Treating MSK conditions Flashcards
what are the 4 main types of bone cells?
osteogenic
osteoblast
osteocyte
osteoclast
what are osteogentic cells?
bone stem cells
what are osteoblasts?
bone forming
secrete osteoid
catalyse mineralisation of osteoid
what are osteocytes?
mature bone cells
formed when osteoid becomes embedded in its secretions
sense mechanical strain to direct osteoclast and osteoblast activity
what are osteoclasts?
bone breaking
dissolve and reabsorb bone by phagocytosis
derived from bone marrow
what form the compact organisation of bone?
osteons- form cortical aspect of bone
how are osteon arranged?
- Few spaces
- Provides protection, support and resists stressed produced by weight and movement
- Made up of:
- Repeated structural units of osteons
- Concentric lamellae around a central haversian canal
- Repeated structural units of osteons
what do haversian canals contain?
blood vells, nerves and lymphatics
what is between haversian canals?
volkmans canal- transverse perforating canals
where do osteocytes exist in bone?
within concentric lamellae- in lacunae (small spaces)
tint canaliculi radiate from lacunae filled with ECF
where are osteoblasts and osteoclasts?
lining of bone (endosteum and periosteum)
what is the structure of bone?
what does the medullary cavity contain?
yellow bone
what is the connective tissue covering bone?
periosteum
what is the proximal structure of long bones in children?
what are the mechanisms of bone fracture?
what are the pathological causes of bone fracture?
what are the fracture patterns?
soft tissue integrity (open or closed)
bony fragments (greenstick, simple, multifragmentary)
movement (displaced, undisplaced)
what is the process of fracture healing pathologically?
- Inflammation
- Hematoma formation
- Release of cytokines
- Granulation tissue and blood vessel formation
- Repair
- Soft callus formation (type II collagen- cartilage)
- Converted to hard callus (type I collagen-bone)
- Remodelling (endochondral ossification)
- Callus responds to activity, external forces, functional demand and growth
- excess bone is removed
what is wolff’s law?
bone grows and remodels in response to the forces that are placed on it
what are the clinical signs of fracture?
- Pain
- Swelling
- Crepitus
- Deformity
- Adjacent structural injury (nerves, vessels, ligaments, tendons)
what are the investigations of a fracture?
radiograph
CT
bone scan
MRI
what are the different angles of fracture displacement description?
when describing a radiograph what is displacement described relative to?
lower joint
what is the management of fractures?
what are the types of reduction techniques?
what are the types of hold techniques?
what are the types of fixation?
what are the rehabilitation techniques?
what are the general fracture complications?
- Fat embolus (hours)
- DVT (days-weeks)
- PE
- Infection/sepsis
- Prolonged immobility (UTI, chest infections (not breathing as deeply), sores)
what are the immediate local complications of fracture?
- Local visceral injury
- Nerve injury
- Vascular injury
- Compartment syndrome
- Hemarthrosis
- Infection
- Gas gangrene
what are the less urgent complications of fracture?
- Fracture blister
- Plaster sores
- Pressure sores
- Nerve entrapment
- Myositis ossificans
- Ligament injury
- Tendon lesions
- Joint stiffness
- Chronic regnal pain syndrome
what are the late local complications of fracture?
- Delayed union
- Malunion
- Non-union
- Avascular necrosis
- Muscle contracture
- Joint instability
- Osteoarthritis
what is the anatomy of the neck of femur?
what are the types of neck of femur fracture?
what are the causes of neck of femur fracture?
- Osteoporosis (older)
- Trauma (younger)
- Combination
what is the important history of neck of femur fracture?
- Age
- Comorbidity
respiratory/cardiovascular/diabetes/cancer - Preinjury mobility
independent/shopping/walking/sports - Social hx: relatives, stairs,
what is the treatment for neck of femur fracture?
what is the classification of joints?
what are the types of synovial joints?
what are synovial joints stabilised by?
- Bone surface congruity
- Ligaments that connect each bone to another bone
- Muscles/tendons that stabilise
- These factors vary by joint
what is cartilage composed of?
- 1) specialized cells (chondrocytes)
- 2) extracellular matrix: water, collagen and proteoglycans
- (mainly aggrecan)
Cartilage is avascular – it has no blood supply
what is aggrecan?
- a proteoglycan that possesses many chondroitin sulfate and keratin sulfate chains
- characterized by its ability to interact with hyaluronan (HA) to form large proteoglycan aggregates
what is the pathophysiology of osteoarthritis?
- a long-term chronic disease
- deterioration of cartilage in joints which results in bones rubbing together and creating stiffness, pain, and impaired movement.
- Degenerative disease of chondral cartilage
- Inflammatory mediators include proteinases, e.g., matrix metalloproteinases (MMPs) and aggrecanases, and inflammatory cytokines, including interleukin (IL)-1β and tumor necrosis factor α (TNFα)
- which enhance the synthesis of proteinases and other catabolic factors to degrade the articular cartilage membrane
what are the early and late stages of oeteoarthritis?
what are the main risk factors of osteoarthritis?
- Age
- Excess weight/obesity
- Mechanical constraints (intense sport, some professions)
- Heredity
- Female, menopause
- Osteonecrosis
- Leg bone malalignment
- Oestrogen deficiency
- Metabolic syndrome
- Advanced hip osteoarthritis caused by spondylarthritis or rheumatoid arthritis
what are other risk factors of osteoarthritis?
- Injury: cruciate ligament rupture
- Meniscectomy (surgical removal of meniscus)
- Metabolic diseases (chondrocalcinosis, genetic haemochromatosis)
- Infectious diseases involving the bone
- Rheumatoid arthritis sequalae
what are the signs of osteoarthritis?
- Pain (exertional/rest/night)
- Disability: walking distance/stairs/giving way
- Deformity
what history should be found out for osteoarthritis?
- Previous history: trauma/infection
- Treatments given (physio/injections/operations)
- Other joints affected
what are the radiographic changes of osteoarthritis?
Osteoarthritis: (LOSS)
L- loss joint space
O- osteophyte
S- subchondral cysts
S- subchondral sclerosis
what is the conservative management of osteoarthritis?
- Analgesics
- Physiotherapy
- Walking aids
- Avoidance of exacerbating activity
- Injections (steroid/viscosupplementation)
what is the operative management of osteoarthritis?
- Replace (knee/hip)
- Realign (knee/big toe)
- Excise (toe)
- Fuse (big toe)
- Synovectomy (Rheumatoid)
- Denervate (wrist)
what is an infection of bone called?
osteomyelitis
what is an infection of joint called?
septic arthitis
what are the features of osteomyelitis?
- Acute or chronic
- Primary or secondary
- Pain/swelling/discharge
- Systemic signs:
- Fevers, sweats wt loss
- often bacterial straight to bone through blood or bacteria on metal from operation
what are the features of septic arthritis?
- Pain
- Joint swelling/ stiffness
- Fevers, sweats, wt loss
- Bacteria in joint (attach joint and synovium) can produce pus
what is septic arthritis?
bacterial infection of a joint (usually caused by spread from blood)
what are the risk factors of septic arthritis?
immunosuppressed
pre-existing joint damage
intravenous drug use (IVDU)
what is the treatment of septic arthritis?
medical emergency -> untreated= destroy a joint
- Surgery: joint washout and drainage (repeated if required)
- Iv antibiotics (days/weeks)
- Immobilise joint in acute phase
- Physiotherapy once over acute phase
what joints are affected in septic arthritis?
- Usually only 1 joint is affected* (monoarthritis)
- *gonococcal septic arthritis is an exception:
- It often affects multiple joints (polyarthritis)
- *gonococcal septic arthritis is an exception:
It is less likely to cause joint destruction
when should septic arthritic be considered?
- Consider septic arthritis in any patient with an acute painful, red, hot, swelling of a joint, especially if there is fever
what is the diagnosis of septic arthritis?
joint aspiration. Send sample for urgent Gram stain and culture
what common organisms cause septic arthritis?
streptococci
gonococcus
staphylococcus aureus
what blood results should be taken with bone infections?
- CRP: acute marker
- ESR slower response
- WCC
- TB culture/PCR
what is the treatment of osteoarthritis?
- Antibiotics: iv weeks
- Surgical drainage: especially collections/sequestrum
- Chronic: antibiotic suppression/dressings
- ??amputation
