Lower Limb Injuries Flashcards
Define fracture.
A breach of integrity of part or the whole of a bone
Define subluxation.
Partial separation of the articular surfaces of the joint
Define dislocation.
Complete separation of the articular surfaces of a joint
Define fracture dislocation.
A dislocation where there is also a fracture involving one or more of the articular surfaces of a joint
Define sprain.
Stretching of the joint capsule and ligaments of a joint, insufficient to produce subluxation or dislocation
What are the mechanisms of fracture formation?
- Bone strength
2. Force/energy
What are some causes of weak bones?
Osteoporosis (e.g. post-menopausal)
Osteogenesis imperfecta (brittle bone disease)
Secondary bone cancer
What are the clinical signs and symptoms of a fracture?
Pain Swelling Tenderness Bruising Deformity Crepitus Abnormal movement
Why do fractures cause pain?
Bones do not have nerves themselves but fractures hurt either due to the surrounding nerves becoming impinged or bleeding as this will increase pressure on soft tissues e.g. muscles
What are the 2 different types of compound fracture?
- From within: bone has come out of the skin
- From without: something has hit a limb with such force that it has gone through the skin and fractured the bone leaving an open wound
What are compound fractures at high risk of?
Infection as they are open wounds
What other structures can be affected by fractures causing complications?
Blood vessels Brain Spinal cord Nerves Contents of chest Abdomen
What are the different types of fracture union?
- Normal: 6 weeks - 3 months
- Delayed: takes longer than expected
- Malunion: joins in wrong alignment (e.g. in clavicle as it is impossible to immobilise it)
- Non-union: does not unite (e.g. if it not immobilised and fixed in the correct position)
How can you diagnose a fracture?
History & examination X-ray Computerised Axial Tomography (CAT) scan MRI US Bone scan
What different X-ray views can be used to look at a fracture?
- Antero-posterior in sagittal plane
2. Lateral in coronal plane
What can a Magnetic Resonance Image (MRI) tell you about a fracture?
Bone density
If fluid is present (by adding contrast)
What type of fractures will most likely need a ultrasound (US) to detect?
Greenstick fractures as they are so fine, you cannot see them on other forms of scan but US waves will go down through the crack and be more obvious
Who are ultrasounds (US) most commonly used on?
Children
What are the main structural bony features of the pelvis?
Ilium
Ischium
Pubis
Acetabulum
What are patients with pelvic fracture at risk of?
Blood loss (can be fatal) Abdominal injury e.g. bladder or male urethra Nerve injury
What vessels do you bleed most from? Why?
Veins as they cannot constrict like arteries can
How is the ilium usually injured?
Lateral blow
When will patients with pubic fractures get the most pain?
When weight bearing on 1 leg
It is important to get fracture patients ____ as quickly as possible.
Moving
What is another term for a pubic symphysis separation?
Open book fracture
How do most fractures need to be fixed?
With metal pins fixating the fracture so the bones are immobilised
How do intra-articular acetabular fractures occur most commonly?
Hit to femur from side OR if patient lands on leg hitting the roof of acetabulum with force (force travels up leg) esp. when weight bearing (force travels down leg)
How can neck of femur (intracapsular/transcervical) fractures occur?
Osteoporosis
Fall
Stress fracture
Spontaneously
What is a common complication of neck of femur (intracapsular/transcervical) fractures?
Avascular necrosis as intra-capsular retinacular arteries (branches of circumflex femoral arteries) are damaged and there is no compensatory blood supply to the femoral head
If a patient has a neck of femur (intracapsular/transcervical) fracture, what will their lower limb look like?
Short
Externally rotated
What might you do instead of using metal fixation in a young, fit and healthy fracture patient?
Hip replacement as metal will erode the bone over time
What type of femur fracture requires the most mechanical fixation?
Head of femur/extra-capsular/subcapital
What type of patients are more at risk of blood supply damage and avascular necrosis with neck of femur (intracapsular/transcervical) fractures? Why?
The younger the patient the higher the risk as the amount of force it takes to fracture a young person’s neck of femur is much greater than in an elderly person
What is the mortality statistics of neck of femur (intracapsular/transcervical) fractures?
40% of patients die within 2 years after
How is the hip likely to become dislocated?
Requires high impact frontal force (e.g. if in a head on car crash) when you are sitting down as this is when the ligaments are laxed allowing the hip to posteriorly dislocate
If a dislocation at a synovial joint (e.g. hip) is not reduced within 6 hours, what can occur?
Chrondrolysis
Avascular necrosis
Degenerative arthritis
What nerve is at risk of damage with a posterior hip dislocation?
Sciatic n.
What options are there to treat a femoral shaft fracture? What one is better?
External fixation allowing bone to heal but requires 3 months in hospital or an internal fixation where a intramedullary nail through the piriform fossa and piriformis so patient can get up and walk around
What are the consequences of a patellar intra-articular fracture?
Haemarthrosis
Loss of knee extension
How can you treat a patella fracture?
Internal fixation
Patellectomy (if patella shattered)
Why are tibial plateau fractures high risk?
They are usually intra-articular so nerves are damaged along with soft tissue and major blood vessels such as the popliteal vessels
Why can meniscal injuries not repair themselves?
As menisci of the knee do not have a blood supply (except round their edge)
What is the main mechanism of meniscal injury?
Rotation of the femur on a fixed tibia (i.e. tibia fixed on ground)
If a meniscal injury becomes more extensive, what can happen?
Cruciate ligament injury
How can you test the cruciate ligaments of the knee?
Anterior or posterior draw test
What is a triad knee injury?
An injury that damages the meniscus, cruciate ligaments AND medial ligaments
How can you fix ligaments of the knee? Whats the problem with this?
Semitendonosus OR patella tendon can be used but artificial tendons require fixation and getting tension right is crucial but difficult
How can a patient get a tibial shaft fracture?
Direct trauma
Rotational strain
How do you treat tibial shaft fractures?
External immobilisation
Internal immobilisation
What is compartment syndrome?
When pressure in the muscle compartment is greater than the systolic pressure
What is a complication of a tibial shaft fracture?
Compartment syndrome
What is a give away sign of compartment syndrome?
Increasing pain even if analgesia is given, the pain goes away for a bit then comes back and continues to get worst
What is the function of the anterior compartment of the leg?
Dorsiflexion of the foot and ankle - important in swing phase of walking
What part of the ankle can be fractured?
Ankle mortice Medial malleolus Lateral malleolus Intra-articular Calcaneus (Os Calcis)
If the ankle is fractured, how must you treat it?
Restore ankle anatomy with surgery
What are ankle fractures commonly associated with? How can this be reduced?
Soft tissue injury so RICE leg straight away to reduce effects of this
What joint can be damaged by a calcaneal fracture?
Subtalar (responsible for inversion/eversion movements of ankle and foot)
What types of soft tissue injury of the lower limb exist?
Skin lesions
Vascular compromise
Diabetes
Vascular insufficiency
How does the Achilles/calcaneal tendon rupture?
Tendon is degenerated due to overuse and then a forceful contraction of the gastrocnemius and soleus ruptures the tendon completely
What is Simmonds test?
Where the patient lies on front and you squeeze their calves to test for Achilles/calcaneal tendon rupture - if it is not ruptured, the foot should move
What is the treatment of Achilles/calcaneal tendon rupture?
Conservative (external immobilisation)
Operative (internal fixation)
What is Lisfranc’s injury?
An injury of the foot in which one or more of the metatarsal bones are displaced from the tarsus at the tarso-metatarsal joint (Lisfranc’s joint) that can cause gangrene and subsequent amputation if not restored quickly
What can Lisfranc’s injury cause?
Soft tissue injury
Vascular damage -> gangrene -> amputation
