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Seronegative spondy Cheat Sheet (DRAFT) by

Seronegative spondyloarthropathies + Imaging

This is a draft cheat sheet. It is a work in progress and is not finished yet.


- Ankylosing Spondy­litis
- Entero­pathic Arthritis
- Psoriatic Arthritis
- Reiter's Syndrome
- Undiff­ere­ntiated
- Targets entheses
- HLA-B27
- Targets Gut, Skin, Eyes and aortic valve
- Often triggered by enviro­nmental factors


- Erosions and Sclerosis of the SI joints
- Can be uni/bi­lat­era­l/s­ymm­etr­ica­l/a­sym­met­rical
- Caused by a systemic inflam­matory disease
- In AS, occurs on iliac side of the joint first because of the thickness of the sacral cartilage

Radiog­raphic Findings of Sacroi­liitis

Loss of smooth cortical bone - iliac side of joint
Affects Lower 2/3 of joint
Eventual Fusion of joint

Ankylosing Spondy­litis (AS)

- Chronic Inflam­matory Arthritis
- 15-35 age of onset
- Men affected more than women
- Starts in SI bilate­rally & symmet­rically
- Syndes­mop­hytes @ T-L Junction
- HLA-B27
- Elevated ESR
- RF -
- Pain and stiffness worse in the morning, improving throughout the day
- Pain during exercise, relieved by rest
- Inflam­mation of discov­ert­ebral, zygapo­phy­seal, costov­ert­ebral and costot­ran­sverse and parver­tebral ligame­ntous structures of Tx spine

AS Radiog­raphy

Vertebral Body corners are eroded and body becomes squared
Syndes­mop­hytes start to bridge over the outer annular fibres

Changes occur at the disco-­ver­tebral junction
1. Romanus Lesion - Active Inflam­mation
2. Shiny corner - Active repair
3. Vertebral Squaring - Permanent Deformity
4. Syndes­mop­hytes - Post-I­nfl­amm­atory calcif­ication of annulus fibrosis "­Bamboo spine"

Clinical Features

Iritis, Conjun­cti­vitis
Aortic Insuff­iciency
Pulmonary Fibrosis
Limited Chest expansion
Decreased Schobers

Entero­pathic Spondy­litis

- Crohn's and Ulcerative Colitis
- Causes similar features to AS

Psoriatic Arthritis

- Compli­cation of Psoriasis
- Male and Female equally affected
- Affects Hands (DIPs) and SI joints

Radiology Findings

- Perios­titis erosions - Mouse ears appearance
- Joint space narrowing
- Bone is fluffy and spiculated
- Ray pattern - joints in a single­-digit more affected than the other side
- Asymme­trical
- Sausage Digits
- Arthritis Mutilans - severely deformed hands resulting from severe inflam­mation
- Acro - osteolysis - resorption of the distal phalanx
- In the Spine, Sacroi­liitis is common - unilat­erally, bilateral but asymme­trical
- Non marginal syndes­mop­hytes
- Increased ADI

Reactive Arthritis (Reiter's syndrome)

Urethr­itis, Conjun­cti­vitis, Arthritis
Usually lower extrem­ities
Radiog­rap­hically identical to Psoriatic Arthritis
STD/GI Infection
"­Can't Pee, Can't See, Can't Dance with me"

Radiology Findings

- Asymme­trical
- Sausage Digits
- Enthesitis - heel pain, achilles tendon­iti­s/pain at insertion of patella
- More males than females

Osteitis Condensans Ilii

- Mechanical Stress of the SI
- Benign Sclerosis of the iliac side, lack of joint space narrowing
- Bilateral + Symmet­rical
- Usually a Triangular shape


- Extension stretches and exercises (reduces Tx kyphosis)
- Myofascial therapy
- Ultrasound and electrical stimul­ation
- SMT contra­ind­icated with acute inflam­mation
- Mobili­sation
- Swimming
- Nutrit­ional Support (calcium, vitamin D, Omega 3 fish oils)