fractures.
Why?
How is this fracture treated?
intertrochanteric- between the tubercles (oblique)
subtrochanteric- below the tubercles
Displaced, intracapsular fractures of the femoral head are likely to disrupt the ascending cervical branches of the MFCA (lead to the head). Ligamentum teres is unable to sustain the metabolic demand of the femoral head
*medial femoral circumflex artery
Femoral head/ full hip replacement (head and acetabulum) due to the rick of necrosis
Who is more likely to experience an
- intracapsular fracture
- extracapsular fracture
- the elderly after a fall, especially women (post-menopausal with osteoperosis)
- young and middle aged due to excessive force. E.g. a road traffic collision
What does the leg look like in a displaced, fractured neck of femur? (#NOF)
Why?
How does the axis of rotation change? What does this cause?
shortened, abducted, externally rotated
The fracture causes the femoral shaft to move independently to the hip joint.
The axis of rotation now passes vertically down the shaft, inferior to the greater trochanter (instead of obliquely through the femoral head and neck).
- Causes external rotation about the new axis
- The deep gluteal muscles/ short rotators contract and the shaft laterally rotates
- Iliapsoas (inserts on the lesser trochanter) pulls the femur anteriorly about the new axis, causing lateral rotation
- the abductors (gluteus minimus and medius) insert on the greater trochanter and cause lateral rotation about the new axis (usually cause medial rotation)
In a displaced #NOF the limb is shortened, abducted and externally rotated?
Why is it shortened?
Why abducted?
The fracture allows the femur to move independently to the hip joint
Shortened bc strong muscles of the thigh pull the distal fragment upwards.
E.g., rectus femoris, adductor magnus, hamstrings
Femur is abducted by the gluteus medius and minimus (abductors) which attach to the greater trochanter
Actions of the deep gluteal muscles; Tensor fascia lata Gluteus maximus Gluteus minimus Gluteus medialis
Which muscle does not share the same innervation?
Tensor fascia lata
- Stabilises the knee
- Assists with hip extension and abduction
Maximus
Hip extension, assists with abduction
Medialis and Minimus
- abduct and medially rotate the thigh
Gluteus maximus is innervated by the inferior gluteal nerve, whilst the others are the superior gluteal nerve
Anterior/ posterior- which hip dislocation is more common?
In which is the limb
- externally rotated
- internally rotated
How is the limb rotated after a displaced #NOF?
Posterior dislocations account for 90% of total
- anterior dislocation / a displaced fractured neck of femur
- posterior dislocation
What is DDH in children?
Developmental dysplasia of the hip; the joint doesn’t form properly and can cause dislocations
How do hip dislocations most often occur?
What does central dislocation mean?
Why can it be life threatening?
road traffic collisions (lots of force)
The femoral head has been driven through the acetabulum and into the pelvis- a fracture disclocation
(palpable on rectal examination).
High risk of intrapelvic haemorrhage due to disruption of the pelvic venous plexuses
What does the limb look like after a posterior hip dislocation?
Explain why
Which nerve palsy can occur?
Shortened, adducted and internally rotated
Femoral head pushed backwards to lie on the lateral surface of the ilium
- Extensors (hamstrings, gluteus maximus) pull the femur upwards
- Anterior fibres of gluteus minimus and medialis pull on the posteriorly displaced greater trochanter to cause internal rotation
sciatic nerve palsy (posterior)
Where does the anterior cruciate ligament attach on the femur and tibia?
Where does the posterior cruciate ligament attach on the femur and tibia?
Femur- Medial aspect of the lateral condyle
Tibia- intercondylar eminence
Femur- lateral aspect of the medial femoral condyle and the posterior aspect of the intercondylar area
PaM’s AppLes
- posterior attaches to medial condyle
- anterior attaches to lateral condyle
Why does the shaft of the femur descend medially?
What does the linea aspera become proximally?
to bring the knees closer to the body’s centre of gravity; increasing body stability
medially- pectineal line
laterally- gluteal tuberosity
Which muscle inserts on the adductor tubercle?
Where is this?
Adductor magnus
The adductor tubercle is at the end of the medial supracondylar line of the posterior femur
Why is the medial femoral condyle larger than the lateral condyle?
The lateral condyle is more ___, why is this advantageous?
Because it bears more weight in the standing position as the body’s centre of gravity passes medially to the knee
more prominent which prevents lateral displacement of the patellar. People with flatter lateral condyles have greater patellar instability
The patellar is what type of bone?
What does the patellar apex and base attach to?
sesamoid because it is within the quadriceps tendon
apex is inferior
quadriceps tendon inserts on the base
patellar ligament attaches to the apex
How does the patellar articulate with the femur?
posterior surface of the femur has two facets; the medial facet (larger) articulates with the (larger medial condyle of the femur and vice versa
Three main functions of the patella?
Protects the anterior knee
Stabilises- reduces frictional forces on the epicondyles
(Major function) leg extension
- Increases the leverage the quadriceps can exert on the femur bc quadriceps tendon crosses over it (acts as a fulcrum)
‘increase the mechanical efficiency of the muscle’
Articulations of the tibia?
Tibia and femur
- tibial plateau (tibial condyles) articulate with femoral condyles
Note; this is the main articulation of the knee joint
- intercondylar tubercles of the tibia and the intercondylar fossa of the femur
Tibia and fibular - proximal tibiofibular joint (lateral condyle of tibia) - inferior tibiofibular joint (fibular notch of the tibia)
What are the intercondylar tubercles of the tibia?
What do they articulate with?
Raised portions either side of the intercondylar eminence and medial to the condyles
The intercondylar fossa of the femur
The tibia and fibula are shaped like ___?
They have how many borders?
prisms
three borders- anterior, posterior, lateral
Medial malleolus
Lateral malleolus
Which bones are they on?
What do they articulate with?
tibia
fibula
medial malleolus- tarsal bones to form ankle joint
lateral malleolus- talus bone of foot
What markings are on the tibial borders?
Anterior border-
tibial tuberosity where the patellar ligament inserts
Posterior- soleal line which blends into the medial edge; attachment for the soleus muscle
Lateral border/ interosseus border (faces the fibula) where the interosseus membrane attaches which binds the tibia and fibula together
What happens at the fibula notch?
The fibula notch of the tibia is where the tibia and femur articulate- the inferior tibiofibular joint
What’s the main function of the fibula?
3 articulations?
Muscle attachment NOT weight bearing
Proximal tibiofibular joint
Inferior tibiofibular joint
Articulates with talus bone in ankle joint
Which nerve is vulnerable to damage in a proximal fibular fracture?
Why?
common peroneal/fibular nerve
bc it winds round the posterior and lateral surface of the neck of the fibula
