the Knee and Osteoarthritis Flashcards
what muscles are contained in the anterior compartment of the thigh
Iliopsoas
pectineus
Sartorius
The quadriceps
what 4 muscles comprise the quadriceps
rectus femoris
vastus lateralis
vastus medialis
vastus intermedius
what muscles comprise the medial compartment of the thigh
THE ADDUCTORS
obturator externus
gracilis
adductor brevis
adductor longus
adductor magnus
origin of the pectineus
superior ramus of pubis
insertion of the pectineus
pectineal line of femur, inferior to lesser trochanter
functions of the pectineus
flexor of the thigh
adductor of the thigh
assists with medial rotation of the thigh
innervation of the pectineus
femoral nerve (L2, L3)
origin of psoas major
sides of T12-L5 vertebrae and intervertebral discs, transverse processes of lumbar vertebrae
origin of iliacus muscle
iliac crest, iliac fossa, ala of sacrum, and anterior sacroiliac ligaments
insertion of the iliopsoas
common insertion for psoas major and iliacus
lesser trochanter of femur
common functions of iliopsoas
flexor of the thigh
stabilises the hip joint
innervation of psoas major
anterior rami of lumbar nerves (L1, L2, L3)
innervation of iliacus
femoral nerve (L2, L3)
origin of sartorius
anterior superior iliac spine (ASIS) and superior part of notch inferior to it
insertion of sartorius
medial surface of proximal tibia (pes anserinus)
functions of sartorius
flexor, abductor and lateral rotator of the thigh
flexor of the leg and the knee
medially rotate the leg when knee is flexed
innervation of sartorius
femoral nerve (L2, L3)
origin of the rectus femoris (Quad)
Anterior inferior iliac spine and ilium superior to acetabulum
origin of vastus lateralis (quad)
greater trochanter and lateral lip of linea aspera
origin of vastus medialis (quad)
intertrochanteric line and medial lip of linea aspera
origin of vastus intermedius (quad)
anterior and lateral surfaces of femoral shaft
common insertion of quadriceps
quadriceps tendon to patella and then indirect attachment via patellar ligament to tibial tuberosity
common function of quadriceps
extensor of the leg
function of rectus femoris alone
helps in flexion of the hip joint
common innervation of quadriceps
femoral nerve (L2, L3, L4)
origin of obturator externus
hip bone around external obturator foramen and membrane
insertion of obturator externus
trochanteric fossa
functions of obturator externus
lateral rotator of the thigh
innervation of obturator externus
obturator nerve (L3, L4)
origin of gracilis
body and inferior ramus of pubis
insertion of gracilis
medial surface of proximal tibia (pes anserinus)
functions of gracilis
adductor of the thigh
flexor of the leg at the knee joint
innervation of gracilis
obturator nerve (L2, L3)
origin of adductor brevis
body and inferior ramus of pubis
origin of adductor longus
body of pubis inferior to pubic crest
insertion of adductor brevis
pectineal line and proximal part of linea aspera of femur
insertion of adductor longus
middle third of linea aspera of femur
common function of adductors longus and brevis
adductor of the thigh
common innervations of adductor brevis and longus
obturator nerve and branch of anterior division (L2, L3, L4)
origin of adductor magnus
adductor part: inferior ramus of pubis and ramus of ischium
hamstring part: ischial tuberosity
insertion of adductor magnus
adductor part: gluteal tuberosity and linea aspera
hamstring part: adductor tubercle
functions of adductor magnus
powerful adductor of the thigh
adductor part: flexes the thigh
hamstring part: extends the thigh
innervation of the adductor magnus
adductor part: obturator nerve (L2, L3)
hamstring part: tibial division sciatic nerve (L4)
what is the adductor hiatus formed by
the insertions of adductor magnus (both adductor and hamstring part)
what is the adductor hiatus
a gap in the thigh that allows the femoral artery and vein to pass from the anterior thigh to the posterior lower leg
what does the femoral artery become through adductor hiatus
popliteal artery
what does the popliteal vein become through adductor hiatus
femoral vein
Describe the knee joint
Synovial hinge joint = extension and flexion
BUT
The hinge movements are combines with gliding and rolling and with rotation about a vertical axis
What are the 3 bones articulating the knee joint
Femur
Tibia
Patella
what is the joint between the femur and tibia
Femerotibial
What is the contact area between the patella and femur
Femeropatellar
What are the five extracapsular ligaments of the knee
Patella ligament
Fibular (lateral) collateral ligament = cord-like
Tibial (medial) collateral ligament = broad
Oblique popliteal ligament = posterior
Arcuate popliteal ligament = posterior
What are the 2 intra-articular ligaments
Anterior cruciate ligament (ACL)
Posterior cruciate ligament (PCL)
How do you test for ACL tears
Lachman test
ACL intact = firm feel
ACL tear = soft feel
Describe the shape of the medial meniscus
C Shaped
Semi-circular
Describe the shape of the lateral meniscus
O shaped
Almost circular
Describe the movements of the knee
Extension - locking mechanism or scre-home mechanism of the knee
Flexion
Medial rotation - foot turns with knee flexed
Lateral rotation - foot turns with knee flexed
What is the popliteal fossa
Area posterior to the knee joint
Fat filled space
Flexed knee - diamond shaped or rhomboid shaped depression
Contents - important anatomical structures (arteries, veins, nerves)
What are the boundaries of the popliteal space
Roof = popliteal fascia and skin
Superolateral = biceps femoris
Superomedial = semimembranosus/semitendinosus
Inferolateral = lateral head of gastrocnemius
Inferomedial = medial head of gastrocnemius
Floor = capsule of the knee joint, distal femur, proximal tibia
Superficial contents of the popliteal fossa
Small saphenous vein (drain into popliteal vein)
3 cutaneous veins:
- posterior femoral cutaneous (from sacral plexus)
- medial sural cutaneous nerve
- lateral sural cutaneous nerve
deep contents of the popliteal fossa
from superficial to deep:
- tibial and common fibular nerves (sciatic nerve divisions)
- popliteal vein (will become femoral vein)
- popliteal artery (continuation of femoral artery)
origin of the popliteus muscle
lateral femoral condyle, posterior horn of lateral meniscus of knee joint
insertion of popliteus muscle
posterior tibial surface
functions of popliteus muscle
knee flexor
medial rotator of knee
major stabiliser of the knee posteriorly during weight-bearing activities
innervation of the popliteus muscle
tibial nerve (L4, L5, S1)
function of articular cartilage
smoothe lubricated surface for articulation, facilitate load transmission and low friction movement
composition of articular cartilage
chondrocytes, macromolecules, water
when is healing not stimulated
when the injury doesn’t breach the tide mark. injury must penetrate subchondral bone to reach blood vessels.
what are chondrocytes derived from
mesenchymal stem cells
function of chondrocytes
synthesise and maintain ECM
what is the main type of collagen in the ECM
type 2
define osteoarthritis
chronic degenerative change of damaged articular cartilage (and the attempted repair process)
what is varus
bow legging
what is valgus
knee knocking
what are the four signs of osteoarthritis on an x-ray
narrowing joint space
subchondral cysts
periarticular sclerosis
osteophytes
basic steps in bone remodelling
- activation: osteoclasts
- resorption: bone matrix
- osteoblast recruitment
- osteoid formation
- mineralisation
- quiescence
briefly describe the RANK/RANKL/OPG system
M-CSF expressed by osteocytes/blasts stimulates RANK expression
RANKL binds to receptor RANK on inactive osteoclasts
Results in osteoclast maturation and rapid bone resorption
Meanwhile, OPG is a decoy receptor for RANKL
- secreted by osteoblasts/cytes
- inhibits osteoclastic bone resorption
describe the role of PTH in control of bone remodelling
Increases bone resorption and so builds calcium levels in the blood.
However, when released in a pulse-like manner it can enhance bone formation
What is calcitonin
Hormone secreted by the thyroid gland.
(Opposite to PTH)
Role of sex hormones in bone remodelling
oestrogen and androgens stimulate bone formation and inhibit resorption
role of thyroid hormones in bone remodelling
directly stimulate osteoblast differentiation and mineralisation
role of growth hormone and IGF1 in bone remodelling
increases bone turnover
- stimulates osteoblastic bone formation > resorption
- small net increase in bone mass
non-modifiable risk factors for Osteoporosis
previous history of fracture
parental history of osteoporosis
history of early menopause
modifiable risk factors for osteoporosis
low BMI (<20)
smoking
alcohol (>3.5 units/day)
describe the effect of oral glucocorticoids on osteoporosis
initial and transient reduction in osteoclastic bone resorption, followed by prolonged reduction in bone formation and resorption
leads to bone loss and poorer quality bone
describe bisphosphonates (examples, action and complications)
alendronic acid, zoledronic acid
inhibits osteoclasts
- osteonecrosis of the jaw, atypical femoral fracture
mechanism of denosumab
monoclonal antibody against RANK-L
risk of hypocalcaemia
describe teriparatide
synthetic PTH
increases bone formation more than resorption
What is osteomalacia
Disorder arising from defective mineralisation of bone
If it occurs before bone growth is complete = rickets
Most common causes of osteomalacia
Decreased exposure to light
Decreased calcium intake
Chronic kidney disease
Genetic causes
What is Paget’s disease
Increased osteoclast and osteoblast activity resulting in disorganised bone tissue prone to fracture
Aetiology unknown
what is septic arthritis
infection of the joint
new onset joint pain (not traumatic)
what is osteomyelitis
infection of the bone
can be acute or chronic
can be spread by blood stream or from nearby tissues, or caused by trauma, surgery or prosthetic material
