Rheumatology and Orthopaedics Flashcards
important ank spon features found on examination
- reduced lateral flexion
- reduced forward flexion - Schober’s test - a line is drawn 10 cm above and 5 cm below the back dimples (dimples of Venus). The distance between the two lines should increase by more than 5 cm when the patient bends as far forward as possible
- reduced chest expansion
features of ankylosing spondylitis
- 8 As
- Apical fibrosis
- Anterior uveitis
- Aortic regurgitation
- Achilles tendonitis
- AV node block
- Amyloidosis
- And cauda equina syndrome
- peripheral Arthritis (25%, more common if female)
what is the most useful investigation for ank spon
Plain x-ray of the sacroiliac joints
what does plain x ray of the sacroiliac joints show in ank spon
- sacroiliitis: subchondral erosions, sclerosis
- squaring of lumbar vertebrae
- ‘bamboo spine’ (late & uncommon)
- syndesmophytes: due to ossification of outer fibers of annulus fibrosus
- chest x-ray: apical fibrosis
what should you do if the x ray doesn’t show features of ank spon but your clinical suspicion is still high
MRI
Signs of early inflammation involving sacroiliac joints (bone marrow oedema) confirm the diagnosis of AS
what investigations should you do in ank spon
- FBC and ESR are usually raised but not always
- HLA-B27: positive in 90% ank spon and 10% gen pop
- plain x ray of SI joints
- CXR: apical fibrosis
- MRI if necessary
- Lung function tests show restrictive defect due to a combination of:
- pulmonary fibrosis,
- kyphosis and
- ankylosis of the costovertebral joints.
management of ank spon
- encourage regular exercise such as swimming
- NSAIDs are the first-line treatment
- physiotherapy
- if persistently high disease use anti-TNF such as
- etanercept
- adalimumab
two main fractures that result in compartment syndrome
supracondylar fractures and tibial shaft injuries
clinical features of compartment syndrome
- Pain, especially on movement (even passive)
- excessive use of breakthrough analgesia should raise suspicion for compartment syndrome
- Parasthesiae
- Pallor may be present
- Arterial pulsation may still be felt as the necrosis occurs as a result of microvascular compromise
- Paralysis of the muscle group may occur
The presence of a pulse does not rule out compartment syndrome.
compartment syndrome diagnosis
- Measurement of intracompartmental pressure measurements.
- Pressures in excess of 20mmHg are abnormal
- >40mmHg is diagnostic
- Compartment syndrome will typically not show any pathology on an x-ray
managment of acute compartment syndrome
- Prompt and extensive fasciotomies
- Myoglobinuria may occur following fasciotomy and result in renal failure and for this reason these patients require aggressive IV fluids
- Where muscle groups are frankly necrotic at fasciotomy they should be debrided and amputation may have to be considered
- Death of muscle groups may occur within 4-6 hours
what is the cause of pseudogout
deposition of calcium pyrophosphate dihydrate crystals in the synovium
conditions associated with pseudogout
Pseudogout is strongly associated with increasing age. Patients who develop pseudogout at a younger age (e.g. < 60 years) usually have some underlying risk factor, such as:
- haemochromatosis
- hyperparathyroidism
- low magnesium, low phosphate
- acromegaly
- Wilson’s disease
joints most commonly affected by pseudogout
knee, wrist and shoulders
what do you find on joint aspiration in pseudogout
weakly-positively birefringent rhomboid-shaped crystals
features that distinguish gout from pseudogout
- pseudogout joint aspiration: weakly-positively birefringent rhomboid-shaped crystals
- gout joint aspiration: negatively birefringent needles
- pseudogout x-ray: chondrocalcinosis
management of pseudogout
- aspiration of joint fluid, to exclude septic arthritis
- NSAIDs or intra-articular, intra-muscular or oral steroids as for gout
what causes gout
deposition of monosodium urate monohydrate in the synovium. It is caused by chronic hyperuricaemia (uric acid > 0.45 mmol/l)
about 70% of gout is in the first metatarsal - what are some other commonly affected joints
- ankle
- wrist
- knee
investigation of gout
- Synovial fluid analysis
- needle shaped negatively birefringent monosodium urate crystals under polarised light
- Uric acid
- should be checked once the acute episode has settled down (typically 2 weeks later) as may be high, normal or low during the acute attack
- Radiological features of gout include:
- joint effusion is an early sign
- well-defined ‘punched-out’ erosions
- relative preservation of joint space until late disease
- no periarticular osteopenia (in contrast to rheumatoid arthritis)
- soft tissue tophi may be seen
main side effect of colchicine
diarrhoea
management of acute gout
- NSAIDs or colchicine are first-line
- the maximum dose of NSAID should be prescribed until 1-2 days after the symptoms have settled.
- PPI if giving NSAID
- oral steroids may be considered if NSAIDs and colchicine are contraindicated
- if pt already on allopurinol then they should continue this
long term management of gout
- urate lowering therapy for everyone following their first episode of gout
- allopurinol is first line
- two weeks after symptoms have resolved
- titrate dose every few weeks to aim for a serum uric acid of < 300 µmol/l
- they need colchicine or NSAID cover while starting allopurinol
how to classify hip fractures based on location
- intracapsular (subcapital)
- extracapsular
how do you classify hip fractures
- Type I: Stable fracture with impaction in valgus
- Type II: Complete fracture but undisplaced
- Type III: Displaced fracture, usually rotated and angulated, but still has boney contact
- Type IV: Complete boney disruption
Blood supply disruption is most common following Types III and IV.
how do you treat a displaced hip fracture?
- NICE recommend replacement arthroplasty (total hip replacement or hemiarthroplasty) to all patients with a displaced intracapsular hip fracture
- total hip replacement is favoured to hemiarthroplasty if patients:
- were able to walk independently out of doors with no more than the use of a stick and
- are not cognitively impaired and
- are medically fit for anaesthesia and the procedure.
management of undisplaced hip fracture
- internal fixation, or hemiarthroplasty if unfit
how do you manage an extracapsular hip fracture
- dynamic hip screw
three classic features of a colles fracture
- Transverse fracture of the radius
- 1 inch proximal to the radio-carpal joint
- Dorsal displacement and angulation
Colles’ - Dorsally Displaced Distal radius → Dinner fork Deformity
what are the ottowa rules for ankle x rays
- An ankle x-ray is required only if there is any pain in the malleolar zone and any one of the following findings:
- bony tenderness at the lateral malleolar zone (from the tip of the lateral malleolus to include the lower 6 cm of posterior border of the fibular)
- bony tenderness at the medial malleolar zone (from the tip of the medial malleolus to the lower 6 cm of the posterior border of the tibia)
- inability to walk four weight bearing steps immediately after the injury and in the emergency department
early features of lyme disease
- Early features (within 30 days)
- erythema migrans
- ‘bulls-eye’ rash is typically at the site of the tick bite
- usually painless, more than 5 cm in diameter and slowlly increases in size
- present in around 80% of patients.
- systemic features
- headache
- lethargy
- fever
- arthralgia
later features of lyme disease
- Later features (after 30 days)
- cardiovascular
- heart block
- peri/myocarditis
- neurological
- facial nerve palsy
- radicular pain
- meningitis
- cardiovascular
diagnosis of lyme disease
- erythema migrans is enough to diagnose
- if not present then enzyme-linked immunosorbent assay (ELISA) antibodies to Borrelia burgdorferi are the first-line test
management of tick bites
- if the tick is still present, the best way to remove it is using fine-tipped tweezers, grasping the tick as close to the skin as possible and pulling upwards firmly. The area should be washed following.
- NICE guidance does not recommend routine antibiotic treatment to patients who’ve suffered a tick bite
management of lymes
doxycycline
amoxicillin if doxy is contraindicated (e.g. pregnancy)