Injury and Healing Flashcards
What are the causes/mechanisms of actin for bone fractures?
- Trauma -low energy, high energy
- Stress- abnormal stress on normal bone
- Pathological- normal stresses on abnormal bone
What are the fracture patterns?
Soft tissue integrity:
open or closed
Bony fragments:
greenstick or simple or comminuted/multi-fragmentary
Displacement:
displaced (bone moved) or undisplaced
What does an open fracture mean?
-the skin has been breached
An amateur runner is training for his first marathon. He is trying to make a positive change from his otherwise sedentary lifestyle and has really been pushing himself. What type of fracture might he be at risk of developing?
-stress
What is ‘stress’ on a bone causing fractures?
- stress exerted on bone is greater than bones capacity to remodel
- causes bone weakening
- stress fracture
- risk of complete fracture
What are the weight bearing bones?
- tibia
- metatarsals
- navicular
What are the risk factors for bone fractures due to stress?
- disordered eating
- amenorrhea
- osteoporosis
(-army personnel)
What are pathological bone fractures?
-normal stress on abnormal bone
What are the causes of pathological bone fractures?
- Osteoporosis- soft bone
- Malignancy- primary & bone metastases
- Vit D deficiency- osteomalacia (in adults) & Ricket’s (in children)
- Osteomyelitis (bone infection)
- Osteogenesis imperfecta
- Paget’s disease
When does osteopenia & osteoporosis occur?
- when osteoclast activity>osteoblast activity
- causes disrupted microarchitecture
What are the risk factors for osteopenia & osteoporosis?
- more common in females
- postmenopausal osteoporosis women 50-70
- senile osteoporosis >70
- secondary osteoporosis: any age:
- hypogonadism
- glucocorticoid excess
- alcoholism
- associated with ‘fragility fractures’ - hip, spine, wrist
- low energy trauma - fracture
What are -blastic malignancies?
- prostate
- breasts
What are the -lytic malignancies?
- breasts
- kidney
- thyroid
- lung
What are the primary bone cancer?
- osteosarcoma
- chondrosarcoma
- ewing sarcoma
- chordoma
What primary malignant tumours metastasise to bone?
-prostate, breast, kidney, thyroid, lung
What are the conditions associated with vitamin D deficiency?
Rickets:
- paediatrics
- before physis closure
Osteomalacia:
- adults
- after physis closure
What are physes?
-growth plates founding bones
What is osteogenesis imperfect?
- ‘Brittle Bone Disease’
- hereditary - autosomal dominant or recessive
Decrease in type 1 collagen due to:
- decreased secretion
- production of abnormal collagen
Results in insufficient osteoid production
What areas are affected by osteogenesis imperfect?
- bones
- hearing
- heart
- sight (collagen in sclera of eyes- blue sclera)
What is Paget’s disease?
- genetic and acquired factors
- excessive bone break down and disorganised remodelling
- may transform into a malignant disease
Four stages:
- Osteoclastic activity
- Mixed osteoclastic-osteoblastic activity
- Osteoblastic activity
- Malignant degeneration
What are the effects of Paget’s disease?
- deformity
- pain
- fracture
- arthiritis
A 6-year old South Asian boy moves to Glasgow with his family. His mother is concerned that he is complaining of aches and pains and his growth seems to have plateaued. What test would you order? What’s the diagnosis?
- low vitamin D level
- rickets
What is Wolff’s Law?
-bone grows and remodels in response to the forces that are placed on it
What is the process of fracture healing?
Week 1:
- haematoma formation (due to ruptured blood vessels)
- release of cytokines
- granulation tissue
Week 2-4 & 1-4 months:
- soft callus formation: Type II Collagen- cartilage
- converted to hard callus: Type I collagen -bone
4-12 months:
- callus responds to activity, external forces, functional demands and growth
- excess bone is removed.
What are the two types of bone healing?
Primary bone healing:
- intermembranous healing
- absolute stability
Secondary bone healing:
- endochondral healing
- involves responses in the periosteum and external soft tissues
- relative stability
What is the general fracture healing time?
-3-12 weeks depending on site
depends on blood supply and soft tissue coverage
When are signs of healing visible on x-ray from?
-7-10 days
How long do the phalanges take to heal?
-3 weeks
How long do the metacarpals take to heal?
4-6 weeks
How long does the distal radius take to heal?
4-6 weeks
How long does the forearm take to heal?
8-10 weeks
How long does the femur take to heal?
-12 weeks
How long does the tibia take to heal?
-10 weeks
After sustaining an unstable fracture to his fibula bone, a medical student has an operation with a plate and screws to fix it. 10 weeks later his x-ray shows the fracture has healed nicely. This is an example of what type of bone healing?
-primary
What are the three stages of fracture management?
- reduction- open or closed
- hold- metal or no metal
- rehabilitate- move, physiotherapy, use
What is traction?
-held by skin or skeletal (pins in bones)
What is fixation?
Internal:
- intramedullary- pins or nails
- extramedullary- plate/screw or pins
External:
- monoplanar
- multiplanar
What is reduction?
Open:
- multi-incision
- full exposure
Closed:
- manipulation
- traction- skin or skeletal (pins in bones)
What are the considerations if the fracture is displaced?
Is it stable?
- Are soft tissues ok?
- What other illnesses?
Is it a joint surface?
-What does the patient think?
What are the stages of fracture management?
- Reduce
- Hold
- Fix
- Rehabilitate
What is a ligament?
-connect bone to bone
What is a tendon?
-connects muscle to bone
What can happen to tendons?
Tendinosis
-abnormal thickening
Tendinitis
-inflammation
Rupture
What are the classifications of ligament injury?
Grade I- slight incomplete tear- no notable joint stability
Grade II- moderate/sever incomplete tear
- some joint instability
- one ligament may be torn
Grade III
- complete tearing of 1 or more ligaments
- obvious instability
- surgery usually required
What are the phases of ligament healing?
- Inflammatory phase (1-7 days):
- fibrin clot forms in ligament tears - Proliferation phase (7-21 days):
- tendons and ligaments weakest, tensile strength builds - Remodelling (>14 days):
- tendons and ligaments heal with scar tissue that reduces ultimate strength
- causes adhesions - Maturation (weeks to years):
- max strength reached within year
What are the factors affecting tissue healing?
Mechanical environment:
- movement
- forces
Biological environment:
- blood supply
- immune function
- infection
- nutrition
What are the good and bad effects of immobilisation (brace or plaster) on injured ligamentous tissue?
Good:
-less ligament laxity (lengthening)
Bad:
- less overall strength go ligament repair scar
- protein degradation exceeds protein synthesis r net d in collagen quantity
- production of inferior tissue by blast cells
- resorption of bone at site of ligament insertion
- build tissue tensile strength (50% in 6-9weeks)
What are the benefits of mobilisation (movement) on injured ligamentous tissue?
- ligament scars are wider, stronger, and more elastic
- better alignment/quality of collagen
