Lower Limb Flashcards
What is Coxa Vara and Coxa Valga?
Coxa Vara = Decreased angle of inclination (Riding a horse)
Coxa Valga = Increased angle of inclination (Nock knees)
*Angle of inclination = Angle between long axis of femoral neck and femoral shaft.
Dislocation of epiphysis of femoral head:
- What happens in this?
- Aetiology?
- Fast or slow occurance?
- Which deformity can occur?
- Presentation?
- Epiphysis of head of femur may slip away from the femoral neck
- Occurs with acute trauma or microstresses which put stress on epiphysis (eg. lateral rotation and abduction)
- Dislocation occurs slowly
- Results in progressive coxa vara
- Can present with hip discomfort which radiates to knees. Radiological examination is often needed for diagnosis.
Neck of femur fracture:
- Why is it so vulnerable?
- Who is most at risk of this?
- Complication?
- Thinnest and weakest part of the femur. Also, it lies at a marked angle to the line of weight bearing.
- Increasing aged women (due to increased risk of osteoporosis).
- Can be intracapsular and damage retinacular arteries (branches of the medial circumflex artery). Can lead to avascular necrosis of the head of the femur.
Proximal Femur Fracture:
- Give the 2 locations it could happen.
- Aetiology?
- Why are these fractures not stable?
- Presentation of fracture?
- Transcervical (middle of neck) or intertrochanteric.
- Often from indirect trauma (eg. stumbling off a curb)
- Not stable due to angle of inclination.
- Presents with external rotation + limb shortening.
Fractures of Greater Trochanter + Femoral Shaft:
- Aetiology?
- What type of fracture can occur here? Complication?
- Often occurs from direct trauma, during active years.
- Can have a spiral fracture - this leads to foreshortening as the fragments override (or as a fracture may be comminuted). Muscle pull can pull fragments in different directions.
Fracture of Distal Femur:
- What can complicate this fracture?
- What happens to the knee joint?
- Why can we get haemorrhage?
- If the condyles separate, we can get a complication.
- The knee joint articulation can be altered as there is misalignment of the articulation.
- Popliteal artery can be compromised - we can get haemorrhage. Blood supply to leg can be compromised.
Tibial Fractures:
- Where is the narrowest part of the tibia? Why is there slow healing here?
- Why is the tibia liable to open fractures/compound fractures?
- Which artery can be damaged, leading to non-union of bone fragments?
- Between the middle and inferior 1/3s of the tibia. Slow healing as there is a poor blood supply.
- This is due to its subcutaneous nature.
- Nutrient artery can be damaged, leading to non-union of bone fragments.
Transverse Stress Fracture:
- Where does this occur?
- Aetiology?
- Across inferior 1/3 of tibia
- Common in people taking hikes when they aren’t conditioned for them. The strain may fracture the anterior cortex.
What type of fracture can result from severe torsion in skiing?
Diagonal fracture of tibial shaft. Especially at inferior-medial thirds junction (along with a fracture of the fibula).
How can a boot top fracture occur?
Skiing with high speed and a front fall - angles leg over rigid ski boot. Fracture tibia and fibula.
Fibular Fractures:
- Which region is most liable to fractures?
- How can excessive foot inversion cause fibular fracture?
- Why is walking disrupted?
- 2-6cm proximal to distal end of lateral malleolus
- With excessive inversion, ankle ligaments can rupture and talus can press against lateral malleolus - shearing it off.
- Walking is disrupted as muscle attachments are affected and the bone normally plays an important role in ankle stability.
Why is the fibula ideal for bone grafts? Which region do we generally take?
Ideal as it is superficial and some removal generally does not cause complications. Take from middle 1/3 as this is where the nutrient foramen is located (take this as it allows free vascularised fibular transfers - graft can grow).
When would we use an intramedullary infusion into the tibia?
In dehydrated or shocked children.
Calcaneal Fracture:
- Aetiology?
- Why is this fracture often distabling?
- Hard fall onto heel, causing comminuted fracture
- Fracture interrupts subtalar joint.
Fractures of Talar Neck:
- Aetiology
- Which direction can the body of talus be dislocated to?
- From severe dorsiflexion of ankle (eg. pressing hard on brake pedal in head on crash)
- Body of talus can be dislocated posteriorly
Fracture of metatarsals:
- Aetiology
- What is a Dancer’s Fracture?
- What are fatigue fractures?
- What can occur if the foot is suddenly inverted violently?
- Crush injuries or in dancers
- Dance fractures are from when a dancer loses balance and puts full weight on metatarsals.
- Fatigue fractures of the metatarsals can occur with prolonged walking - transverse fracture from repeated stress on metatarsals.
- If suddenly, violently inverted, the tuberosity of the 5th metatarsal can be avulsed by peroneus brevis muscle. Associated with a severe sprain of the ankle + oedema at the base of the 5th metatarsal.
Os Trigonum:
- What is this?
- Bilateral or not?
- During talus ossification, 2ndary ossification centre may occasionally fail to unite with the body of the talus. This can be caused by forceful plantarflexion/stresses in early teens. OR a partly or fully ossified centre may fracture and become non-union. Both of these events lead to an os trigonum.
- Often bilateral.
Fracture of sesamoid bones:
- Where are the sesamoid bones in the foot?
- What are the function of these bones?
- Aetiology?
- Found in the flexor hallucis longus tendon of the great toe
- Function of weight bearing the body (especially in push-off phase of the gait cycle)
- Fracture from crush injury
Fractures involving epiphyseal growth plates:
- What can these jeopardise?
- What is osgood-schlatter disease?
- Can jeopardise normal bone growth
- Osgood-schlatter disease is when inferior bone growth from superior epiphyseal centre fails to form tibial tuberosity due to being disrupted. Leads to inflammation of the tuberosity and chronic recurring pain in adolescence.
Compartment Syndrome:
- What is it?
- What can be compressed?
- Presentation?
- Treatment?
- This is when haemorrhage, oedema, or inflammation occurs within a compartment surrounded by fascia - there is an increase in intracompartmental pressure.
- Small vessels of nerves + muscles can be most vulnerable to compression.
- Presents with cold to touch distal limb + lack of distal pulse
- Treatment can include a fasciotomy (slice the fascia).
Varicose Veins:
- Which vessel is most likely to develop these?
- What is it?
- Great saphenous veins + their tributaries frequently become varicose (dilated).
- Due to valves in veins becoming incompetent (eg. due to dilation or rotation) and no longer functioning properly. Blood can then back flow, causing varicose veins.
Deep Vein Thrombosis:
- Presentation?
- Venous stasis is an important cause of DVTs - what can cause stasis?
- What is the term used to described inflammation of veins, with associated thrombosis.
- What is a severe complication?
- Presents with swelling, warmth, erythema (superficial reddening of the skin).
- Loose/incompetent fascia (not resisting muscle expansion so musculovenous pump is less effective); Low muscular activity; External pressure on veins (eg. bedding, cast, bandages).
- Thromboplebitis
- Pulmonary Embolism
Saphenous Vein Graft:
- Which vein is often grafted for a coronary arterial bypass?
- Why is this vein ideal for the job?
- What do we have to do to the graft for it to be useful.
- Great saphenous vein
- Available in good lengths, easily accessible, has ideal muscular + elastic fibres in wall. Very little effect on circulation due to anastomosis.
- We need to invert the graft so that valves do not function.
Saphenous Cutdown:
- What is this?
- Where is the vein found?
- Which nerve is at risk of damage during this procedure?
- This is a procedure to insert a cannula for prolonged administration of blood, plasma expanders, drugs, electrolytes, etc. Insert into great saphenous vein.
- Anterior to medial malleolus
- Saphenous nerve (as it lies close)
Enlarged Inguinal Lymph Nodes:
- When do lymph nodes enlarge?
- Where else should we examine if a lymph node is enlarged?
- When they are diseased (Diseased lymph node = lymphadenopathy)
- Examine all nodes which drain into this one. In females, consider uterus cancer for enlarged inguinal lymph nodes. Also examine all other palpable lymph nodes.
Regional Nerve Blocks of Lower Limb:
- How do we interrupt peripheral nerve conduction?
- Where would we inject for femoral nerve block?
- We inject a perineural injection of anaesthesia
- We would inject 2cm inferior to the mid-point of the inguinal ligament (about a fingers width lateral to the femoral artery).