MSK Flashcards
Epidemiology and risk factors for RA
Increased in women (2-4x)
Peak age is 40s
RFs Smoking Genetics - HLA DR4 and 1 Winter Others - increased birth weight, silica exposure, alcohol abstention, obesity, diabetes,
Presentation of RA
ARTHRITIS
Insidious symmetrical polyarthritis
Small joints of hands or feet
Morning stiffness >30 minutes
PIP, MCP, wrist, MTP, ankle, knee, cervical spine (SPARES DIP)
Hand deformities - ulnar deviation, swan neck, Boutonnieres, Z deformity of thumb, piano key deformity of wrist
SYSTEMIC SIGNS
- Eyes: scleritis, episcleritis
- Skin: leg ulcers, rashes, raynauds
- Rheumatoid nodules
- Neuro: carpal tunnel, polyneuropathy
- Resp: pleuritic, pulmonary fibrosis
- CV: pericardial involvement, vasculitis, increased MI
- Kidneys: RARE
- Liver: mild hepatomegaly, raised transaminases
Thyroid disorders, osteoporosis, depression, splenomegaly, lymphadenopathy
Pain, fatigue, myalgia, weight loss
Investigations for RA
- ESR, CRP, plasma viscosity - usually raised (can be normal)
- FBC - normochromic normocytic anaemia, thrombocytosis, raised ferritin
- LFTs - mildly raised ALP and GGT
- Antinuclear antibody in 30% +
Rheumatoid factor - positive in 60-70% (and 10% normal population)
Anti-CCP
X-ray - soft tissue swelling, periarticular osteopaenia, decreased joint space, erosions, deformity
Management of RA
Start within 3 months
Simple analgesia + NSAIDs
DAS28 - number of joints and ESR. For active disease >5.1, remission <2.6
- Methotrexate + alt DMARD + short course steroid (min 6 months)
- different mono/combined DMARD therapy (min 6 month)
- TNF alpha inhibitors (adalimumab, etancercept, infliximab)
- Rituximab (anti CD20) + methotrexate
- Toclizumab (anti IL6)
Surgery if persistent pain, worsening joint function, progressive deformity, nerve entrapment, stress fracture
Complications of RA
Decrease mobility, restricted ADLs
Inability to work
Depression
Vasculitis
Systemic effects - pleuracy, heart complications, lymphadenopathy, neuropathy, anaemia, dry eye syndrome, anaemia, carpal tunnel, tendon rupture
Osteoporosis
Felty’s syndrome - enlarged spleen, decreased WCC + RA
Prognosis of RA
40% disabled in 10 years
Worse prognosis if: <30, male, insidious onset, persistent anaemia, increased number of joints, raised anti-CCP, early Xray changes
Pregnancy beneficial for RA
Criteria for RA
4 or more of:
- morning stiffness >1 hour >6 weeks
- at least 3 joints
- hand joints
- symmetrical
- rheumatoid nodules
- positive for rheumatoid factor
- radiological changes
Epidemiology and risk factors for osteoarthritis
24% adults - knee, 11% hips
RFs Genetic Female Obesity High or low bone density joint injury decrease muscle strength joint laxity or misalignment
Presentation of OA
Clinical without investigation if over 45, pain activity related and no morning stiffness
- Pain exacerbated by exercise, relieved by rest
- Stiffness after rest
- Decreased function and range of movement
- Swelling, tenderness
- Crepitus
- No systemic features
- Heberdens DIP, Bouchards PIP
Investigations for OA
X-ray: osteophytes, decreased joint space, bone cysts, subarticular sclerosis
- MRI for other causes of joint pain
- Blood tests will be normal, should do baseline prior to starting NSAIDs
Management of OA
- Promote function, physio, OT
- Annual review if pain, multiple joints or regular meds
- Encourage exercise
- Encourage weight loss
- Paracetamol +/- topical NSAIDs
- Oral NSAIDs or COX2 inhibitors + PPI
- Intra-articular corticosteroids
NO glucosamine, no arthroscopic lavage or debridement
- Surgery if there is substantial limits on life
Xray changes in OA
Joint space narrowing Subarticular sclerosis Subchondral cysts Bone collapse Osseous loose bodies
Epidemiology and RFs for septic arthritis
1-2% of prosthetic joint replacements
20% of joint surgery revisions
Most commonly staph aureus
RFs Increasing age Prior joint damage Diabetes Joint surgery - hip or knee Immunodeficiency Recent Steroid injection
Presentation of septic arthritis
Single/few joints - acute, very painful Fever Bacteraemia Swollen, warm, tender Effusion
TRIAD - fever, pain, impaired range of motion
Causes of septic arthritis
Staph aureus
Gonococcal
Group B Strep
Lyme disease
Investigations for septic arthritis
FBC - raised WCC, CRP
Synovial fluid examination - raised leukocytes, culture (also exclude crystal arthropathy)
Blood cultures
Imaging - US or MRI/CT
Have a higher index of suspicion if prosthetic joint
Treatment for septic arthritis
Surgical drainage + Lavage + High dose IV antibiotics
Antibiotics
- Start empirically before cultures, cover staph and strep as minimum, for minimum of 2-3 weeks
Flucloxacillin (if staph) - allergy to penicillin = clindamycin
Vancomycin = if MRSA
Cefotaxime - gonococcal
Corticosteroids may decrease extent of cartilage destruction
Splint in position of function
Prognosis of septic arthritis
10-20% mortality
Worse prognosis - over 65, shoulder, elbow or multiple sites
Staph - 50% get back to baseline
Referral for joint replacement
Should have tried all basic treatments (weight loss, pain relief)
If New Zealand score
<39 - primary care
40-69 - non-surgical
70+ then refer for surgery
Patient age, sex, smoking status or BMI should not be a barrier for referral
Complications for joint replacement
Joint infection DVT/PE Stiffness Implant loosening/failure Hip dislocation Time span - need replacement after 10-15 years Bleeding Haemotoma
Classifications of gout
Deposition of monosodium urate monohydrate crystals
- asymptomatic
- hyperuricaemia
- acute gout
- chronic tophaceous gout
PRIMARY - in men 30-60 with acute attacks
SECONDARY - due to chronic diuretic therapy and associated with OA
Epidemiology and RF for gout
Increased in men 9:1
Increased in Asians and South Pacific
High meat diet Diabetes Seafood Alcohol Chronic renal failure Diuretic therapy Obesity High cholesterol HTN CHD Psoriasis
Presentation of gout
First MTP joint (knee, tarsals, wrists, ankles, hands)
Acute pain in swollen joint that reaches crescendo in 6-12 hours
Florid synovitis
Will resolve in 5-15 days
If tophaceous gout - irregular firm nodules with chalky appearance beneath skin
Investigations for gout
Synovial fluid - MSU crystals
Gram staining and culture as infection and gout can co-exist
Serum uric acid - can be raised
Testing fasting lipids and glucose for hyperglycaemia