injury and healing Flashcards
- What are the mechanisms of bone fracture?
- Trauma
Low energy or high energy transfer
- StressAbnormal stresses on normal bone
- PathologicalNormal stresses on abnormal bone
- What are the weight bearing bones of the human body?
Femur, tibia, metatarsals and navicular
- What is the female athlete triad?
Amenorrhoea - absence of periods; low oestrogen levels
Osteoporosis - Reduction in bone mineral density, thus increasing porous structure; susceptible to fracture Disordered eating - Ca2+ deficiency
- Give examples of conditions that can lead to a pathological/insufficiency fracture
Osteopenia and osteoporosis - Soft bone
Malignancy- primary or bone mets Vitamin-D deficiency - Insufficient exposure to sunlight, reduced vitamin-D source → Osteomalacia + Ricket's Osteomyelitis Osteogenesis Imperfecta - Collagen deficiency Paget's disease
- What causes osteopenia and osteoporosis?
- what is primary osteoporosis?
Bone remodelling imbalance → Osteoclast activity greater than osteoblast activity
Leads to disrupted microarchitecture
Osteoporosis due to age. senile osteoporosis- 70
- What fractures is osteoporosis associated with?
- What can secondary osteoporosis be caused by?
Fragility fractures - Hip, spine, wrist
Low energy trauma fractures
Hypogonadism - low oestrogen. postmenopausal osteoporosis 50 Glucocorticoid excess - glucocorticoids inhibit insulin growth factor-1 which can directly or indirectly reduce osteoblast function Alcoholism - increases PTH which leaches Ca2+ from the bone and excess alcohol can kill osteoblasts
- What can inadequate calcium or phosphate lead to in bones?
Defect in osteoid matrix mineralisation, leads to soft bone, predisposed to fractures
- Explain the pathogenesis of congenital OI
- what are the effects of OI?
Decreased type one collagen due to
- Reduction in type I collagen secretion
- production of abnormal collagen
causes insufficient osteoid production, so increased bone weakness
effects on heart, bone, hearing and sight.
blue schlera can be present
short stature
- Explain what Paget’s disease is
Excessive bone degradation and disorganised bone remodelling → Deformity, pain, fracture or arthritis. bone turnover is disturbed
May transform into malignant disease
- Outline the 4 stages of Paget’s disease
- Osteoclastic activity (Increased bone resorption)
- Mixed osteoclastic-osteoblastic activity (Imbalance) results in disorganised bone remodelling, considering the osteoid scaffold is disrupted and diverted through osteoclastic activity → Deformities arises
- Osteoblastic activity
- Malignant degeneration
- List the primary bone cancers
- What is a secondary bone cancer?
Osteosarcoma
Chondrosarcoma
Ewing sarcoma
Lymphoma
Metastatic bone tumours from other tissues. other tissues have spread metastases to bone
- How do we describe fractures?
- Soft tissue integrity
- Bony fragments
- Movement
Open - Fracture in which at least one end of the bone penetrates the skin; presenting potential risk of infection
Closed - A fracture in which the skin remain intact
Greenstick - Partial fracture in which one side of the bone is broken
Simple
Multifragmentory (comminuted)
Displaced
Un-displaced
- What are the types of secondary bone cancers that can lead to a pathological bone fracture?
Lytic - Bone eating; Kidney, thyroid, lung and breast
Blastic - Bone forming; Prostate and breast
How do stress fractures occur
Overuse of bone stress exerted on bone is greater than the bones capacity to remodel leads to bone weakening stress fracture occurs leads to risk of complete fracture
- Outline the inflammation process of fracture healing
Bleeding/ Haematoma → Release of cytokines - Inflammation
Granulation (Connective/fibrotic) tissue deposited + blood vessel formation
- Outline the Repair process of fracture healing
Fracture is bridged with soft callus (Type II collagen → Cartilage; fibroblasts, woven blood
Hard callus formation succeeds (laying down of osteoid → Type 1 collagen) facilitated by increased osteoblast activity (more like bone)
- Outline the remodelling process of fracture healing
3.Remodelling- Callus responds to activity, external forces, and the functional demands exerted onto bone; therefore this stimulates a balance of osteoblast and osteoclast activity to remodel bone (removal of excess)
- Outline the differences between primary and secondary bone healing
Primary: Intramembranous healing
Mesenchymal stem cell goes straight to the bone cells in fracture to start replacing bone cells
occurs when there is a very stable fracture that is almost completely back together
Secondary: Endochondral healing involving responses in the periosteum and external soft tissues + Relative stability; Endochondral ossification → More callus Mesenchymal stem cell goes to the chondral precursor to start producing new bone cells
- When do you see signs of healing visibly on an X-ray?
From 7-10 days
- What is the duration for each step in fracture/bone healing?
Inflammatory - Hours to days
Repair - Days to weeks Remodelling - Months to years
- What are the general principles of fracture management?
Reduce → Closed, open (bringing both ends of fracture back together again)
Hold → Metal; no metal (hold fracture together) Rehabilitate → Move, physiotherapy, use (because bone will probably be stiff or weak
- What is ‘reduction’ in terms of fracture management?
- what are the closed methods
- what are the open methods
Involves restoring the anatomical alignment of a fracture or dislocation of the deformed limbs
manipulation, traction
mini incision, full exposure
- What is skin and skeletal traction?
Skin - Wrap bandage around fracture and then add a weight to bring limb into natural alignment
Skeletal - Put a pin through bone and use a larger weight (you can apply more force to bone than skin)
- What are the different types of ‘hold’?
Fixation
Closed → Plaster and traction (skin; skeletal)
what are the different types of fixation
- Plaster (Closed hold)
- Intra-medullary internal fixation- pins or nails
- Extra-medullary internal fixation - pins plates or screws
- Mono-planar external fixation
- Multi-planar external fixation
- What methods are there to rehabilitate (intensive period of physiotherapy following fracture management)?
Use - Pain relief and retrain (physio)
Move Strengthen (Muscles) Weight-bear (for lower limbs)
- Give examples of soft tissue injury
Tendinopathy:
Tendinitis - Inflammation of tendon associated from overuse (In additions to infection or rheumatic disease). Swelling + pain → reduced mobility of tendon and muscle. Tendinosis - Caused by overuse of a tendon → Abnormal thickening. Rupture - (Mainly ligaments/tendons tearing)
- List and explain ligament injury classifications
Grade I - Slight incomplete tear → No notable joint instability.
Grade II - Moderate/severe incomplete tear → Some joint instability. One ligament may be complete torn. Grade III - Complete tear of 1+ ligaments → Obvious indication of stability of instability surgical requirement.
- How can we treat tendon or ligament tears?
Immobilise - Plaster OR boot/brace
Surgical repair - Suture
- What are the good and bad effects of immobilisation on injured tissue?
- Good
Less ligament laxity (lengthening)- BadLess overall length of ligament repair scar
Protein degradation exceeds protein synthesis
Production of inferior tissue by blast cells
Resorption of bone at site of ligament insertion
Decreased tissue tensile strength (50% in 6-9 weeks)
- BadLess overall length of ligament repair scar
- What are the benefits of mobilisation on injured ligamentous tissue?
Ligament scars are wider, stronger and more elastic
Better alignment/quality of collagen
- What factors affect tissue healing?
Mechanical environment - Movement and forces
Biological environment - Blood supply, immune function, infection, nutrition
