IMAGING IN ARTHRITIS

DR ARCHANA

1) Flow chart shows approach to radiographic evaluation of arthritis.

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Inflammatory arthritis – synovitis, and pannus (P) causing cartilage destructionOsteoporosis . Marginal bone erosion(bare areas)

Uniform joint space narrowing. Soft-tissue swelling.

Inflammatory Arthritis

RA•Proximal involvement in hand & feet.•No bone proliferation•Enthesopathy less common.•Symmeteric

Seronegative spondyloart

hritis

•Distal involvement in the hands and feet/ Large jts involved.•Features of bone proliferation. •Cartilaginous joints and entheses are involved to a greater extent.•Asymmeteric.

Seronegative Spondyloarthropathies

• Ankylosing spondylitis• Psoriatic arthritis,• Reactive arthritis &• Enteropathic arthritis.

Ankylosing Spondylitis

• Chronic inflammatory disorder primarily affecting synovial jts, ligaments & tendons of spine & pelvis, often resulting in polyarticular ankylosis.

• Age- 15 to 35 yrs.• M: F= 3:1• Symptoms- chronic low back pain, stiffness

more in the morning, sciatica, heel pain, muscle spasm & atrophy.

• Extraskeletal- iritis, aortitis, valvular incompetence, aneurysms, conduction blocks, pulmonary fibrosis (upp lobe), IBD & renal failure.

• Lab inv- –↑ESR,– ↓Hb ,– RF –ve, –HLA B27 +ve

Pathologic changes- involves synovium & entheses Synovial articulation-

• Normal joint.• Inflammation with pseudo widening of jt.• Bony ankylosis with jt space loss.

Enthesopathy – inflammatory infiltrate at bone- ligament or bone-tendon jn. Seen as cortical erosion &

periostitis.

Radiologic features-

• Sites- sacroiliac, apophyseal, costovertebral, discovertebral, pubic symphysis, & manubriosternal jts. Other peripheral joints- hips and shoulder joints.

Sacroiliac joint

• B/L , symmetric and usually precedes spinal involvement.

• Early erosions - inferior 2/3 rd of SI joints , along the iliac surface .

• X-ray- prone with cephalad angulation or oblique view.

AP pelvis radiograph shows bilateral symmetric bone erosions, sclerosis, and widening of sacroiliac joints (arrows).

AP radiograph of sacrum shows fusion of sacroiliac joints (arrows).

Star sign- upper ligamentous portion of jt shows bridging ossification as triangular opacity.

Axial CT- erosions & subchondral sclerosis along iliac region.

CT- sensitive for jt space changes & small erosions. May be used to differentiate bone erosions from osteophytes.

Coronal T1WI MR image shows subchondral fatty marrow changes (arrows) & irregularity of sacroiliac joint. MRI - joint fluid, erosions, subchondral sclerosis, marrow edema & enhancement on contrast study. Useful when radiographs are normal or equivocal.

• Spine involvement is characterized by- – osteitis, – syndesmophyte formation, – facet inflammation, – facet joint and vertebral body fusion.

• Thoracolumbar or lumbosacral junction, progress in ascending manner.

• Coned-down lateral radiographs optimally depict subtle and early abnormalities.

Lateral radiograph- early anterior body marginal erosion(Romanus sign) & reactive sclerosis (shiny corner sign)

Lateral lumbar spine radiograph shows sclerosis at anterior aspect of the end plate (shiny corner sign) with squaring of anterior margin of vertebral body.

Thin , vertical and slender marginal syndesmophytes represent ossification of the outer layer of the annulus fibrosis.

AP lumbar spine radiograph shows bridging syndesmophytes, symm & multiple segments, undulating contour (bamboo spine) .

Lateral lumbar spine radiograph shows anterior bridging syndesmophytes and facet joint fusion (arrowheads).

AP lumbar spine radiograph shows ossification of interspinous ligament and facet joint fusion (trolley-track sign)

AP lumbar spine radiograph shows ossification of the interspinous ligament (dagger sign)

Complications---Andersson’s lesion- fracture of ankylosed segment with non union, pseudoarthrosis, sclerosis ,

fragmentation & loss of end plates.

Axial CT image- erosions along the inner aspects of lamina bilaterally (Arachnoid diverticula)

Other joints----Hip jt- B/L .Uniform joint space loss , axial migration, acetabular protrusion, ankylosis. Entheseal changes.

AP pelvis radiograph shows bilateral diffuse joint space narrowing and bone erosions of each hip joint (arrowheads), with sacroiliac joint fusion (arrows).

Enthesopathy- periosteal new bone at b/l ischial tuberosity (whiskering)

• Shoulder jt- Bone erosions and remodeling(enthesitis of rotator cuff) in the lateral proximal aspect of the humerus produce a “hatchet” appearance.

• Calcaneus- posterior Achilles & plantar aponeurosis. Erosion, osteoporosis & periostitis.

Psoriatic arthritis

• Common skin disorder with erosive & deforming arthropathy.

• Etiology- environmental and hereditary factors, with as many as to 60% of patients being HLA-B27 positive .

• Age -20 to 50 yrs.• Equal sex predilection.• Skin lesions- erythematous plaques along extensor

aspects, with silvery scales.• Nail changes- pitting, ridging, discolouration,

subungual hyperkeratosis. 80% with jt disease.

• General features-(B/L, U/L, symm/asymm)– Marginal erosions with tapered ends.– Fluffy juxta-articular periostitis.– Soft tissue swelling.– Normal bone density (no synovial hyperemia).

• Sites- In the hands and feet, a distal distribution (DIP jt ) is characteristic.

• SIJ, spine- Spondylitis(20%–40%) is uncommon in the absence of sacroiliitis.

• The facet joints are relatively spared, and there is absence of vertebral body “squaring.”

• Other sites – wrist, knees , elbows, ankles, and joints about the shoulders.

PA finger radiograph shows marginal bone erosions with adjacent fluffy periosteal reaction (Mouse ears sign)

PA finger radiograph shows narrowing of distal inter phalangeal joint. Note bone proliferation and peri ostitis throughout phalanges (arrows), with partial incorporation of new bone into the cortex. There is soft-tissue swelling of entire digit. (Sausage digit)

AP foot radiograph shows inflammatory and destructive changes of fifth MTP and several IP joints .Note pencil-and-cup deformity (arrowhead) .Because of the degree of bone destruction, with one end of the joint forming a cup and the other a pencil that projects into this cup.

Psoriatic arthritis. AP radiograph shows increased density and bone proliferation of distal phalanx (ivory phalanx) of the first digit (arrows), with sclerosis, enthesitis, periostitis, and soft-tissue swelling .

Arthritis mulitans- severe destruction of all joints with carpal ankylosis.

Psoriatic arthritis. Lateral knee radiograph shows irregular thick bone proliferation and periostitis of posterior aspect of the tibia (arrows).

Psoriatic arthritis. AP sacrum radiograph shows bone erosions and narrowing of sacroiliac joints with partial fusion .SI jt involvement is B/L asymmeteric. Ankylosis is infrequent.

Psoriatic arthritis.AP lumbar spine radiograph shows comma-shaped paravertebral ossifications (arrows). Coarse , asymmeteric , non- marginal syndesmophytes.MC- L1 to L3, T11 & T12.

Reactive arthritis(Rieter’s syndrome)

• It is a sterile inflammatory arthritis that follows an infection at a different site, commonly enteric or urogenital .

• An association with urethritis and conjunctivitis, as well as seropositivity for the HLA-B27 antigen has been described .

• Most common – Male, aged 25–35 years.

• The radiographic features of reactive arthritis are similar to those of psoriatic arthritis (joint inflammation,bone proliferation, periostitis, and enthesitis).

• The features allowing differentiation relate to clinical history, patient age, and distribution of joint involvement.

• Lower-extremity involvement is more common than upper-extremity involvement.

Reactive arthritis. Lateral radiograph of calcaneus shows bone sclerosis and irregular inflammatory enthesopathy at Achilles & plantar insertions.(Lover’s heel)

Reactive arthritis. PA finger radiograph shows involvement of multiple joints with joint space narrowing, bone erosions, and bone proliferation (arrows).

Reactive arthritis. AP radiograph of great toe shows bone sclerosis, marginal bone erosions, and bone proliferation (arrows) about interphalangeal joint and distal phalanx, with soft-tissue swelling.

Enteropathic Arthritis

• Group of diseases of GIT origin that produces articular abnormalities.

• Causes- UC, CD, Whipple’s & infections.• HLA B27 is +ve .• Types-– Spondylitis & sacroilitis like AS.– Peripheral asymmetric arthropathy- soft tissue

swelling & periostitis.

IBD- AP radiograph of sacrum shows bilateral and symmetric bone erosions, bone sclerosis, and widening of sacroiliac joints .

Septic arthritis

• If joint inflammation is limited to a single joint, infection must first be carefully excluded.

• The cause of septic arthritis is usually related to hematogenous seeding owing to staphylococcal or streptococcal microorganisms.

• The radiographic features of a septic joint encompass those of any inflammatory arthritis—namely, periarticular osteopenia, uniform joint space narrowing, soft-tissue swelling, and bone erosions

• The joint space may be initially widened owing to the effusion or also in tuberculosis and fungal infections.

Septic arthritis .Mortise radiograph of ankle shows erosions (arrows) of talus and distal tibia with osteopenia. Joint space widening is due to diffuse synovitis.

Septic arthritis. (a) Posteroanterior and (b) oblique radiographs of finger show joint space narrowing (arrows), osteopenia, soft-tissue swelling, and a bone erosion (arrowhead).

Gout

• Metabolic disorder with deposition of monosodium urate crystals in joints & soft tissue.

• Primary- inborn error of purine metabolism/ renal excretion.

• Secondary- myeloproliferative disorder, acqd renal cause or drug induced.

• Lab inv- ↑ESR, hyperuricemia, MSU crystals in synovium.

• Age- 30 to 50 yrs. MC in males.

• Four stages-– Asymptomatic gout- ↑uric acid.– Acute gouty arthritis- mono/oligoarticular, MC-

MTP jt of great toe, ITJ, knee jt.– Polyarticular gouty arthritis- MC in lower limb,

hand, wrist & elbow. Radiographic changes seen.– Chronic tophaceous gout- tophi in tendon,

ligaments, cartilage, bone, soft tissue, synovium, SC in periarticular reg.

Imaging-

• Site- 1st MTP, ankle, knee, elbow, wrist & SIJ.• Marginal erosions with sclerotic borders,

overhanging edges.• Aysmm paraarticular lumpy- bumpy soft tissue

swellings.• Normal bone density.• Normal jt space.• Chondrocalcinosis-5%.• AVN- femur, humerus.

Frontal radiograph of foot – erosions, sclerosis, soft tissue

swelling in 1st MTP jt.

Radiograph of 1st MTP jt – well defined periarticular erosions with overhanging edges.

Tophi- 5mm to 5 cm , eccentric, periarticular. Tophi have intermediate to low signal intensity on T1- WI , variable on T2WI but heterogeneous low signal intensity should prompt consideration of this entity .Contrast enhancement +ve particularly in acutely

symptomatic patients

Tophaceous in a 56-year-old man with hyperuricemia who presented with foot pain and swelling. Axial T1WI MR image shows low-signal-intensity tophi (long arrows) and adjacent periarticular erosions with characteristic overhanging edges (short arrows). The joint spaces are preserved, as is typical in gout. T1W Fat sat CE MRI shows increased contrast enhancement of the tophi (arrows) and juxta-articular bone

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease

• Joint disease with deposition of CPPD cystal in synovium or articular cartilage.

• Age- >30 yrs, peak at 60 yrs. M:F = 1.• Acute- like gout or RA.• Chronic- like DJD.• Asymptomatic- only chondrocalcinosis.• Sites- knee, wrist & MCP jt , elbow, shoulder.

Imaging

• Chondrocalcinosis.• Soft tissue calcification.• Like DJD- but– Unusual articular distribution(wrist, elbow).– Prominent, large geodes.– Rapid progressive subchondral changes,

fragmentation.– Variable osteophytes- large or absent.

Frontal radiograph of the knee showing dense meniscal calcification plus mild joint narrowing, irregularity of the articular surfaces, and beginning hypertrophic osteophyte formationcompatible with early degenerative osteoarthrosis

Early calcification of the triangular fibrocartilage of the wrist.

Pseudogout syndromeCalcification in the supraspinatus tendon at the attachment of the rotator cuff plus calcification in the joint capsule of the shoulder in a patient with chronic intermittent pain in both shoulders for many years.

Frontal roentgenogram of the pelvis- fibrocartilage of the symphysis pubis shows dense calcification

Hemochromatosis

• Rare metabolic disorder.• Deposition of iron in liver, pancreas & skin.• Age- 40 to 60 yrs. MC in males.• Arthropathy- iron & CPPD in cartilage & synovium.• Sites- 2nd & 3rd MCP, knee, hip & shoulder.

Involvement of the MCP Jt appears to be more common in hemochromatosis than in the other arthropathies associated with chondrocalcinosis.

Imaging

• Chondrocalcinosis.• Uniform jt space loss, osteophytes,

subchondral cysts, sclerosis.

Joint narrowing, sclerosis, and subchondral cyst formation localized to the 2nd and 3rd MCP jts in a patient with hemochromatosis . Actual bony enlargement of the metacarpal heads, not present in this case, also occurs.

Wilson’s disease

• Rare, AR, inherited.• Deposition of copper in liver, basal ganglia,

cornea.• Arthropathy – Cu in cartilage & synovium.• Imaging- chondrocalcinosis, osteopenia, irr

cortex, cysts, osteophytes, Schmorl’s nodes & squaring of vertebra.

AP/ Lateral radiograph of knee- chondrocalcinosis, cysts, irr cortex,

osteophytes. Patellofemoral jt narrowing suggests crystal

induced arthropathy.

Ochronosis (alkaptonuria)

• Disorder in tyrosine metabolism.• Hereditary degenerative arthritis.• Age- 20 to 40 yrs. MC in males.• Imaging- – Advanced premature DJD.– Spine- multiple contagious disc calcification, ↓disc

ht, vacuum phenomenon, osteophytes, ↑kyphosis, ↓lordosis.

– Chondrocalcinosis.

AP/ lateral lumbar spine- intradiscal calcification at

multiple levels.

Neuropathic arthropathy(Charcot’s A)

• Destructive articular disease sec to loss or impairment of jt proprioception.

• Causes- DM, leprosy, MS, neurosyphilis, syringomyelia, myelomeningocele.

• Premature & excessive traumatic degenerative changes seen.

• Phases- • Atrophic – resorbed articular surface, tapered

bone ends. MC in(UL) shoulder, wrist, forefoot.• Hypertrophic- lumbar spine, hip, knee, ankle(wt).

• Distension(jt eff)• Density(subchondral sclerosis)• Debris(intraarticular fragment)• Dislocation(jt malalignment)• Disorganisation(bag of bones)• Destruction(loss of bone)

Hypertrophic- density, debris, destruction & dislocation. Atrophic- bone resorption

& no debris.

Atrophic change in shoulder- resorption of humeral head in a pt with syringomyelia.

Diabetic foot- Licked candy app due to pencil like tapering of long bone toward a jt coz of

atrophic resorption.

Early neuropathic osteoarthropathy in a 49-year-old diabetic man .The patient had no history of trauma .(a) Axial T1WI MRI shows a serpentine band of low signal intensity in the lateral

cuneiform bone representing a subchondral fracture (short arrows). Adjacent low-signal-intensity bone marrow edema is also present within the proximal third metatarsal bone (long arrows).

(b) (b) Axial T1W fat sat CE- shows contrast enhancement of periarticular bone (arrows) and adjacent soft tissues.

THANK U

• Disk calcification may also occur, possibly due to relative immobilization of the vertebral column.

28-year-old man with ankylosing spondylitis for 10 years. Laboratory results and clinical findings were as follows: C-reactive protein, 7.3 mg/L; erythrocyte sedimentation rate, 5 mm/h; Bath

Ankylosing Spondylitis Functional Index (BASFI), 80.0; Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), 60.2; inflammatory back pain score, 94; nocturnal back pain score, 83; total back

pain score, 82. Coronal T1-weighted MR image shows subchondral fatty marrow changes (arrows). There is irregularity of sacroiliac joint.

• The differential diagnosis of bilateral sacroiliac joint erosions includes IBD and hyperparathyroidism.

• In hyperparathyroidism, SIJ space widening is more dramatic, and typically there are other clinical and radiographic features of hyperparathyroidism.

• The differential diagnosis for bone production at the vertebral margins includes diffuse idiopathic skeletal hyperostosis, or DISH, althoughthis latter condition more commonly reveals a flowing and undulating appearance.

Contralateral wrist radiograph shows bone erosion and irregular periostitis of the scaphoid, with more distal periostitis involving the metacarpal base (arrows).

• Periostitis may take several forms: It may appear as a thin periosteal layer of new bone adjacent to the cortex, a thick irregular layer, or irregular thickening of the cortex itself.

Hyperparathyroidism. Anteroposterior radiograph of sacrum shows bilateral and symmetric bone sclerosis and irregularity of sacroiliac joints (arrow). Note marked widening of sacroiliac joints and renal dialysis catheter.

• Degenerative arthritis-– Osteophytes– Non uniform jt space narrowing– Bone sclerosis– Subchondral cysts(geodes)

Oblique wrist radiograph shows irregular bone proliferation and periostitis about radial and ulnar aspects of the wrist (arrows), with erosion of the ulnar styloid process. It is important to note that periostitis may occur in an area without bone erosions; one such site is the radial aspect of the wrist extending into the first metacarpal bone.