General MSK Laurie Lomasney MD Professor Department of

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 Psoriasis Preserved density Asymmetric swelling Prox + Distal asymm erosions

Arthropathy Variable density No erosions Eccentric joint narrow Marginal proliferation Osteoarthritis

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