Musculoskeletal & Rheumatology Flashcards
Define osteoarthritis
- Degenerative joint disorder
- Wear and tear in the synovial joints
- NOT INFLAMMATORY (RA = inflammatory)
Pathology of OA
Combination of genetic factors + overuse + injury
Imblance between:
* Cartilage wearing down
* Chondrocytes repairing it
* → leading to structural issues in the joints
Progressive loss of articular cartilage, underlying bone of synovial joints
Rx for OA
- Obesity
- Age >50yrs
- Occupation
- Trauma
- Female
- Family history
- Mutations of cartilage building collagens (types II, IX, XI)
- Inflammation
- Increased proinflammatory cytokines (IL1, IL6, TNF)
What are the key presentations of OA?
- Joint pain + stiffness
- Worsens with activity - contrast to inflammatory arthritis that is worse in the morning
- OA = leads to deformity + instability + reduced joint function
What is crepitus on movement? When does it occur?
Joint sounds + bone cracking
OA
Signs of OA
- Bulky bone enlargement of joint
- Restricted range of motion
- Crepitus on movement (joint sounds + bone cracking)
- Effusions (fluid) around the joint
What are the commonly affected joints in OA?
- Hips
- Knees
- Sacro-iliac joints
- Distal-interpharyngeal (DIP) joints in the hands
- Carpometacarpal (CMC) joint at the base of the thumb
- Wrist
- Cervical spine (cervical spondylosis)
What is the mnemonic for the x-ray changes in OA?
LOSS
* L - Loss of joint space
* O- Osteophytes (bone spurs)
* S - Subarticular sclerosis (increased density of the bone along the joint line)
* S - Subchondral cysts (fluid-filled holes in the bone)
What are the OA signs in the hands?
-
Heberden’s nodes (DIP joints)
- (H for high)
-
Bouchard’s nodes (PIP joints)
- (B for below)
- Squaring at the base of the thumb (carpometacarpal joint)
- Weak drip
- Reduced range of motion
What are Heberden’s and Bouchard’s nodes and in which condition are they found?
Osteoarthritis
* Heberden’s node = DIP joints
* Bouchard’s nodes = PIP joints
What is the criteria of an OA diagnosis (without investigations)?
- Over 45
- Typical activity-related pain
- No morning stiffness OR stiffness lasting LESS than 30 minutes
Ix for OA?
First line:
* X-ray of affected joints
* Inflammatory markers (serum CRP and ESR)
Other:
* Rheumatoid factor (negative)
* MRI of affected joints
DDx of OA
- Gout
- Pseudogout
- Rheumatoid arthritis (RA)
- Psoritatic arthritis
First line management for OA
- Patient education + lifestye changes (weight loss, physiotherapy, occupational therapy + orthotics
- Stepwise use of analgesia (symptom control)
- Oral paracetamol + topical NSAIDs or capsaicin
- ADD: Oral NSAIDs (+ PPI)
- Opiates (codeine, morphine)
What is the second line Tx for OA?
-
Intra-articular steroid injections
- Temporary reduction in inflammation + improve symptoms
- Methylprednisole acetate
-
Joint replacement (severe cases)
- Typically hips + knees
What is the corticosteroid used in the intra-articular injections in OA?
Methyprednisolone acetate
Name 2 complications of OA?
- Functional decline + inability to perform activities of daily living
- Spinal stenosis in cervical + lumbar OA
- NSAID-related GI bleeding
-
Effusion
- Arthrocentesis + corticosteroid injection and/or referral to rheumatology, should be considered
- NSAID-related renal dysfunction
What is rheumatoid arthritis (RA)?
-
Autoimmune condition that causes chronic inflammation of the synovial lining of the joints + tendon sheaths and bursa
- Inflammation of tendons (increase risk of tendon rupture)
- Inflammatory arthritis
- Synovitis = synovial inflammation
What pattern does RA present in?
Symmetrical + affects multiple joints = Symmetrical polyarthritis
What typical patient presents with RA?
Middle aged woman
What are the genetic associations in RA?
- HLA DR1
- HLA DR4 (often present in RF positive patinets)
Name the two auto-antibodies found in RA patients, and which is more sensitive + specific?
- Rheumatoid factor (RF) (70% of RA patients)
-
Anti-cyclic citrullinated peptide antibodies (anti-CCP antibodies)
- More sensitive + specific than RF
- Often predates RA development
What are the key presentations of OA?
-
Symmetrical distal polarthropathy
- Pain
- Swelling
- Stiffness
What is the onset like for RA?
Very varied!
* Very rapid (i.e. overnight)
* Over months to years
What are the systemic symptoms of RA?
- Fatigue
- Weight loss
- Flu-like symptoms
- Muscle aches + weakness
What is the difference in pain in RA (inflammatory arthritis) and OA (mechanical problem)?
RA: Worse after rest, improves with activity
OA: Worse with activity, improves with rest
If a patient presents with arthritis Sx, including affected distal interphalangeal joint (DIP), which arthritis is more likely?
OA
(DIP joint almost never affected in RA)
What are the joints in RA most commonly affected?
- Proximal Interphalangeal Joints (PIP) joints
- Metacarpophalangeal (MCP) joints
- Wrist and ankle
- Metatarsophalangeal joints
- Cervical spine
- Large joints can also be affected such as the knee, hips and shoulders
What auto-antibody is the most sensitive + specific found in RA?
Anti-CCP
(Anti-cyclic citrullinated peptide antibodies)
What are the signs in the hands in RA?
- Palpitation of the synovium in around the joints when disease is active → ‘boggy’ feeling
- Z-shaped deformity to the thumb
- Swan neck deformity (hyperextended PIP + flexed DIP)
- Ulnar deviation of the fingers at the knucke (MCP joints)
- Boutonnieres deformity (hyperextended DIP + flexed PIP)
What are the thumb deformities seen in RA and OA?
- OA → squaring of base of thumb
- RA → Z-shaped deformity of thumb
What are the extra-articular manifestions that can be seen in RA patients?
- Secondary Sjogren’s syndrome AKA sicca syndrome
- Pulmonary fibrosis
- Anaemia of chronic disease
- Felty’s syndrome (RA, neurtopenia + splenomegaly)
What is the pattern of RA presention?
Symmetrical polyarthropathy affecting small joints
What are the first line Ix for RA
required to make a diagnosis alongside clinical presentations
- RF → if neggy, check anti-CCP antibodies
- ESR/CRP
- X-ray of hands + feet
-
Ultrasound scan of joints
- Evaluate + confirm synovitis
What is a RA diagnosis involve?
Diagnosis criteria for RA = American College of Rheumatology (ACR)
Patients are scored based on:
- The joints that are involved (more and smaller joints score higher)
- Serology (RF and anti-CCP)
- Inflammatory markers (ESR and CRP)
- Duration of symptoms (more or less than 6 weeks)
Scores are added up and a score greater than or equal to 6 indicates a diagnosis of rheumatoid arthritis.
What scoring system monitors the disease activity in RA?
DAS28 Score (Disease Activity Score) - assessment for 28 joints:
* Swollen joints
* Tender joints
* ESR/CRP result
(Monitoring disease activity + response to treatment)
What are the X-ray changes seen in RA?
- Joint destruction + deformity
- Soft tissue swelling
- Periarticular osteopenia
- Boney erosions
A RA patient complains of experiencing self-limiting short episodes of inflammatory arthritis - with joint pain + stiffness + swelling. It only lasted just over a day. What is this phenomenom called?
Palindromic rheumatism
DDx for RA
- Psoriatic arthritis (PsA)
- Infectious arthritis
- Gout
- Systemic lupus erythematosus
- Osteoarthritis
Why do you monitor the DAS28 in RA?
Aim to reduce the dose to the ‘minimal effective dose’ that controls the disease
What are DMARDs and what are they used in?
Disease modifying Anti-rheumatic drugs
(Used in RA)
What is the course of treatment for RA?
First line: Methotrexate or sulfasalazine (hydroxychloroquine in mild dsease)
Second line: 2 DMARDs (methotrexate + sulfasalazine)
Third line: Methotrexate + infliximab
Fourth line: Methotrexate + rituximab
Biological therapies lead to what?
Immunosuppression
What are the complications of immunosuppressants?
- Patients are prone to serious infections
- Can lead to reactivation of dormant infections (TB + HepB)
What class of drug is infliximab?
Anti-TNF
What class of drug is rituximab?
Anti-CD20
What are the DMARDs used in pregnancy?
- Sulfasalazine
- Hydroxychoroquine
How does methotrexate work and what needs to be prescribed with it?
- Methotrexate = works by interfering with the metabolism of folate + suppressing certain components of the immune system
- Folic acid = prescribed with methotrexate (taken on a different day)
What are the major side effects of methotrexate?
- Liver toxicity
- Mouth ulcers + mucositis
- Bone marrow suppression + leukopenia (low WBCs)
-
TERATOGENIC
- Needs to be avoided prior to conception in mothers + fathers
Read: Complications of main drugs used in RA
- Methotrexate: Bone marrow suppression and leukopenia and highly teratogenic
- Anti-TNF medications: Reactivation of TB or hepatitis B
- Rituximab: Night sweats and thrombocytopenia
- Hydroxychloroquine: Nightmares and reduced visual acuity
- Sulfasalazine: Male infertility (reduces sperm count)
- Leflunomide: Hypertension and peripheral neuropathy
Name 2 complications of RA
- Work disability
- Increased joint replacement surgery
- Increased coronary artery disease
- Increased mortality
- Carpal tunnel syndrome (CTS)
- Methotrexate-related liver toxicity and lung involvement
Name the crystal athropathies
- Gout
- Pseudogout
Which sex is more likely to develop gout?
Male
(x5)
What are the Rx for gout?
- Guanosine in beer
- Diuretics
- Male
- Obesity
- Renal impairment
- Renal impairment
What causes of gout? (pathology)
- Gout = crystal athropathy
- Chronically high blood uric acid levels
- Urate crystals = deposited → hot + swollen + painful
What are gouty tophi?
Subcutaneous deposits of uric acid
Where are gouty tophi most commonly found?
Typically affects small joints + connective tissues:
* Hands (DIP joints = most affected)
* Elbows
* Ears
If a patient presents with a single hot, swollen and painful joint. What is a possible diagnosis that is not septic arthritis?
Gout
What are the most common joints affected by gout?
- Base of the big toe (metatarsopharyngeal joint)
- Wrists
- Base of thumb (carpometacarpal joints)
Larger joints:
* Knee
* Ankle
What are the two Ix for gout?
- Aspiration of joint fluid (arthrocentesis with synovial fluid analysis)
- No bacterial growth
- Monosodium urate crystals
- Negatively birefringment of polarised light
- Joint x-ray
- Lytic lesions in the bone
- Punched out lesions
What are characteristics of synovial fluid analysis of gout?
- Needle-shaped crystals
- Negatively birefringment of polarised light
- Monosodium urate crystals
What are the first to third line Mx options for gout?
- First line: NSAID (unless renal impairment)
- Second line: Colchicine (S/E diarrhoea)
- Third line: Intra-articular or oral
What are the pharmacological and non-pharmacological options for gout prophylaxis?
- Allopurinol = reduces uric acid level
- Lifestyle changes:
- Wt loss
- Staying hydrated
- Minimise alcohol consumption + purine-based food (meat + seafood)
What is a complication of gout?
Renal calculi!
Pseudogout is caused by which type of crystal?
Calcium pyrophosphate crystals
What is the typical patient that has pseudogout?
Older women
(Overlaps with OA)
What are two causes of pseudogout?
- Direct trauma to the joint
- Intercurrent illness
- Surgery – especially parathyroidectomy
- Blood transfusion, IV fluid
- T4 replacement
- Joint lavage
Rx for pseudogout?
- Old age
- Osteoarthritis
- Hyperparathyroidism
- Haemochromatosis
- Hypophosphatemia
- Diabetes
What is chrondrocalcinosis
Pseudogout
Typical presentation of pseudogout
- Acute synovitis, acute hot + swollen joint or OA joint
- (Severe joint pain, fever and stiffness)
- Can affect multiple joints
What are the signs of pseudogout on an x-ray?
Similar osteoarthritis:
- L–Loss of joint space
- O–Osteophytes
- S–Subarticular sclerosis
- S–Subchondral cysts
What is the gold standard Ix for pseudogout
Aspiration of synovial fluid:
- No bacterial growth
- * Calcium pyrophosphate crystals
- * Rhomboid shaped crystals
- * Positive birefringent of polarised light
How do distinguish pseudogout from OA?
- Pattern of involvement – knee, wrists, shoulders, ankles, elbows
- Marked inflammatory component
- Superimposition of acute attacks
Septic arthritis = needs to be excluded
What are the management options for pseudogout?
- Symptoms usually resolve themself
- NSAIDs
- Colchicine
- Joint aspiration
- Steroid injections (dexamethasone)
- Oral steroids
Severe cases:
* Joint washout (athrocentesis)
What drug can you use for recurrent gout?
Allopurinol
(Reduces uric acid levels)
Name two forms of infective arthritis
- Septic arthritis
- Osteomyelitis
What is osteomyelitis?
Inflammation in a bone + bone marrow
(usually caused by bacterial infection)
What are the two types (/causes) of osteomyelitis?
-
Haematogenous contamination
- = pathogen carried via blood → seeded into bone
-
Direct contamination (of bone)
- = osteomyelitis at fracture site (or during an orthopaediac operation)
What bacteria is the most common cause of osteomyelitis?
Staphylcoccus aureus
Rx for osteomyelitis
- Open fractures
- Orthopaedic operations
- (Perioperative prophylactic antibiotics used)
- IV drug use
- Immunosuppression
- Diabetes (diabetic foot ulcer)
What is the typical presentation of osteomyelitis?
Non-specific → generalised Sx of infection
* Fever
* Lethargy
* Nausea
* Muscle aches
Inflammation (DR CT)
* Dolor (pain)
* Rubor (red)
* Calor (warm)
* Tumour (swelling)
What first line Ix would you perform if osteomyelitis is suspected?
First line:
* X-ray (cannot pick up early stages)
- Localised osteopenia(thinning of the bone)
- Destruction of areas of the bone
- Periosteal reaction(changes to the surface of the bone)
* Blood tests - raised inflammatory markers
- WBC, CRP, ESR
* Bone + blood cultures (stapylcoccus aureus) + antibiotic sensitivities
What is a diagnostic scan for osteomyelitis?
MRI scan
What are two differentials for osteomyelitis?
- Septic arthritis
- Reactive arthitis
- Necrotising fasciitis
A patient presents with osteomyelitis, what is the treatment?
-
Surgical debridement of infected bone + tissues
AND -
6 weeks of flucloxacillin
- Alternatives: Clindamycin or Vancomycin (if MRSA)
Chronic osteomyelitis = requires 3 months or more of antibiotics
Complications of osteomyelitis
- Infection recurrence
- Fracture
- Amputation
- Joint stiffness
When should you suspect osteomyelitis?
- Unwell child/immunocompromised patient with a limp
- Chronic osteomyelitis in adults with a history of open fracture, previous orthopaedic surgery or a a discharging sinus
What is septic arthritis?
- Infection within a joint (native or replacement)
- Medical emergency! - the infection can quickly destroy the bone → cause systemic illness (10% mortality)
What are the 2 routes in which a pathogen can enter a joint and cause septic arthritis?
- Haematogenous = bloodstream
- Direct inoculation = from nearby infection/direct (e.g. open fracture
What are the two routes staphylococcus can cause osteomyelitis (infection of bone) and septic arthritis (infection of joint)?
- Haematogenous = bloodstream
- Direct inoculation = from nearby infection/direct (e.g. open fracture
Read: Pathology of septic arthritis
Infection of joint → endotoxin production → cytokine release → neutrophil attraction → inflammation → damage of joint structures
Septic arthritis is an important complication of what surgery?
Joint replacement
- 1% occurrence of straight forward hip or knee replacements
- Higher in revision surgery
What is the most common causative bacteria in septic arthritis?
- Staphylococcus aureus (most common)
- Escherichia coli(E. coli)
- Neisseria gonorrhoea in sexually active individuals
- Group A Streptococcus(most commonlyStreptococcus pyogenes)
- Haemophilus influenza
Rx for septic arthritis?
Joints:
* Underlying joint disease
* Prosthetic/artificial joint, surgical procedure
* Osteomyelitis
Immunosuppression:
* Immunosuppressuin
* Age
* HIV
* Diabetes
A patient comes into A&E with a rapid onset of a hot, red, swollen and painful knee joint. They complain that its stiff and they have a reduced range of motion. They also have systemic syptoms of fever, lethargy and potentially spsis. What is a potential diagnosis?
Septic arthritis
When condition should you suspect, when a young patient presents with a a single acutely swollen joint.
Gonococcus specific arthritis
A patient with suspected septic arthritis has a synovial fluid aspiration and its cultured. It comes back as a gram-negative diplococcus. What is the casusative organism?
Neisseria gonorrhoea
Ix for septic arthritis
-
Synovial fluid aspiration:
- Culture + sensitivies
- Gram stain (and crystal/polarising microscopy)
- WBC count
- Joint fluid = may ve purulent (full of pus)
- Blood culture (bc of haematogenous spread) - before antibotics
- Inflammatory markers (ESR and CRP)
- FBC (Raised WBC count)
- Plain x-ray (not diagnostic)
DDx of septic arthritis
- Gout
- Pseudogout
-
Reactive arthritis - triggered by:
- Urethritis
- Gastroenteritis
- Conjuctivitis (associated with)
- Haemarthrosis (bleeding into the joint)
First line treatment of septic arthritis
Antibiotics (before sensitivities are known) - 3-6 weeks:
* First line: Flucloxacillin + rifampicin
* Vancomycin + rifampicin → penicillin, MRSA, prosthetic joint
- Clindamycin = an alternative
IV 2 weeks + oral 4 weeks
Complications of septic arthritis
- Osteomyelitis (infection spread to surrounding bone)
- Joint destruction (permanent irreversible damage)
What is osteoporosis?
- Low bone density + micro-architectural defects in the bone tissue
- Increased bone fragility + susceptibility to fracture
- Low bone mass → bone fragility → increased fracture risk
What is osteopenia?
Less severe reduction in bone density than osteoporosis
* Osteopenia = precursor to osteoporosis
* Bone mineral density 1-2.5 standard deviations below young adult mean value
What is osteomalacia?
- Poor mineralisaton (lack of calcium) → soft bones
- Osteomalacia = adult form of rickets
What is the adult form of rickets?
Osteomalacia
What is the primary cause of osteoporosis?
Post-menopausal
What are the secondary causes of osteoporosis?
SHATTERED (increases bone turnover)
- S – steroid use (prednisolone)
- H – hyperthyroidism/hyperparathyroidism
- A – alcohol/smoking
- T – thin (low BMI)
- T – testosterone low
- E – early menopause
- R– renal or liver failure
- E – erosive/inflammatory bone disease e.g. RA, myeloma
- D – dietary calcium low
What should you thibk about when thinking about the Rx of osteoporosis?
Patient, disease, medication
* Patient:
- Older age
- Female (post-menopausal)
* Disease:
- Malabsorption (decreased Ca2+)
- Endocrine disorders (Cushing’s and hyperparathyroidism)
- Rheumatoid arthritis
* Medication:
- Long-term corticosteroids (prednisolone)
- SSRIs, PPIs
A post-menopausal women presents to A&E with a hip fracture. What could be an underlying disease?
Osteoporosis
Where are pathological fractures most likely to be in a patient with osteoporosis?
- Vertebral colum
- Ribs
- Hips
- Wrist
A patient presents with sudden back pain, spinal cord compression, cauda equina syndrome. O/E you see loss of height, hunched posture, kyphosis (curvature of spine). Possible diagnosis?
Compression fracture of the vertebral column secondary to osteoporosis
What is the first line and gold standard scan for osteoporosis?
DEXA scan
(Dual Energy X-ray Absorptiometry)
What soes a DEXA scan measure?
Bone mineral density (BMD)
(Key classifiction + management is osteoporosis)
What are the 2 scores that are given from a DEXA?
- Z score: Number of standard deviations the patients bone density falls below the mean for their age.
-
T scores: Number of standard deviations below the mean for a healthy young adult their bone density is.
- T SCORE = MORE IMPORTANT
Give the T scores + classifications for osteopenia, osteoporosis and sever osteoporosis
- > -1 = normal
- -1 to -2.5 = osteopenia
- < -2.5 = osteoporosis
- < - 2.5 plus fracture = severe osteoporosis
(Measure in SDs below the mean for a healthy young adult)
What is the the FRAX tool used for?
Gives prediction of the risk of a fragility fracture over the next 10 years
* Major osteoporotic fracture
* Hip fracture
FRAX Tool = first step in assessing someone’s risk of osteoporosis
What information in used in the FRAX tool?
- Bone mineral density (from DEXA scan)
Variables: - Age
- Sex
- BMI
- Previous fractures
- Steroids
Name some lifestyle changes for osteoporosis
- Avoiding falls
- Activity and exercise
- Maintain a healthy weight
- Adequate calcium intake
- Adequate vitamin D
First line management of osteoporosis
- Oral bisphosphonates (alendronate)
- Calcium + vitamin D supplemenation
- (inhibits bone reabsorption)
Name some primary prevention from osteoporosis
- Calcium-rich diet e.g. dairy or sardines, white beans
- HRT – menopausal women
- Corticosteroids – consider prophylactic bisphosphonates
- Smoking + alcohol cessation