MSK Flashcards
In a patient with chronic osteomyelitis where can cultures be most reliably obtained in order to identify the primary causative organism?
Biopsy of affected bone
What is the most appropriate treatment for acute tibial osteomyelitis?
High-dose broad-spectrum IV antibiotics to cover likely organisms
Immobilise affected limb in a splint
Regular, appropriate analgesia
Optimise nutrition
What are 4 likely complications of severe, distal femoral osteomyelitis in a child?
Angular deformity of the limb
Chronic localised osteomyelitis with a sinus
Limb length discrepancy
Bacterial endocarditis
What are 3 likely presentations of TB in the knee?
Involuntary weight loss over several months
Ongoing treatment of HIV
Swelling of the knee with restricted movement
What is the most common causative organism for acute osteomyelitis?
Staphylococcus aureus
What are 6 risk factors for developing osteoarthritis?
Obesity
Increased age
Occupation - high impact
Trauma
Female sex
Family history
What are the 4 key X-ray changes in osteoarthritis?
LOSS
L - loss of joint space
O - osteophytes
S - subarticular sclerosis (increased density of bone along the joint line)
S - subchondral cysts (fluid filled holes in the bone)
X-ray findings may be incidental and the patient does not report any symptoms)
What are the common presenting symptoms of osteoarthritis?
Joint pain and stiffness of the affected joint. The pain and stiffness tend to be worsened on activity and relieved by rest. Any stiffness in the morning should not last any longer than 30 minutes.
There may also be deformity, instability and reduced function in the affected joint.
What are Haberden’s nodes?
Small bony growths on the distal interphalangeal joints (DIPs) that are indicative of osteoarthritis
What are Bouchard’s nodes?
Small bony growths on the proximal interphalangeal joints (PIPs) that are indicative of oseoarthritis
What are 5 osteoarthritic changes that can be seen in the hands
Haberden’s nodes
Bouchard’s nodes
Squaring at the base of the thumb at the carpometacarpal (CMC) joint
Weak grip
Reduced range of motion
What is the non-pharmacological management of osteoarthritis?
Lifestyle changes - weight loss if overweight
Physiotherapy
Occupational therapy and orthotics
What are the pharmacological managements of osteoarthritis?
Stepwise analgesia
1. Oral paracetamol and topical NSAIDs
2. Add oral NSAIDs and consider PPI (omeprazole) for stomach protection
3. Consider opiates such as codeine or morphine
Intra-articular steroid injections can provide temporary relief
What is the surgical management of osteoarthritis in severe cases?
Joint replacement
What are the typical presentations of rheumatoid arthritis?
Symmetrical distal polyarthropy:
Pain (worse on rest and relieved by movement)
Swelling
Tenderness
Warmth, redness
Stiffness (lasts longer than 30 minutes in the morning)
Immobility/limitation of movement
Poor function
Presentation is usually of symptoms in the small joints of the hands and feet
Systemic presentations
Fatigue
Weight loss
Flu-like illness
Muscle aches and weakness
What are 5 signs in the hands that are indicative of rheumatoid arthritis?
“Boggy” feeling of synovium around the joints where/when the disease is active
Z-shaped deformity to the thumb
Swan neck deformity (hyperextended PIP with flexed DIP)
Boutonnieres deformity (hyperextended DIP with flexed PIP)
Ulnar deviation
What investigations are required for diagnosis of rheumatoid arthritis?
Rheumatoid factor
Anti-CCP antibodies
ACPA
Baseline bloods (FBC, U&E, LFT)
Inflammatory factors (ESR, CRP)
X-ray of hands and feet
US of joints (confirm synovitis)
What X-ray changes would be seen in rheumatoid arthritis?
Joint destruction and deformity
Soft tissue swelling
Periarticular ostepenia
Boney erosions
What risk factors are there for developing rheumatoid arthritis?
Genetic (HLA-DRbeta1)
Cigarette smoking
Chronic infection (Periodontal disease, EBV, Parvovirus B19)
What are the long-term clinical systemic/extra-articular effects of rheumatoid arthritis
Non-specific: fatigue/lassitude, weight loss, anaemia
Specific: eyes, lungs, nerves, skin, kidneys
Long-term: CVS, malignancy
What does the DAS28 score mean in terms of rheumatoid arthritis?
DAS<2.6 represents clinical remission
DAS>5.1 represents eligibility for biologic therapy
What is the pharmacological treatment for rheumatoid arthritis?
Early and aggressive treatment with a stepwise approach consisting of analgesia, anti-inflammatories and biologics with the aim of treating to target DAS28 score.
1. NSAIDs
2. DMARDs (disease modifying anti rheumatic drugs)
3. Biologics
4. Corticosteroids (oral, IM, IA)
What DMARDs are typically prescribed in rheumatoid arthritis?
Methotrexate (first line)
Sulfasalazine
Hydroxychloroquine
Leflunomide
What are some examples of biologics used in the NHS to treat rheumatoid arthritis?
TNF-alpha inhibitors
IL-1 inhibitors (Anakinra)
Anti B cell therapies (CD20, Rituximab)
Anti T cell therapies (Abatacept)
IL-6 inhibitors (Tocilizumab, Sarilumab)
Oral kinase inhibitors
What are relevant parts of a clinical history which increase the likelihood of developing acute osteomyelitis?
History of trauma
Diabetes
Rheumatoid arthritis
Immune compromised
Long term steroid use
Sickle cell
What are likely sources of infection in acute osteomyelitis?
Haematogenous spread (children and elderly)
Local spread from contiguous site of infection - trauma (open fracture), surgery (ORIF), joint replacement
Secondary to vascular insufficiency
Infected umbilical cord
Boils, tonsilitis, skin abrasion (in children)
UTI
Arterial line
What does ORIF mean?
Open reduction, internal fixation - surgery to fix broken and dispaced bone that won’t heal through conservative measures)
What is the pathogenesis (pathway) of acute osteomyelitis?
- Starts at metaphysis (role of trauma?)
- Vascular stasis (venous congestion + arterial thrombosis)
- Acute inflammation (=> increased pressure)
- Suppuration
- Release of pressure (medulla, sub-periosteal, into joint)
- Necrosis of bone (sequestrum)
- New bone formation (involucrum)
- Resolution (or not - chronic osteomyelitis)
What is a sequestrum?
A piece of dead bone that has become separated from normal or sound bone during the process of necrosis
What are some of the clinical features seen in infants with acute osteomyelitis?
May be minimal signs or may be very ill
Failure to thrive
Possibly drowsy or irritable
Metaphyseal tenderness and swelling
Decreased range of movement
Positional change
Commonest around knee but is often at multiple sites which may not be apparent
What are some of the clinical features seen in children with acute osteomyelitis?
Severe pain
Reluctant to move (neighbouring joints held flexed, not weight bearing, may be tender)
Fever (swinging pyrexia)
Tachycardia
Malaise (fatigue, nausea, vomiting, fretful)
Toxaemia
What are some of the clinical features seen in adults with acute osteomyelitis?
Backache
History of UTI or urological procedure
Elderly
Diabetic
Immunocompromised
Why do some adults present with backache when they have acute osteomyelitis?
Primary osteomyelitis often presents in the thoracolumbar spine
