2.01 Trauma and Orthopaedics - General Principles Flashcards
What is a fracture?
A discontinuity of bone resulting from mechanical forces, which exceed the bone’s ability to withstand them.
What is an insufficiency fracture?
Give some disease states that may increase the risk of insufficiency fractures occurring.
An insufficiency fracture occurs when a bone fractures as a result of forces that would normally be insufficient to cause a fracture, due to weakening of the skeleton.
Metabolic disorders (e.g. osteoporosis) or genetic abnormalities (e.g. osteogenesis imperfecta) can increase cause weakening of the skeleton.
What are fatigue fractures?
Fractures that occur as a result of chronic application of abnormal stresses (e.g. running), which result in the accumulation of microfractures faster than the body can heal.
What are pathological fractures?
Fractures that occur in bone weakened by a lesion, for example metastases or bone cysts.
What should be included when describing the location of a fracture?
- which bone is fractures
- which part of the bone is affected (ie. epiphysis, physis, metaphysis, diaphysis)
What is the difference between a complete and an incomplete fracture?
Complete fractures extends all the way across the bone (most common).
Incomplete fractures do not cross the bone completely (more common in children).
What are the 4 types of complete fracture?
a) transverse fracture - fracture line that is perpendicular to the axis of the bone.
b) oblique fracture - fracture line that is oblique across the bone.
c) spiral fracture - helical fracture path in the diaphysis of long bones.
d) comminuted fracture - a fracture in more than two parts of the bone.
What are the 3 types of incomplete fracture?
a) bowing fracture - the plastic deformity caused by stress beyond the bone’s capacity for elastic recoil.
b) buckle (torus) fracture - a complete minimally impacted fracture with an intact periosteum, occurring at the metaphysis.
c) greenstick fracture - the cortex breaks on one side.
Describe the following types of fracture displacement:
a) fracture translation
b) fracture angulation
c) fracture rotation
d) fracture shortening
a) describes the movement of fractured bones away from each other.
b) describes the normal axis of the bone has been altered so the fractures bone points in a different direction.
c) describes where there has been rotation of the distal fracture fragment in relation to the proximal portion.
d) describes the movement of fractures bones towards each other.
Which are the three main phases of fracture healing?
- Inflammatory phase
- Reparative phase
- Remodelling phase
Outline what happens during the inflammatory phase of fracture healing.
Immediately at the time of the fracture, a haematoma forms within the space between fracture ends, stopping additional bleeding and providing structural and biochemical support for the influx of inflammatory cells, fibroblasts, chondroblasts and the ingrowth of capillaries.
At the end of the inflammatory phase (approx. 1 week), a soft callus has formed.
Outline what happens during the reparative phase of fracture healing.
Over the next few weeks, the primary callus is transformed into a bony callus by the activation of osteoprogenitor cells.
The osteoprogenitor cells lay down woven bone, which stabilises the fracture site.
Outline what happens during the remodelling phase of fracture healing.
The remodelling phase lasts months to years, representing the gradual formation of compact cortical bone influenced by mechanical stresses placed upon the bone.
Generally, what is the surgical management in traumatic orthopaedic complaints?
Reduce - Hold - Rehabilitate
In the context of high-energy injuries, resuscitation following Advanced Trauma Life Support (ATLS) may be needed.
What are the principles of fracture reduction?
Reduction involves restoring anatomical alignment of a fracture, allowing for:
- tamponade of bleeding
- reduction in traction on surrounding soft tissues, reducing swelling
- reduction in traction on transversing nerves, reducing risk of neuropraxia
- reduction of traction on traversing blood vessels, restoring any affected blood supply.
How is fracture reduction typically performed?
Reduction is painful and requires analgesia, therefore:
- where regional or local blockade is sufficient, this is analgesia of choice
- where this is not sufficient, patient may require a short period of conscious sedation
Specific manouevres can be employed to correct the deforming forces that resulted in injury, typically performed closed in the emergency room. However, some fractures need to be reduced open intra-operatively.
What are the principles of fracture ‘hold’?
Hold is the generic term used to describe immobilising a fracture, commonly via simple splints or plaster casts.
The definitive method of holding the fracture might be surgical intervention.
When is traction indicated when immobilising a fracture?
Most commonly needed where the muscular pull across the fracture sight is strong and the fracture is inherently unstable, fore example:
- neck of femur fractures
- femoral shaft fracture
- acetabular fracture
When applying plaster cast, what is the most important principles to remember in the following cases:
a) for the first two weeks
b) if there is axial instability
a) plasters are not circumferential, allowing the fracture to swell. If this is not adhered to, the cast will become tight and the patient is left at risk of compartment syndrome.
b) if the fracture is able to rotate along its axis, the plaster should cross both the joint above and below
NB: for most fractures, the plaster needs only to cross the joint immediately distal to it.
What advice should be given to a patient when their fracture is immobilised (ie. wearing plaster cast or splint)?
- advise the patient whether they can weight bear
- if the patient is immobilised and is non-weight bearing, it is common to provide thromboprophylaxis
- provide advice about the symptoms of compartment syndrome
What are the principles of fracture rehabilitation?
Most patients need to undergo an intensive period of physiotherapy following fracture management, to reduce stiffness and improve recovery.
Give some possible differentials for an acutely swollen joint.
- septic arthritis
- haemarthrosis
- crystal arthropathies
- rheumatological causes
- osteoarthritis
- musculoskeletal injury
- sponyloarthropathies
What is gout?
An inflammatory arthritis caused by the collection of monosodium urate crystals in a joint, due to hyperuricaemia leading to crystalisation of urate in the joint space.
Presentation of gout.
- acutely swollen joint (commonly 1st MTPJ)
- painful
- episodic (triggers including stress, illness, dehydration) with long symptom-free remission periods
Extra-articular features include gouty tophi or uric acid nephropathy.
How is gout diagnosed?
Joint aspiration and microscopy, showing thin, needle shaped, negatively bifringent monosodium urate crystals in the synovial fluid.
What is the treatment for:
a) acute gout
b) recurrent gout episodes
a) NSAIDs, for example ibuprofen or naproxen
b) prophylactic agents, for example allopurinol
What is pseudogout?
An inflammatory arthritis caused by deposits of calcium pyrophosphate crystals within the joint.
What are the risk factors for pseudogout?
- advanced age
- hyperparathyroidism
- hypophosphatemia
Presentation of pseudogout.
Psuedogout often mimics the presentation of gout, but most commonly affects the knee and wrist:
- acutely swollen joint
- painful
- episodic (triggers including stress, illness, dehydration) with long symptom-free remission periods
How is pseudogout diagnosed?
Joint aspiration and microscopy, showing positively bifringent rhomboid-shaped crystals.
What is the treatment for pseudogout?
- treated acutely using NSAIDs, for example ibuprofen or naproxen
- treat any underlying cause identified (e.g. hypophosphatemia, hyperparathyroidism)
What is rheumatoid arthritis?
An autoimmune disease that affects the articular cartilage between joints, giving rise to arthritic symptoms.
Presentation of rheumatoid arthritis.
Small joints in the hands and feet are most commonly affected, sparing DIPJ.
- swollen, painful, and red joints
- stiffness worse in the morning
- joints affected symmetrically
- fatigue
- pyrexia
- weight loss
- rheumatoid nodules
How is rheumatoid arthritis diagnosed?
- raised CRP and ESR (inflammatory markers)
- raised rheumatoid factor (FR)
- raised ACPA
- radiographic changes
What is the typical radiographic appearance of rheumatoid arthritis?
- soft tissue swelling
- periarticular osteopenia
- juxta-articular erosions
- narrowed joint space
- subluxations
What is the treatment for rheumatoid arthritis?
Treatment usually initiated by rheumatologists:
- NSAIDs for pain
- DMARDs, for example sulfasalazine or methotrexate
- biological agents, for example infliximab or etanercept
Which criteria can be used to diagnose rheumatoid arthritis?
The diagnostic criteria for RA is the EULAR classification - if EULAR ≥6/10 then definite RA is indicated.
Presentation of septic arthritis.
- single swollen joint
- severe pain
- pyrexia (absence should not rule out septic arthritis)
- red, swollen and warm joint
- pain on active and passive movement - may be unable to tolerate any passive movement
- effusion may be present
- unable to weight bear
It requires a high index of suspicion and can affect both native and prosthetic joints.
What are the investigations indicated when osteomyelitis is suspected?
- routine blood tests (FBC, CRP, ESR)
- blood cultures should be performed
- plain film radiograph
- definitive diagnosis achieved through MRI imaging
- bone biopsy at debridement
What is an open fracture?
A fracture in which there is direct communication between the fracture site and the external environment, most often through the skin.
Note, pelvic fractures can be internally open via the vagina or rectum.
What investigations are indicated when a patient presents with an open fracture?
- plain film radiograph of affected areas
- basic blood tests (incl. clotting screen)
- Group & Save blood test
What is osteoid osteoma?
A primary, benign tumour of the bone that arises from osteoblasts.
They are small tumours located around the metaphysis of the long bones (ie. proximal femur or tibia).
Overall, they have a good prognosis, with most resolving spontaneously.
What are the radiological features of:
a) benign bone tumours
b) malignant bone tumours
a) sharp and well-defined, lacking soft tissue involved and no cortical destruction.
b) poorly defined with rough borders, involving soft tissues and have cortical destruction.
See image.
Describe how compartment syndrome leads to leg ischaemia.
- Injury causes an increase in intra-compartmental pressure
- Veins compressed by pressure, increasing hydrostatic pressure within them.
- Fluid moves down its gradient into the compartment, increasing compartmental pressure further.
- Traversing nerves are compressed, causing sensory and/or motor defects (ie. paraesthesia)
- When intra-compartmental pressure reaches diastolic blood pressure, arterial inflow is compromised leading to ischaemia.
How is compartment syndrome managed?
Early recognition and immediate surgical treatment via urgent fasciotomy.
- keep the limb at a neutral level
- give high-flow oxygen
- remove all dressings, splints, casts, down to the skin
- give analgesia
- monitor renal function due to the effects of rhabdomyolysis / reperfusion injury
