OSTEOCHONDRITIS ,Caisson disease,OSTEOCHONDRITIS ,Caisson disease,Caffey’s diseaseCaffey’s disease

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OSTEOCHONDRITIS DESSICANSOSTEOCHONDRITIS DESSICANSMisnomer.

Refers to post-traumatic osteochondral/chondral fractures.

Occuring at articular surface.

After injury---detached portion

* remain in situ.

*Mildly displaced.

* Become loose body.

(most common cause of loose body in young adults is OCD)

Fragmented part—avascular

Bed of defect ---vital

SITES INVOLEDSITES INVOLED CONVEX ARTICULAR SUFACES:

Medial femoral condyles. Capitellum of humerus. Trochlear surface of talus.

RARE SITES OF INVOLVMENT:

Shoulder—humeral head ,glenoid. Scaphoid. Navicular.

INCIDENCEINCIDENCE

M:F =2:1.

One third cases are bilateral.

Adolescence.

RADIOGRAPHIC FEATURES.RADIOGRAPHIC FEATURES.PLAIN RADIOGRAPHS

May be normal.

When visible =radiolucent ring surrounding bony fragment.

=in profile-loose body opposite to pit in bone.Loss of sharp cortical line of articular surface.

CT FINDINGS Usually axial cuts.

For cortical defects & loose bodies. Island of bone demarcated by rare field zone.

MRI FINDINGS vitality of underlying bone integrity of overlying cartilage.

NUCLEAR MEDICINE Non specific mild to moderate increased uptake of isotope in involved bone.

MRI CLASSIFICATION OF OCDMRI CLASSIFICATION OF OCD STABLE * articular cartilage is breached.

*marrow edema.

UNSTABLE *pocket of fluid around undetached ,undisplaced

fragment.

*displaced osteochondral fragment.

X-ray knee frontal view---radiolucent line on lateral aspect of medial condyle extending up to articular surface. Joint space normal.

Lateral radiograph of the knee reveals a calcified loose body (white arrowhead) in the infrapatellar fat pad and lucency in the articular surface of the patella (black arrowhead).

Ankle frontal view---radiolucent line on dome of talus ,medial aspect. resulting in detachment of fragment. No displacement.

Axial CT of the knee demonstrates a completely detached osteochondral fracture (arrowhead) in the lateral aspect of the medial femoral condyle.

Coronal CT of the ankle demonstrates a nondisplaced osteochondral fragment

CT ankle axial cuts.OCD of talar dome.

T1W & STIR---coronal & sagittal.unstable.

Stable –adjacent edema

Stable OCD –coronal & sagittal T2W shows lesion of medial condyle and marrow edema .

Coronal T2W unstable OCD with fluid at base of lesion

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CAISSON DISEASECAISSON DISEASE DYSBARIC OSTEONECROSIS.

exposure to hyperbaric atmosphere.

Undersea diving ,space craft.

Result in decompression sickness.

MECHANISMMECHANISMNitrogen bubbles liberated from bone marrow –

bone infarct by small blood vessel occlusion

Resultant osteonecrosis..

Shoulder most commonly involved.

PresentationPresentation Joint pain

Motion aggravates pain.

RADIOGRAPHIC FINDINGSRADIOGRAPHIC FINDINGS Juxta articular defects transradiant subcortical band. collapse of articular cortex. sequestration of articular cortex. secondary osteoarthritis.

Neck and shaft lesions dense areas. irregular calcified areas.

COMPLICATION

1. Malignant fibrous histiocytoma.

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CAFFEY’S DISEASECAFFEY’S DISEASE INFANTILE CORTICAL HYPEROSTOSIS.

Unknown etiology

In twins ,siblings & cousins.

Remission & relapses with patchy distribution of lesion.

SITESSITES Mandible.

Ribs.

Clavicle.

Scapulae.

No spine involvement.

Diapysis involvement.

PRESENTATIONPRESENTATIONChild upto 1 year.

High grade fever & hyperirritability.

Painful deep soft tissue swelling. occur before bone lesion appear.

RADIOGRAPHIC FEATURESRADIOGRAPHIC FEATURESMarked periosteal proliferation.

Cortical thickening.

Soft tissue swelling.

OUTCOMEOUTCOMEBone returns to normal by 12 weeks.

Osteoblastic periosteal lesion involving shaft of ulna ,also lateral aspect of radius.

Deformity, periosteal reaction. Soft tissue swelling.