1b Management of Orthopaedic Conditions Flashcards
What are osteoblast cells?
Bone forming
Secrete Osteoid
Catalyse mineralisation of osteoid
what is an osteocyte cell?
Mature bone cell
What are osteocytes formed?
Formed when an osteoblast becomes imbedded in its secretions
What do osteocyyte cells sense?
Mechanical strain to direct osteoclast and osteoblast activity
What is an osteoclast?
Bone breaking - dissolves and reabsorbed bone by phagocytosis
What investiagtions should be done to look for a fracture?
Radiograph
CT Scan
Bone Scan
MRI Scan
What should you include when describing a fracture?
Location: which bone and which part of bone?
Pieces: simple/multifragmentary?
Pattern: transverse/oblique/spiral
Displaced/undisplaced?
Translated/angulated?
X/Y/Z plane
What are the two ways a fracture might be displaced?
Translation
Angulation
Why is childrens bone more elastic than adults?
Children’s bone can bend – more elastic than adult
Increased density of haversian canals
What are the clinical signs of a fracture?
Pain
Swelling
Crepitus
Deformity
Adjacent structural injury:
Nerves/vessels/ligament/tendons
Describe the stages of fracture healing?
Step 1: Bleeding/Haematoma – prostaglandins/cytokines released; growth factors increase local blood flow – Periosteal supply takes over
Step 2: Granulation Tissue/connective tissue/Fibrous tissue laid down / Soft Callus
Step3: Once fracture is bridged with soft callus- hard callus is formed ( laying down of Osteoid/ bone)
Step4 : Bone is remodelled via endochondral ossification lamellar bone in its place.
What is Wolff’s Law?
Bone grows and remodels in response to the forces that are placed on it
What is used to describe the soft tissue integity of a fracture?
Open / Closed
What is used to describe the number of bony fragments of a fracture?
Green stick
Simple
Multifragmentary
What is used to describe the movement of a fracture?
Displaced / undisplaced
What are the general principles of managing a fracture?
reduce
Hold
Rehabilitate
What are the causes of a fractured neck of femur?
Osteoporosis (older)
Trauma (younger)
Combination
What treatment would you use for an extracapsular fracture?
Minimal risk to blood supply and AVN: fix with plate and screws
How would you treat an intracapsular fracture is undisplaced?
Fix with screws as there is less risk to the blood supply
How would you treat an intracapsular fracture if displaced?
25-30% risk AVN: replace in older patients; fix if young
How would you treat an intracapsular, displaced fracture in patients over 65?
Fit and mobile - total hip replacement
Less fit = hemiarthroplasty
what are the types of fibrous joints?
Sutures
Syndesmosis
Interosseous membrane
What are the types of cartilaginous joints?
Synchondroses
Symphyses
What are the types of synovial joints?
Plane
hinge
Condyloid
Pivot
Saddle
Ball and Socket
How are synovial joints stabilised?
muscles / tendons
ligaments
bone surface congruity
What are the components of a synovial joint?
Synovium
Synovial Fluid
Articular cartilage
What does the articular cartilage consist of?
Type 2 Collagen
Proteoglycan (Aggrecan)
What is the synovial fluid?
Hyaluronic rich viscous fluid
What is the synovium?
1-3 cell deep lining containing macrophage-like phagocytic cells (type A synoviocyte) and fibroblast-like cells that produce hyaluronic acid (type B synoviocyte), with type 1 collagen
What is cartilage composed of?
Cartilage is composed of:
1) specialized cells (chondrocytes)
2) extracellular matrix: water, collagen and proteoglycans
(mainly aggrecan)
What is aggrecan?
Aggrecan is:
-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 the two major divisions of arthritis?
Osteoarthritis and Inflammatory arthritis
What is OA?
Degenerative arthritis
What is joint space narrowing?
joint space narrowing indicates articular cartilage loss. This can occur in osteoarthritis (primary abnormality) and in Rheumatoid Arthritis (secondary damage due to synovitis)
What radiographic changes will you see in a patient with RA?
joint space narrowing
osteopenia
bony erosions
What type of osteopenia is a common radiographic sign of inflammatory arthritis?
juxta-articular osteopenia
Where do bony erosions occur in RA?
erosions occur initially at the margins of the joint where the synovium is in direct contact with bone (the ‘bare’ area; see rheumatoid arthritis lecture)
What features might you see in a radiograph of patients with OA?
Joint space narrowing
Subchondral cysts
Sclerosis
Osteophytes
What is OA?
deterioration of chondral cartilage in joints which results in bones rubbing together and creating stiffness, pain, and impaired movement.
What are the inflammatory mediators of RA?
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 signs and symptoms of OA?
Pain (exertional/rest/night)
Disability: walking distance/stairs/giving way
Deformity
what deformity might occur in OA?
Valgus deformity
Which procedure can be done for ACL injury?
Lachmann’s
Which test suggests ACL injury?
Anterior draw
what are the risk factors for OA?
Age
Weight
Menopause as less oestrogen
Injury
Overuse
What are the conservative principles of OA management?
Analgesics
Physiotherapy
Walking aids
Avoidance of exacerbating activity
Injections (steroid/viscosupplementation)
What are the operative management principles of OA?
Replace (knee/hip)
Realign (knee/big toe)
Excise (toe)
Fuse (big toe)
Synovectomy (Rheumatoid)
Denervate (wrist)
What is infection of the bone called?
Osteomyelitis
What is septic arthritis?
Infection of the joint resulting in swelling, stiffness, fevers and weight loss
What causes septic arthritis?
Bacterial infection of a joint (usually caused by spread from the blood)
Why is septic arthritis important?
Medical emergency
How many joints are effected in septic arthritis?
usually one
Why is gonococcal septic arthritis an exception?
Affects multiple joints, and less likely to cause joint destruction so do not need to aspirate the joint
What are the signs and symptoms of a septic arthritis?
Consider septic arthritis in any patient with an acute painful, red, hot, swelling of a joint, especially if there is fever
How is septic arthritis diagnosed?
by joint aspiration. Send sample for urgent Gram stain and culture
what is the treatment of septic arthritis?
Treatment is with surgical wash-out (‘lavage’) and intravenous antibiotics
What bloods are done for septic arthritis?
CRP: acute marker
ESR slower response
WCC
TB culture/PCR
What are the treatments for osteomyelitis?
Antibiotics: iv weeks
Surgical drainage: especially collections/sequestrum
Chronic: antibiotic suppression/dressings
??amputation
What are the treatments for septic arthritis?
Surgery: joint washout and drainage (repeated if required)
Iv antibiotics (days/weeks)
Immobilise joint in acute phase
Physiotherapy once over acute phase
Describe the organisation of compact bone?
Repeated structural units ‘Osteons’ – concentric ‘Lamellae’ around a central ‘Haversian Canal’
What is a haversian canal?
‘Haversian Canal’ – contain blood vessels, nerves and lymphatics.
What are Volkmans canals?
transverse perforating canals
What are lacunae?
small spaces containing osteocytes
What does the medullary cavity contain?
Yellow bone marrow
What is the difference between a stress and pathological fracture?
Stress = Abnormal stresses on normal bone
Pathological = Normal stresses on abnormal bone
