General MSK Laurie Lomasney, MD Professor Department of Radiology

General MSK Disease Categories –Arthropathy –Infection –Congenital –Vascular –Tumor Locale –Axial –Appendicular

General MSK by Disease Category Disease processes often follow predictable patterns of radiographic change Disease processes usually follow particular distribution patterns Pretest probability enhances image interpretation and directed reporting

General MSK Disease Categories –Arthropathy –Infection –Congenital –Vascular –Tumor

Arthropathy Characteristics –Bone density –Erosions –Alignment Distribution –Poly vs mono –Symmetric vs asymmetric –Peripheral small vs central large

Arthropathy Periartic demin Prox/Symmetric swelling Wrist/MCP erosions Palmar/Ulnar deviat Rheumatoid Arthritis

Arthropathy Preserved density Asymmetric swelling Prox + Distal asymm erosions Psoriasis

Arthropathy Osteoarthritis Variable density No erosions Eccentric joint narrow Marginal proliferation

Arthropathy Preserved density Debris Sclerosis Malalignment Charcot Arthropathy

General MSK Disease Categories –Arthropathy –Infection –Congenital –Vascular –Tumor

Infection Characteristics –Periarticular demineralization –Bone erosion –Periosteal new bone –(Adjacent ST defect or Foreign body) Distribution –Focal/monostotic vs Multifocal (uncommon)

Infection Metaphyseal osteomyelitis

Infection DIP Pyarthrosis Hip Pyarthrosis

General MSK Disease Categories –Arthropathy –Infection –Congenital –Vascular –Tumor

Congenital Variable appearance Variable consequence –Incidental –Pathologic Always Sometimes –Unknown

Congenital Ossification neural groove

Congenital Os Acromiale

Congenital Os tibiale externum

Congenital = 80% Narrow Bony Canal

General MSK Disease Categories –Arthropathy –Infection –Congenital –Vascular –Tumor

Vascular (Avascular necrosis) Multiple etiologies –Steroid therapy –Collagen vascular disease –Post-traumatic Staged appearance –Sclerosis –Collapse –Secondary osteoarthritis

Avascular necrosis Lunate AVN

Avascular necrosis Femoral head AVN

General MSK Disease Categories –Arthropathy –Infection –Congenital –Vascular –Tumor

Tumor Etiologies – Multiple Distribution – Specific to process –Axial vs appendicular –Monostotic vs polyostotic –Medullary vs eccentric –Child vs Adult

Tumor Characteristics to observe –Well-defined vs permeative –Cortical destruction –Periosteal new bone –Internal matrix –Soft tissue mineralization/mass

Tumor Non-ossifying fibroma

Tumor Giant cell tumor

Tumor Enchondroma

Tumor Chondrosarcoma

Tumor Osteogenic sarcoma

Tumor Osteosarcoma Gross pathology

General MSK Radiology is a four-year residency Pathology generally follows a predictable imaging pattern Knowledge of patterns can enhance image interpretation

You know you’re in medicine when: You compliment strangers on the size of their veins. You occasionally have to leave a patient's room before you start laughing uncontrollably.. You have recurring nightmares about being knocked to the floor and run over by a portable x-ray machine.

Thank you Laurie Lomasney, MD