Spondyloarthropathies Flashcards
What are spondyloarthopathies?
A group of inflammatory joint disorders w/ similar symptoms - mainly pain & stiffness around the spine:
Ankylosing spondylitis
- Non-radiographic axial spondylitis - pain & stiffness around spine but no physical changes on x-ray
- Earlier stage of Ankylosing SpA. - Changes can be seen on MRI.
Reactive arthritis
Psoriatic arthritis
Enteropathic arthritis - associated w/ inflammatory bowl disease, Crohn’s disease & ulcerative colitis.
Undifferentiated - spondylarthritis where the cause is unknown.
NOTE: they are seronegative = negative for RhF…
What are the features of inflammatory back pain?
- Longer than 3 months
- Gradual onset - insidious
- Early morning stiffness
- Worse at rest
- Better w/ movement & exercise
- No radicular signs
- Usually at younger age
- Good response to NSAIDs
What is ankylosing spondylitis?
Sacroilitis (inflammation of sacroiliac joint) w/ pain, stiffness & structural changes to the spine.
Epidemiology of ankylosing spondylitis (risk factors)
Males> females (3 : 1)
Common 20-40 yrs
90% HLA B27 +ve in Europe - HLA B27 codes for a type of MHC class I molecule. - These are the molecules that present antigens to cytotoxic T cells.
Rare after 45 years.
Pathophysiology of ankylosing spondylitis
Interaction btw environmental pathogens & immune system.
- May be due to abnormal host immune response to intestinal microbiota.
- Th17 cells are in involved - play a role in mucosal immunity.
- Cytokines IL-22, IL-23, IL-17 & TNF-⍺ are produced in response
- IL-23 - produced by macrophages & dendritic cells in the intestinal submuscosa. IL-23 acts on T cells, neutrophils & mast cells to produce IL-17.
- IL-17 - large role in inflammation, causing sacroilitis & enthesitis.
- TNF-⍺ - produced by activated T cells & macrophages. Contributes to the inflammation.
- IL-22 - produced by T cells. Involved in causing new bone formation.
Syndesmophyte formation:
- due to ossification (new borne formation by osteoblasts)
- Fibroblasts replace destroyed cartilage in joint w/ fibrin
- Osteoblasts are activated & fibrin is ossified = back & neck more stiff.
- Severe disease = bones may fuse = bamboo spine (this is the ossification of the annulus fibrosis).
- Bone marrow oedema - fluid builds up in bone marrow
Presentation of ankylosing spondylitis: description of pain, MSK, extra-skeletal/ complications, joint distribution?
Description of pain:
- Lower back pain- gradual onset & for more than 3 months
- Worse in morning (at least 30 mins)
- improves on exercise but not rest
- Responds to NSAIDs
- Night pain- wakes patient in 2nd half of night
- Fatigue, fever, weight loss
- Osteoporosis
MSK:
- Sacroilitis - tender sacroiliac joints.
- Pain/Stiffness in buttock region - alternating.
- Loss of movement in spine - reduced lumbar lordosis, lateral flexion, anterior flexion & extension of spine
- Protruded abdomen + reduced chest expansion due to kyphosis- question mark posture = breathless.
- Kyphosis If untreated
Extra-skeletal complications:
- Aortic incompetance- reduced pulmonary function
- Apical lung fibrosis (rare)
- Atlanto-axial subluxation
- Achilles involvement (enthesitis)- inflammation of area where tendons / ligaments attach to bone e.g. Achilles tendon = soreness in heel. Plantar fasiitis = heel & arch pain.
- Acute uveitis= inflammation of eye
- psoriasis
- dactylitis
Joint distribution:
- Asymmetrical oligoarthritis
- Sacroiliac joints
- Spine
- Asymmetrical involvement of large or medium joints - usually shoulders or hips.
- Enthesitis is common at: iliac crests, gluteal & tibial tuberosities & heels.
Investigations for ankylosing spondylitis: Blood tests & examination
Blood tests:
- FBC - shows anaemia of chronic disease.
- ESR & CRP - high in active SpA
- RhF negative
- HLA B27 positive - useful for prognosis
Examination
- Schobers test- measuring length of back
- Sacroiliac squeeze test- applying pressure on anterior iliac spines whilst patient is supine.
- lateral flexion of spine
Radiological findings for ankylosing spondylitis
MRI:
- Sacroilitis & bone oedema = inflammation
- only seen on MRI!
- Note- view image on notes
X-ray:
- Lumbar spine squaring- calcification of adjacent intervertebral discs & new bone forms along anterior aspect of vertebral body- this reverses normal concavity & produces squared appearance
- Subchondral erosions- erosions that occur at corners of vertebral bodies
- Dagger sign- caused by ossification of infraspinous & supraspinouse ligament
- Sacroillitis- usually bilateral & symmetrical, loss of clarity of joint margins, erosions, joint space widening, sclerosis
- Syndesmophytes- due to ossification of longitudinal ligament= bamboo appearance
- Bone density- may be reduced, osteoporosis is a presentation
NOTE: view x-ray images on notes!
Management of ankylosing spondylitis
Conservative:
- Physiotherapy - mobilising exercises
- Occupational therpay
- Disease monitoring- BASDAI, BASFI, BASMI (Bath Ankylosing Spondylitis Disease Activity Index). FI = functional index; MI = metrology index.
Pharmacological:
1. NSAIDs e.g. Naproxen + PPI e.g Lansoprizole
2. Biologics e.g. TNF-⍺ inhibitors (Adalimumab, Etanercept)
3. Secukinumab (anti-IL-17 biologic) - used if NSAIDs or anti-TNFs haven’t worked. Only recommened if a discount has been negotiated.
4. Glucocorticoids injection - for persistent plantar fasciitis or enthesitis.
5. Oral glucocorticoids - for acite uveitis.
6. DMARDs for peripheral joints only -LIMITED USE e.g. sulfasalazine.
Surgical
- Arthroplasty - for secondary OA
- Spinal osteotomy - correct stoop
Epidemiology of psoriatic arthritis
Common in patients w/ psoriatic nail involvement
Men = women
25-40 years - but can vary
Juvenile forms exist
risk factor- HLA-B 27 positive
Pathophysiology of Psoriatic arthritis?
Local trauma causes dysreuglated immune response > local tissue destruction
Presentation if psoriatic arthritis?
Patterns of joint involvement:
1. Asymmetrical oligoarthritis(affecting 2-4 joints) - most common.
- Usually knees & small peripheral joints e.g. hands & toes.
2. DIP joint predominant
3. Symmetrical polyarthritis - just like RA - PIP, MCP, wrists, elbows & MTP of feet.
4. Spondylitis- inflammation of spine.
5. Arthritis mutilans - rare - affects DIP, PIP, MCP joints of hands & phalanges & metocarpal bones.
- Can also be seen in feet.
MSK features:
- Sacroilitis - often asymmetrical & asymptomatic.
- Dactylitis - swollen fingers & toes
- Enthesitis - inflammation at tendon/ligament insertion. MRI shows inflammatory changes where the plantar fascia inserts under the foot.
- Synovitis - joint pain, stiffness, swelling.
- Telescoping of digits - due to resorption of bone.
Extra-articular features:
- Psoriasis- might not be obvious, check scalp, naval & naval cleft
- Nail pitting
- Nail lifting
NOTE- family history of psoriasis is clinically important.
NOTE- view images on notes!
Investigations for psoriatic arthritis?
Blood tests:
- FBC- may show anemia
- ESR- high
- CRP- high
Radiological findings for psoriatic arthritis?
Radiological changes are asymmetrical & target small joints of hands & feet, particularly DIP joints
- Sacroilitis - asymmetrical - joint space narrowing, sclerosis & irregular margins. May be hard to see the joint.
- Erosions w/ proliferation of the adjacent bone - well-defined, peri-articular (surrounding joint) & asymmetric.
- Spondylitis - syndesmophytes - boney projections from spine. Bridging is less common.
- New bone formation at entheses e.g.Achilles tendon; plantar fascia to the calcaneum; & entheseal sites around pelvis.
- Pencil-in-cup deformities - progressive bone destruction & osteolysis. Bone destruction at the phalanx tip & new bone formation at the base of the adjacent phalax gives this appearance.
- Periostitis - inflammation of periosteum (connective tissue that surrounds bone) Looks ‘fluffy’ on x-ray.
NOTE- view x-ray images on notes!
Management of psoriatic arthritis
Conservative
- Physiotherapy
- Monitoring - DAS28, HAQ
Pharmacological:
- NSAIDs e.g. Naproxen, Diclofenac, Celecoxib + PPI e.g. Lansopizole
- DMARDs- Methotrexate, Sulfasalazine, Leflunomide, Ciclosporin + folic acid.
- Biologic DMARDs - anti-TNFs e.g. Adalimumab, Etanercept, Infliximab.
NOTE: Usekinumab & Apremilast - used when anti-TNFs are contra-indicated.
- JAK inhibitors - type of DMARD that tamp down overactive immune systems.
NOTE: in some patients, skin activity mirrors joint activity, so treat the skin, the joints improve.
