Musckuloskeletal MCQs

Aneurysmal Bone Cyst (ABC) Definition expansile lesion of bone containing thin-walled blood- filled cystic cavities Etiology (a) primary nonneoplastic lesion (2/3) (b) arising in preexisting bone tumor (1/3): giant cell tumor (39%),osteoblastoma, chondroblastoma,solitary bone cyst,fibrous dysplasia,nonossifying fibroma, metastatic carcinoma Histology intraosseous arteriovenous malformation" with honey- combed spaces filled with blood + lined by granulation tissue / osteoid; areas of free hemorrhage

Aneurysmal Bone Cyst (ABC) Types: INTRAOSSEOUS ABC : originating in bone marrow cavity. EXTRAOSSEOUS ABC :posttraumatic hemorrhagic cyst; originating on surface of bones Age: peak age 16 years (range 10 - 30 years) Location: Spine: with slight predilection for posterior elements long bones: eccentric in metaphysis of femur, tibia, humerus, fibula; pelvis

Respect epiphyseal plate soap-bubble Thin internal trabeculations Almost invesible cortex Expansile lesion No periosteal reaction except in case of fracture

Doughnut sign in scintigraphy

Aneurysmal Bone cyst : Occur secondary to fibrous dysplasia Can present with scoliosis May contain fluid-fluid level at MRI Contain calcified matrix Doughnut sign at scintigraphy is pathognomonic (√ ) (√ ) (√ ) (X ) (X )

Multiple Myeloma

Mulyiple osteolytic Punched-out lesion

Mulyiple osteolytic Punched-out lesion Absence of perilesional sclerosis

Complicated by pathological fracture Associated with osteopenia

PET PET-CT coronal view

(√ ) also following radiotherapy Regarding Multiple Myeloma : It is the commonest 1ry neoplasm of bone Generalised osteopenia is a recognised appearance Scintigraphy over-estimates disaese extent Lesions becomes scleotic following chemotherapy Vertebral pedicle destruction is an early event (√ ) (√ ) in 15 % (X ) under estimates (√ ) also following radiotherapy (X ) (Ref: Grainger and Allison pp1913-1915,Daenhartppp121-122, Chapman 2003pp575-576)

Rheumatoid arthritis :

Joint deformity Periarticular osteopenia Narrowing of the joint spaces Soft tissue swelling Joint instability due to ligament rupture Articular erosion

High ridding of the humerus Lateral erosion of the clavicle Marginal erosion Narrowing of the glenohumoral joint

Lateral deviation of toes , Hammer toes Erosion of the MTP

ligamentous destruction can result in atlantoaxial impaction Erosion of Odontoid process Pannus proliferation directly compresses the spinal cord. Erosion of facet joints

(X ) Hyperparathyroidism Erosion of the lateral 3rd of the clavicle is seen in the following: Rheumatoid arthritis Ankylosing spondylitis Langerhans cell histiocytosis Hypoparathyroidism Multiple myeloma (√ ) (X ) (X ) (X ) Hyperparathyroidism (√ )

Concerning Malignant Bone Lesions

(X ) 90% in basisphenoid and sacrum Concerning Malignant bone lesion: Chordoma is most common in the thoracolumbar spine Fibrosarcoma is the commonest tumour 2ry to paget’s disease Adamantinoma occursin the tibia in over 90% of cases Angiosarcoma has a soap bubble appearance at radiography Chondroblastoma are typically found in the diaphysis (X ) 90% in basisphenoid and sacrum

Sacral Chordoma

Basisphenoid Chordoma

(X ) 90% in basisphenoid and sacrum Concerning Malignant bone lesion: Chordoma os most common in the thoracolumbar spine Fibrosarcoma is the commonest tumour 2ry to paget’s disease Adamantinoma occurs in the tibia in over 90% of cases Angiosarcoma has a soap bubble appearance at radiography Chondroblastoma are typically found in the diaphysis (X ) 90% in basisphenoid and sacrum (√ ) (√ )

Adamantinoma

(X ) 90% in basisphenoid and sacrum (X ) they are epiphyseal lesions Concerning Malignant bone lesion: Chordoma os most common in the thoracolumbar spine Fibrosarcoma is the commonest tumour 2ry to paget’s disease Adamantinoma occursin the tibia in over 90% of cases Angiosarcoma has a soap bubble appearance at radiography Chondroblastoma are typically found in the diaphysis (X ) 90% in basisphenoid and sacrum (√ ) (√ ) (√) (X ) they are epiphyseal lesions

Chondroblastoma

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