How to Treat Musculoskeletal Conditions Flashcards
What is an osteocyte?
- mature bone cell
- formed when an osteoblast becomes imbedded in its secretions
- sense mechanical strain to direct osteoclast and osteoblast activity
What is an osteoblast?
- bone forming
- secretes osteoid
- catalyses the mineralisation of osteoid
What is an osteoclast?
- bone breaking
- dissolve and resorb bone by phagocytosis
- derived from bone marrow
What is an osteon?
- repeated structural units
- concentric lamellae around a central haversian canal
What is a haversian canal?
contains blood vessels, nerves and lymphatics
What are lacunae?
- small spaces containing the osteocytes
- tiny canaliculi radiate out, filled with extracellular fluid
What is Volkmans canal?
transverse perforating canals
What is the structure of long bones?
- periosteum
- outer cortex
- cencellous bone
- medullary cavity
- nutrient artery
- articular cartilage
What is the periosteum?
connective tissue covering
What is the outer cortex comprised of?
compact bone
What is in the medullary cavity?
yellow bone marrow
Where is articular cartilage found?
on the surface of a bone at a joint
What are the different mechanisms of bone fracture?
- trauma
- stress
- pathological
What are the different trauma mechanisms of fracture?
- low energy
- high energy
What is the stress mechanism of bone structure?
abnormal stresses on normal bone
What is the pathological mechanism of bone fracture?
normal stresses on abnormal bone
What are the possible causes of pathological bone fracture?
- osteoporosis
- malignancy
- vitamin D deficiency (osteomalacia, rickets)
- osteomyelitis
- osteogenesis imperfecta
- Paget’s
What is the first step of fracture healing?
Inflammation
- hematoma
- release of cytokines/prostaglandins
- granulation tissue and blood vessel formation
What is the second step of fracture healing?
Repair
- soft callus formation (type 2 collagen - cartilage)
- converted to hard callus (type 1 collagen - bone)
What is the third step of fracture healing?
Remodelling
- callus responds to activity: external forces, functtional demands 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 a fracture?
- pain
- swelling
- crepitus
- deformity
- adjacent structural injury (nerves/vessels/ligament/tendons)
What investigations can be done in a fracture?
- radiograph
- bone scan
- CT scan
- MRI scan
What are the steps to describe a fracture radiograph?
- location?
- pieces?
- pattern?
- displaced/undisplaced?
- translated/angulated?
- X/Y/Z plane?
What is considered an urgent complication of fractures?
- local visceral injury
- vascular injury
- nerve injury
- compartment syndrome
- haemarthrosis
- infection
- gangrene
What is considered a less urgent complication of fractures?
- fracture blisters
- plaster sores
- pressure sores
- nerve entrapment
- myositis ossificans
- ligament injury
- tendon lesions
- joint stiffness
- algodystrophy
What is considered a late complication of fractures?
- delayed union
- malunion
- non-union
- avascular necrosis
- muscle contracture
- joint instability
- osteoarthritis
What treatment is given to an extracapsular neck of femur fracture?
fix with plate and screws (dynamic hip screw)
What treatment is given to an intracapsular, undisplaced neck of femur fracture?
fix with screws
What treatment is given to an intracapsular, displaced neck of femur fracture?
- replace in older patients
- fix in younger patients
What are the 3 different classifications of joints?
- fibrous
- cartilaginous
- synovial
What are the different types of fibrous joints?
- sutures
- syndesmosis
- interosseous membrane
What are the different types of cartilaginous joints?
- synchondroses (spine)
- symphyses (pubic)
What are the different types of synovial joints?
- plane
- hinge
condyloid - pivot
- saddle
- ball and socket
How are synovial joints stabilized?
- muscles and tendons
- ligaments
- bone surface congruity
What are the components of synovial joints?
- synovium
- synovial fluid
- articular cartilage
What is synovium?
1-3 cell deep lining containing:
- macrophage like phagocytic cells (type A synoviocyte)
- fibroblast-like cells that produce hylauronic acid (type B synoviocyte)
- Type 1 collagen
What is synovial fluid?
hylauronic acid-rich viscous fluid
What is articular cartilage comprised of?
- Type 2 collagen
- Proteoglycan (aggrecan)
What is cartilage comprised of?
- specialised cells (chondrocytes)
- extracellular matrix (water, collagen and proteoglycans (aggrecan)
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 are common knee conditions for 15-45 years old?
- Patellofemoral maltracking
- ACL/PCL
- Meniscal tears
- fractures
What are common knee conditions for 45-60 years old?
- OA
- Patellofemoral maltracking
- ACL/PCL
- Meniscal tears
- Fractures
What are common knee conditions for people above 60 years old?
OA
What are common hip conditions for 15-45 years old people?
- developmental dysplasia
- leg length discrepancy
- impingement
What are common hip conditions for 45-60 years old people?
- OA
- Avascular necrosis
- impingement
What are common hip conditions for people above 60 years old people?
- OA
- post total hip replacement
What are common shoulder conditions for 15-45 years old people?
- dislocation
- fractures
What are common shoulder conditions for 45-60 years old people?
- impingement
- dislocation
- ACJ OA
- rotator cuff tears
- fractures
What are common shoulder conditions for above 60 years old people?
- glenohumeral OA
- impingement
- cuff tears
- fracture
What are the risk factors of septic arthritis?
- immunosuppressed
- pre-existing joint damage
- intravenous drug use
How is septic arthritis diagnosed?
joint aspiration (gram stain and culture)
What common organisms are responsible for septic arthritis?
- Staphylococcus aureus
- Streptococci
- Gonococcus (affects multiple joints)
What is the treatment of septic arthritis?
- surgical wash-out
- IV ABx
- immobilise in acute phase
What is osteoarthritis?
Degenerative disease of chondral cartilage
What happens in the processes of developing osteoarthritis?
- Inflammation occurs late in disease cf. rheumatoid
- 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 risk factors of developing osteoarthritis?
- age
- obesity
- mechanical constraints
- hereditary
- female, menopause
- osteonecrosis
- leg bone malalignment
- estrogen deficiency
- metabolic syndrome
- advanced hip OA (spondylarthritis and RA)
What conservative management is available for OA?
- analgesics
- physiotherapy
- walking aids
- avoidance of exacerbating activity
- injections (steroid/viscosupplementation)
What operative management is available for OA?
- replace (knee/hip)
- realign (knee/big toe)
- excise (big toe)
- fuse (big toe)
- synovectomy (R)
- denervate (wrist)
What radiographic changes can be seen with OA?
- subchondral cysts
- loss of joint space
- sclerosis
- osteophyte
How does OA present?
- pain (exertional/rest/night)
- disability (waliing/stairs)
- deformity
Hx - trauma/infection
What is a bone infection?
osteomyelitis
How does osteomyelitis present?
- acute or chronic
- pain
- swelling
- discharge
- fevers
- sweats
- weight loss
What is septic arthritis?
infection of the joint
How does septic arthritis present?
- pain
- swelling
- stiffness
- fevers
- sweats
- weight loss
How is osteomyelitis treated?
- IV ABx
- surgical drainage
- chronic: ABx suppression
- ?amputation
What radiological investigations can be done for bone/joint infections?
- Plain films
- MRI scans: bony architecture/collections
- CT if MRI not available
- Bone scans: multifocal disease
- Labelled White cell scans
What blood investigations can be done for bone/joint infections?
- CRP (acute marker)
- ESR (slower response)
- WCC
- TB culture/PCR
