T&O Flashcards
What is the biggest sesamoid bone in the body?
patella
What bones make up the knee joint?
femur
tibia
patella
NOT fibula!!!
What are menisci?
fibrocartilagenous structures between the bones in the knee joint
there is a medial and a lateral one
they are shock absorbers and stabilise the joint
they also have a role in distribution of synovial fluid
Ligaments of the knee
- lateral collateral ligament
- medial collateral ligament
- patella ligament
- transverse ligament
- Anterior Cruciate Ligament
- posterior Cruciate Ligament
- posterior meniscofemoral ligament
Which structures does the patellar ligament arise from?
quadriceps tendon which is formed by the rectus femoris and the vastus muscles
Where does the patellar ligament attach distally?
tibial tuberosity
bursae of the knee
- suprapatellar
- prepatellar
- infrapatellar (deep and superficial, there are 2)
bursae can get inflamed (usually the latter 2)
role of the transverse ligament of the knee
joins the anterior part of the medial and lateral meniscus
it supposedly prevents the meniscus from moving forwards
Where do the ACL and the PCL attach?
named after where they attach on the tibial bone
ACL: from back of femur to anterior tibia (prevents the tibia from sliding out in front of the femur)
PCL: from the medial femur to posterior tibia (prevents knee from hyperextending, tibia from going behind the femur)
LAMP:
lateral (ACL) -> moves medially
medial (PCL) -> moves laterally
What is the pes anserie?
anterior medial knee
made up of three tendons (semitenosus, gracilis, sartorius; behind it sits the pes anserine bursa)
you can have bursitis there
Iliotibial band
runs laterally over the lateral condyle and attaches to anterior lateral tibia; helps stabilise and move the knee joint.
formed from: fascia of gluteus maximus, gluteus medius and tensor fasciae later muscles
can get irritated at the lateral condyle
can cause iliotibial band syndrome
What are the borders of the popliteal fossa?
inferiomedially: lateral head of gastrocnemius AND plantaris
inferolaterally: medial head of the gastrocnemius
superomedially: biceps femoris
superolaterally: semimembranosus
What is inside the popliteal fossa?
- tibial nerve (branches into the common perineal (fibular) nerve and wraps around head of fibular bone)
- popliteal vein (cont of femoral V)
- popliteal artery (cont of femoral A)
What is inside the popliteal fossa?
- tibial nerve (branches into the common perineal (fibular) nerve and wraps around head of fibular bone)
- popliteal vein (cont of femoral V)
- popliteal artery (cont of femoral A)
Baker cyst
does not usually require surgery
causes swelling in the popliteal fossa
Causes of popliteal swelling
baker cyst
popliteal aneurysm (also check for AAA, present in 50%) -> popliteal aneurysm requires surgery!!
What should you check for if you diagnose someone with a popliteal aneurysm?
AAA, present in 50%
What occurs clinically if there is damage to the common perineal nerve?
foot drop
What is foot plantarflexion?
Pushing down on a pedal
What is foot dorsiflexion?
Extend your feet backwards like youβre trying to point them up towards your head
Weber Classification
A - below the stndesmosis; stable, no surgery.
B - at the level of syndesmosis. Variable stability. May need surgery.
C - above the syndesmosis; unstable; requires surgery
Signs of OA on radiograph
- narrowing of joint space
- subchondral cysts
- osteophyte formation
- subchondral sclerosis
What is a hemiarthroplasty?
Half joint replacement
When do you see green stick fractures? What are they?
In children
Shentonβs Line
If there is a discontinuity in Shentonβs line there is probably a fracture
How much blood loss would you see in a broken femur?
1.5 L
a lot of blood is lost
acronym for describing fractures on radiographs
STAR
S - shortening
T - translation
A - angulation
R - rotation
What does βcompoundβ refer to in the context of fractures?
It is an old term for open fractures
What are the principles of managing a fracture?
- reduce deformity
- immobilise to let the # heal
- rehab
Management of osteomyelitis
- Abx for 6 weeks
a. Flucloxacillin
b. clindamycin if allergic to penicillin
c. If MRSA osteomyelitis is suspected, vancomycin or
teicoplanin.
For all these, consider adding rifampicin/fusidic acid for the first 2 weeks.
- Surgery
debridement
if there is an abscess - Pain management (paracetamol, NSAIDs, if there is need for stronger perhaps morphine)
If there is chronic osteomyelitis or if there are prostheses involved, seek further advice.
Blood supply to the neck of femur
- retrograde from medial and lateral femoral circumflex arteries
- artery of the ligamentum teres (foveolar artery - branch of the Obturator A)
- femur itself (bone marrow)
- synovial intracapsular arterial ring
double check this
When do you replace the hip and when do you fixate with screws?
It is a matter of blood supply
if the fracture is intracapsular, likely to need to replace the hip because of AVN
in extracapsular fractures the blood supply should be intact and therefore screw fixation in preferable
? double check this
Septic arthritis definition
Septic arthritis is defined as the infection of 1 or more joints caused by pathogenic inoculation of microbes. It occurs either by direct inoculation or via haematogenous spread.
What are the sx of septic arthritis?
- red, hot, swollen and painful joint
- limited range of movement
- acute presentation
Also likely:
- fever
- large joint
- single joint
- prosthetic joint
- sexual activity (can indicate gonococcal infection)
What are risk factors for septic arthritis?
- immunosuppression
- prosthetic joint
- age: >80 (but can happen at any age)
- underlying joint disease (e.g. RA or OA)
- contiguous spread
- exposure to ticks (lyme disease)
Incidence of septic arthritis in the population and in individuals with prosthetic joints
6 in 100 000 generally (0.006%)
70 in 100 000 in people with prosthetic joints (10x increased risk; 0.07% incidence)
What pathogens can cause septic arthritis?
- staphylococci and streptococci make up 91%
- gonococcal (in sexually active poeple)
- anaerobes do not usually cause SA (unless there was perforating trauma)
tuberculous arthritis can be suspected in immunocompromised people or people from areas where TB is prevalent.
when are gram -ve organisms causing septic arthritis more common?
in older people and immunocompromised individuals they are more common than in healthier/younger people. However, in this population staphylococcal and streptococcal infections are still more common.
How do you manage septic arthritis
a) Inpatient admission
b) IV antibiotics (refer to local guidelines; start after cultures, joint aspirate, swabs if possible, unless this were to cause delays); after 2 weeks can usually be switched to oral abx
c) therapeutic joint aspiration (call ortho!) - this will help clear out the pathogen and decrease pain caused by pressure
d) Analgesia (e.g. paracetamol or NSAIDs)