Week 11 - Musculoskeletal Flashcards
What is the purpose of a tendon?
Transmits force from muscle to achieve movement
Describe the structure of a tendon?
- Parallel collagen fibrils with tenocytes
- Surrounded by paratenon / tendon sheath
How does the tendon get its nutrition?
Largely avascular, nutrition via paratenon
What are 3 results of chronic tendon injury over use (repetitive loading)?
- Degeneration, disorganisation of collagen fibres
- Increased cellularity
- Little inflammation
Describe tendinopathy?
Loss of balance between micro damage from overuse & reparative mechanisms
List 7 risk factors for tendinopathy?
- Age
- Chronic Disease
- Diabetes, Rheumatoid Arthritis
- Adverse Biomechanics
- Repetitive Exercise
- Recent increase in activity
- Quinolone Antibiotics
Describe the pathology of tendinopathy?
- Deranged collagen fibres / Degeneration with a scarcity of inflammatory cells
- Increased vascularity around the tendon
- Failed healing response to micro tears
List the 3 inflammatory mediators released in tendinopathy?
- IL-1
- Nitric Oxide
- Prostaglandins
What do the released inflammatory mediators cause in tendinopathy?
- Apoptosis
- Pain
- Provoke degeneration through release of matrix metalloproteinas
List 8 common tendinopathies?
- Achilles Tendinopathy
- Rotator cuff tendonitis
- Tennis Elbow (Lateral epicondylitis)
- Golfers Elbow (Medial epicondylitis)
- Patella Tendinopathy
- Hamstring tendonitis
- Adductor tendonitis
- Plantar fasciitis
List the 5 clinical features of Tendinopathy?
- Pain
- Swelling
- Thickening
- Tenderness
- Provocative tests
What are 3 ways to diagnose Tendinopathy?
- X-ray
- Ultrasound
- MRI- Tendinopathy best seen on T1
List the 9 non-operative treatment for Tendinopathy?
- NSAID’s
- Activity modification
- Physiotherapy
- GTN patches
- PRP injection
- Prolotherapy- irritant injection, dextrose
- Extracorporeal Shockwave Therapy
- Topaz- radiofrequency coblation
- Steroid injection
Describe the physiotherapy intervention for Tendinopathy?
- Eccentric loading
- Contraction of the musculotendinous unit whilst it elongates
- Beneficial in approx 80%
Describe the GTN patch intervention for Tendinopathy?
- ¼ patch 125 mcg
- Vasodilator, Increases local perfusion
- Takes up to 12 weeks to see effects
What is the side effect of GTN patch intervention for Tendinopathy?
Headaches
Describe Extra Corporeal Shockwave Therapy for Tendinopathy?
- 3 weekly treatments
- Approx 75% improve
Describe the operative treatment for Tendinopathy?
- Debridement
- Excision of diseased tissue
- Possible to debride 50% of tendon without loss of function
- Tendon transfers
What is the outcome for Tendinopathy?
- Most will improve over time with activity modification
- Most non-operative measures improve symptoms in 70-80% over 1-2 years
- Surgical treatment effective in approx 80% if non-operative methods fail
What is the definition of compartment syndrome?
Elevated interstitial pressure within a closed fascial compartment resulting in microvascular compromise
What are the 3 common sites for compartment syndrome?
- Leg
- Forearm
- Thigh
How severe is compartment syndrome?
Orthopaedic Emergency causing loss of function, limb or life
Describe the pathophysiology of compartment syndrome?
- Pressure within the compartment exceeds pressure within the capillaries
- Reduced local blood flow
- Reduced tissue perfusion
Describe the muscular effect of compartment syndrome?
- Muscles become ischemic & develop oedema through increased endothelial permeability
- Necrosis begins in the ischaemic muscles after 4 hours
What happens to the ischaemic nerves in compartment syndrome?
- Become neuropraxic
- This may recover if relieved early, permanent damage may result after as little as 4 hours
What happens in late compartment syndrome?
Compromise of the arterial supply
What is the equation for Local Blood Flow (LBF)?
LBF = (Pa – Pv)/R
List the 6 pathophysiological outcomes for compartment syndrome?
- Decreased perfusion
- Muscle ischaemia & swelling
- Increased permeability- fluid leaks into interstitial space
- Increased pressure
- Autoregulatory mechanisms overwhelmed
- Muscle necrosis and myoglobin release
Describe the effect of 1hr ischaemia in compartment syndrome?
Nerve conduction normal, Muscle viable
Describe the effect of 4hr ischaemia in compartment syndrome?
- Neuropraxia in nerves, reversible
- Reversible Muscle ischaemia
Describe the effect of 8hr ischaemia in compartment syndrome?
- Nerve axonotmesis & irreversible change
- Irreversible muscle ischaemia & necrosis
List the 4 end stage features of compartment syndrome?
- Stiff fibrotic muscle compartments
- Impaired nerve function
- Clawing of limbs
- Loss of function
What are the 2 different causes of compartment syndrome?
- Internal pressure
2. External compression
List the 5 types of internal pressure causing of compartment syndrome?
- Trauma- fractures, entrapment
- Bleeding
- Muscle oedema / myositis
- Intracompartmental administation of fluids / drugs
- Re-perfusion- vascular surgery
List the 4 types of external compression causing compartment syndrome?
- Impaired consciousness / protective reflexes (drug / alcohol misuse, Iatrogenic)
- Positioning in theatre- lithotomy
- Bandaging / casts
- Full thickness burns
List the 6 clinical features of compartment syndrome?
- Pain out of proportion to that expected from the injury
- Pain on passive stretching of the compartment
- Pallor
- Parathesia
- Paralysis
- Pulselessness
List the 3 signs & symptoms of compartment syndrome?
- Swelling
- Shiny Skin
- Autonomic Responses- sweating, tachycardia
Describe the pulses in compartment syndrome?
Pulses present (until late stages) unless associated vascular injury
What occurs later in compartment syndrome?
Parasthesia & paralysis as the deep nerves affected
How is the majority of compartment syndrome diagnosed?
Clinically
What is the normal & exercise compartment pressure?
- Normal pressure 0-4 mmHg
- Exercise pressure 10mmHg
Describe the urgent treatment of compartment syndrome?
- Open any constricting dressings / bandages
- Reassess
- Surgical release
- Later wound closure
- Skin grafting / Plastic surgery input
Describe the surgical release in compartment syndrome?
- Full length decompression of all compartments
- Excise any dead muscle
- Leave wounds open
- Repeat debridement until pressure down & all dead muscle excised
How many compartments does the forearm have?
3 (extensor, flexor, mobile wad of three)
How many compartments does the leg have?
4 (deep posterior, anterior, lateral, superficial posterior)
How many compartments does the thigh have?
3 (anterior, adductor, posterior)
List the 6 peri-operative things to monitor/treat in compartment syndrome?
- Adequate hydration
- Fluid loss
- Monitor & regulate electrolytes (K+)
- Correct acidosis
- Myoglobinuria
- Renal function
Describe the 4 factors of a late compartment syndrome presentation diagnosis?
- Irreversible damage already present
- Fasciotomy will predispose to infection
- Consider non-operative treatment
- Splint in position of function
List the 4 signs & symptoms of septic arthritis?
- Pain
- Fever
- Swollen joint
- Loss of function
List 3 causative organisms of septic arthritis?
- Staphylococcus aureus
- Neisseria gonorrhoea
- Haemophilus influenzae (children)
What 2 things give you an increased risk of septic arthritis?
- Steroids
2. Rheumatoid arthritis
What are the 5 routes in which bacteria can reach the joint and cause septic arthritis?
- Haematogenous
- Dissemination from osteomyelitis
- Spread from an adjacent soft tissue infection
- Diagnostic or therapeutic measures
- Penetrating damage by puncture or trauma
What are the 4 investigations for septic arthritis?
- Joint aspirate- microbiology for gram stain & culture
- Blood culture
- FBC- leucocytosis
- X-ray is of no value
Describe the synovium in septic arthritis?
Inflamed with fibrin exudation & numerous neutrophil polymorphs
How do you treat septic arthritis?
Antibiotics immediately IV
How can you get secondary osteoarthritis with septic arthritis?
When articular cartilage is lost
What is important in septic arthritis & why?
Tuberculosis- blood spread from focus elsewhere, usually spine (Potts disease), hip, knee, tubular bones of hands
What are 3 other specific types of septic arthritis?
- Lyme disease- borrelia burgdoferi
- Brucellosis
- Syphilitic arthritis- congenital & acquired
What are the 2 types of crystal arthropathy?
- Gout
2. Pseudogout
Describe crystal arthropathy?
- Excess levels of uric acid
- Leads to deposition of urate crystals in joints or soft tissue (tophi)
Describe acute gout?
Precipitation in joint stimulates acute inflammatory process
What is the main factor of chronic gout?
Tophi formation
How is gout diagnosed?
By aspirate- negatively birefringent needle shaped crystals on polarized microscopy
What are 2 other tests you would do for gout?
Serum urate levels & U&Es
Describe primary gout?
Hyperuricaemia due to genetic predisposition eg Lesch-Nyhan syndrome
Describe secondary gout?
High uric acid due to myeloproliferative disorder (PCRV), leukaemia treated by chemo, thiazides, chronic renal disease
What is the general rule for uric acid levels?
Higher in older people, obesity, high alcohol consumption, high protein diet, diabetes mellitus
What is the main type of drug for managing gout?
NSAIDs- high doses rapidly reduce pain & swelling
What are 2 alternatives of NSAIDS for managing gout?
- Colchicine
2. Corticosteroids
What are the 2 treatments if gout attacks are repeated?
- Allopurinol- xanthine oxidase inhibitor
2. Uricosuric agent (probenecid)- increases secretion of uric acid into urine
Describe Pseudogout?
- Calcium pyrophosphate crystal deposition
- Synovium (pseudogout)
- Cartilage & extra-articular tissues (chondrocalcinosis)
What are the 2 different types of Pseudogout?
- Acute or Chronic
2. Primary or Secondary (hyperparathyroidism, haemochromatosis)
Describe the appearance of Pseudogout on aspiration?
Positively birefringent rhomboid shaped crystals
What are 3 ways to manage Pseudogout?
- Aspiration helps reduce the pain & swelling
- NSAIDs
- Colchicine
What is reactive arthritis?
- Sterile synovitis which occurs following an infection
- Preceding illness usually a urethritis or diarrhoeal
List 4 trigger organisms for reactive arthritis?
- Salmonella
- Shigella
- Yersinia
- Chlamydia trachomatis
What is reactive arthritis associated with?
HLA B27 (75%)
Describe the clinical features of reactive arthritis?
- Acute, asymmetrical lower limb arthritis
- More common in men
- Days to weeks post infection
List 6 other clinical signs of reactive arthritis?
- Enthesitis (eg plantar fasciitis)
- Sacroiliitis
- Spondylitis
- Anterior uveitis
- Conjunctivitis
- Keratoderma blenorrhagica
How do you manage reactive arthritis?
- Little evidence that treating the triggering infection alters the course of the disease
- Pain control: NSAIDs, intra-articular steroids
Describe the prognosis of reactive arthritis?
- Usually self limited, lasts up to 6 months
- May be chronic
What complication can occasionally occur in reactive arthritis?
Cardiac complications eg aortic regurgitation, aortitis & amyloidosis
What is Enteropathic arthritis?
Form of reactive synovitis seen in association with UC & Crohn’s disease
Describe the appearance of Enteropathic arthritis?
Asymmetrical lower limb arthritis
How do you treat Enteropathic arthritis?
Treatment of the bowel disease & NSAIDs
Describe Osteoarthritis?
- Degenerative joint disease
- Commonest form of arthritis
- Middle aged/elderly
- Weightbearing joints ie. hip, knee
Describe the pathology of osteoarthritis?
Disorder of articular cartilage
Describe primary generalised osteoarthritis?
Multiple joints, hands
Describe secondary osteoarthritis?
Fracture, previous sepsis, RA, osteonecrosis, CDH, steroids, chronic overuse, gout, haemochromatosis, ochronosis, peripheral neuropathy
List 4 X-ray features of osteoarthritis?
- Loss of joint space
- Osteophytes
- Subchondral cysts
- Subchondral Sclerosis
What are the 2 main clinical symptoms of osteoarthiris?
- Pain
2. Stiffness
Describe the synovium in osteoarthritis?
Hyperplastic, mild inflammation, bony detritus
What is the diagnostic criteria used for septic arthritis?
- Kocher Criteria for SA hip in children
- Modified Newman
Describe the 4 points of the Modified Newman criteria for septic arthritis?
- Isolation of pathogenic organism from affected joint
- Isolated of pathogenic organism from another source (blood) in context of a hot red joint suspicious of sepsis
- Typical clinical features & turbid joint fluid in the presence of previous antibiotic treatment &
- Postmortem/ pathological features suspicious of septic arthritis
List the 9 risk factors of septic arthritis?
- Rheumatoid/OA & other inflammatory arthritides
- Biologic disease-modifying anti-rheumatic drugs (bDMARDs)
- Joint prosthesis/surgery
- Low socioeconomic status
- IV drug abuse
- Alcoholic liver disease
- Diabetes
- Previous IA corticosteroid injection
- Cutaneous infection/ulcers
What are 4 differentials for an acute hot joint?
- Septic Arthritis
- Crystal arthropathy
- Trauma/Haemarthrosis
- Early presentation of polyarthropathy (RA/PsA/AS/ReA)
What 4 populations have a higher risk of gram negative bacteria causing septic arthritis?
- Children
- Elderly
- Immunocompromised
- IV drug users
What increasing number of septic arthritis cases are there?
ESBL cases
How may <30 day arthroplasty be managed?
- Debridement
- Exchange of PE liners & prolonged IV antibiotics
- > 1 month almost always need full explant to cure
What is the duration of antibiotics for treating septic arthritis?
- IV for up to 2 weeks or until signs improve
- Orally for 4 weeks
- If prosthetic joint, duration is usually longer (6+ weeks IV then oral suppressive therapy)
What are the medical & surgical treatments for septic arthritis?
- Medical- closed needle aspirations
2. Surgical- arthrotomy, arthroscopy
Describe the triad in reactive arthritis (ReA)?
- Post-infectious arthritis
- Non-gonococcal urethritis
- Conjunctivitis
What type of people are more prone to reactive arthritis & why?
20-40 year Caucasians, probably due to the higher HLA-B27 frequency
For gout management what is the serum uric acid (SUA) aim?
<300 using urate lowering therapy
What are the PROS & CONS of Febuxostat in gout management?
- PROS: can use in renal failure
- CONS: more expensive than Allopurinol
What are the 2 side effects of Febuxostat (gout treatment)?
- LFT abnormalities
2. Increased cardiovascular events
Give 3 examples of drugs used in the long term management of gout?
- Allopurinol- Xanthine Oxidase inhibitor
- Febuxostat- Xanthine Oxidase inhibitor
- Rasburicase- recombinant urate oxidase given IV
What is the active metabolite in Allopurinol?
Oxypurinol, which is excreted renally
Describe Rasburicase in long term gout management?
Effective & rapid at lowering SUA, but limited by antigenicity & progressive risk of anaphylaxis esp with repeated doses
What are the 2 main functions of bone?
- Structural- support, protection, movement
2. Mineral storage- calcium, phosphate
Describe cortical bone?
- Compact or tubular bone
- Slow turnover rate / metabolic activity
- Higher Young’s modulus & resistance to torsion & bending
What % of bone is made up of cortical bone?
80%
Describe cancellous bone?
- Spongy or trabecular bone
- Higher turnover rate & undergoes greater remodelling
- Lower Young’s modulus & is more elastic
What are the 2 types of bone matrix?
- Organic (40%)
2. Inorganic (60%)
What are the 4 cells in bone?
- Osteoprogenitor
- Osteocyte
- Osteoblast
- Osteoclast
Describe the function of osteoblast bone cells?
Produce new bone under the influence of parathyroid hormone
Describe the function of osteocyte bone cells?
- 90% of the cells in mature bone
- Maintain extracellular calcium levels
Describe the function of osteoclast bone cells?
Resorb bone
List the 6 chemicals present in the organic matrix of bone?
- Collagen (mainly type I)
- Mucopolysaccharides
- Non-collagenous proteins
- Proteoglycans
- Growth factors
- Cytokines
List the 2 chemicals present in the inorganic matrix of bone?
- Calcium hydroxyapatite
2. Calcium phosphate
Describe the 3 part structure of bone?
- Diaphysis (shaft)
- Epiphysis (end)
- Metaphysis (transitional flared area between diaphysis & epiphysis)
What is Physis?
- Unique feature of childrens’ bone
- Responsible for skeletal growth
What does Physis allow for?
Remodelling of angular deformity after fracture
What will happen if the physeal blood supply is damaged?
Will lead to growth arrest (either partial or complete)
What are the 2 types of fracture healing?
- Indirect healing (Secondary via callus formation)
2. Direct healing (Primary)
Describe the “fracture haematoma & inflammation” stage of indirect fracture healing?
- Blood from broken vessels forms a clot
- 6-8 hours after injury
- Swelling & inflammation to dead bone cells at fracture site
Describe the “Fibrocartilage (SOFT) callus” stage of indirect fracture healing?
- Lasts about 3 weeks
- New capillaries organise fracture hematoma into granulation tissue - ‘procallus’
- Fibroblasts & osteogenic cells invade procallus
- Make collagen fibres which connect ends together
- Chondrocytes begin to produce fibrocartilage
Describe the “Bony (HARD) callus” stage of indirect fracture healing?
- After 3 weeks & lasts about 3-4 months
- Osteoblasts make woven bone
Describe the “Bone remodelling” stage of indirect fracture healing?
- Osteoclasts remodel woven bone into compact bone & trabecular bone
- Often no trace of fracture line on X-rays
What are the 4 stages of indirect fracture healing?
- Haematoma +Inflammation
- Soft Callus
- Hard Callus
- Remodelling
Describe direct fracture healing?
- Unique ‘artificial’ surgical situation
- ‘Direct formation of bone via osteoclastic absorption & osteoblastic formation, without the process of callus formation, to restore skeletal continuity’
What does direct fracture healing rely on?
Compression of the bone ends
Describe the strength of direct fracture healing?
Fracture stable with no movement under physiological load
What is the appearance of direct fracture healing?
- No callus
- Cutting cones cross fracture site
- Lay down new osteones directly
What must bones have in order to heal?
A blood supply
What are the 2 types of bone blood supply?
- Endosteal- inner 2/3rds
2. Periosteal- outer 1/3rd
What are 2 ways bone blood supply can be injured?
- Fracture
2. Surgery
List the 4 fractures what are prone to problems with union or necrosis (bone death) because of potential problems with blood supply?
- Proximal pole of scaphoid fractures
- Talar neck fractures
- Intracapsular hip fractures
- Surgical neck of humerus fractures
List 8 patient factors that leads to inhibition of fracture healing?
- Increasing age
- Diabetes
- Anaemia
- Malnutrition
- Peripheral vascular disease
- Hypothyroidism
- Smoking
- Alcohol
List 3 medications that lead to inhibition of fracture healing?
- NSAIDs
- Steroids
- Bisphosphonates
Describe how NSAIDs can lead to inhibition of fracture healing?
- Reduce local vascularity at fracture site
- Reduction in healing effect independent of blood flow
- Mainly animal studies, some surgeons avoid use post-operatively
What type of NSAIDS inhibit fracture healing more?
COX 2 NSAIDS inhibit fracture healing more than non-specific NSAIDS
What is the magnitude of NSAID effect on fracture healing related to?
Duration of treatment
Describe how bisphosphonates inhibit fracture healing?
- Inhibit osteoclastic activity
- Delay fracture healing as a result
- Long half life
List 4 things that can be seen on radiographs?
- Trauma
- Arthritis
- Congenital
- Tumour
List 2 things seen on computed tomography (CT) ?
- Bone detail
2. Complex fractures
List 5 things seen on Ultrasound (US)?
- Small superficial lumps
- Tendons
- Joints
- Ligaments
- Synovitis
What is nuclear medicine & PET scanning good for detecting?
Cancer staging
What is Magnetic Resonance Imaging (MRI) good for assessing?
Gold standard for assessing diseases of joints, soft tissues, bones
What is DEXA scanning good for detecting/monitoring?
Osteoporosis
Give 3 examples of guided interventional procedures?
- CT or US guided biopsy
- Drainage
- Radiofrequency ablation
Describe the different density and how anatomy is seen on Xray?
- Air= black
- Fat= dark grey
- Water (muscle)= grey
- Bone= white
List the 10 different types of fractures?
- Displaced
- Angulated
- Rotated
- Overriding
- Distracted
- Comminuted
- Compound
- Transverse
- Oblique
- Spiral
What are the 2 types of joint fractures?
- Extra articular
2. Intra-articular
Describe the appearance of a supracondylar fracture on X-ray?
Malunion will result in the classic ‘gunstock’ deformity due to rotation or inadequate correction of medial collapse
What can posterolateral displacement of the of the distal fragment in a supracondylar fracture be associated with?
Injury to the neurovascular bundle which is displaced over the medial metaphyseal spike
Describe the prognosis of nerve injury due to a Supracondylar fracture?
Almost always results in neuropraxis that resolves in 3-4 months
Describe the appearance of vascular injury due to a Supracondylar fracture?
Usually results in a pulseless but pink hand
What sign needs exploration in a Supracondylar fracture?
Pulseless & white hand after reduction
What important structure is located around the supracondylar area?
Brachial artery which could result in a loss of blood supply to the distal forearm
What is the most common location for a femoral fracture?
Neck of femur
List 6 different femoral fractures?
- Subcapital neck fracture
- Transcervical neck fracture
- Intertrochanteric fracture
- Subtrochanteric fracture
- Fracture of the greater trochanter
- Fracture of the lesser trochanter
What 2 femoral fractures are at a risk of damaging the intracapsular vascular supply?
- Subcapital neck fracture
2. Transcervical neck fracture
What is pathophysiology of Paget’s disease of bone?
Increased bone turnover- osteoclastic & osteoblastic activity either monostotic or polyostotic
Describe the population most affected by Paget’s disease of bone?
- Age >40 years
- M>F
What is the aetiology of Paget’s disease of bone?
- Unknown
- Viral?
- Racial predilection
What is raised in Paget’s disease of bone?
Alkaline phosphatase (ALP)
What are the 2 complications of Paget’s disease of bone?
- Fracture deformity
2. Rarely sarcoma
What imaging sign is coherent with Paget’s disease of bone?
Blade of grass sign- lucent leading edge in a long bone seen during the lytic phase
What can osteoarthritis look like on X ray?
Avascular necrosis
What is the hallmark for degenerative arthritis?
Bone production
What is the hallmark for inflammatory arthritis?
Periarticular erosions
What is the hallmark for depositional arthritis?
Periarticular soft tissue masses (gout & amyloid)
Give 3 examples of reactive bone formation?
- Sub-chondral sclerosis
- Osteophytosis
- Periostitis
What are the 2 locations for bone erosions?
- Peri-articular
2. Para-articular
What are the 2 appearances of bone erosions?
- Ill-defined= active
2. Well defined= old
What are 2 symmetrical joint space narrowing signs?
- Erosions
2. Soft tissue swelling
What are 2 asymmetrical joint space narrowing signs?
- Osteophytes
2. Sclerosis
What are the 2 categories of Joint Space narrowing?
- Inflammatory
2. Degenerative
Describe the 2 different types of inflammatory joint space narrowing?
- 1 Joint: infection
- >1 Joints: Rheumatoid arthritis, seronegative spondyloarthropathy
Describe the 2 different types of degenerative joint space narrowing?
- Typical osteoarthritis
- Atypical osteoarthritis: trauma, crystal depositions, neuropathic, haemophilia
What is Atypical osteoarthritis defined as?
Unusual distribution, severity or age
What is the distal signs of seronegative spondyloarthropathy?
Bony proliferation
What is the proximal signs of rheumatoid arthritis?
No bony proliferation
Describe Primary Degenerative Arthritis?
- Intrinsic degeneration of articular cartilage
- Excessive wear and tear, commonly in hips & knees
What are the 3 X-ray features of Primary Degenerative Arthritis?
- Narrowed joint space
- Osteophytes
- Subchondral sclerosis / cysts
Describe primary degenerative arthritis in the hands?
- DIP, PIP & 1ST MCP joints
- Sclerosis
- Marginal osteophytes
What is secondary degenerative arthritis?
Another process destroys articular cartilage
What are 3 ways to recognise secondary degenerative arthritis?
- Atypical locations
- Atypical appearance
- Atypical age
What are 6 common causes of secondary degenerative arthritis?
- Trauma
- Infection
- Avascular Necrosis
- Calcium pyrophosphate dihydrate disease (CPPD)
- Rheumatoid arthritis
- Haemophilia
What are 4 uncommon causes of secondary degenerative arthritis?
- Haemachromatosis
- Acromegaly
- Ochronosis
- Wilson’s disease
What can any arthritis end up as?
Degenerative arthritis
What are 3 features of Rheumatoid Arthritis with secondary degenerative changes?
- Loss of joint space
- Mild subarticular sclerosis
- Lack of osteophytes
What are the 2 causes of Calcium Pyrophosphate Dihydrate Deposition Disease (CPPD)?
- Idiopathic
2. Associated with Hyperparathyroidism & Haemachromatosis
Describe the appearance of Calcium Pyrophosphate Dihydrate Deposition Disease (CPPD)?
- Symmetrical
- Similar to osteoarthritis but unusual distribution
- Calcification of articular cartilage (Chondrocalcinosis)
- Triangular fibrocartilage of wrist, knee, hip, shoulder & symphysis pubis
What are the 3 clinical signs & symptoms of Calcium Pyrophosphate Dihydrate Deposition Disease (CPPD)?
- Sudden onset of pain / fever
- Tender, swollen, red
- May mimic septic arthritis
What are the 4 types of inflammatory arthritis?
- Infection
- Rheumatoid (seropositive) arthritis
- Seronegative arthropathies
- Other Connective tissue diseases
What are 4 examples of inflammatory Seronegative arthropathies?
- Psoriatic arthritis
- Reactive arthritis
- Ankylosing spondylitis
- Inflammatory bowel disease
What are 2 examples of connective tissue diseases causing inflammatory arthritis?
- Systemic Sclerosis (scleroderma)
2. Systemic lupus erythematosis
What is infectious arthritis usually due to?
Staph, Strep, TB from local injury or surgery
Describe infectious arthritis?
- Destruction of cartilage & cortex
- Tends to affect 1 joint (monoarticular)
- Fingers from bites, Feet in diabetes
- Hips with total hip replacements
List 6 clinical signs of infectious arthritis?
- Soft tissue swelling
- Destruction of cartilage/bone
- Rapid loss of joint space
- +/- periosteal reaction
- Osteoporosis
- Later subluxation, OA, fusion
What is the normal duration of discitis?
1-3 weeks
List the 5 radiographic findings of discitis?
- End-plate erosion
- Disc space narrowing
- Bone destruction
- Paravertebral mass
- Ankylosis
What is a radiographic finding in LATE discitis?
Sclerosis
Who is more commonly affected by rheumatoid arthritis?
2F:1M, middle aged
What is rheumatoid arthritis?
Erosive arthropathy
List the 6 common skeletal locations affected by rheumatoid arthritis?
- Hands
- Feet
- Elbows
- Knees
- Hips
- Cervical spine
What does the newer classification of rheumatoid arthritis include?
Presence of bilateral wrist, MCP or PIP joint enhancement on MRI & leads to a more accurate diagnosis of early RA
List the 6 parts of the rheumatoid arthritis old criteria (4/6 needed for diagnosis)?
- Morning stiffness
- > 2 joints
- Hand & wrist joints
- Rh Nodules
- RF positive
- XR changes
What are the 9 clinical features of rheumatoid arthritis?
- Hyperaemia
- Soft tissue swelling
- Synovitis
- Effusion
- Bone marrow oedema
- Erosions, cysts
- Joint space narrowing
- Secondary degenerative changes
- Loose bodies
What are the 2 types of MRI to show joint changes?
- STIR (Short TI Inversion Recovery)
2. T1W contrast
What is better at showing joint changes- MRI or X-ray?
MRI
Describe the genetics of Sero-negative inflammatory arthropathies?
- Negative rheumatoid factor
- Positive HLA-B27
In what 4 ways does Sero-negative inflammatory arthropathies differ from rheumatoid arthritis?
- Normal bone density
- Periostitis
- Ankylosis (fusion)
- Asymmetrical pattern
Who is more prone to Psoriatic arthritis?
- M = F
- Young adults
Describe the features of psoriatic arthritis?
- Usually skin & nail changes
- DIP joints of hands>feet
- Pencil in cup deformity
- Resorption of distal phalanges
Who is more prone to reactive arthritis (Reiter’s syndrome)?
- M > F
- 20 – 40yrs
- White > black
What are the 5 clinical signs/features of reactive arthritis (Reiter’s syndrome)?
- Urethritis
- Arthritis (50%)
- Conjunctivitis
- Periostitis
- Enthesopathy
What are 2 common skeletal locations for reactive arthritis (Reiter’s syndrome)?
- Lower limb
2. Sacroiliac joint
When does reactive arthritis (Reiter’s syndrome) occur?
1-3 weeks after infection
Who is more prone to Ankylosing spondylitis?
- 3M:1F
- 20-40yrs
What are the 6 clinical signs/features of Ankylosing spondylitis?
- Low back pain
- Stiffness
- Bilateral sacro-iliitis- symmetrical
- Squaring of vertebral bodies
- Bamboo spine
- Peripheral large joint arthritis
What is the positive genetic factor for Ankylosing spondylitis?
HLA B27 +ve
What are the 3 main spinal features of Ankylosing spondylitis?
- Romanus lesions
- Bamboo spine
- Spinal fractures
Who is more prone to gout?
- Elderly males
- Hereditary
List the 3 clinical features of gout?
- Olecranon bursitis common
- Para-articular erosions
- Soft tissue mass
List 4 skeletal locations of gout?
- 1st foot MTP joint
- Knee
- Hand
- Elbow
List the 7 radiographic features of gout?
- Para-articular erosions
- Sharply marginated with sclerotic rims
- Overhanging edges
- No joint space narrowing till late
- Little or no osteoporosis
- Soft tissue swelling
- Tophi not usually calcified
What 2 things should you suspect in a young person with gout?
- Renal disease
2. Myeloproliferative disorder
What 4 things does crystal deposition in gout induce?
- Inflammation
- Idiopathic
- Enzyme defects
- Secondary to myeloproliferative disorders.
Describe the progression of gout?
Several years before X-ray changes occur, cartilage OK until late
What is rhyme for reactive arthritis (Reiter’s syndrome)?
Can’t see, can’t pee and can’t climb a tree!
What are the 4 causes of reactive arthritis (Reiter’s syndrome)?
- Chlamydia
- Salmonella
- Shigella
- UTI’s
What 3 joint pathologies light up with MRI dye (T1W contrast, STIR)?
- Bone marrow oedema
- Soft tissue swelling
- Erosion
What hand joints are typically affected in rheumatoid arthritis?
All of the joints apart from the distal joints
What are 3 types of bone tumours & how common are they?
- Secondary tumours in bone: very common
- Myeloma: commonest primary bone tumour
- Primary bone tumours: rare
How common is secondary tumours in bone?
60% of patients dying of cancer
Give 5 locations of metastatic carcinomas causing secondary bone tumours?
- Bronchus
- Breast
- Prostate
- Kidney
- Thyroid (follicular)
What are 2 childhood malignancies causing secondary bone tumours?
- Neuroblastoma
2. Rhabdomyosarcoma
Which bones are more prone to tumours?
Those with good blood supply- long bones, vertebrae
What are the 6 effects of metastases?
- Often asymptomatic
- Bone pain
- Bone destruction
- Long bones: pathological fracture
- Spinal metastases: vertebral collapse, spinal cord compression, nerve root compression, back pain
- Hypercalcaemia
What is the benefit of combining PET & CT?
Anatomical detail can now be achieved as well as functional data
What are the 2 types of bone metastasis?
Lytic & Sclerotic
Describe the mechanism of bone destruction?
- Osteoclasts, not tumour cells
- Stimulated by cytokines from tumour cells
What is bone destruction inhibited by?
Bisphosphonates
Where is sclerotic metastasis typically from in males & females?
- Males: prostate cancer
- Females: breast cancer
What is the less common origin of sclerotic metastases?
Carcinoid tumour
What is the main feature of Sclerotic metastases?
Reactive new bone formation, induced by tumour cells
What are the 2 typical origins of solitary bone metastases?
Renal & thyroid carcinomas
What is the prognosis of solitary bone metastases?
- Often long survival
- Surgical removal often valuable
Describe a Myeloma?
- Monoclonal proliferation of plasma cells
- Solitary (plasmacytoma) or multiple myeloma